[Federal Register Volume 79, Number 84 (Thursday, May 1, 2014)]
[Rules and Regulations]
[Pages 24814-24994]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-09084]
[[Page 24813]]
Vol. 79
Thursday,
No. 84
May 1, 2014
Part II
Department of Labor
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Mine Safety and Health Administration
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30 CFR Parts 70, 71, 72, et al.
Lowering Miners' Exposure to Respirable Coal Mine Dust, Including
Continuous Personal Dust Monitors; Final Rule
Federal Register / Vol. 79 , No. 84 / Thursday, May 1, 2014 / Rules
and Regulations
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DEPARTMENT OF LABOR
Mine Safety and Health Administration
30 CFR Parts 70, 71, 72, 75, and 90
RIN 1219-AB64
Lowering Miners' Exposure to Respirable Coal Mine Dust, Including
Continuous Personal Dust Monitors
AGENCY: Mine Safety and Health Administration, Labor.
ACTION: Final rule.
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SUMMARY: The Mine Safety and Health Administration (MSHA) is revising
the Agency's existing standards on miners' occupational exposure to
respirable coal mine dust in order to: Lower the existing exposure
limits; provide for full-shift sampling; redefine the term ``normal
production shift''; and add reexamination and decertification
requirements for persons certified to sample for dust, and maintain and
calibrate sampling devices. In addition, the rule provides for single
shift compliance sampling by MSHA inspectors, establishes sampling
requirements for mine operators' use of the Continuous Personal Dust
Monitor (CPDM), requires operator corrective action on a single, full-
shift operator sample, changes the averaging method to determine
compliance on operator samples, and expands requirements for medical
surveillance of coal miners.
Chronic exposure to respirable coal mine dust causes lung diseases
that can lead to permanent disability and death. The final rule will
greatly improve health protections for coal miners by reducing their
occupational exposure to respirable coal mine dust and by lowering the
risk that they will suffer material impairment of health or functional
capacity over their working lives.
DATES: Effective Date: August 1, 2014. The incorporation by reference
of certain publications listed in the rule was approved by the Director
of the Federal Register as of October 12, 1999.
FOR FURTHER INFORMATION CONTACT: Sheila McConnell, Acting Director,
Office of Standards, Regulations, and Variances, MSHA, 1100 Wilson
Boulevard, Room 2350, Arlington, Virginia 22209-3939. Ms. McConnell can
be reached at [email protected] (email), 202-693-9440 (voice),
or 202-693-9441 (facsimile).
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Executive Summary
A. Purpose of the Regulatory Action
B. Legal Authority for Regulatory Action
C. Summary of Major Provisions
D. Major Provisions in the Proposed Rule That Are Not in the
Final Rule
E. Projected Costs and Benefits
II. Introduction and Background Information
A. MSHA's Existing Respirable Dust Standards
B. 1992 Coal Mine Respirable Dust Task Group Report, 1995 NIOSH
Criteria Document, and 1996 Dust Advisory Committee Report
C. 2000 and 2003 Plan Verification Proposed Rules
D. 2000 Single Sample Proposed Rule
E. Continuous Personal Dust Monitors (CPDM)
F. Regulatory History of This Final Rule
G. Government Accountability Office Activities
III. Discussion of the Final Rule
A. Health Effects
B. Quantitative Risk Assessment (QRA)
C. Feasibility
IV. Section-by-Section Analysis
V. Executive Order 12866: Regulatory Planning and Review; and
Executive Order 13563: Improving Regulation and Regulatory Review
A. Population at Risk
B. Benefits
C. Compliance Costs
D. Net Benefits
VI. Regulatory Flexibility Act and Small Business Regulatory
Enforcement Fairness Act
A. Definition of a Small Mine
B. Factual Basis for Certification
VII. Paperwork Reduction Act of 1995
A. Summary
B. Procedural Details
VIII. Other Regulatory Considerations
A. National Environmental Policy Act (NEPA)
B. The Unfunded Mandates Reform Act of 1995
C. The Treasury and General Government Appropriations Act of
1999: Assessment of Federal Regulations and Policies on Families
D. Executive Order 12630: Government Actions and Interference
With Constitutionally Protected Property Rights
E. Executive Order 12988: Civil Justice Reform
F. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
G. Executive Order 13132: Federalism
H. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
J. Executive Order 13272: Proper Consideration of Small Entities
in Agency Rulemaking
IX. References
X. Appendix A--Excessive Concentration Values
Availability of Information
Federal Register Publications: Access rulemaking documents
electronically at http://www.msha.gov/regsinfo.htm or http://www.regulations.gov. Obtain a copy of a rulemaking document from the
Office of Standards, Regulations, and Variances, MSHA, by request to
202-693-9440 (voice) or 202-693-9441 (facsimile). (These are not toll-
free numbers.)
Information Collection Supporting Statement: The Information
Collection Supporting Statement is available at http://www.reginfo.gov/public/do/PRAMain on MSHA's Web site at http://www.msha.gov/regs/fedreg/informationcollection/informationcollection.asp and at http://www.regulations.gov. A copy of the Statement is also available from
MSHA by request to Sheila McConnell at [email protected], by
phone request to 202-693-9440, or by facsimile to 202-693-9441.
Regulatory Economic Analysis (REA): MSHA will post the REA on
http://www.regulations.gov and on MSHA's Web site at http://www.msha.gov/rea.htm. A copy of the REA also can be obtained from MSHA
by request to Sheila McConnell at [email protected], by phone
request to 202-693-9440, or by facsimile to 202-693-9441.
I. Executive Summary
A. Purpose of the Regulatory Action
The purpose of this final rule is to reduce occupational lung
diseases in coal miners. Chronic exposure to respirable coal mine dust
causes lung diseases including coal workers' pneumoconiosis (CWP),
emphysema, silicosis, and chronic bronchitis, known collectively as
``black lung.'' These diseases are debilitating and can result in
disability and premature death. Based on data from the National
Institute for Occupational Safety and Health (NIOSH), new cases
continue to occur among coal miners. The prevalence rate of lung
disease among our nation's coal miners continues despite the fact that
incurable black lung is preventable. Additionally, young miners are
showing evidence of advanced and seriously debilitating lung disease
from excessive dust exposure.
Over the decade 1995-2004, more than 10,000 miners died from black
lung.\1\ As of December 2011, according to the Department of Labor's
Office of Workers' Compensation Programs, Division of Coal Mine
Workers'
[[Page 24815]]
Compensation, the federal government has paid over $44 billion in
Federal Black Lung benefits to beneficiaries (former miners, widows,
dependents) since 1970 (U.S. Department of Labor, Division of Coal Mine
Workers' Compensation. 2012. Black Lung Program Statistics).
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\1\ http://www.cdc.gov/niosh/docs/2008-143/pdfs/2008-143a-iii.pdf, DHHS (NIOSH) Publication No. 2008-143a, Work-Related Lung
Disease Surveillance Report 2007, Vol. 1, Table 2-4. Coal workers'
pneumoconiosis: Number of deaths by state, U.S. residents age 15 and
over, 1995-2004, p. 34, September 2008.
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The final rule is changed from the proposal. This final rule will
reduce coal miners' occupational exposure to respirable coal mine dust.
As a result, it will lower their risk of developing black lung disease
and suffering material impairment of health or functional capacity.
B. Legal Authority for Regulatory Action
Sections 101(a)(6)(A), 103(h), and 508 of the Federal Mine Safety
and Health Act of 1977 (Mine Act), provide the legal authority for this
final rule. (30 U.S.C. 811(a)(6)(A), 813(h), and 957).
Section 101 of the Mine Act gives the Secretary of Labor
(Secretary) the authority to promulgate mandatory health standards
involving toxic materials or harmful physical agents. It requires that
the Secretary set standards to assure, based on the best available
evidence, that no miner will suffer material impairment of health from
exposure to toxic materials or harmful physical agents over his working
life. (30 U.S.C. 811(a)(6)(A)). In developing these standards, the Mine
Act requires the Secretary to consider the latest available scientific
data in the field, the feasibility of the standards, and experience
gained under other laws. Id.
Section 103(h) of the Mine Act gives the Secretary the authority to
promulgate standards involving recordkeeping. (30 U.S.C. 813(h)).
Section 103(h) provides that every mine operator must establish and
maintain records and make reports and provide such information as the
Secretary may require. Id.
Section 508 of the Mine Act gives the Secretary the authority to
issue regulations to carry out any provision of the Act. (30 U.S.C.
957).
C. Summary of Major Provisions
1. Lowers the Existing Concentration Limits for Respirable Coal
Mine Dust. After August 1, 2016, the concentration limits for
respirable coal mine dust are lowered from 2.0 milligrams of dust per
cubic meter of air (mg/m\3\) to 1.5 mg/m\3\ at underground and surface
coal mines, and from 1.0 mg/m\3\ to 0.5 mg/m\3\ for intake air at
underground mines and for part 90 miners (coal miners who have evidence
of the development of pneumoconiosis). Lowering the concentration of
respirable coal mine dust in the air that miners breathe is the most
effective means of preventing diseases caused by excessive exposure to
such dust.
2. Requires the Use of the Continuous Personal Dust Monitor (CPDM).
On February 1, 2016, mine operators are required to use the continuous
personal dust monitor (CPDM) to monitor the exposures of underground
coal miners in occupations exposed to the highest respirable coal mine
dust concentrations and the exposures of part 90 miners. Use of the
CPDM is optional for surface coal mines, non-production areas of
underground coal mines, and for underground anthracite mines using the
full box, open breast, or slant breast mining methods. The CPDM is a
new sampling device that measures continuously, and in real-time, the
concentration of respirable coal mine dust and provides sampling
results at specific time intervals and at the end of the work shift. It
is jointly approved for use in coal mines by MSHA and NIOSH under
criteria set forth in Title 30, Code of Federal Regulations (30 CFR)
part 74. When the CPDM is used, mine operators, miners, and MSHA will
be notified of the results in a more timely manner than when the
existing approved Coal Mine Dust Personal Sampler Unit (CMDPSU) is
used. This will enable mine operators to take earlier action to
identify areas with dust generation sources, reduce the dust levels in
those areas, and prevent miners from being overexposed.
3. Redefines the Term ``Normal Production Shift''. The term normal
production shift is redefined to require that underground mine
operators take respirable dust samples in the mechanized mining unit
(MMU) when production is at least 80 percent of the average production
over the last 30 production shifts. The MMU is a unit of mining
equipment used in the production of material. Under the existing
definition, underground mine operators are required to sample when
production is at least 50% of the average production reported during
the operator's last sampling period (i.e., last set of five valid
samples). Under the revised definition, miners will be better protected
because samples will be collected during periods that are more
representative of normal mining operations and dust levels to which
miners are exposed.
4. Requires Full-Shift Sampling. The final rule requires the
operator to collect respirable dust samples for the full shift that a
miner works. If a miner works a 12-hour shift, respirable dust samples
must be taken with an approved sampling device for the entire work
shift, rather than a maximum of 8 hours as required under the existing
standards. Full-shift sampling provides more representative
measurements of miners' respirable dust exposures and increases their
health protection.
5. Changes the Averaging Method to Determine Compliance on Operator
Samples. Under existing standards, corrective action is required only
after the average of five operator samples exceeds the respirable coal
mine dust standard and a citation is issued. This permits miners to be
exposed to levels of respirable coal mine dust that exceed the standard
without requiring any corrective action by the operator to reduce
concentrations to meet the standard. The final rule requires immediate
corrective actions to lower dust concentrations when a single, full-
shift operator sample meets or exceeds the excessive concentration
value (ECV) for the dust standard. These corrective actions will result
in reduced respirable dust concentrations in the mine atmosphere and,
therefore, will provide better protection of miners from further high
exposures.
6. Provides for the Use of Single, Full-Shift Samples, by MSHA
inspectors, to Determine Compliance. MSHA inspectors will use single,
full-shift samples to determine noncompliance with the respirable dust
standards. MSHA has determined that the average concentration of
respirable dust to which each miner in the active workings of a coal
mine is exposed can be accurately measured over a single shift. MSHA is
rescinding the ``1972 Joint Finding'' \2\ by the Secretary of the
Interior and the Secretary of Health, Education, and Welfare, on the
validity of single-shift sampling. MSHA considers a single, full-shift
measurement of respirable coal mine dust to ``accurately represent''
atmospheric conditions (Section 202(f) of the Mine Act) at the sampling
location, if the sampling and analytical method used meet the NIOSH
Accuracy Criterion. Limiting the respirable dust concentration in the
active workings ensures that the respirable dust concentration inhaled
by any miner is limited.
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\2\ In 1972, acting under the Federal Coal Mine Health and
Safety Act of 1969 (Coal Act), the Secretaries of the Interior and
Health, Education and Welfare made a joint finding (1972 Joint
Finding), under Sec. 202(f) of the Coal Act, which concluded that a
single shift measurement of respirable dust will not, after applying
valid statistical techniques to such measurement, accurately
represent the atmospheric conditions to which the miner is
continuously exposed (37 FR 3833, February 23, 1972).
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7. Expands Medical Surveillance Requirements. The final rule adds
spirometry testing, occupational history,
[[Page 24816]]
and symptom assessment to the periodic chest radiographic (x-ray)
examinations required to be offered by mine operators to underground
miners under NIOSH's existing standards. The additional medical
surveillance requirements will alert miners to any abnormal declines in
lung function, which is common evidence of Chronic Obstructive
Pulmonary Disease (COPD) and not detected by chest x-rays. Notification
of reduced lung function will enable miners to be proactive in
protecting their health. The final rule extends the same medical
surveillance requirements afforded underground miners, including chest
x-ray examinations, to surface miners since they are also at risk of
developing lung diseases and material impairment of health or
functional capacity from exposure to respirable coal mine dust. In
addition, the final rule extends part 90 miner transfer rights, which
are currently provided to underground miners who have x-ray evidence of
pneumoconiosis, to surface miners who have evidence of pneumoconiosis.
Under 30 CFR part 90, these miners can elect to work in less dusty
atmospheres to prevent the progression of disease. The medical
surveillance requirements will provide improved health protection for
all coal miners.
8. Strengthens Requirements for Certified Persons. The final rule
revises requirements for certified persons who perform dust sampling
and who maintain and calibrate sampling equipment. To strengthen the
certification process, the final rule adds a requirement that persons
must complete an MSHA course of instruction. This complements the
existing requirement that, to be certified, the candidate must pass an
MSHA examination to demonstrate competency in the tasks needed for
respirable dust sampling procedures and in maintenance and calibration
procedures. Completing the MSHA course and passing the MSHA examination
will ensure that only trained persons perform these important
functions. Certified persons are required under the final rule to pass
the MSHA examination every three years to maintain their certification.
The final rule adds procedures allowing MSHA to revoke a person's
certification for failing to properly carry out the required sampling
or maintenance and calibration procedures.
The final rule was strategically developed to provide a
comprehensive, integrated approach to achieve MSHA's goal of reducing
miners' exposure to respirable coal mine dust in a protective and
feasible manner.
D. Major Provisions in the Proposed Rule That Are Not in the Final Rule
1. Sampling Frequency. The proposed rule would have required that
CPDM sampling be conducted 7 days per week, 52 weeks per year for
occupations exposed to the highest respirable coal mine dust
concentrations and for part 90 miners.
2. CPDM Performance Plan. The proposed rule would have required
operators who use CPDMs to develop and submit for approval a CPDM
Performance Plan prior to using the sampling devices.
3. Revisions to the Approved Ventilation Plan. The proposed rule
would have required operators to submit to the District Manager for
approval the corrective actions to lower respirable dust
concentrations.
4. Equivalent 8-hour Concentration. The proposal would have
required the respirable coal mine dust sampled to be expressed in terms
of an 8-hour equivalent concentration for shifts longer than 8 hours.
5. Separate Intake Air for each MMU. The proposed rule would have
required a separate intake airway for each MMU.
E. Projected Costs and Benefits
Lowers miners' exposure to respirable coal mine dust, thus
reducing and preventing Black Lung.
Significant reductions in CWP, progressive massive
fibrosis (the most severe stage of CWP), severe emphysema, and deaths
from non-malignant respiratory disease.
Estimated annualized benefits: $36.9 million: (3% discount
rate) and $20.0 million (7% discount rate).
Estimated annualized costs: $24.8 million (3% discount
rate) and $28.1 million (7% discount rate).
II. Introduction and Background Information
This final rule promotes the Secretary of Labor's vision of
``Promoting and Protecting Opportunity'' \3\ and supports the
Department of Labor's (DOL's) goal of securing safe and healthy
workplaces, particularly for vulnerable workers in high-risk industries
such as mining, by reducing workplace deaths and improving the health
of coal miners.
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\3\ Department of Labor 2014-2018 Strategic Plan Outreach,
www.dol.gov/sec/stratplan/2014outreach/.
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This final rule is an important element in MSHA's Comprehensive
Initiative to END BLACK LUNG--ACT NOW! Launched in December 2009, this
initiative will significantly reduce disabling occupational lung
disease in coal miners. It includes four components: Collaborative
outreach, education and training, enhanced enforcement, and rulemaking.
This final rule represents one aspect of MSHA's comprehensive and
integrated approach to reduce and eliminate continued risks to miners
from exposure to respirable coal mine dust. MSHA is committed to
working with stakeholders to develop comprehensive outreach materials
and to resolve any implementation issues. MSHA also intends to hold
stakeholder seminars related to implementation of the final rule in
locations accessible to the mining public.
Throughout the preamble, the terms ``respirable coal mine dust'',
``coal mine dust'', and ``respirable dust'' are used interchangeably.
This final rule combines the following rulemaking actions: (1)
``Occupational Exposure to Coal Mine Dust (Lowering Exposure);'' (2)
``Verification of Underground Coal Mine Operators' Dust Control Plans
and Compliance Sampling for Respirable Dust'' (Plan Verification) (65
FR 42122, July 7, 2000, and 68 FR 10784, March 6, 2003); (3)
``Determination of Concentration of Respirable Coal Mine Dust'' (Single
Sample) (65 FR 42068, July 7, 2000, and 68 FR 10940 March 6, 2003); and
(4) ``Respirable Coal Mine Dust: Continuous Personal Dust Monitor
(CPDM)'' (74 FR 52708, October 14, 2009). MSHA is withdrawing Plan
Verification and Single Sample as separate rulemaking actions. However,
the rulemaking records for the Plan Verification, Single Sample, and
the CPDM rulemaking actions are incorporated into the rulemaking record
for this final rule.
Several provisions in this final rule will singularly lower coal
miners' exposure to respirable dust and reduce their risk of disease
and disease progression. These provisions include lowering the
respirable dust standards, using CPDMs for sampling, basing
noncompliance determinations on MSHA inspectors' single shift sampling,
full-shift sampling to account for occupational exposures greater than
8 hours per shift, changing the definition of normal production shift,
changing the operator sampling program to require more sampling,
requiring operator corrective action on one operator sample, and
changes in the averaging method for operator samples to determine
compliance. MSHA's quantitative risk assessment (QRA) in support of the
final rule estimates the reduction in health risks when two provisions
of the final rule are implemented--the final respirable dust standards
and single shift sampling. The QRA shows that these two provisions
would reduce the risks of CWP, severe
[[Page 24817]]
emphysema, and death from non-malignant respiratory disease (NMRD). The
QRA projects, over a 45-year occupational lifetime, improvements in
almost every underground job category and at least 6 surface
categories. Large aggregated improvements are also projected for
longwall tailgate operators and continuous mining machine operators
(See the QRA discussion in Section III.B. of this preamble).
While the final 1.5 mg/m\3\ and 0.5 mg/m\3\ standards will reduce
the risk of impairment, disease, and premature death, MSHA's QRA
estimates remaining risk at the final standard. It is important to note
that other provisions of this comprehensive and integrated final rule
(e.g., use of CPDMs for sampling, changes in the definition of normal
production shift, sampling for a full shift, changes in the sampling
program, requiring operator corrective action on one operator sample,
and changes in the averaging method to determine compliance on operator
samples) will reduce these risks. The impacts of these other final
provisions were not considered in the QRA. MSHA expects the final
provisions, implemented in a comprehensive and integrated manner, will
reduce the continued risks that miners face from exposure to respirable
coal mine dust and would further protect them from the debilitating
effects of occupational respiratory disease.
A. MSHA's Existing Respirable Dust Standards
MSHA's existing respirable dust standards, promulgated on April 8,
1980 (45 FR 23990) under Section 101 of the Mine Act, superseded
Section 202(b) of the Mine Act. The standards require coal mine
operators to continuously maintain the average concentration of
respirable dust to which each miner is exposed during each shift at or
below 2.0 milligrams per cubic meter of air (2.0 mg/m\3\) (30 CFR
70.100, underground coal mines; and 71.100, surface coal mines and
surface areas of underground coal mines). Miners who have evidence of
pneumoconiosis and are employed at underground coal mines or surface
work areas of underground coal mines have the option to work in areas
where average respirable dust concentrations do not exceed 1.0 mg/m\3\
of air (30 CFR 90.100, part 90 miners). There is no separate standard
for respirable silica; rather, where the respirable coal mine dust
contains more than five percent quartz, the respirable coal mine dust
standard is computed by dividing the percentage of quartz into the
number 10 (30 CFR 70.101 (underground coal mines), Sec. 71.101
(surface coal mines and surface areas of underground coal mines), and
Sec. 90.101 (part 90 miners)).
Under MSHA's existing standards, mine operators are required to
collect bimonthly respirable dust samples and submit them to MSHA for
analysis to determine compliance with respirable dust standards
(compliance samples). If compliance samples do not meet the
requirements of the dust standard, MSHA issues a citation for a
violation of the standard and the operator is required to take
corrective action to lower the respirable dust concentration to meet
the standard. Further, the operator must collect additional respirable
dust samples during the time established for abatement of the hazard or
violation (abatement sampling).
Underground coal mine operators collect and submit two types of
samples during bimonthly sampling periods: (1) ``Designated
occupation'' (DO) samples taken for the occupations exposed to the
greatest concentrations of respirable dust in each mechanized mining
unit (Sec. 70.207); and (2) ``designated area'' (DA) samples collected
at locations appropriate to best measure concentrations of respirable
dust associated with dust generation sources in the active workings of
the mine (Sec. 70.208). The operator's approved ventilation and
methane and dust control plan, required in existing Sec. 75.370, must
show the specific locations in the mine designated for taking the DA
samples. In addition, mine operators take respirable dust samples for
part 90 miners (Sec. Sec. 90.207 and 90.208).
For surface work areas of underground mines and for surface mines,
mine operators are required to collect bimonthly samples from
``designated work positions'' (DWPs), which are designated by the
District Manager (Sec. 71.208).
Compliance determinations are based on the average concentration of
respirable dust measured by five valid respirable dust samples taken by
the operator during five consecutive normal production shifts or five
normal production shifts worked on consecutive days (multiple-shift
samples). Compliance determinations are also based on the average of
multiple measurements taken by the MSHA inspector over a single shift
(multiple, single-shift samples) or on the average of multiple
measurements obtained for the same occupation on multiple days
(multiple-shift samples).
Under the existing program, sampling results are often not known to
mine operators, miners, and MSHA for at least a week or more after the
samples are collected. Due to the delay in receiving sampling results,
operators are unable to take timely corrective action to lower dust
levels when there are overexposures.
B. 1992 Coal Mine Respirable Dust Task Group Report, 1995 NIOSH
Criteria Document, and 1996 Dust Advisory Committee Report
In May 1991, the Secretary directed MSHA to conduct a review of the
coal mine respirable dust control program and to develop
recommendations on how the program could be improved. MSHA established
an interagency task group (Task Group) which published their findings
and recommendations in the June 1992, Review of the Program to Control
Respirable Coal Mine Dust in the United States. The Task Group Report
can be accessed electronically at http://www.regulations.gov/#!documentDetail;D=MSHA-2010-0007-0211.
On November 7, 1995, NIOSH submitted to the Secretary a criteria
document recommending reduced standards for respirable coal mine dust
and crystalline silica. On April 25, 1996, MSHA published a Federal
Register notice (61 FR 18308) stating that it had decided to respond to
the 1995 NIOSH Criteria Document by developing a proposed rule
``derived from the recommendations'' in the NIOSH Criteria Document.
MSHA further stated that, although it would begin ``the background work
necessary to develop such a rule,'' it would defer development of the
rule until it received a report from the Secretary of Labor's Advisory
Committee on the Elimination of Pneumoconiosis Among Coal Mine Workers
(Dust Advisory Committee), which the Secretary had established on
January 31, 1995, and to which MSHA had referred the NIOSH criteria
document. One of the NIOSH recommendations in the Criteria Document was
to use single, full-shift samples to compare miners' exposures with the
NIOSH recommended exposure limit. The NIOSH Criteria Document can be
accessed electronically at http://www.cdc.gov/niosh/docs/95-106/.
On November 14, 1996, the Dust Advisory Committee submitted its
report to the Secretary. The Dust Advisory Committee Report can be
accessed electronically at http://www.msha.gov/S&HINFO/BlackLung/1996Dust%20AdvisoryReport.pdf. The report contained 20 wide-ranging
principal recommendations, subdivided into approximately 100 action
items, aimed at eliminating coal miners' pneumoconiosis and silicosis.
The report recommended that MSHA consider lowering the level of
allowable
[[Page 24818]]
exposure to coal mine dust, with any reduction accompanied by a phase-
in period to allow allocation of sufficient resources to the compliance
effort. The report also recommended that MSHA should change the
compliance sampling program to allow use of single, full-shift samples
for determining compliance. On January 24, 1997, MSHA published a
Federal Register notice (62 FR 3717) responding to the 1996 Dust
Advisory Committee Report. In the response, MSHA stated its intent to
conduct an in-depth evaluation of the recommendations and respond to
them.
C. 2000 and 2003 Plan Verification Proposed Rules
On July 7, 2000, MSHA published the Plan Verification proposed rule
(65 FR 42122, July 7, 2000). The proposal would have required
underground mine operators to have a verified mine ventilation plan,
with MSHA collecting samples to verify the adequacy of dust control
parameters specified in the ventilation plan to maintain respirable
dust standards (``verification sampling'').
In response to comments urging MSHA to withdraw the proposal, MSHA
published a new proposed rule on March 6, 2003, (68 FR 10784), which
would have required mine operators to have a ``verified'' mine
ventilation plan and conduct verification sampling on each mechanized
mining unit (MMU). Under the proposal, mine operators would have to
demonstrate the adequacy of dust control parameters specified in the
ventilation plan to maintain the concentration of respirable coal mine
dust and quartz at or below dust standards. In addition, the mine
operators' existing bimonthly respirable dust sampling program for each
MMU and DA would have been eliminated and MSHA would have assumed
responsibility for compliance and abatement sampling in underground
coal mines.
The 2003 proposal would have also provided for the use of CPDMs
once the CPDM was verified as reliable under mining conditions and
commercially available.
Public hearings were held in May 2003. The closing date for the
comment period for the Plan Verification proposed rule was extended
indefinitely to obtain information concerning CPDMs being tested by
NIOSH (68 FR 39881, July 3, 2003).
The following provisions from the 2003 Plan Verification proposal
have been revised and integrated into this final rule: (1) Use of the
CPDM in monitoring respirable dust exposures; (2) recording the amount
of material produced by each MMU during each production shift and
retaining the record; (3) sampling for respirable dust during the
entire time that a miner works to account for shifts longer than 8
hours; (4) requiring that dust control parameters in the mine's
ventilation plan be revised when respirable dust overexposures are
indicated; and (5) threshold values that would be used to determine
violations based on single sample measurements.
D. 2000 Single Sample Proposed Rule
On July 7, 2000, MSHA and NIOSH jointly published a proposed rule
on Determination of Concentration of Respirable Coal Mine Dust (Single
Sample) (65 FR 42068). The proposal would have rescinded the 1972 Joint
Finding and established that a single, full-shift measurement of
respirable coal mine dust may be used to determine the average
concentration on a shift if that measurement accurately represents
atmospheric conditions to which a miner is exposed during such shift.
MSHA proposed the 2000 Single Sample rule following the 11th
Circuit Court of Appeals decision in National Mining Association (NMA)
et al. v. Secretary of Labor, et al., 153 F.3d 1264 (11th Cir. 1998).
In this case, the Court reviewed the 1998 Final Joint Notice of Finding
issued by MSHA and NIOSH. The 1998 Final Joint Finding, issued on
February 3, 1998, concluded that the 1972 Joint Finding was incorrect
and stated that the average respirable dust concentration to which a
miner is exposed can be accurately measured over a single shift (63 FR
5664). The Court vacated the 1998 Joint Finding on procedural grounds.
It found that MSHA was required by section 101(a)(6)(A) of the Mine Act
to engage in rulemaking and demonstrate that a single, full-shift
measurement adequately assures that no miner will suffer a material
impairment of health, on the basis of the best available evidence; uses
the latest available scientific data in the field; is technologically
and economically feasible; and is based on experience gained under the
Mine Act and other health and safety laws (153 F.3d at 1268-1269).
On March 6, 2003, MSHA and NIOSH reopened the rulemaking record to
allow further comment on the Single Sample rulemaking and to solicit
comment on new data and information added to the record (68 FR 10940).
In May 2003, joint public hearings were held on the 2000 Single Sample
proposal and the 2003 Plan Verification proposal. The comment period
for the Single Sample proposal was extended indefinitely in order to
obtain information on CPDMs being tested by NIOSH (68 FR 47886, August
12, 2003). The Single Sample proposal is integrated into and a part of
this final rule, which permits MSHA inspectors to use single, full-
shift samples to determine compliance with the respirable dust
standard.
E. Continuous Personal Dust Monitor (CPDM)
On April 6, 2010 (75 FR 17512), MSHA and NIOSH published a final
rule, effective June 7, 2010, revising approval requirements under 30
CFR part 74 for the existing coal mine dust personal samplers. It also
established new approval requirements for the CPDM.
The CPDM is new technology that provides a direct measurement of
respirable dust in the miner's work atmosphere on a real-time basis. In
September 2006, NIOSH published the results of a collaborative study
designed to verify the performance of the pre-commercial CPDM in
laboratory and underground coal mine environments. According to the
NIOSH Report of Investigations 9669, ``Laboratory and Field Performance
of a Continuously Measuring Personal Respirable Dust Monitor,''
(Volkwein et al., U.S. Department of Health and Human Services, Centers
for Disease Control and Prevention, National Institute for Occupational
Safety and Health (USDHHS, CDC, NIOSH) 2006), the CPDM is accurate,
precise, and durable under harsh mining conditions in providing
continuous exposure information previously not available to coal miners
and coal mine operators.
On October 14, 2009, MSHA published a Request for Information (RFI)
on potential applications of CPDM technology to monitor and control
miners' exposure to respirable coal mine dust during a work shift (74
FR 52708). The comment period closed on December 14, 2009.
On September 6, 2011, NIOSH approved a commercial CPDM as meeting
the CPDM requirements of 30 CFR part 74 (USDHHS, CDC, NIOSH, 2011).
F. Regulatory History of This Final Rule
On October 19, 2010, MSHA published a proposed rule, Lowering
Miners' Exposure to Respirable Coal Mine Dust, Including Continuous
Personal Dust Monitors (75 FR 64412). The comment period was scheduled
to close on February 28, 2011. The QRA in support of the proposal and
Preliminary Regulatory Economic Analysis (PREA) were made publicly
available at that time.
[[Page 24819]]
On October 20, 2010, MSHA held a meeting at MSHA Headquarters in
Arlington, Virginia, and via conference call to brief interested
stakeholders on the proposed rule.
On November 15, 2010, MSHA published a Notice scheduling six public
hearings on the proposed rule in locations accessible to the mining
public (75 FR 69617). In response to requests from the public, two of
the hearings were rescheduled and an additional hearing was added, for
a total of seven, to provide a maximum opportunity for public
participation in the rulemaking (75 FR 73995). Hearings were held:
December 7, 2010, in Beckley, WV; January 11, 2011, in Evansville, IN;
January 13, 2011, in Birmingham, AL; January 25, 2011, in Salt Lake
City, UT; February 8, 2011, in Washington, PA; February 10, 2011, in
Prestonsburg, KY; and February 15, 2011, in Arlington, VA.
On January 14, 2011, MSHA extended the comment period from February
28, 2011 to May 2, 2011 (76 FR 2617). On May 4, 2011, MSHA again
extended the comment period to May 31, 2011 (76 FR 25277). On May 27,
2011, MSHA extended the comment period to June 20, 2011 (76 FR 30878).
On March 8, 2011, MSHA published a Federal Register notice (76 FR
12648) requesting comment on information that was included in the
preamble to the proposed rule and other issues that were raised during
the public hearings. The notice requested comment on 25 specific issues
and included two clarifications.
Public comments and supporting documentation submitted were posted
on the MSHA Web site and on www.regulations.gov, along with transcripts
and exhibits from the public hearings.
Several commenters, referring to an MSHA response to a request for
documents under the Freedom of Information Act (FOIA), stated that they
were denied access to documents that were critical to a thorough
evaluation of the proposed rule. The request involved documents
specifically related to the QRA in support of the proposed rule, and
documents generally related to the rulemaking.
All documents that were critical to a thorough evaluation of the
proposed and final rules are in the rulemaking record, and posted on
MSHA's Web site and on www.regulations.gov, as noted above. These
publicly available documents include Agency materials considered in the
development of the proposed and final rules, public comments and
supporting documentation submitted, along with transcripts and exhibits
from the public hearings. If materials included in the docket are
copyrighted, they are listed on www.regulations.gov but are not
reproduced there. MSHA also posted additional historical information
and data on respirable coal mine dust on its Web site at the request of
the public. MSHA's complete rulemaking docket, including studies,
articles, and reports reviewed by MSHA in the development of the
proposed and final rules, is available in hard copy for inspection at
its headquarters office. Peer reviewed documents of the QRA for the
proposed rule prepared by NIOSH and the Occupational Safety and Health
Administration (OSHA) at MSHA's request, as well as the QRA for the
proposed rule, have been available on the Black Lung Single Source Page
on MSHA's Web site since the October 19, 2010 publication of the
proposed rule at http://www.msha.gov/S&HINFO/BlackLung/Homepage2009.asp.
G. Government Accountability Office Activities
The Consolidated Appropriations Act, 2012, required that the
Government Accountability Office (GAO) review and report on the data
collection, sampling methods, and analyses MSHA used to support its
proposal. In August 2012, GAO issued a report, ``Mine Safety: Reports
and Key Studies Support the Scientific Conclusions Underlying the
Proposed Exposure Limit for Respirable Coal Mine Dust'', which assessed
the strengths and limitations of the data and the analytical methods
MSHA used to support its proposal to lower the exposure limit for
respirable coal mine dust. GAO concluded that the evidence MSHA used
did support its conclusion that lowering the limit as proposed would
reduce miners' risk of disease.
In May 2013, GAO was requested to conduct an additional analysis on
MSHA's proposed rule. In April 2014, GAO issued a report, ``Basis for
Proposed Exposure Limit on Respirable Coal Mine Dust and Possible
Approaches for Lowering Dust Levels''. GAO examined (1) the extent to
which MSHA used recent CWP trend data as a basis for its proposed
exposure limit, and (2) expert views on ways to lower the dust levels
in coal mines, including their associated advantages, disadvantages,
and cost. In the report, GAO concluded that MSHA appropriately did not
use recent trend data on CWP as a basis for its proposal to lower the
permissible exposure limit for respirable coal mine dust. According to
GAO, these recent data from NIOSH were inappropriate for this purpose
because they do not include the types of detailed information about
individual miners needed to estimate the likelihood that miners would
develop CWP at different exposure levels, such as historical dust
exposures. With the help of the National Academies, GAO convened a
group of experts knowledgeable about underground coal mining and
methods for reducing coal mine dust. GAO did not make any
recommendations in this report. MSHA has reviewed both GAO reports and
has determined that no further action is necessary.
MSHA has also reviewed the explanatory statement by the Chairman of
the House Committee on Appropriations in the 2014 Appropriations Act
regarding the coal mine dust rule. Consistent with the explanatory
statement, MSHA has taken into consideration all relevant information
and conclusions from the GAO study when addressing compliance
assistance, training, or post-implementation needs in connection with
the final rule. MSHA also considered all available technologies and
work practices that would allow mine operators to reduce miners'
exposures to respirable coal mine dust in a manner that is not
economically prohibitive for the long-term viability of the affected
mines, while reducing miners' exposure to respirable (coal) mine dust.
(MSHA discusses feasibility in section III.C. of this preamble and in
chapter IV of the REA.) MSHA intends to develop outreach materials
related to implementation of the final rule and hold stakeholder
seminars in locations accessible to the mining public. MSHA also
intends to develop compliance assistance materials to ensure that
operators have a sufficient number of certified persons to perform
sampling and maintenance and calibration of CPDMs.
III. Discussion of the Final Rule
A. Health Effects
The health effects from occupational exposure to respirable coal
mine dust consist of interstitial and obstructive pulmonary diseases.
Miners develop Coal Workers' Pneumoconiosis (CWP) or nonmalignant
respiratory disease (NMRD). There are no specific treatments to cure
CWP or NMRD. These chronic effects may progress even after miners are
no longer exposed to respirable coal mine dust resulting in increased
disability and death. Other complications may follow, such as pulmonary
and cardiac failure, that result in total disability and premature
death.
[[Page 24820]]
The health effects from occupational exposure to respirable coal
mine dust were discussed in the preamble to MSHA's proposed rule on
Plan Verification published on March 6, 2003 (68 FR 10784). The
literature referenced in that document pre-dated 1999. More recent
literature, from 1997 to mid-2009 with occasional references to earlier
papers, was discussed in the Health Effects section of the preamble to
the proposed rule for this final rule (75 FR 64412, 64458).
Reduction of coal mine dust exposure is the only effective way to
prevent either CWP or NMRD. Screening and surveillance programs detect
trends and clusters of disease occurrences and allow secondary
preventive intervention to slow the rate of progression in miners. Data
from screening and surveillance programs provide estimates of the
prevalence of occupational respiratory disease among working coal
miners.
At the existing respirable coal mine dust standard of 2.0 mg/m\3\,
cases of CWP and NMRD continue to occur. In recent years, the
prevalence of CWP has increased among experienced miners, and in some
cases, CWP has progressed rapidly to the more advanced form-progressive
massive fibrosis (PMF). The persistence of disease requires that
additional action be taken to reduce coal mine dust exposures. The
final rule will reduce occupational pulmonary disease, disability, and
premature mortality in coal miners.
Although not a basis or rationale for the final rule, in May 2011,
CWP prevalence in a West Virginia mining population was reported in the
Governor's Independent Investigation into the April 5, 2010, explosion
at the Upper Big Branch (UBB) mine in southern West Virginia (p. 32).
This investigation reported the prevalence of CWP as determined by
autopsies in the 29 miners who died. Twenty-four of the 29 miners had
sufficient lung tissue available to make a determination relating to
CWP. Prevalence of CWP in these 24 miners was 71 percent (17 of 24
miners), which compares with the national prevalence rate for CWP among
active underground miners of 3.2 percent, and the prevalence rate in
West Virginia of 7.6 percent. The ages of the UBB miners with CWP
ranged from 25 to 61 years. Of the 7 miners who were not identified as
having CWP, 4 had what was characterized as ``anthracosis'' on their
autopsy reports. This term is often used in lieu of the term
pneumoconiosis, or may refer to a black pigment deposition without the
fibrosis and other characteristics needed to make a firm diagnosis of
pneumoconiosis. Three of the 24 miners had no pneumoconiosis or
anthracosis noted.
Of the 17 UBB miners with CWP, 5 had less than 10 years of
experience as coal miners, while 9 had more than 30 years of coal
mining experience. At least 4 of the 17 worked almost exclusively at
UBB. All but 1 of the 17 with CWP began working in the mines after the
2.0 mg/m\3\ respirable coal mine dust standard became effective in
1973.
There was support for the proposed rule from many commenters who
agreed with MSHA's conclusions in the health effects and QRA
discussions in the preamble to the proposed rule. Commenters supported
the proposed rule which would lower the existing dust standards,
require the use of continuous personal dust monitors (CPDMs), base
compliance determinations on single, full-shift samples, address
extended work shifts, redefine a normal production shift, and extend
medical screening and surveillance. These commenters stated that there
has been an alarming increase of CWP within the past 10 years and that
MSHA's existing standards have not succeeded in eliminating Black Lung.
Other commenters stated that the proposed rule is not needed. Some
stated that MSHA should better enforce its existing standards rather
than propose new standards. Some stated that black lung rates have been
declining since 2000 when MSHA and NIOSH began using enhanced
surveillance methods and that the Agency used selective data to support
the proposed reduction in the standard. Others stated that MSHA should
only address the health concerns in particular areas of the country,
which include Virginia, West Virginia, and Kentucky. Several commenters
stated that the proposal is not based on the best available evidence
but, rather, is based on faulty science and medical data. One commenter
suggested that MSHA, NIOSH, industry, and labor conduct a nationwide
study using the CPDM to determine what dust concentrations are
protective and achievable. The comments are discussed below.
In the health effects section of the proposed rule, MSHA reported
results from NIOSH publications and studies that were based on grouped
surveillance data. In response to commenters requesting that the
underlying demographic information be made available, MSHA points out
that these results are part of NIOSH's coal miner surveillance data
included in the proposed rule's hazard and risk assessment analyses.
NIOSH posts summary surveillance data on U.S. coal miners on its Web
site at http://www.cdc.gov/niosh/topics/surveillance/ords/. These data
are generated based on the requirements of 42 CFR part 37,
Specifications for Medical Examinations of Underground Coal Miners.
Because of privacy protection laws, such as the Health Insurance
Portability and Accountability Act (HIPAA) of 1996, the Privacy Act of
1974, and the Freedom of Information Act, MSHA cannot provide
underlying personal identifying information.
Some commenters stated that the proposed rule was based on three
data sources: The NIOSH 1995 Criteria Document, a literature update by
NIOSH entitled ``Current Intelligence Bulletin 64, Coal Mine Dust
Exposure and Associated Health Outcomes, A Review of Information
Published Since 1995'' (``NIOSH CIB 64'') (USDHHS, CDC, NIOSH (2011a)),
and various NIOSH papers on its enhanced surveillance studies. MSHA did
not use the NIOSH literature update in the development of the proposed
rule because it was published in April 2011 and, therefore, not final
when the proposed rule was published on October 19, 2010. However, the
NIOSH CIB 64 provides supplementary information that supports the final
rule and is referenced later in this section of the preamble. NIOSH
submitted CIB 64 to MSHA during the comment period for the proposed
rule.
Some commenters stated that MSHA did not produce for independent
analysis the underlying data from the NIOSH Criteria Document and X-ray
program. One commenter stated that this is a violation of the Office of
Management and Budget (OMB) and MSHA guidelines on data quality which
prevented stakeholders from being able to comment on the scientific
basis of the proposed rule.
The Data Quality Act or Information Quality Act directs OMB to
issue guidelines to agencies to ensure and maximize the quality,
objectivity, utility, and integrity of information that agencies
maintain and disseminate (Section 515 of the Treasury and General
Government Appropriations Act for FY 2001 (Pub. L. 106-554)). MSHA has
satisfied the requirements of OMB's 2002 data quality Guidelines, for
Ensuring and Maximizing the Quality, Objectivity, Utility, and
Integrity of Information Disseminated by Federal Agencies (36 FR 8452,
February 22, 2002). MSHA has adopted well-established quality assurance
techniques to ensure the quality of information disseminated.
Information
[[Page 24821]]
is subject to internal agency quality control and audit, and any
appropriate Department of Labor level review before being disseminated
to the public. MSHA's Information Quality Guidelines are available on
the Agency's Web site at: http://www.msha.gov/infoquality/mshainfoquality.htm.
MSHA explained in the preamble to the proposed rule that the
proposal was developed in part on the recommendations in the 1995 NIOSH
Criteria Document. NIOSH is the agency in possession of the underlying
data associated with the Criteria Document and has posted data relevant
to the Criteria Document on its Web site at http://www.cdc.gov/niosh/topics/surveillance/ords/. In accordance with Section 101(a) of the
Mine Act, NIOSH submitted the Criteria Document to the Secretary of
Labor for consideration in developing standards to reduce health risks
associated with miners' exposure to respirable dust.
In addition, the Health Effects section in the preamble to the
proposed rule contains a comprehensive inventory and summarizes key
aspects of scientific literature and studies on the health effects from
occupational exposure to respirable coal mine dust. Regarding the NIOSH
X-ray data, NIOSH posts summary surveillance data on U.S. coal miners
on the Web site previously noted at http://www.cdc.gov/niosh/topics/surveillance/ords/.
One commenter stated that using data from the NIOSH surveillance
program violates the data quality guidelines because NIOSH self-selects
the program participants and therefore the data is biased. The
commenter also stated that data from the B-reader program is imprecise,
inaccurate and biased because the B-reader program gives significant
false-positive readings thereby exaggerating the incidence of CWP.
The relatively low participation rates, potential self-selection
biases, and a lack of correspondent exposure histories for the
individual miners involved limit the use of the NIOSH surveillance data
as support for the Quantitative Risk Assessments. Additional discussion
is included in Section III.B., Quantitative Risk Assessment, of the
preamble. NIOSH instituted the B-reader program to ensure competency
and consistency in radiographic reading by evaluating the ability of
readers to classify a test set of radiographs. A discussion of NIOSH's
B-reader program is included in Section III.A., Health Effects, of the
preamble.
In developing the proposed rule, MSHA evaluated over 150 peer-
reviewed papers as part of the Agency's health effects assessment (75
FR 64460, October 19, 2010), in addition to the data from MSHA's
proposed rule on Plan Verification. The literature review focused on
studies of morbidity and mortality among coal miners in many countries,
including the United States, South Africa, Europe, Britain, China,
Australia, Turkey, and Japan. This research evaluated the relationship
between respirable coal mine dust exposure and the respiratory disease
it causes. The research reported on the etiology of adverse respiratory
diseases, including CWP, PMF, and NMRD, such as chronic obstructive
pulmonary disease (COPD) and emphysema. The fact that similar results
have been found in decades of research, covering a wide variety of
populations at various respirable coal mine dust exposure levels and
working conditions, supports the determination that exposure to
respirable coal mine dust is a significant causal factor in the
development of respiratory diseases in coal miners. The conclusion of
MSHA's review of this research and of NIOSH's 2011 literature update is
that chronic coal mine dust exposure causes respiratory health effects
including CWP, PMF, COPD, and emphysema.
Recognition that long-term respirable coal dust exposure causes
irreversible respiratory health effects has been accepted by the
medical community for decades. On March 26, 1969, Charles C. Johnson,
Jr., Administrator, Consumer Protection and Environmental Health
Service, Public Health Service, U.S. Department of Health, Education,
and Welfare, testified before the General Subcommittee on Labor, and
presented remarks of the Surgeon General addressing the level of
medical understanding about the etiology of CWP at that time.\4\
Johnson testified that CWP is a chronic chest disease caused by the
accumulation of fine coal mine dust particles in the human lung that,
in its advanced forms, leads to severe disability and premature death.
---------------------------------------------------------------------------
\4\ 91st Congress House of Representatives Report, 1st Session
No. 91-563, Federal Coal Mine Health and Safety Act, October 13,
1969.
---------------------------------------------------------------------------
Johnson's testimony also pointed out that, by 1969, medical
researchers in both Britain and the United States had repeatedly shown
that coal miners suffer from more respiratory impairment and
respiratory disability than the general population. These respiratory
problems were frequently accentuated by chronic bronchitis and
emphysema.
Estimates of the severity of disease risk at that time were derived
from British research. This research provided the only quantitative
exposure-response relationship available in 1969 and supported lowering
the respirable coal mine dust standard from 3.0 mg/m\3\ to 2.0 mg/m\3\.
Adoption of the 2.0 mg/m\3\ standard was believed to be protective
against the risk of disability and premature mortality that accompanies
PMF. However, NIOSH has noted that as more research was completed over
the next 25 years, this assumption turned out to be inaccurate (NIOSH
CIB 64, 2011a).
In 1995, NIOSH published ``Criteria for a Recommended Standard--
Occupational Exposure to Respirable Coal Mine Dust'', an analysis of
research up through the early 1990s that further investigated the
etiology of CWP and other adverse health effects associated with
respirable coal mine dust exposure. NIOSH recommended that the federal
coal mine dust limit be reduced to 1.0 mg/m\3\. This recommendation was
based on risk estimates of CWP derived from two NIOSH studies of U.S.
coal miners. Predictions were derived from each study for a working
lifetime of 45 years at two exposure levels: 2.0 mg/m\3\ and 1.0 mg/
m\3\. The recommendation was also based on information that predicted
excess lung function decrements following working lifetime exposures to
2.0 mg/m\3\ and 1.0 mg/m\3\ respirable coal mine dust. NIOSH also
evaluated information from other epidemiologic studies in reaching its
1995 recommendations. NIOSH estimated, and MSHA concurs, that miners
exposed to respirable coal mine dust at the existing 2.0 mg/m\3\
standard are at significant risk of developing adverse health effects,
such as CWP and NMRD, including COPD and emphysema.
Some commenters disagreed with NIOSH surveillance and research
results as the basis for the proposed rule. These commenters stated
that the prevalence of CWP and PMF in U.S. coal miners was overstated,
surveillance was incomplete, and the 1.0 mg/m\3\ standard was not
justified. They presented various analyses of the NIOSH studies and
submitted for the rulemaking record a NIOSH study that was published
after the proposed rule (Suarthana et al., 2011). The Suarthana study
is discussed in this Health Effects section of the preamble.
Some commenters suggested that MSHA should collect data from a
representative or mandatory surveillance program and study the data in
a scientifically sound manner to better understand the incidence of
CWP.
MSHA believes that this program already exists in the National Coal
Workers Health Surveillance Program (NCWHSP, also known as CWHSP) that
is administered by NIOSH. MSHA has
[[Page 24822]]
used data generated from this program in the development of both the
proposed and final rules.
Occupational health surveillance tracks occupational injuries,
illnesses, hazards, and exposures to improve worker safety and health
and to monitor trends and progress over time. Surveillance includes
both population- or group-based activities and individual or case-based
activities. Worker screening and monitoring detects early disease in
high-risk individuals.
The purpose of federal and state surveillance programs for chronic
lung diseases, such as CWP, PMF, and NMRD, is to identify not only
cases of disease, but also conditions under which the cases develop in
order to improve disease control and prevention. There are three levels
of prevention. Primary prevention in the case of dust-related lung
disease includes reducing exposure to dust, generally through
engineering controls. Secondary prevention focuses on early detection
of disease and intervention in order to slow or eliminate progression.
Much of the medical surveillance conducted by NIOSH is secondary
prevention. Tertiary prevention involves miners seeking further medical
care only after they have symptoms, progression to later stages is more
likely, and the primary treatment is to manage symptoms of disease
since it is too late to prevent disease.
There is a spectrum of respiratory disease development in coal
miners exposed to respirable coal mine dust. Pathologic changes occur
during the subclinical stage of disease development that are not
detectable by either spirometry or chest x-ray (CWP 0/0). For this
reason, all miners should have an initial medical examination to
establish a baseline health status on which future medical surveillance
can be compared to determine disease presence or progression. NIOSH and
many of the research papers on which the proposed health effects
assessment was based use CWP 1/0+ as the category where disease
progression is evident; many of these miners may not have overt
symptoms, but the chest x-ray shows signs of fibrotic changes. The use
of this CWP category as a sign of the development of minimal illness
dates from the 1969 Coal Act, where the Surgeon General recommended
that miners be removed from dusty environments as soon as they showed
``minimal effects'' of dust exposure on chest-x-ray, i.e., pinpoint,
dispersed micro-nodular lesions. Many miners may also report symptoms
of developing respiratory disease, such as chronic cough, phlegm
production, wheezing, and shortness of breath.
Many comments focused only on detection of clinical disease
(tertiary prevention), once disease has advanced well beyond the
clinical horizon when symptoms appear (CWP category 2/0+). One
commenter submitted an analysis of CWP mortality in a subgroup of
miners with advanced disease at the CWP 2/0+ level. While this analysis
may help to understand the etiology of advancing disease, it does not
identify how the disease process begins or how to prevent disease from
developing. Miners with this level of disease present pulmonary
symptoms and are likely to suffer from disease progression.
The focus of federal coal workers' health surveillance programs is
on prevention of clinical disease, not detection of disease that has
progressed well beyond the clinical horizon. The Coal Workers' X-Ray
Surveillance Program (CWXSP) was established under the Federal Coal
Mine Health and Safety Act of 1969, as amended by Section 203(a) of the
Mine Act (30 U.S.C. 843(a)). The CWXSP Program, which is part of the
National Coal Workers Health Surveillance Program (NCWHSP), began in
1970. It is administered by NIOSH. The CWXSP provides all underground
coal miners with periodic, x-ray examinations, at no cost to the miner,
at least every five years (42 CFR part 37).
The National Coal Study (NCS) was a long-term epidemiologic study,
limited to workers in a selected group of mines with various seam
heights, mining methods, coal types, and geographic locations. Many of
the published peer-reviewed epidemiological studies reported in the
proposed rule's health effects section grew out of the NCS. Commenters
suggested that many of NIOSH's studies were incomplete due to design or
other limitations and suggested that a detailed, nationwide
epidemiological study be conducted based on mandatory screening before
any action to lower the respirable dust standard is initiated.
MSHA does not believe that a nationwide epidemiological study,
based on mandatory screening, as suggested by the commenter is needed
before regulatory action is taken be reduce the respirable dust
standard. Underground coal miners in the United States have been
studied since before the 1969 Coal Act by the Public Health Service and
State health agencies. Those studies were the basis for the current
surveillance programs in this country. Numerous pre-Coal Act studies
and studies since that time have characterized the respiratory system's
response to various levels of respirable coal mine dust, a known
fibrogenic dust. Significant levels of adverse lung diseases are
continuing to develop in coal miners who have been exposed to
respirable coal mine dust at the current standard.
Some commenters stated that x-rays are insensitive for detecting
CWP and that surveillance programs suffer from inconsistent reading of
the x-rays.
Early changes due to CWP are frequently identifiable on a high
quality chest x-ray before the miner seeks medical attention due to
symptoms. NIOSH instituted the B-reader program to ensure competency
and consistency in radiographic reading by evaluating the ability of
readers to classify a test set of radiographs. This creates and
maintains a pool of qualified readers having the skills and ability to
provide consistent and accurate ILO classifications. B-readers must
retest every 4 years to maintain their B-reader status. A reader who
fails the retest must take and pass the original approval examination
before the expiration of the 4-year approval period in order to retain
B-reader status. The implementation of this program in the mid-1970s,
the update of the program to adjust to the ILO guidelines in 1980, and
the revised ILO guidelines in 2000 and 2011 ensure B-reader consistency
in reading x-rays.
In order to preserve continuity and consistency in the
classifications, the images used in reproducing the 2011 ILO version of
the standard radiographs are identical to those used for the 1980 set
of standard radiographs, aside from one image which demonstrates
pleural abnormalities. The ILO did endeavor to improve image quality in
the 2000 set by using advanced computer imaging techniques. The NIOSH
CWXSP requires that readers submit classifications adhering to the 2011
Revised Edition of the Guidelines for the Use of the ILO International
Classification of Radiographs of Pneumoconiosis. The sets of standard
images used in the 2011 and 1980 classifications are nearly identical,
and thus it is the individual reader's choice which of these two sets
of standard radiographs to use. However, because the quality of the
2011 standard radiographs has been enhanced by the ILO Guidelines,
NIOSH recommends that readers use the 2011 standard radiographs for
classifying films for NIOSH programs and studies (http://www.cdc.gov/niosh/topics/chestradiography/breader-info.html).
Classifying films can be variable, especially in lower disease
categories, with differences of opinion between B-readers and by the
same B-reader at different times (Attfield et al., 2007; Naidoo et al.,
2004). To account for this
[[Page 24823]]
variability, the ILO classification system allows readers to determine
profusion severity by indicating the most likely category and also by
indicating a neighboring category that might also be valid. For
example, a score of 1/2 means the disease state is classified as
category 1, but could also be considered category 2. Another means of
compensating for variability is to have a panel of readers interpret
films by consensus rather than using a single reader. When the ILO
system is used for surveillance and screening purposes, it has been
demonstrated to be a valid means for identifying trends and disease
clusters (Attfield et al., 2007; Naidoo et al., 2004; NIOSH, 2008). The
CWXSP uses a profusion score of 1/0+ as indicative of CWP development.
Section 203(a) of the Mine Act specifically requires that operators
provide periodic chest x-ray examinations to underground coal miners,
and such other tests as the Secretary of Health and Human Services
deems necessary to supplement the x-rays (30 U.S.C. 843(a)). In
addition to pneumoconiosis apparent on x-rays, miners are at increased
risk for the development of COPD. Chest x-rays alone cannot provide a
measure of airflow obstruction and, therefore, often miss important
lung disease. Spirometry, a simple breathing test, is an additional
component of the health assessment of miners that is particularly
useful. NIOSH has recommended periodic medical history and spirometry
tests for both surface and underground coal miners since 1995, to
facilitate preventive actions, increase miners' participation in
programs for early detection of disease, and improve the derivation of
representative estimates of the burden, distribution, and determinants
of occupational lung disease in relation to coal mining in the United
States. Final Sec. 72.100 requires spirometry testing of both
underground and surface miners.
A few commenters stated that a recent study by Suarthana et al.
(2011) states that dust exposure is a poor predictor of CWP prevalence.
In response, MSHA notes that dose-response relationships between
cumulative dust exposure and cases of respiratory diseases have been
studied by NIOSH as part of the National Coal Study. The Suarthana
study stated that: ``Epidemiological modeling of CWP prevalence and
incidence undertaken on underground coal miners in the USA and
elsewhere has shown that the main predictor of CWP is cumulative
exposure to respirable coal mine dust.''
As stated previously, NIOSH studies the causes and consequences of
coal-related respiratory disease and, in cooperation with MSHA, carries
out a program for early detection of coal workers' pneumoconiosis.
These activities are administered through the CWXSP.
In the early 2000s, MSHA with assistance from NIOSH piloted the
Miners' Choice Program (MCP) to offer all coal miners the opportunity
to participate in the CWXSP by having medical staff travel to mines or
other areas to conduct medical surveillance of mining populations at no
cost to the mine operator. The MCP used a mobile medical examination
unit to bring the medical exams, including chest x-rays, to the miners
in remote areas to provide early detection of dust-related pulmonary
disease. MSHA wanted to determine the state of miner health because
participation in the CWXSP decreased from the high of 100% in 1970 to
1974 to a low of 20.6% in 1990 to 1994 (Table III-2). MSHA found that
participation rates increased to 25.5% in 1995 to 1999; 34.1% in 2000
to 2004; and 41.7% in 2005 to 2009. MSHA further found that as more
miners were screened, the prevalence of CWP detected fluctuated. CWP
was detected in 2.0% of the miners who were x-rayed from 1995 to 1999;
3.6% from 2000-2004; and 2.7% from 2005 to 2009 (Table III-1). Although
commenters stated that this increase was not real, additional miner
participation resulting from the enhanced surveillance identified more
cases of CWP that otherwise would have gone undetected.
The Miners' Choice Program was expanded into the Enhanced Coal
Workers' Health Surveillance Program (ECWHSP) in March 2006 by NIOSH to
continue increasing miner participation by providing additional
respiratory health evaluations to coal miners. The ECWHSP uses a mobile
medical examination unit to bring the medical exams to the miners in
the field to provide early detection of dust-related pulmonary disease
and target additional areas for prevention. This program offers lung
function testing in addition to chest x-rays as part of the medical
examination and asks miners to fill out occupational and health
surveys.
The National Coal Workers' Autopsy Study, which is part of the
NCWHSP, provides autopsies of deceased coal miners at the request of
miners' next-of-kin at no cost to the family. Autopsy results may help
support a black lung benefit claim and also help scientists and medical
doctors learn more about CWP. Doctors collect standardized lung
specimens during autopsies to be used in ongoing scientific research as
well as to provide information to the next-of-kin regarding the
presence and extent of CWP in the lungs of the deceased miner. Because
one basic reason for the post-mortem examination is research (both
epidemiological and clinical), a minimum of essential information is
collected regarding the deceased miner, including occupational history
and smoking history. The data collected are used by scientists for
research purposes in defining the diagnostic criteria for
pneumoconiosis and in correlating pathologic changes with exposures and
x-ray findings.
NIOSH reports overall prevalence of CWP 1/0+ across all MSHA
districts, as well as a national prevalence (Table III-1). These
numbers are based on the average number of miners employed per time
period (1995-1999, 2000-2004, and 2005-2009) and the number x-rayed per
time period. When more information is available from complete medical
examination records, NIOSH refines the estimates as in the case with
reporting CWP prevalence based on tenure, i.e., the length of time
worked in coal mining (Table III-2).
During the 2005 to 2009 period, for example, over 18,500 active
underground coal miners were screened as part of the CWXSP. As shown in
Table III-1, this is approximately 42% of all active underground miners
(NIOSH, 2011--Work-Related Lung Disease Surveillance System, CWXSP.
ref. no. 2011T02-17, May 2011). Active miners from all MSHA districts
participated in this screening.
Some commenters stated that the NIOSH surveillance programs are not
``well-established scientific processes for data collection'' and that
black lung rates have declined since 2000.
NIOSH surveillance of CWP started in 1970 and continues today using
the same case definition of CWP 1/0+ (Tables III-1 and III-2). The
number of miners participating in the program has fluctuated through
the years. NIOSH's active surveillance programs have reached additional
miners, as shown in Table III-2; the percentage participating in the
period from 2005 to 2009 was 41.7% as compared to a low of 20.6% in the
period from 1990 to 1994. In addition, the number of underground coal
miners in the United States has declined from over 150,000 in the 1975-
1979 time period to under 45,000 in the 2005-2009 time period. The
number of miners examined that provided tenure data on the health
questionnaire forms was approximately 85,000 in the 1970-1974 time
period to approximately 11,000 in the late 2000s.
Miners who stop working in mining are lost to follow-up. Since
their health status is not known, surveillance of only
[[Page 24824]]
active miners may underestimate the prevalence of disease. Cohen et al.
(2008) reported that disease progression continues after exposures
stop, increasing lung function impairment and pneumoconiosis levels in
miners once they leave employment (i.e., ex-miners and retired miners).
Coal mine dust clearance from the lungs is slow and incomplete,
allowing continued contact between the cytotoxic dust and lung tissues.
This progression of disease after retirement from coal mining (i.e.,
after exposure ceased) was also observed in other countries (Cohen et
al., 2008). Ex-miners displayed higher levels of respiratory disease
than current miners illustrating the progression of CWP to PMF even
after exposure ceased (Naidoo et al., 2005 and 2006). Miners with
advanced disease are forced to retire because they can no longer
perform mining tasks (Cohen et al., 2008).
Exposures, as estimated by MSHA inspector samples, have decreased
since passage of the 1977 Mine Act from a mean of 0.796 mg/m\3\ (with
18.7% of samples above the 2.0 mg/m\3\ standard) in 1979 to 0.468 mg/
m\3\ (with 3.2% of samples above the 2.0 mg/m\3\ standard) in 2003 at
underground coal mines; and from 0.384 mg/m\3\ (5.0% above the 2.0 mg/
m\3\ standard) in 1979 to 0.148 mg/m\3\ (0.8% above the 2.0 mg/m\3\
standard) in 2003 at surface coal mines (NIOSH, 2011--Work-Related Lung
Disease Surveillance System, CWXSP. ref. no. 2007T02-14; http://www2.cdc.gov/drds/WorldReportData/FigureTableDetails.asp?FigureTableID=529&GroupRefNumber=T02-14). As
exposures were reduced, the prevalence of CWP 1/0+ was also reduced, on
average. Prevalence information on CWP 1/0+ among miners from the
NCWHSP, reported on NIOSH's Web site, was 2.0% in the 1995-1999 time
period; 3.6% in the 2000-2004 time period; and 2.7% in the 2005-2009
time period (Table III-1). When tenure is considered, however, the
prevalence increased to 2.6%, 4.1%, and 4.1%, respectively (Table III-
2). Table III-2 shows that disease progression continues even after
exposures were reduced.
[[Page 24825]]
[GRAPHIC] [TIFF OMITTED] TR01MY14.000
``-'' indicates fewer than five miners examined or with CWP (to
protect identification of miners screened who have been diagnosed with
disease because of privacy laws).
Note: The average number employed during the period, based upon
quarterly reports by coal mine operators to MSHA. Because of hiring and
layoffs, the total number of individuals who worked at underground
mines in any period may exceed the average employment.
Source: CWP data from NIOSH's CWXSP. Coal District codes from MSHA.
http://www2a.cdc.gov/drds/WorldReportData/FigureTableDetails.asp?FigureTableID=2551&GroupRefNumber=T02-17.
[[Page 24826]]
Table III-2--CWXSP: Number and Percentage of Examined Underground Miners With CWP (ILO Category 1/0+) by Tenure Information Provided on Medical Questionnaire, 1970-2009
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Time Period
-------------------------------------------------------------------------------------------------------------------------------
1970-1974 1975-1979 1980-1984 1985-1989 1990-1994 1995-1999 2000-2004 2005-2009\*\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Average No. Employed at 104,705 150,475 131,113 91,122 69,424 50,319 39,544 44,546
Underground Mines.
Number of X[dash]rays......... 105,841 99,610 45,797 19,049 14,283 12,674 16,644 18,563
% of Miners X[dash]rayed...... 101.1 66.2 34.9 20.9 20.6 25.2 42.1 41.7
% of Miners X[dash]rayed That 80.9 59.1 78.1 67.3 82.1 71.8 82.9 60.4
Reported Tenure Information.
Tenure (years in underground Total No. of Miners Examined.. 85,644 58,864 35,787 12,816 11,727 9,100 13,794 11,211
mining).
Total No. with CWP............ 13,288 2,887 1,083 460 424 233 570 455
Total % with CWP.............. 15.5 4.9 3 3.6 3.6 2.6 4.1 4.1
0-9............................. No. of Miners Examined........ 36,303 43,296 23,190 5,063 1,638 806 4,261 4,281
No. with CWP.................. 803 475 186 44 20 7 47 27
% with CWP.................... 2.21 1.1 0.8 0.9 1.2 0.9 1.1 0.6
10-14........................... No. of Miners Examined........ 6,464 5,460 7,050 4,345 2,968 642 562 311
No. with CWP.................. 586 328 166 111 68 7 10 \**\
% with CWP.................... 9.1 6 2.4 2.6 2.3 1.1 1.8 1
15-19........................... No. of Miners Examined........ 6,210 2,705 2,253 2,071 4,037 1,778 1,156 235
No. with CWP.................. 910 298 139 118 125 34 37 5
% with CWP.................... 14.7 11 6.2 5.7 3.1 1.9 3.2 2.1
20-24........................... No. of Miners Examined........ 8,769 2,044 993 683 2,178 3,475 3,100 958
No. with CWP.................. 1877 380 102 63 115 86 152 47
% with CWP.................... 21.4 18.6 10.3 9.2 5.3 2.5 4.9 4.9
25+............................. No. of Miners Examined........ 27,898 5,359 2,301 654 906 2,399 4,715 5,426
No. with CWP.................. 9,112 1,406 490 124 96 99 324 376
% with CWP.................... 32.7 26.2 21.3 19 10.6 4.1 6.9 6.9
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\*\ Number from Table III-1, 2005-2009 number of miners X-rayed.
\**\ Indicates fewer than 5 miners with CWP.
Source: CWP data from NIOSH's Coal Workers' X-ray Surveillance Program (CWXSP). Ref. No. 2007F02-06, 2011T02-12.
[[Page 24827]]
Some commenters stated that the prevalence of disease was
overstated in the proposed rule. Annual prevalence data are reported on
NIOSH's Web site and summarized in Table III-3 for 1970 through 2009.
Prevalence in 1970, the first year of surveillance, was 2,162 cases
(30.5%). The respirable dust standard at the time was 3.0 mg/m\3\. As
shown in Table III-3, the percent of miners show a downward trend until
after 1999. In the last decade, the observed prevalence of CWP 1+ in
examined miners has varied from a low of 46 cases (2.6%) in 2004 to 167
cases (5.8%) in 2006. The number of miners examined in 2005 was only
706 miners; 37 of them, or 5.2%, were diagnosed with CWP 1/0+. In
comparison in 2000, 6,264 miners were examined and 242 (3.9%) were
diagnosed with CWP 1/0+.
Table III-3--CWXSP: Number and Percentage of Examined Underground Miners (Who Provided Tenure Information) With
Coal Workers' Pneumoconiosis (ILO Category 1/0+) Yearly Totals, 1970-2009, (Using Data From Table III-2)
----------------------------------------------------------------------------------------------------------------
Total No. of
Year Miners Total No. with Total % with
Examined CWP CWP
----------------------------------------------------------------------------------------------------------------
1970............................................................ 7,085 2,162 30.5
1971............................................................ 30,703 5,154 16.8
1972............................................................ 6,916 717 10.4
1973............................................................ 8,001 961 12.0
1974............................................................ 32,939 4,294 13.0
1970-1974....................................................... 85,644 13,288 15.5
1975............................................................ 8,779 482 5.5
1976............................................................ 7,581 174 2.3
1977............................................................ 7,870 194 2.5
1978............................................................ 10,235 386 3.8
1979............................................................ 24,399 1,651 6.8
1975-1979....................................................... 58,864 2,887 4.9
1980............................................................ 7,532 303 4.0
1981............................................................ 9,201 234 2.5
1982............................................................ 4,536 80 1.8
1983............................................................ 4,833 133 2.8
1984............................................................ 9,685 333 3.4
1980-1984....................................................... 35,787 1,083 3.0
1985............................................................ 3,056 69 2.3
1986............................................................ 848 30 3.5
1987............................................................ 2,867 92 3.2
1988............................................................ 3,589 168 4.7
1989............................................................ 2,456 101 4.1
1985-1989....................................................... 12,816 460 3.6
1990............................................................ 891 61 6.8
1991............................................................ 1,036 38 3.7
1992............................................................ 3,578 140 3.9
1993............................................................ 3,640 95 2.6
1994............................................................ 2,582 90 3.5
1990-1994....................................................... 11,727 424 3.6
1995............................................................ 1,920 57 3.0
1996............................................................ 607 27 4.4
1997............................................................ 1,625 32 2.0
1998............................................................ 883 31 3.5
1999............................................................ 4,065 86 2.1
1995-1999....................................................... 9,100 233 2.6
2000............................................................ 6,264 242 3.9
2001............................................................ 2,618 104 4.0
2002............................................................ 1,723 109 6.3
2003............................................................ 1,423 69 4.8
2004............................................................ 1,766 46 2.6
2000-2004....................................................... 13,794 570 4.1
2005............................................................ 706 37 5.2
2006............................................................ 2,877 167 5.8
2007............................................................ 2,923 82 2.8
2008............................................................ 3,457 111 3.2
2009............................................................ 1,248 58 4.6
2005-2009....................................................... 11,211 455 4.1
----------------------------------------------------------------------------------------------------------------
Source: CWXSP--Coal Workers' X-ray Surveillance Program--Ref. No. 2011T02-12, http://www2a.cdc.gov/drds/WorldReportData WorldReportData.
Some commenters, who stated that current risks of CWP were
overstated in the proposed rule, suggested that recently observed cases
were due to high coal ranks and/or excessive silica exposures
associated with geographically limited areas within the United States.
These commenters stated that the increase in prevalence of CWP is
distinctly regional and that the proposed 1.0 mg/m\3\ standard should
not apply to regions that do not have an increase. Some of these
commenters also said that CWP has been eliminated in the Midwest (i.e.,
Indiana, Illinois, and Western Kentucky) and pointed out that MSHA
District 8 has a high participation rate in the CWXSP and the
[[Page 24828]]
lowest CWP rate in the country. A few commenters acknowledged that the
prevalence of PMF has increased but, citing Wade et al. (2010),
attributed the increase to greater silica exposure from drilling
through rock. Some commenters also stated that MSHA should have
examined its own silica exposure data before concluding that recently
observed cases of CWP were caused by respirable coal mine dust
exposures under the existing standard.
As noted in the proposed rule (75 FR 64462-64463), MSHA is aware
that some cases of rapidly progressive CWP have been detected in a
small percentage of miners diagnosed initially with CWP 1/0+; however,
these cases are a small proportion of the larger group of miners across
the U.S. who have been diagnosed with CWP 1/0+ that need to be studied
to determine the reasons for the rapid progression (see Antao et al.
2005, 2006; Attfield and Petsonk, 2007).
The Wade et al. paper cited by commenters reported on a
retrospective chart review of a group of 138 coal miners with PMF who
were approved for benefits by the West Virginia State Occupational
Pneumoconiosis Board between January 2000 and December 2009. The mean
age of this group of miners was 52.6 years (40-77 years) and they had
an average tenure of 30 years (7.5 to 47 years). Miners who worked as
continuous mining machine operators or roof bolting machine operators
had the highest occurrence of PMF (41% and 19%, respectively). The time
of progression to PMF was studied in a subgroup of these miners when
normal x-rays were available for comparison to x-rays showing advanced
disease. In this subgroup of 43 miners, the time between the last
normal chest x-ray and one showing advanced disease averaged 12.2 years
(5 to 27 years). No data on quartz exposure or respirable coal mine
dust was provided by Wade et al.
McCunney et al. (2009) noted in their review of epidemiology
literature that coal dust has been described as ``able to mask the
fibrogenic activity of quartz'' and that there are ``distinct
pathological differences between simple pneumoconiosis of CWP and
silicosis.'' Researchers initially thought that the active agent in
respirable coal mine dust that was responsible for CWP development was
quartz. However, research reported a poor correlation between
radiological evidence of CWP and quartz concentration in the
corresponding coal dust; there was no pattern between the quartz
content of mixed dust and the probability of developing simple
pneumoconiosis at quartz levels averaging 5 percent. Based on the
collective weight-of-evidence of human epidemiology studies, animal
investigations and in vitro evaluations contained in the preambles to
the proposed rule (75 FR 64458, October 19, 2010) for this final rule
and to the 2003 proposed rule on Verification of Underground Coal Mine
Operators' Dust Control Plans and Compliance Sampling for Respirable
Dust (68 FR 10837, March 6, 2003), it is apparent that quartz is not
the predominant factor in the development of CWP. In fact, the results
of large-scale epidemiological studies in Germany, the United Kingdom,
France, and the United States indicate varying levels of risk of CWP,
based on the type of coal regardless of silica content.
McCunney et al. (2009) also reported on the results of research
conducted by Miller et al. (1995) in British coal miners. These miners
participated in the Pneumoconiosis Field Research (PFR) program. As
reported in the preamble to the proposed rule (75 FR 64462), that
program, in addition to periodic chest x-rays, also collected separate
industrial hygiene data that quantified typical concentrations of
respirable dust and quartz for a variety of occupations within the
mines. These exposure measurements were used to determine individual
exposure profiles for participating miners. Miller et al. suggested
that the rapid progression in radiological abnormalities, their
relationship with quartz exposure estimates, and the strength of their
relationship with lung function decrements resembled classical
silicosis rather than CWP in a subpopulation exposed to quartz
concentrations of about 10% at one specific mine. According to McCunney
et al., however, recorded progressions of CWP to PMF in such cases may
have resulted from misdiagnosing silicosis as CWP. McCunney et al. also
reported similar findings of misdiagnosis in a case/control study of
British coal miners that showed an effect of unusually high levels of
quartz exposure on rapid CWP-progression.
The preamble to the proposed rule reported that NIOSH researchers
determined that cases of rapidly progressive CWP are sentinel health
events (75 FR 64468). Antao et al. (2005) identified a total of 886
cases of CWP among 29,521 miners examined from 1996 to 2002 in the
CWXSP. CWP progression was evaluated in 783 of these miners; 277
(35.4%) were cases of rapidly progressive CWP, including 41 with PMF.
The miners with rapidly progressive CWP were younger than miners
without rapid progression, worked in smaller mines, and reported longer
mean tenure in jobs involving work at the face (production area) of the
mine. Many of these cases of rapidly progressive CWP developed in
miners from eastern Kentucky and western Virginia. Eight cases showed
progression of one subcategory over 5 years, 156 cases had progression
equivalent to two or three subcategories over a 5-year period, and 72
cases had progression equivalent to more than three subcategories over
a 5-year period.
Rounded opacities were the primary shape/size in 73% of the rapidly
progressive cases compared to 50% in the non-rapidly progressive cases.
Overall, the miners with rapidly progressive CWP were somewhat younger
(mean age 48) than the remaining miners evaluated (mean age 51), but
were similar in mean work tenure (27 to 28 years). Rapidly progressive
cases were more likely to have worked in smaller mines than in larger
mines. Rapidly progressive CWP cases reported longer mean tenure in
jobs involving work at the face of the mine (19 years), compared to
miners without rapid progression (17 years). These particular cases
occurred in miners from eastern Kentucky and western Virginia (Antao et
al., 2005).
Clusters of newly identified cases of advanced pneumoconiosis were
surveyed in 2006 by ECWSHP teams that visited two counties in Virginia
(Antao et al., 2006) and in eastern Kentucky and southwestern Virginia
(Attfield and Petsonk, 2007). In March and May of 2006, a total of 328
underground coal miners employed in Lee and Wise counties in Virginia
were examined. This was 31% of the estimated 1,055 underground miners
in those counties. The mean age of examined miners was 47 years, and
their mean tenure working in underground coal mines was 23 years. A
total of 216 (66%) had worked at the coal face for more than 20 years;
and 30 of the 328 miners (9%) had radiographic evidence of
pneumoconiosis (i.e., category 1/0 or higher profusion of small
opacities). Of these, 11 miners had advanced cases of CWP, including
five with large opacities consistent with PMF and six with coalescence
of small opacities on a background profusion of category 2. Among the
11 miners with advanced cases, the mean age was 51 years (range: 39-62
years), the mean tenure in underground coal mines was 31 years (range:
17-43 years), and the mean number of years working at the coal face was
29 years (range: 17-33 years). All 11 advanced cases met the
radiographic criteria for rapidly progressive CWP. All reported at
least one respiratory symptom (i.e., productive cough, wheeze, or
shortness
[[Page 24829]]
of breath), the most common being shortness of breath (dyspnea). Four
of the nine who underwent spirometry testing had abnormal results
(Antao et al., 2006).
In a separate ECWSHP survey in 2006, pneumoconiosis rates were
determined for 26 sites in seven counties in eastern Kentucky and
southwestern Virginia (Attfield and Petsonk, 2007). A total of 975
(20%) of the 4,897 active underground miners in the counties
participated; 37 (4%) of those tested had advanced pneumoconiosis.
Medical records indicated that all 37 miners with advanced disease had
worked underground for at least one interval of 10 years without a
chest x-ray; 22 (59%) had worked for at least one interval of 20 years
without a chest-ray, and 2 others had worked for more than 30 years
without a chest x-ray. Attfield and Petsonk found that miners who
worked at the coal face (not typically associated with silica dust
exposure) and roof bolting machine operators (typically associated with
higher silica dust exposure) with similar tenure underground (about 30
years) developed PMF at high rates. PMF was identified in 64% of the
face workers and 42% of the roof bolting machine operators. Attfield
and Petsonk examined disease development patterns in this population of
miners since silicosis can develop faster than CWP. They found that 1
of 26 roof bolting machines operators (4%) progressed to PMF in less
than 10 years, compared with 2 of 11 coal-face workers (18%).). Silica
exposure was identified as only one of several factors possibly related
to rapid disease progression in this population. The authors listed
various potential explanations for the continued occurrence of advanced
pneumoconiosis: The respirable dust standard may have been too high;
failure to comply with or enforce respirable dust regulations; lack of
adjusting disease prevention practices to accommodate changes in mining
practices; and missed opportunities for miners to be screened for early
disease. The 3 mm rounded opacities may or may not be associated with
silica.
Suarthana et al. (2011) cited references by Laney et al. (2009) and
Laney and Attfield (2010). These papers attempted to further illustrate
what factors may be involved in the rapid progression of CWP to PMF by
focusing on the presence of a specific type of x-ray findings
frequently associated with silicosis (rounded pneumoconiotic opacities
exceeding 3 millimeter (mm)--r-type) (Laney et al., 2009) and mine size
(Laney and Attfield 2010) in U.S. coal miners who participated in the
CWXSP. Laney examined NIOSH CWXSP data between 1980 to 2008 (2,868
radiographs showing ILO category 1 or greater small opacities out of a
total of 90,973 available) found that r-type opacities, frequently
associated with silica exposure, occurred in 201 radiographs
representing 0.22% of the total number of radiographs examined. The 3
mm rounded opacities may or may not be associated with silica. It is a
matter of sensitivity and specificity. It is not a silica-specific
finding, but is often or frequently associated with silica exposure.
Laney and Attfield examined NIOSH CWXSP data collected between 1970 and
2009 and evaluated the effect of mine size on the development of CWP
and PMF. They found that miners working in small mines (fewer than 50
employees) had a significantly higher prevalence of CWP compared to
miners who worked in large mines (with 50 or more employees). They
reported that miners from small mines were five times more likely to
have radiographic evidence of PMF (1% of miners) compared to miners
from larger mines (0.2%). The Laney and Attfield (2010) study was the
first to directly examine the relationship between miners' respiratory
health and mine size in the U.S. They concluded that: there are
distinct differences between large and small mines that potentially
influence the amount and type of exposures; and the effect of small
mine size on development of CWP risk was consistent across all mining
states and was not confounded with coal rank or geographical region.
They also found the small mine effect on CWP in other states, not just
in thin seam mines that are primarily concentrated in Kentucky,
Virginia, and West Virginia.
Other epidemiological studies on U.S. coal miners, discussed in the
proposed rule (75 FR 64459), conclude that the rank of coal mined
influences CWP rates among coal workers, suggesting that coal's carbon
content is a factor in CWP risk (Huang et al., 2005, McCunney et al.,
2009). According to these studies, coal from districts with lower rates
of CWP (while considering similar levels of exposure to coal, both in
concentration and duration) show that coal high in bioavailable iron
(BAI) is associated with the highest risk of CWP. Results of in vitro
studies with human and animal cell lines are consistent with the
epidemiological data that suggest that risk of CWP is not based on
quartz, but most likely due to the concentration of BAI. In vitro
studies provide further support for the role of iron in the
inflammatory process associated with CWP. (Huang et al., 2005; Zhang
and Huang 2005; Zhang et al., 2002).
Huang evaluated the quality of coal, including BAI, as determined
by the U.S. Geological Survey database of coal quality, across seven
regions of the U.S. These data were compared to data from the first
National Study of Coal Workers' Pneumoconiosis. The authors found that
CWP prevalence was correlated with pyritic sulfur or total iron in the
coals but not with coal rank or silica. They concluded that a
significant correlation between CWP prevalence and levels of BAI exist,
moderated by certain minerals in the coals that can interact and
contribute to different levels of BAI and, therefore, different levels
of CWP and associated COPD.
Although CWP and silicosis may have some similar clinical patterns,
their etiology is different (McCunney et al., 2009; 75 FR 64458,
October 19, 2010). Recent studies on U.S. coal miners illustrate this
point (Antao et al., 2006; Attfield and Petsonk 2007; Laney et al.,
2009, Laney and Attfield 2010, and Wade et al., 2011).
Miller et al. (1997, 2007) and Miller and MacCalman (2009) reported
on the results of mortality research conducted in a group of British
coal miners. These miners participated in the Pneumoconiosis Field
Research (PFR) program. As reported in the preamble to the proposed
rule (75 FR 64462), industrial hygiene data was collected as part of
that program to quantify typical concentrations of respirable dust and
respirable quartz for a variety of occupations within the mines. The
data was used to determine individual exposure profiles for
participating miners. The mortality of this large cohort of 17,820 coal
miners was followed from 1970 through 2006 (Miller et al. 2007). The
researchers presented alternative regression analyses to predict risk
of mortality in relation to time-dependent estimates of individual
exposures to respirable dust and respirable quartz. The researchers
concluded that CWP mortality is directly related to exposure to
respirable coal mine dust, which is a better single predictor of CWP
risk than is respirable quartz exposure. These results are consistent
with earlier findings (Hurley et al. (1982); Miller et al. (1997)) that
respirable coal mine dust exposure is more closely associated with the
development of pneumoconiosis than is quartz. Based on all of the
available evidence, MSHA believes that respirable coal mine dust has a
fibrogenic effect on the development of CWP in coal miners independent
of the quartz or silica content of the coal. High silica content may
accelerate the progression of CWP to PMF, the most severe form of CWP,
but there is no evidence to suggest that
[[Page 24830]]
the presence of silica is a necessary condition for CWP, PMF, severe
emphysema, or NMRD mortality.
Exposure to respirable coal mine dust from high rank coal is
associated with greater risks of CWP and nonmalignant respiratory
disease (NMRD) mortality. However, evidence of high risks in identified
hot spots does not imply that risks in other areas are insignificant.
Exposure to respirable coal mine dust from lower rank coal still places
miners at significant excess risk for CWP and NMRD mortality. MSHA's
Quantitative Risk Assessment (QRA) for the final rule shows that
significant excess risks of CWP and NMRD mortality under the existing
standard are present for miners at low rank coal mines--i.e., outside
the geographic ``hot spots'' identified by some commenters. (See QRA,
Tables 13, 14, 15, 17, and 18).
The CWXSP data from 2005-2009 published by Suarthana et al. show
that some regions with lower rank coal, i.e., regions not identified as
hot spots, also tend to have younger miners with less tenure. For
example, in MSHA Districts 8, 9, and 10, tenure underground was less
than 5 years for 49.1%, 47.0%, and 49.4% of the miners, respectively.
Surveillance of underground coal miners in these regions indicates that
CWP is occurring, though at lower rates, primarily due to the age and
tenure profile of the miners. In the remaining Districts that mine
bituminous coal, the median tenure was over 20 years (Table III-4).
Suarthana did not publish data from MSHA District 1, which mines
anthracite, the highest ranked and most fibrogenic coal. District 1
surveillance data from NIOSH (USDHHS, CDC, NIOSH, Statistics for
Underground Miners Working in MSHA District 01 (Anthracite Coal Mining
Regions in Pennsylvania, 2011b) shows that during the period of 2004-
2008, 67 anthracite miners participated in the ECWHSP. Age information
was available for 58 miners. Mean age was 41 (range 18-69 years).
Tenure information was available on 55 of these miners. The mean tenure
was 17 years (range 0-45 years). Information on tenure at the face
(production area) was available for 51 miners; mean years of face work
was 17 years (range 1-45 years). The prevalence of CWP 1+ in 58
examined miners was 6 cases (or 10%). Commenters did not include
anthracite coal mines in MSHA District 1 in their discussions of
regional hot spots or suggest that silica was responsible for CWP at
anthracite coal mines. Nevertheless, at exposure levels experienced
over a 45-year occupational lifetime under the existing standard,
anthracite coal mines present significant excess risks of CWP and NMRD
mortality. (See QRA, Tables 13, 14, 15, 17, and 18). In the case of
NMRD mortality, risks for anthracite coal miners are estimated to be
far greater than for miners in the same occupations at high rank
bituminous coal mines (QRA, Tables 17 and 18).
Overall, NIOSH surveillance data indicate that pneumoconiosis at
the CWP 1/0+ level is occurring in underground coal miners across each
MSHA Coal District in the United States; not just in the ``hot spot''
areas of southern West Virginia, eastern Kentucky, and western Virginia
highlighted by some commenters.
Table III-4 shows that almost 50 percent of CWXSP participants in
Districts 8, 9, and 10 have tenure of less than five years; and, yet,
miners in those districts continue to develop CWP 1/0+ at 0.6% (16
cases), 1.2% (28 cases), and 2.3% (27 cases) respectively. As shown in
Table III-1, miners continue to develop CWP in all MSHA Districts.
The commenters who questioned the validity of the reduction in the
existing 2.0 mg/m\3\ standard focused on the dose-response relationship
and asserted that data generated from pre-1970 were out-of-date and
should not be used for risk assessment purposes. MSHA's QRAs for the
proposed and final rules assessed risk at current exposure levels. Data
shown in Tables III-1 and III-2 indicate that CWP is continuing to
develop, especially in miners with more underground tenure, as stated
in MSHA's QRA. Almost all of these miners have worked only during the
period while the existing 2.0 mg/m\3\ standard has been in effect.
While average exposures have been reduced, current exposure conditions
place miners at significant risk of incurring material impairment of
health or functional capacity over their working lives.
Other commenters suggested that MSHA selectively chose CWP data to
include in the health effects assessment. They suggested that CWP
prevalence is not increasing. In response, MSHA notes the data show
that there was a reduction in prevalence of CWP in the 1990s until
continued surveillance indicated that many cases of CWP were missed or
newly developed (Attfield et al., 2009). Also, the prevalence of CWP
increased with age and tenure. (See Tables III-1, III-2, III-3, and
III-4.)
[[Page 24831]]
Table III-4--Coal Workers' X-Ray Surveillance Program (CWXSP)--Underground Coal Mining Survey Summaries of Observed Prevalence of CWP--2005-2009 1 2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MSHA District
Parameters ---------------------------------------------------------------------------------------------------------------------------------
2 3 4 5 6 7 8 9 10 11
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Median Dust................................................... 0.79 0.96 0.80 0.55 0.75 0.69 1.14 0.98 1.14 0.99
(in mg/m\3\).................................................. (0.54-1.05) (0.46-1.20) (0.31-3.08) (0.18-2.34) (0.36-1.17) (0.28-1.12) (0.73-1.70) (0.30-1.30) (0.76-1.21) (0.52-1.12)
Number of Miners.............................................. 911 1,504 1,280 689 423 522 2,713 2,351 1,190 825
Age of Miners Examined:
<=19...................................................... 1 10 0 0 0 6 43 73 28 3
20-29..................................................... 84 148 106 29 29 67 682 686 339 64
30-39..................................................... 129 207 216 79 70 103 613 529 346 91
40-49..................................................... 142 218 282 242 174 192 564 524 222 175
50-59..................................................... 471 785 607 316 132 143 729 464 240 424
>=60...................................................... 84 136 69 23 18 11 82 75 15 68
Median Tenure (range)......................................... 25 22 25 27 24 20 5 5 5 24
(0-44) (0-50) (0-44) (0-42) (0-44) (0-42) (0-45) (0-42) (0-40) (0-50)
Tenure %:
0-4 years................................................. 20.1 20.6 11.0 7.8 8.5 14.0 49.1 47.0 49.4 25.5
5-10 years................................................ 11.5 12.9 12.1 6.5 10.9 11.5 14.1 14.6 16.2 6.6
11-20 years............................................... 11.5 14.0 18.9 14.7 19.4 24.7 12.9 14.8 14.1 10.6
21-30 years............................................... 28.2 25.3 26.7 44.0 40.9 33.3 17.6 18.0 13.4 40.1
41-40 years............................................... 28.3 26.5 30.6 26.6 19.6 16.3 6.2 5.4 6.9 17.0
> 40 years................................................ 0.3 0.7 0.7 0.4 0.7 0.2 0.1 0.1 0.0 0.4
Observed Prevalence of X[dash]ray Findings:
CWP 1/0+.................................................. 22 (2.4%) 39 (2.6%) 125 (9.8%) 62 (9.0%) 58 (13.7%) 49 (9.4%) 16 (0.6%) 28 (1.2%) 27 (2.3%) 20 (2.4%)
Age of Cases:
<=19...................................................... 0 0 ........... ........... ........... 0 0 0 0 0
20-29..................................................... 1 1 0 0 0 0 2 1 2 0
30-39..................................................... 0 0 1 1 0 1 2 5 2 0
40-49..................................................... 3 8 23 25 28 19 1 8 10 4
50-59..................................................... 14 23 89 30 29 28 10 13 12 10
>=60...................................................... 4 7 12 6 1 1 1 1 1 6
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Inspector-measured coal mine dust concentration data at mine level 1970-2008.
\2\ Observed prevalence is reported; Suarthana et al. estimated predicted CWP prevalence by using the 1992 Attfield and Morring (1992b) model. Attfield and Morring used mean job-specific dust
levels used in the 1992 estimates, not mean mine specific dust levels. The paper reported median dust levels.
Source: Suarthana et al., 2011.
[[Page 24832]]
NIOSH reports prevalence in 5-year intervals for miners who
voluntarily participate in the CWXSP. The numbers of miners who
volunteer for medical surveillance vary over time (Table III-2) and the
degree of detailed information provided also varies over time.
Participation rates are dependent, in part, on availability of
screening resources. NIOSH screens as many miners as possible through
both the CWXSP (regular screening program) and the ECWHSP (enhanced
screening program). Over time, the percentage of actively employed
miners who volunteered for medical surveillance varied from 26% for the
1995-1999 time period to 34% for the 2000-2004 time period to 42% for
the 2005-2009 time period, across all MSHA Districts (Table III-1). The
requirements in final Sec. 72.100 will increase participation rates.
Final Sec. 72.100 requires that each operator provide to each miner,
including each surface coal miner, who begins work at a coal mine for
the first time, an initial examination consisting of chest x-rays,
spirometry, symptom assessment, and occupational history, and the
opportunity to have the medical examinations at least every 5 years
thereafter. MSHA expects that participation rates will increase due to
the inclusion of surface miners in the screening/surveillance program.
Other commenters suggested that more studies need to be completed
before a revised standard can be developed since MSHA did not
demonstrate that cases of CWP can be prevented under the proposed
standard.
The QRA to the proposed rule demonstrated that cases of CWP, along
with emphysema, silicosis, and chronic bronchitis, known collectively
as ``black lung,'' could be prevented under the proposed respirable
dust standards. The QRA relied on MSHA inspector and operator sampling
data collected during the 5-year period 2004-2008 and predominantly
relied on 4 epidemiologic studies from 1995, 2007, 2008, and 2009.
These studies relied on coal mine dust samples and data collected from
1968 to 1988. The researchers, who conducted the studies that MSHA
relied on for the proposed rule, took steps to mitigate biases in the
data used to estimate the health effects of miners' exposure to
respirable coal dust. The relationship between exposure to respirable
coal mine dust and disease prevalence is essentially unchanged since
the studies that MSHA relied on were conducted. In addition, MSHA
upwardly adjusted operator samples and excluded abatement samples taken
by MSHA to mitigate biases in the MSHA data. The QRA showed that
exposures under the existing respirable coal mine dust standards are
associated with cases of CWP, chronic obstructive pulmonary disease
(COPD) including severe emphysema, and death due to non-malignant
respiratory disease (NMRD). All of these outcomes constitute material
impairments to a miner's health or functional capacity.
The QRA also analyzed and quantified the excess risk of miners
incurring CWP or COPD, or dying due to NMRD, after 45 years of full-
shift occupational exposure at levels currently observed in various
exposure categories. Miners having different occupations and working at
different locations face significantly different levels of respirable
coal mine dust exposure. In every exposure category, including clusters
of occupational environments showing the lowest average dust
concentrations, current exposure conditions place miners at significant
risk of incurring each of the material impairments considered.
Finally, the QRA projected the risk of material impairments after
the proposed respirable dust standards were applied to each shift.
Several provisions in this final rule will singularly lower coal
miners' exposure to respirable dust and reduce their risks of disease
and disease progression. These provisions include lowering the
respirable dust standard, full-shift sampling to account for
occupational exposures greater than 8 hours per shift, changing the
definition of normal production shift, use of CPDMs for sampling,
basing noncompliance determinations on MSHA inspectors' single shift
sampling, revising the sampling program, requiring operator corrective
action on a single full-shift operator sample, and changing the
averaging method to determine compliance on operator samples. MSHA's
QRA estimates the reduction in health risks when two provisions of the
final rule are implemented--the final respirable dust standard and
single shift sampling. The QRA shows that these two final provisions
would reduce the risks of CWP, severe emphysema, and death from non-
malignant respiratory disease (NMRD). For instance, the QRA for the
final rule projects, over a 45-year occupational lifetime, significant
improvements in almost every underground job category and at least 6
surface categories. Large aggregated improvements are also projected
for longwall tailgate operators and continuous mining machine
operators.
While the final 1.5 mg/m\3\ standard will reduce the risk of
impairment, disease, and premature death, estimates from MSHA's revised
QRA reveals remaining risk at the final standard. However, MSHA
believes that other provisions of the final rule will diminish these
risks. The impacts of these other final provisions were not considered
in the QRA. Cumulatively, MSHA expects that the final provisions will
reduce the continued risks that miners face from exposure to respirable
coal mine dust and would further protect them from the debilitating
effects of occupational respiratory disease.
It has been over 40 years since the 1969 Coal Act was enacted.
Exposures to respirable coal mine dust have been reduced with resultant
reduction in disease prevalence. Table III-2 shows that: In the time
period from 2005 to 2009 miners with over 25 years of tenure in
underground coal mining have a CWP 1/0+ prevalence of 6.9%; and miners
with only 0-9 years of tenure have CWP 1/0+ prevalence of 0.6% for that
same time period. These miners are younger and have less cumulative
exposure to respirable coal mine dust. The average prevalence of CWP 1/
0+ for the period 2005 to 2009 was 4.1%.
The overall prevalence of CWP 1/0+ in all miners was 2.7% (See
Table III-1) for the 2005-2009 time period. However, NIOSH data show
that CWP 1/0+ is still occurring at significant levels in the active
mining population. With continued surveillance over time, the number of
CWP 1/0+ cases detected annually fluctuates; however, significant risk
of material impairment of coal miners' health still remains, as noted
in the QRA for this final rule.
Smoking in miners was mentioned by some commenters as a causative
factor for observed lung disease in miners.
Exposure to coal mine dust is an independent factor in the
development of CWP. Smoking is a risk factor for the development of
lung disease, including cancer, COPD, and emphysema. Smoking and
exposure to respirable dust have an additive effect on the development
of COPD in miners. However, as shown in the Health Effects section of
the preamble to the proposed rule, significant levels of NMRD, such as
COPD and emphysema, occur in nonsmoking miners caused by their exposure
to respirable coal mine dust.
In the first round of the CWHSP, 54.4% of underground coal miners
were smokers, 25.5% were former smokers, and 20.1% were never smokers
(Beeckman, et al., 2001; Beeckman, et al., 2002). Estimates of the
current prevalence of smoking in coal miners (by MSHA District) are
shown in Table III-5. This data set was reported as part
[[Page 24833]]
of the ECWHSP data on NIOSH's Web site. Smoking status among surveyed
coal miners is currently estimated to be 22% smokers, 27% former
smokers, and 51% never smoked. Again, since respirable coal dust
exposure and smoking have an additive effect on the occurrence of COPD
in smoking miners, MSHA believes the reduction in respirable dust
levels in mining due to implementation of the final rule, coupled with
the reduction in smoking in the mining population, also would have a
beneficial effect on reducing the occurrence of NMRD in this population
over time. (See Section IV, Health Effects, in the preamble to the
proposed rule (75 FR 64458), Green et al., 1998a, and Kuempel et al.,
2009b.)
Table III-5--Smoking Prevalence Among Coal Miners Participating in the ECWHSP, 2006-2010
----------------------------------------------------------------------------------------------------------------
Smoking status
MSHA district Number of -----------------------------------------------
miners Never (%) Former (%) Current (%)
----------------------------------------------------------------------------------------------------------------
1............................................... 58 22 (38) 8 (14) 28 (48)
2............................................... 664 356 (54) 200 (30) 108 (18)
3............................................... 1,019 531 (52) 264 (26) 224 (22)
4............................................... 1,059 573 (54) 250 (24) 236 (22)
5............................................... 629 314 (50) 170 (27) 145 (23)
6............................................... 374 182 (49) 79 (21) 113 (30)
7............................................... 443 205 (46) 109 (25) 128 (29)
8............................................... 667 312 (47) 205 (31) 150 (22)
9............................................... 879 462 (53) 262 (30) 155 (18)
10.............................................. 135 78 (58) 39 (29) 18 (13)
11.............................................. 565 299 (53) 158 (28) 108 (19)
---------------------------------------------------------------
Total....................................... 6,492 3,334 (51) 1,744 (27) 1,413 (22)
----------------------------------------------------------------------------------------------------------------
Source: USDHHS, CDC, NIOSH, CWHSP, Statistics for Underground Miners, Districts 1 to 11, 02/13/2011.
MSHA's existing standard permits overexposures above the respirable
coal mine dust standard due to averaging samples. Some commenters
expressed concern that the proposed single sample provision would
increase the number of citations that a mine operator receives, but
would not affect a miner's long-term exposure and the subsequent
development of chronic health effects.
The single sample provision in this final rule is changed from the
proposal and only applies to MSHA inspector samples. MSHA does not
anticipate that this final provision will, over the long term, increase
the number of operator citations. A single sample that exceeds the
standard would not cause or significantly contribute to disease.
However, cumulative overexposures--masked when used as part of an
average based on multiple samples--could cause or significantly
contribute to development or progression of diseases, with each
overexposure being an important factor contributing to disease.
Compared to the current method of dust sampling, single full-shift
samples will reduce a miner's cumulative exposure to respirable coal
mine dust and the risk of developing occupational respiratory disease.
For these reasons, single full-shift samples above the standard must be
controlled so that miners' cumulative exposure is not increased beyond
the level that will induce disease.
Final Sec. 72.800 provides that the Secretary will use a single,
full-shift measurement of respirable coal mine dust to determine the
average concentration on a shift since that measurement accurately
represents atmospheric conditions to which a miner is exposed during
such shift. Additional discussion on single full-shift sampling is
located elsewhere in this preamble under Sec. 72.800.
Some commenters questioned the relationship between respirable coal
mine dust exposure and development of NMRD, such as COPD and chronic
bronchitis. Epidemiological studies that were discussed in the Health
Effects section of the preamble to the proposed rule (75 FR 64460)
found that coal miners from the United States, Great Britain,
Australia, France, Asia, and South Africa developed decreased lung
function that was proportional to the miners' cumulative respirable
coal mine dust exposure. Exposure to higher respirable coal mine dust
levels over a working lifetime resulted in more miners experiencing a
significant loss of lung function. These studies illustrate a strong
dose-dependent relationship between respirable coal mine dust exposure
and subsequent development of obstructive lung diseases, such as lung
function impairment, chronic bronchitis, and emphysema (75 FR 64465).
The decline in lung function is not linear; studies indicate that there
may be some recovery following a year or two of exposure. But, the
recovery can be temporary and is affected by continued exposure. As the
number of years working in mining grows, the adverse effect on lung
function does as well.
Chronic exposure to respirable coal mine dust causes chronic
bronchitis, as was found in 35% of a mining population in the United
States. This disease is different from that caused by tobacco smoke.
Coal mine dust-related bronchitis is associated with deposits of
fibrous tissue, mineral pigment, and inflammatory cells in the walls of
membranous and respiratory bronchioles and alveolar ducts. This
condition is referred to as mineral dust airways disease. Emphysema is
caused both by smoking and coal mine dust exposure. Severity of disease
has been related to dust content of the lungs and cumulative lifetime
coal mine dust exposure. Kuempel et al. (1997b) showed that significant
decrements in lung function occur by the age of 65 years in long-term
nonsmoking miners exposed to an average respirable coal mine dust
concentration of 0.5 mg/m\3\.
One commenter stated that for proper evaluation of the health
effects studies, more information is needed; such as miner jobs, number
of job changes, time spent on specific jobs, number and size of mines,
and employment in different mines.
Many of the studies reported in the proposed rule had this type of
detail in the data collected from certain mining populations, although
only summary data were reported in the published papers. This type of
detail was available in the industrial hygiene (IH) surveys conducted
by British researchers as part of the Pneumoconiosis Field Research
(PFR) program established in the early
[[Page 24834]]
1950s and explained in the proposed rule (75 FR 64462). Concurrent with
the health surveys, a separate IH assessment was conducted as part of
the PFR program that quantified typical concentrations of respirable
dust and quartz for a variety of occupations within the mines. These
exposure measurements were linked to data from payroll systems on the
times worked by each miner in the same occupations. This IH assessment
produced individual and period-specific estimates of exposure to
respirable dust and quartz (MacCalman and Miller, 2009; Attfield and
Kuempel, 2003; Scarisbrick and Quinlan, 2002).
In addition, the U.S. National Coal Study (NCS) is a long-term
epidemiologic study, limited to miners in a selected group of mines
with various seam heights, mining methods, coal types, and geographic
locations. Many of the published peer-reviewed epidemiological studies
reported in the proposed rule's health effects section are based on
data from the NCS. In those studies, estimates of cumulative dust
exposures were given. Examples of these studies include Henneberger and
Attfield (1997) and Kuempel et al. (1997b). These papers were reviewed
in the development of the proposed rule (75 FR 64460).
Similarly, some commenters identified seam height or mine size as
potential factors that were not modeled in the regression analyses but
could potentially contribute to the observed frequency of adverse
health effects. To date, there are some epidemiological studies that
have directly explored the association of coal seam height or mine size
and CWP, PMF, non-malignant respiratory diseases, emphysema, or
FEV1 declines. However, no epidemiological coal miner
studies have modeled respirable coal mine dust and non-malignant
respiratory diseases while examining the confounding effect of coal
seam height. The available studies are described below.
Peters et al. (2001) studied the influence of coal seam height on
lost-time injury and fatality rates at small underground bituminous
coal mines. Nonetheless, Peters did not examine the association of coal
seam height and NMRDs or FEV1 declines among coal miners.
Suarthana et al. (2011) stated that low seam height likely
contributed to excess CWP cases. It was also noted that thin seam
mining poses difficulties because the rock surrounding the coal seam
often has to be cut to permit equipment to be employed effectively
(also see Pollock et al., 2010). Suarthana et al. (2011) noted that the
average coal seam height was lower in central Appalachia than in other
regions (median seam height 60 (range 26-138) inches versus 79 (range
31-168 inches; p<0.001). Data on seam height were obtained from the
MSHA Standardized Information System (MSIS) for the time period of
2005-2009. Suarthana concluded that the observed prevalence of CWP
substantially exceeded predicted levels in central Appalachia.
Therefore, coal seam height was reported as a likely factor
contributing to the observed elevated CWP rates. However, Suarthana
stated that further study is needed to characterize the factors
responsible for elevated CWP rates. Overall, no direct association
between CWP and coal seam height was observed.
Cowie et al. (2006) found FEV1 deficits in 1,267 (18%)
British coal miners. Cumulative respirable dust exposure ranged up to
726 gh/m\3\ (gram hours per cubic meter) with a mean of 136 gh/m\3\; on
average an exposure to cumulative respirable dust of 100 gh/m\3\ was
associated with a reduction in FEV1 of 0.0631. In addition,
an increase of 50 gh/m\3\ was associated with an increase of about 2%
in the proportion of men with small deficits in FEV1 (-0.367
deficit); 1.5% to 2% for medium deficits (-0.627) depending on age; and
a similar pattern was observed for large deficits (-0.993), but with
smaller increases. Cowie stated that these results may be due to
differences in seam height, mechanical breathing efficiencies, or the
workload associated with limb size or body mass. Yet, the association
of FEV1 deficits among coal workers and seam height was not
explored.
In terms of FEV1 declines, Wang et al. (1999)
investigated the association between occupational exposure to dust and
clinically important FEV1 declines in a group of 310
underground coal miners (cases) and their matched mining referents with
stable lung function. This study defined a seam height <50 inches as a
low seam mine, and compared the total years worked in low seam mines
between two groups 1) cases (310 underground coal miners) and 2)
matched partners (referents); cases and referents averaged 7.2 and 5.4
total years worked (p=0.21), respectively. However, the authors did not
investigate the association between clinically important
FEV1 declines and mine seam height and mine size. Overall,
logistic regression models conducted in this analysis did not explore
the relationship between clinically important declines in
FEV1 and seam height.
Laney et al. (2010) acknowledged that their study is the first to
directly examine miner respiratory health and mine size. Laney also
highlighted that the prevalence of CWP and PMF increased between the
1900s and the 2000s for mines of all sizes. The prevalence of CWP is
6.5% in the 1970s, 2.5% in the 1980s, 2.1% in the 1990s and 3.2% in the
2000s. The prevalence of PMF was higher in larger mines (50+ miners) in
the 1970s and 1980s; whereas, the prevalence was higher in smaller
mines (<50 miners) in the 1990s and 2000s.
Laney and Attfield (2010) examined NIOSH CWXSP data collected
between 1970 and 2009 and evaluated the effect of mine size on the
development of CWP and PMF. They found that miners working in small
mines (fewer than 50 employees) had a significantly higher prevalence
of CWP compared to miners who worked in large mines (with 50 or more
employees). They reported that miners from small mines were five times
more likely to have radiographic evidence of PMF (1% of miners)
compared to miners from larger mines (0.2%).
Suarthana et al. (2011) found that mine size (e.g., number of
employees in a mine) may be associated with higher CWP prevalence
levels. The researchers used the Attfield and Morring (1992b) exposure
response model versus the original Attfield and Morring (1992a) model
that used mean job-specific dust levels. The researchers stated that
they did not have the dust level information specific to all jobs;
instead, the researchers estimated dust exposure using the mean mine-
specific dust level based on MSHA compliance data. The median measured
dust concentration and range are reported at the mine level. However,
the QRA for the proposed rule estimated CWP risk based on mean job-
specific dust levels. The authors excluded underground coal miners from
MSHA district 1 due to the small number of participants (n=55) and
difference in coal type (anthracite) compared to the other districts in
the analysis (bituminous). In addition, the authors state that further
study is needed to characterize the factors responsible for elevated
CWP rates; the results point to a need for greater vigilance in
controlling coal mine dust, especially that which arises from rock
cutting.
One commenter said that MSHA failed to consider in the proposed
rule other factors that NIOSH discussed in its 2011 Current
Intelligence Bulletin 64, such as free radicals, particle occlusion,
and bioavailable iron.
[[Page 24835]]
MSHA did not use the 2011 NIOSH literature update in the
development of the proposed rule because it was not final when the rule
was published on October 19, 2010. However, the Health Effects section
in the preamble to the proposed rule included a section called Hazard
Identification (75 FR 64458) that discussed these factors and how they
affect the toxicity of coal particles.
One commenter stated that MSHA analyzed only part of the NIOSH
data. This commenter, however, did not provide detail about what data
were missing.
The preamble to the proposed rule stated that it summarized the
health effects from occupational exposure to respirable coal mine dust.
This summary included a literature review on this same subject
published in its proposed rule on Plan Verification, which was
published on March 6, 2003 (68 FR 10784). The literature referenced in
that document pre-dated 1999. The October 19, 2010, proposed rule
updated the health effects information that was published in 2003 and
discussed the more recent literature dating from 1997 to mid-2009 (75
FR 64458). MSHA reviewed extensive literature not only published by
NIOSH but also published by researchers in other countries, such as
France, Britain, Taiwan, Netherlands, Germany, China, and South Africa.
One commenter stated that during the 2009 spot inspections, MSHA
personnel routinely observed improper sampling procedures for dust
collection, improper handling of sampling devices, and improper
maintenance and calibration of approved sampling devices. This
commenter stated that improper procedures must be corrected before
lowering the respirable dust standards.
In response, MSHA points out that the QRA to the proposed rule was
based on both MSHA inspector samples and operator samples during 2008
and 2009. MSHA's enforcement experience is that most mine operators
attempt to be in compliance with the existing respirable dust standards
during MSHA inspector sampling. However, even if proper sampling
procedures, proper handling of sampling devices, and proper maintenance
and calibration of approved sampling devices had been used, this Health
Effects section and the QRA to the proposed rule establish that at the
existing standard of 2.0 mg/m\3\, cases of CWP and COPD continue to
occur.
A commenter stated that MSHA does not really know how much dust
that miners are exposed to and therefore needs to conduct a study using
the CPDM to determine the exposure before reducing the exposure level.
Dose-response relationships have been determined by using the
approved sampling device (gravimetric or CMDPSU) over the last 35
years. NIOSH and MSHA will continue to study the effects of respirable
coal mine dust; however, the relationship between exposure and effect
is well established. The final rule will lower miner exposure to
respirable coal mine dust thus resulting in less respiratory disease in
the miner population.
B. Quantitative Risk Assessment (QRA)
Below is a summary of the quantitative risk assessment (QRA) in
support of the final rule. The QRA for the final rule revises the QRA
in support of the proposed rule. The QRA for the proposed rule (US
Department of Labor, Quantitative Risk Assessment in Support of
Proposed Respirable Coal Mine Dust Rule, September 2010) addressed the
proposed respirable coal mine dust standard of 1.0 mg/m\3\, and 0.5 mg/
m\3\ for intake air and for part 90 miners. The QRA for the final rule
addresses the final 1.5 mg/m\3\ respirable coal mine dust standard as
well as the 0.5 mg/m\3\ standard for intake air and part 90 miners. In
response to public comments, it also includes an uncertainty analysis.
The QRA for the proposed rule was peer reviewed by independent
scientific experts at NIOSH and OSHA. The full text of that QRA and the
peer reviewers' reports can be accessed electronically at http://www.msha.gov/regs/QRA/CoalDust2010.pdf and www.regulations.gov. MSHA
posted all comments on the QRA for the proposed rule at http://www.msha.gov/REGS/Comments/2010-25249/CoalMineDust.asp and on
www.regulations.gov. The full text of the QRA for the final rule can be
accessed electronically at http://www.msha.gov/regsqra.asp and
www.regulations.gov.
The QRA for the final rule, like the QRA for the proposal,
addresses three questions: ``(1) whether potential health effects
associated with current exposure conditions constitute material
impairments to a miner's health or functional capacity; (2) whether
current exposure conditions place miners at a significant risk of
incurring any of these material impairments; and (3) whether the final
rule will substantially reduce those risks.''
After summarizing respirable coal mine dust measurements for miners
in various occupational categories, Part 1 of the QRA for the final
rule shows that exposures at existing levels are associated with CWP,
COPD including severe emphysema, and death due to NMRD. All of these
outcomes constitute material impairments to a miner's health or
functional capacity.
Part 2 of the QRA for the final rule analyzes and quantifies the
excess risk of miners incurring CWP or COPD, or dying due to NMRD,
after 45 years of full-shift occupational exposure at levels currently
observed in various exposure categories. Miners having different
occupations and working at different locations face significantly
different levels of respirable coal mine dust exposure. In every
exposure category, including clusters of occupational environments
showing the lowest average dust concentrations, current exposure
conditions place miners at a significant risk of incurring each of the
material impairments considered.
Part 3 of the QRA for the final rule projects the risk of material
impairments after the final respirable coal mine dust standards are
applied to each shift. It estimates the reduction in health risks when
two provisions of the final rule are implemented--the final respirable
dust standard and single shift sampling. The QRA shows that these two
provisions would reduce the risks of CWP, severe emphysema, and death
from NMRD. Additionally, MSHA believes that other provisions of the
final rule (e.g., full-shift sampling, changing the definition of
normal production shift, use of CPDMs for sampling, revising the
sampling program, and requiring operator corrective action based on a
single full-shift operator sample will further diminish these risks.
The final rule is projected to have a greater impact on reducing
risk for underground miners than for surface miners. Although the final
rule will benefit coal mine workers who are exposed to average
respirable dust concentrations both above and below the final 1.5 mg/
m\3\ and 0.5 mg/m\3\ standards, it is projected to have its greatest
impact on workers who currently experience frequent exposures to dust
concentrations above the final standards. Underground work locations
exceed the final respirable dust standards on many more shifts than
surface locations and also tend to experience higher average dust
concentrations.
The final rule is expected to reduce the risks of CWP, severe
emphysema, and NMRD mortality attributable to respirable coal mine dust
exposures. Table 28 of the QRA for the final rule contains the
projected reduction in these risks for each occupational category. For
progressive massive
[[Page 24836]]
fibrosis (PMF), the most severe stage of CWP considered, reductions of
up to 56 excess cases per thousand are projected for underground
workers at age 73, depending on occupation. For severe emphysema at age
73, the projected improvements for underground workers range up to a
reduction of 34 cases per thousand depending on occupation. Again for
underground workers, the reduction in excess cases of death due to NMRD
by age 85 is projected to range up to 6 per thousand, depending on
occupation. For surface workers, reductions exceeding 1 case per
thousand exposed miners are projected for PMF and severe emphysema in
several occupational categories. Excess risks per thousand part 90
miners are projected to decline by 19 cases of PMF at age 73, 14 or 22
cases of severe emphysema at age 73 (depending on race), and 4 cases of
NMRD mortality by age 85.
Part 4 of the QRA for the final rule contains an analysis of
uncertainties in the projected reductions in risk. This includes both a
quantitative analysis of sensitivity to the assumptions and methods
used and a qualitative discussion of the maximum range of credible
estimates for projected reductions in respirable coal mine dust
exposures. MSHA's best estimates were found to lie near the middle of
the range produced by alternative assumptions.
In all of its calculations, the QRA assumes that miners are
occupationally exposed to respirable coal mine dust for a total of
86,400 hours over a 45-year occupational lifetime (e.g., either 48
weeks per year at 40 hours per week, 32 weeks per year at 60 hours per
week, or any other work pattern that amounts to an average of 1,920
exposure hours per year). Current health risks are greater than those
shown in the QRA for miners working more than 1,920 hours per year.
In addition, the final rule also tightens the requirement for
normal coal production necessary for a valid dust sample, requires the
use of CPDMs, revises the dust sampling program, and requires operator
corrective action on a single, full-shift operator sample. These
provisions are expected to further reduce respirable dust exposures,
thereby resulting in improvements greater than those shown in the QRA.
For a discussion of the benefits of the final rule, see Chapter V of
the REA.
Public comments on the QRA for the proposed rule addressed five
issues: (1) Hazard identification, (2) exposure-response models and
possible threshold effects, (3) reliance on mean and cumulative
exposures, (4) method of projecting exposures and risk reductions under
successful implementation of final rule, and (5) uncertainty in the
QRA's results.
1. Hazard Identification
Some commenters stated that the QRA for the proposed rule did not
contain a hazard identification section, consisting of toxicological,
epidemiological, or clinical evidence addressing whether the existing
standard of 2.0 mg/m\3\ causes incremental harm to miners' health.
MSHA provided a comprehensive evaluation of the critical scientific
evidence supporting a causal connection between respirable coal mine
dust exposures at the current level and adverse health effects in
Section IV, Health Effects, of the preamble to the proposed rule, and
in Section 1(d) of the QRA for the proposal which pertained to health
effects and material impairment under current exposure conditions.
MSHA agrees with the commenters that the hazard identification step
should reflect current biological understanding of the inflammatory
mode of action for lung diseases induced by inhalation of coal mine
dust. Section IV.B.4 of the preamble to the proposed rule discussed a
variety of biological mechanisms including inflammation.
A few commenters stated that the QRA relied on spurious
associations among historical trends to establish a causal relationship
between respirable coal mine dust exposures and adverse health effects.
Associations among historical trends played no role in the QRAs for the
proposed or final rules. None of the three published regression
analyses on which the QRAs rely regress one time trend against another.
Instead, they quantify the relationship between varying levels of
accumulated respirable coal mine dust exposure and the relative
frequency of CWP (CWP1+, CWP2+, and PMF), severe emphysema, and
premature death due to NMRD.\5\ The subjects, i.e., data points, of
these regression analyses are not rates of disease corresponding to
aggregated exposure levels in particular years. Rather, the data points
of the regression models are individual miners who were more or less
simultaneously exposed to different levels of respirable coal mine
dust. Thus, those miners who were exposed to low cumulative exposures
serve as an internal control group compared to miners who were exposed
to higher cumulative exposures.
---------------------------------------------------------------------------
\5\ See Appendices I, J, and K of the QRAs for the proposed and
final rules.
---------------------------------------------------------------------------
Since the pertinent studies included miners whose lifetime
cumulative exposures fell well below the existing standards, these
studies provide MSHA with a basis for determining whether exposure
levels under the existing respirable coal dust standards cause
incremental harm to miners' health. This topic was addressed in
sections 1(d) and 2 of the QRA for the proposal. The conclusion,
subject to assumptions described in Section 2(f) of the QRA, is that
current exposure conditions which, as shown in Tables 6 and 12 of the
QRA for the proposal, are generally below the existing 2.0 mg/m\3\ and
1.0 mg/m\3\ standards, place miners at a significant risk of incurring
each of the material impairments considered. MSHA reaches the same
conclusion in the QRA to the final rule.
A few commenters stated that MSHA improperly relied on estimates of
current disease prevalence from the NCWHSP, which was initiated in 1970
and is administered by NIOSH. These commenters stated that the NCWHSP
surveillance data is biased due to issues related to the accuracy and
precision in the diagnosis of CWP and PMF, low miner participation
rates, limited exposure data, and other design and analysis
limitations, e.g., participant self-selection.
MSHA did not rely on the NCWHSP surveillance data in its QRAs for
either the proposed or final rules. The relatively low participation
rates, potential self-selection biases, and a lack of correspondent
exposure histories for the individual miners involved limit the use of
the surveillance data as support for the QRAs. The QRAs primarily
relied on three epidemiologic studies: Attfield and Seixas (1995);
Kuempel et al. (2009a); and Attfield and Kuempel (2008). These three
studies are consistent with the commenters' statement that estimates of
current disease prevalence should characterize historical exposures of
individual miners and incorporate cumulative exposure metrics in the
analyses to check for a pattern of increasing disease risk with
increased dust exposure level.
However, NCWHSP surveillance data are useful in establishing that
significant health hazards persist under existing respirable coal dust
exposure conditions. Although the utility of these data for
quantitative risk assessment is limited, they do show there is an
unacceptably high incidence of respirable coal mine dust-related
disease among miners whose exposure came entirely after adoption of the
existing respirable coal dust standards. (See Section III.A., Health
Effects, in this preamble.)
Sections 1(d) and 2 of the QRAs for the proposed and final rules
use the
[[Page 24837]]
National Study of Coal Workers' Pneumoconiosis (otherwise known as NCS)
data to address the question of whether a lifetime of occupational
respirable coal mine dust exposure at the existing standard presents a
significantly increased risk of adverse health effects (also see
Goodwin and Attfield (1998) and Brower and Attfield (1998)). Unlike the
surveillance data, the NCS data contain information on both the health
and the respirable coal mine dust exposure of individual miners.
Dust exposure estimates are calculated by summing the products of
time worked in each job within an individual miner's work history with
dust concentration data from the exposure matrix derived by Seixas et
al. (1991). Brower and Attfield (1998) found that the self-reported
occupational history information on standardized questionnaires in the
NCS collected from U.S. underground coal miners is reliable and that
the amount of bias introduced by recalling past employment history is
minimal. The NCS is further described in Section III.A of this
preamble.
Some commenters discussed possible radiological misclassification
in the NCS data.\6\ However, these commenters did not dispute the
appropriateness of using this type of study to establish a dose-
response relationship that can be used effectively in a quantitative
risk assessment.
---------------------------------------------------------------------------
\6\ Uncertainty due to radiological misclassification is
addressed separately in Section 2, Exposure-Response Models and
Possible Threshold Effects, (b) Bias due to Errors in Diagnosis and
(c) Bias due to Errors in Exposure Estimates. See Wagner et al.,
1992.
---------------------------------------------------------------------------
Some commenters challenged the QRA's findings of significant health
risks from exposure at the existing 2.0 mg/m\3\ standard over an
occupational lifetime. MSHA addresses issues raised by these commenters
in the following subsections: (a) CWP, including PMF; (b) severe
emphysema; and (c) mortality due to NMRD.
a. CWP, including PMF
Some commenters acknowledged that the exposure-response analyses of
respirable coal mine dust and CWP2+ show strong associations for high
rank coal, with increased prevalence below the existing standard.
However, these commenters maintained that there are no apparent
increases in CWP2+ for low rank coals at exposures below the existing
2.0 mg/m\3\ standard. According to the commenters, the prevalence of
CWP2+ and PMF predicted by the exposure-response models for miners
experiencing an occupational lifetime of exposure to respirable coal
dust at 2.0 mg/m\3\ from low or medium rank coal is less than the
``background'' rate, or prevalence, of positive radiographic findings
among workers with no occupational exposure to respirable coal mine
dust.
The commenters assumed, in reaching their conclusion, that the
background prevalence, which had been shown to be approximately five
percent for CWP1+ among 60-year-old non-exposed workers, was also five
percent for CWP2+ and PMF. MSHA stated during one of the public
hearings on the proposed rule that it is not appropriate to compare
predictions of CWP2+ prevalence to the background prevalence for CWP1+.
The 1995 Attfield/Seixas study provides a formula, shown in
Appendix I of the QRAs for the proposed and final rules, that enables
estimation of the background prevalences for CWP1+, CWP2+, and PMF.
Based on this formula, Table III-6 below shows the estimated background
prevalences specific to CWP1+, CWP2+, and PMF, along with the
corresponding prevalences predicted for miners exposed to respirable
coal mine dust concentrations averaging 2.0 mg/m\3\ for an occupational
lifetime of 45 years. The predicted prevalences of CWP1+, CWP2+, and
PMF for miners exposed to respirable coal mine dust from low/medium
rank coal are all far greater than the corresponding background
prevalence. For miners exposed to high rank coal, the difference is
even greater.
All of the estimated excess risks shown in both QRAs for exposed
miners are denoted as ``excess'' risks precisely because the background
prevalence has been subtracted from the predicted prevalence among
exposed miners. Therefore, the calculation of excess risk always yields
zero when exposure equals zero (i.e., no known occupational exposure);
and, for exposed miners, excess risk is the increase in predicted
prevalence from background. For example, at age 73, the center graph in
Figure 10 of the QRAs for the proposed and final rules shows an excess
risk of 156 cases of CWP2+ per thousand miners exposed for 45 years to
respirable coal mine dust from low/medium rank coal at an average
concentration of 2.0 mg/m\3\. The same result is obtained from Table
III-6 below by subtracting the background prevalence of 6.2 percent (62
cases per thousand) from the prevalence of 21.8 percent (218 cases per
thousand) shown for exposed miners (i.e., 21.8%-6.2%=15.6%: 156 cases
per thousand miners, compare with Figure 10 in both QRAs).
Table III-6--Expected Prevalence (Percentage) of Radiographic Findings Indicating CWP and PMF, Based on Attfield/
Seixas Logistic regression model
----------------------------------------------------------------------------------------------------------------
Background (zero exposure) 45-year exposure at 2.0 mg/m\3\ top entry is
------------------------------------------------ for low/medium rank coal bottom entry is for
Age high rank coal
CWP 1+ CWP 2+ PMF -----------------------------------------------
CWP 1+ CWP 2+ PMF
----------------------------------------------------------------------------------------------------------------
60 5.3 1.1 0.7 17.8 4.7 2.2
2 .............. .............. .............. 32.7 14.7 9.3
65 7.6 2.2 1.3 24.1 8.7 4.2
2 .............. .............. .............. 41.7 25.2 16.9
73 13.3 6.2 3.9 37.1 21.8 11.6
2 .............. .............. .............. 57.0 49.6 37.8
----------------------------------------------------------------------------------------------------------------
Moreover, systematic error or bias due to systematic
misinterpretation of radiographic data would be equally present in the
results for both exposed and unexposed miners. Therefore, the effect,
if it exists, of such misinterpretations should be canceled when
background prevalence is subtracted from predicted prevalence to form
the estimates of excess risk provided in the QRAs for the proposed and
final rules. Some commenters
[[Page 24838]]
emphasized potential biases of this type but failed to mention that
comparing the frequency of positive radiographic findings for exposed
miners with the appropriate background rates serves to control for such
biases.
b. Severe Emphysema
Some commenters stated that the weight of the epidemiological
evidence fails to support any clinically significant deficits in forced
expiratory volume (FEV1) or any increased occurrence of
chronic obstructive pulmonary disease (COPD) at cumulative respirable
coal mine dust exposures equivalent to an occupational lifetime at the
existing standard. [See the proposed rule discussion on emphysema;
Green et al., 1998a; Kuempel et al., 2009a and 1997b]. However, the
only metric used to support this assertion was the average loss in
FEV1 attributable to respirable coal mine dust exposure,
across the entire population of exposed miners. Section 1(d)(ii) of the
QRAs for the proposed and final rules points out that averaging
FEV1 loss across a population can mask the effects of
exposure on susceptible sub-populations. Averaging fails to reveal the
risk of FEV1 reductions that exceed the average by a
clinically significant amount.\7\ Dust exposure at a given level may
affect susceptible individuals to a far greater extent than what is
suggested by the average effect. This type of masking is avoided when,
as in NIOSH's 1995 Criteria Document, findings are expressed in terms
of the prevalence of clinically significant outcomes.
---------------------------------------------------------------------------
\7\ The term ``clinical significance'' is defined as a
difference in effect size considered by experts to be important in
clinical or policy decisions, regardless of the level of statistical
significance (Last, John M., ed. 2001. A Dictionary of Epidemiology,
Fourth Edition. New York: Oxford University Press, Inc.
---------------------------------------------------------------------------
For example, the average reduction in FEV1 predicted by
the Soutar/Hurley (1986) estimate is less than 140 ml after 45 years of
occupational exposure to respirable coal mine dust at 2.0 mg/m\3\.
However, this average reveals little or nothing about the effects on
individual miners. If the exposure effects were clinically significant
in as little as one percent of all cases (10 cases per thousand), then
this would constitute a significant increase in risk associated with
exposure. An average reduction in FEV1 of 140 ml or less
does not preclude the possibility that the reduction exceeds 300 ml or
even 1,000 ml in a substantial portion of the exposed population.
Instead of solely focusing on the average loss in pulmonary function
associated with respirable coal mine dust exposure, MSHA also considers
the rate at which clinically significant lung function deficits have
occurred. Table III-7 (reproduced from Table 7-3 of the NIOSH Criteria
Document) provides estimates of the excess risk, i.e., the number of
miners expected to develop a clinically significant deficit in
FEV1 per thousand exposed miners after an occupational
lifetime of exposure to various concentrations of respirable coal mine
dust.\8\ Although the commenters correctly counted the Attfield and
Hodous (1992) study that showed no clinically significant average
reduction in FEV1, Table III-7 shows that the average
reduction is not the only outcome of interest. As shown in Table III-7,
the Attfield and Hodous (1992) study also shows clinically significant
reductions in FEV1 in a substantial number of cases per
thousand exposed miners. Specifically, for miners at age 65
occupationally exposed to a mean respirable coal mine dust
concentration of 2.0 mg/m\3\ over a 45-year working lifetime, the
estimated excess risk of FEV1 < 65% of the predicted normal
value is 9 per 1,000 for never smokers in the western region and 12 per
1,000 for the eastern region.\9\
---------------------------------------------------------------------------
\8\ The values shown in Table III-7 represent excess risks
because they are adjusted to discount background rates of clinically
significant deficits in FEV1 for unexposed workers at age
65.
\9\ Table III-7 is based on two studies: Attfield and Hodous
(1992) and Seixas et al. (1993). The commenters indicated that the
first study is a sound study methodologically--except for the
exposure estimates that are biased to increase the exposure-response
slope of the study group of pre-1970 miners exposed to high and
unregulated respirable coal mine dust levels. MSHA discusses the
comments on bias in the exposure estimates in Section III.B.2.c of
this preamble.
---------------------------------------------------------------------------
[[Page 24839]]
[GRAPHIC] [TIFF OMITTED] TR01MY14.001
Source: Reproduced from Table 7-3 of the NIOSH Criteria Document.
[[Page 24840]]
Similarly, the QRAs for the proposed and final rules focus on
excess risk, rather than mean response, to show that respirable coal
mine dust exposures for an occupational lifetime at the existing
standard can significantly increase the risk of FEV1
reductions associated with severe emphysema. Based on the exposure-
response model described in Kuempel et al. (2009a), Figure 14 in both
QRAs shows that among never-smoking white coal miners, the excess risk
at 2.0 mg/m\3\ ranges from approximately 12 percent (117 cases per
1,000) at age 65 to approximately 16 percent (162 cases per 1,000) at
age 80. These percentages represent the estimated probability that a
miner exposed to an average respirable coal mine dust concentration of
2.0 mg/m\3\ over a 45-year occupational lifetime will develop severe
emphysema attributable to that exposure.
The QRAs for the proposed and final rules use the pulmonary
response model described in Kuempel et al. (2009a) as the basis not
only for the estimates discussed previously, but also for the
calculation of all current and projected excess risks of severe
emphysema attributable to respirable coal mine dust exposures.\10\
---------------------------------------------------------------------------
\10\ See QRA for the proposed rule, Tables 16, 24, and Appendix
J.
---------------------------------------------------------------------------
Some commenters criticized the Kuempel et al. (2009a) study and the
related study, Kuempel et al. (2009b) which relied on the same study
population of 722 autopsied miners and non-miners. These commenters
stated that the Kuempel et al. studies had little to no relevance to
the existing or proposed dust standards because the exposures of the
autopsied miners studied were pre-1970 and likely to have been much
higher than current exposures. The commenters did not provide evidence
to support their criticism of the Kuempel et al. (2009a and 2009b)
studies.
Table 1 of the Kuempel et al. 2009b study and section 1(d)(ii) of
the QRAs for the proposed and final rules show that the study group in
question consisted of 616 deceased coal miners and 106 deceased non-
miners (who presumably had no respirable coal mine dust exposure but
functioned as internal controls in the statistical analysis).\11\ Among
the coal miners, the mean cumulative respirable coal mine dust exposure
was 103 mg-yr/m\3\, with a standard deviation ([sigma]) of 40.6 mg-yr/
m\3\.
---------------------------------------------------------------------------
\11\ The commenters stated that the study population in Kuempel
et al., 2009a ``is comprised of 116 individuals with spirometry
drawn from the same 722 autopsied miners and non-miners just
discussed [in connection with Kuempel et al., 2009b].'' In response
to commenters, although 116 subjects with FEV1 data were
used to define cutoff points for clinically significant emphysema
severity, the logistic regression models relating respirable coal
mine dust exposure to the probability of meeting these cutoff points
used all 342 members of the study population with complete data.
(See Kuempel et al., 2009a, Tables 1 and 2).
---------------------------------------------------------------------------
Since miners in the study had an average tenure of 34.3 years, they
were exposed to an average respirable coal mine dust concentration of
3.0 mg/m\3\ (i.e., 103 mg-yr/m\3\/34.3 yr) over their occupational
lifetimes, with [sigma] = 1.184. Assuming an approximately lognormal
distribution,\12\ this would suggest that approximately 58% of these
miners experienced average respirable coal mine dust concentrations
less than 3.0 mg/m\3\ and 19% of them averaged less than 2.0 mg/m\3\.
---------------------------------------------------------------------------
\12\ If X is Lognormally distributed with mean = 3.0 and
standard deviation = 1.184, then Loge(X) is Normally
distributed with mean = 1.026 and standard deviation = 0.380.
---------------------------------------------------------------------------
The QRAs for the proposed and final rules are designed to evaluate
risks expected for exposures accumulated over a 45-year occupational
lifetime. Therefore, it is also relevant to examine the distribution of
respirable coal mine dust concentrations that would, after a 45-year
occupational lifetime, give rise to the same exposure totals as those
experienced by miners in the Kuempel et al. 2009b study. This result in
an average respirable coal mine dust concentration of 2.3 mg/m\3\, with
[sigma] = 0.902 mg/m\3\. In this case, again assuming an approximately
lognormal exposure distribution,\13\ approximately 82% of the miners
would experience average respirable coal mine dust concentrations less
than 3.0 mg/m\3\, 43% would average less than 2.0 mg/m\3\, and 18%
would average less than 1.5 mg/m\3\.
---------------------------------------------------------------------------
\13\ If X is Lognormally distributed with mean = 2.3 and
standard deviation = 0.902, then Loge(X) is Normally
distributed with mean = 0.756 and standard deviation = 0.380.
---------------------------------------------------------------------------
Consequently, considering either the 34.3-year average tenure of
miners in the study group (Kuempel et al., 2009b), or the 45-year
occupational lifetime MSHA uses to evaluate occupational risks, it
appears that the Kuempel et al., 2009a, 2009b reports are relevant to
exposure conditions under the existing respirable coal mine dust
standard.\14\ Table 8 of the QRAs for the proposed and final rules show
that MSHA's enforcement of the existing respirable dust standard has
not eliminated work locations exhibiting average respirable coal mine
dust concentrations greater than 1.5 mg/m\3\ or even 2.0 mg/m\3\. At
the very least, these studies are highly relevant to risks at such work
locations.
---------------------------------------------------------------------------
\14\ Since these studies used the same methods for estimating
pre-1970 exposures as the NCWHSP studies, the comments on possible
biases in these exposure estimates also apply here. Comments on bias
in the exposure estimates are addressed in the Section III.B.2.c.
---------------------------------------------------------------------------
The commenters, in referring to the Kuempel et al. (2009a and
2009b) study population, identified self-reporting of smoking histories
as a potential source of bias and rejected a suggestion by the studies'
authors that the timing of self-reported data collection on smoking
added to the studies' strengths. According to the studies' authors,
data collection had occurred in the 1960s and 1970s, when smoking was
not a contentious issue and Federal compensation programs for smoking-
related illnesses had not yet been introduced. The commenters, however,
contended that the authors' mention of possible smoking exposure
misclassification ``tends to negate'' their claim that non-contentious
smoking histories comprised a strength of the study. The commenters
further argued that the studies' finding that dust exposure had a
greater effect than smoking was unconvincing and that both of these
factors were questionable for the study cohort because smoking
histories were self-reported and ``when compensation matters are
involved, smoking histories are likely to be unreliable.'' Commenters
further stated that occupational dust exposure can have an effect on
the development of emphysema and COPD, but the general literature still
considers ``ordinary'' levels of occupational pollution to be minor
compared to cigarette smoking and aging.
First, in response to commenters, as suggested by the studies'
authors, MSHA points out that the reliability of the miners' smoking
histories is unlikely to have been compromised by compensation programs
in that the programs did not exist at the time of the studies. Kuempel
et al. (2009a and 2009b) mention misclassification of smoking history
only in a list of ``potential limitations'' and make no suggestion that
this has anything to do with compensation incentives. Second, as
demonstrated in the preceding discussion, respirable coal mine dust
exposures for the autopsied miners were not ``far in excess of today's
standard'', 2.0 mg/m\3\, as the commenters state. Third, respirable
coal mine dust exposure estimates were not biased to overestimate high
exposures and underestimate low exposures. (See discussion in the
subsequent preamble section on bias due to errors in exposure
estimates, Section III.B.2.c.). Finally, the commenters interpreted the
finding that each mg-year/m\3\ of respirable coal mine dust exposure
is, on average, similar in effect to each ``pack-year'' of cigarette
[[Page 24841]]
smoking as somehow undermining the studies' credibility.\15\ The
commenters did not provide any references to support their view that
the general literature still considers adverse health effects of
ordinary levels of occupational pollution to be minor relative to those
from cigarette smoking; nor did they provide evidence that this
generalization applies specifically to respirable coal mine dust and
emphysema.\16\
---------------------------------------------------------------------------
\15\ With regard to the probability of developing clinically
relevant emphysema (i.e., emphysema associated with FEV1
less than either 80% or 65% of predicted normal values, ``the
contribution of cumulative dust exposure was greater than that of
cigarette smoking at the cohort mean values, although not
significantly so . . . [emphasis added]'' In the cohort used for the
logistic regression analysis supporting this part of the analysis,
mean cumulative respirable coal mine dust exposure was 87 mg-year/
m\3\ among miners and mean cigarette smoking was 42 pack-years.
(Kuempel et al., 2009a).
\16\ The relative magnitude of estimated coefficients of the
emphysema severity index regression model for smoking history and
respirable coal mine dust exposure should not be interpreted as
representing the relative potencies of cigarette smoke and
respirable coal mine dust as toxic agents. See Appendix J, Table 66
of the QRAs for the proposed and final rules. The estimated smoking
history coefficient is 0.0099 (packs/day X years) and the estimated
respirable coal mine dust coefficient is 0.010 (mg/m\3\ X years).
The magnitude of each coefficient depends on the choice of units
used to represent exposure to the respective agent. For example, if
the unit used to represent respirable coal mine dust exposure had
been [micro]g-year/m\3\ instead of mg-year/m\3\, then the estimated
coefficient for respirable coal mine dust would have been
approximately 1/1,000 of that for smoking. Furthermore, a ``pack-
year'' does not represent the same duration of exposure as an
occupational mg-year/m\3\. A pack-year represents an average
consumption of one pack of cigarettes per day for a year. Each pack
normally contains 20 cigarettes. If it took an average of five
minutes to consume each cigarette, then a pack-year would represent
36,500 minutes of exposure to cigarette smoke. In contrast, assuming
1,920 occupational exposure hours per year, each mg-year/m\3\
represents 115,200 minutes of exposure to respirable coal mine dust
(i.e., 1,920 hrs of exposure per yr X (60 minutes/1 hr) = 115,200
minutes of exposure per yr).
---------------------------------------------------------------------------
With respect to the data used in Kuempel et al. (2009a) to relate
clinically significant cutoff points of emphysema severity to
respirable coal mine dust exposures, the commenters stated, without any
supporting evidence, that miners were coached to distort pulmonary
measurements.
In addition, commenters stated that there was a significant trend
between the emphysema index and FEV1, but much of the
variability was unexplained. The FEV1 data (available for a
small subset of the autopsied subjects) were used in this study only to
establish appropriate cutoff points for clinically significant values
of the emphysema severity index; the unexplained variability seen while
establishing these cutpoints has no direct bearing on the logistic
regressions that relate respirable coal mine dust exposures to the
probability of exhibiting clinically significant emphysema severity.
The average cumulative dust exposure was reported to be 87 mg-year/
m\3\ among the autopsied miners used in the logistic
regressions.17 18 This is notably less than the 103.0 mg-
year/m\3\ average reported for miners in the study population as a
whole. Assuming the same coefficient of variation in exposures as
reported for all miners in the study population (approximately 39%), it
follows that autopsied miners included in the logistic regressions
experienced exposures equivalent to a respirable coal mine dust
concentration of 1.93 mg/m\3\ averaged over a 45-year occupational
lifetime, with [sigma] = 0.762 mg/m\3\.\19\ Once again assuming an
approximately lognormal exposure distribution,\20\ this means that
approximately 62% of these miners would have experienced average
respirable coal mine dust concentrations less than 2.0 mg/m\3\ and 32%
of them would have averaged less than 1.5 mg/m\3\. This calculation
contradicts the commenters' claim that the study is applicable only to
the pre-1970 era, when ``miners were exposed to respirable dust far in
excess of today's standard.''
---------------------------------------------------------------------------
\17\ With regard to the probability of developing clinically
relevant emphysema (i.e., emphysema associated with FEV1
less than either 80% or 65% of predicted normal values), ``the
contribution of cumulative dust exposure was greater than that of
cigarette smoking at the cohort mean values, although not
significantly so. . . .'' In the cohort used for the logistic
regression analysis supporting this part of the analysis, mean
cumulative respirable coal mine dust exposure was 87 mg-year/m\3\
among miners and the mean cigarette smoking was 42 pack-years
(Kuempel et al. (2009a).
\18\ Neither the standard deviation of cumulative exposure nor
information on tenure in mining was reported for this subset of the
study population.
\19\ The coefficient of variation is the ratio of the standard
deviation to the mean. The coefficient of variation is independent
of the unit in which the measurement is taken, i.e., dimensionless.
The coefficient of variation for the coal mine population in the
logistic regression model is assumed to be the same as that for the
entire miner study population in the Kuempel et al. (2009a) study.
\20\ The log-normal distribution is a continuous probability
distribution of a random variable whose logarithm is normally
distributed. The distribution of respirable coal mine dust is not
normally distributed; therefore, respirable coal mine dust was
assigned a random continuous probability distribution termed the
lognormal distribution represented by Loge (respirable
coal mine dust). The transformation was conducted to run parametric
statistics models (i.e., model respirable coal mine dust with an
analysis of variance (ANOVA), analysis of covariance (ANCOVA), and
regression models). If X is Lognormally distributed with mean = 1.9
and standard deviation = 0.762, then Loge(X) is Normally
distributed with mean = 0.585 and standard deviation = 0.380.
---------------------------------------------------------------------------
The commenters generally disagreed with MSHA's reliance on the
Kuempel et al. (2009a) findings by focusing on the possibility of
errors in the FEV1 measurements and cumulative exposure
estimates. Despite MSHA's heavy reliance on these studies in the QRA,
the commenters did not include them in their evaluation of the weight
of evidence. However, potential biases due to exposure and/or
FEV1 misclassification cannot explain all of the results.
Table 4 of Kuempel et al. (2009b) shows that a strong correlation
(R\2\ = 0.44) was observed between the amount of coal dust found in the
lungs of deceased miners and the degree of emphysema severity
determined at autopsy. This result, which depends on neither exposure
estimates nor FEV1 measurements, is statistically
significant at a confidence level greater than 99.99 percent (p <
.0001), after accounting for cigarette smoking, age at death, and race.
The average emphysema severity index observed among never-smoking
miners (302, or 30.2 percent of the lung affected, Kuempel et al.,
Table 2 (2009b)) exceeded the cutoff point (285) corresponding to a 20-
percent reduction in FEV1 from the predicted normal value.
Therefore, this study provides strong evidence that respirable coal
mine dust exposures under current conditions can cause clinically
significant pulmonary effects. This evidence is confirmed and
strengthened by evidence presented in Miller et al. (2007) and Attfield
and Kuempel (2008) that the risk of mortality due to COPD increases
significantly with increasing respirable coal mine dust exposure.
c. Mortality Due to NMRD
Some commenters acknowledged a strong exposure-response
relationship between respirable coal mine dust exposure and mortality
from nonmalignant respiratory diseases (NMRD) but claimed that the
associations appear to be confined to high rank coal dust. According to
these commenters, respirable coal mine dust exposure ``is strongly
associated with significant excess NMRD mortality among anthracite coal
miners,'' but this association ``is not found among miners of lower
rank coals (bituminous and sub-bituminous).'' More specifically, the
commenters stated that ``there appears to be no increased mortality
risk of CWP associated with coal mined in eastern Appalachia, western
Appalachia, and the Midwest.'' \21\ To support this
[[Page 24842]]
conclusion, the commenters cited the results in Tables IX and X of
Attfield and Kuempel (2008). These commenters also noted that the
conclusion is based on only one mortality study, Attfield and Kuempel
(2008), and proposed that NIOSH should test this observation by
analyzing exposure-response trends by coal rank.
---------------------------------------------------------------------------
\21\ The same commenters also claimed that ``Numbers were too
small for a mortality analysis of Western coal, which is the lowest
ranked coal and presumably the lowest risk if the coal rank
hypothesis is correct.'' This is incorrect. The study cohort
described in Attfield and Kuempel (2008) included 952 miners from
the West region, and the study found significant risk of NMRD
mortality for miners exposed to respirable coal mine dust in that
region. As will be explained below, NMRD mortality in the West
region was used as a baseline for the relative risk of NMRD
mortality in the other four regions.
---------------------------------------------------------------------------
The study cohort in Attfield and Kuempel (2008) included a total of
8,899 miners from five coal mining regions across the U.S. There were
498 miners from the Anthracite region, 1,353 from the East Appalachia
region, 4,886 from the West Appalachia region, 1,210 from the Midwest
region, and 952 from the West region. Contrary to the commenters'
interpretation, Tables IX and X of Attfield and Kuempel (2008) show a
statistically significant increase in NMRD mortality associated with
increasing respirable coal mine dust exposure in each of these five
coal mining regions. The commenters' mischaracterization of the
findings presented in Attfield and Kuempel (2008) appear to have
resulted from two misinterpretations.
First, the relative risks shown in Table IX of Attfield and Kuempel
(2008) for four of the five coal mining regions examined are expressed
relative to the risks found for the fifth region (i.e., the West).
Therefore, the fact that, except for Anthracite, the relative risks do
not differ significantly from 1.0 means that only in the Anthracite
region is the observed effect different from the effect observed in the
West.\22\ Although the effects observed in East Appalachia, West
Appalachia, and the Mid-west do not differ significantly from those
observed in the West, this does not imply that any of the observed
effects are insignificant. Specifically, the ``four-fold increased risk
of anthracite,'' shown in Table IX (op. cit.) as having a relative risk
of 4.41, means that (all other factors being equal), the risk of NMRD
mortality in the Anthracite region is probably four to five times what
it is in the West (95% CI: 3.08-5.92). Since the analysis used to
construct Table IX does not show any statistically significant
difference between the West and any other region, except Anthracite, it
shows only that NMRD risk in the Anthracite region is probably four to
five times what it is in the other regions as a group. This says
nothing about what the risk actually is in any of the regions, let
alone the risk attributable to cumulative dust exposure.
---------------------------------------------------------------------------
\22\ For regions other than Anthracite, the 95% CI in Table IX
encompasses the number one (``1.0'') and is therefore not
statistically significant--i.e., the study authors are not 95%
confident that the effects in East Appalachia, West Appalachia, and
the Mid-west region are different from that in the comparison region
(the West).
---------------------------------------------------------------------------
Similarly, the regional coefficients shown for NMRD in Table X of
Attfield and Kuempel (2008) pertain to NMRD mortality risks relative to
the West region--this time based on a statistical analysis that treats
cumulative dust exposure as a continuous variable. It is this analysis
that is used to evaluate current and projected risk in the QRAs for the
proposed and final rules.\23\ For example, all other factors being
equal, the relative risk (RR) in the ``Mid-west'' region is best
estimated to be
---------------------------------------------------------------------------
\23\ Appendix K of the QRAs for the proposed and final rules
shows that for each regional coefficient ([alpha]), RR = e\a\, where
RR = e is the base of the natural logarithms. For the West region,
[alpha] = 0, so the baseline relative risk is RR = e\0\ = 1.
---------------------------------------------------------------------------
RR = e-0.2870 = 0.75
There is considerable uncertainty in this particular estimate, so
all that can be said with high confidence is that NMRD mortality risk
in the Mid-west probably lies somewhere between 51 percent below and 12
percent above that in the West (95% CI: 0.49-1.12). However, just as
NMRD mortality risk in the West depends on age, smoking history, and
cumulative respirable coal mine dust exposure, so does NMRD mortality
risk in the Mid-west. According to the analysis used to construct Table
X, NMRD mortality risk is far greater in the Anthracite region than in
any of the other four regions,\24\ but that does not mean there is no
risk in the other regions or that the other regions exhibit no
relationship between NMRD mortality and cumulative respirable coal mine
dust exposure.
---------------------------------------------------------------------------
\24\ Regional coefficients of the proportional hazards model are
reported by Attfield and Kuempel (2008) in Table X as Anthracite
(1.4844), East Appalachia (0.2187), West Appalachia (-0.3477), and
Mid-west (-0.2870), relative to the West region. Therefore, applying
the formula in Footnote 23, the relative risks are respectively
estimated to be 4.41, 1.24, 0.71, and 0.75.
---------------------------------------------------------------------------
Second, contrary to the commenters' interpretation, both Tables IX
and X of Attfield and Kuempel (2008) show statistically significant
increases in NMRD mortality with increasing respirable coal mine dust
exposure for the region associated with lowest rank coal: The West. The
estimated exposure-response relationship is modified in the other
regions--amplified, relative to the West, in the East Appalachia and
Anthracite regions and attenuated, relative to the West, in the West
Appalachia and Mid-west regions. The following explication is based on
Table X, since that is what is used in the QRAs for the proposed and
final rules, but the same principles apply to interpreting Table IX.
Since the West region comprises the baseline in the relative risk
model, no regional coefficient is applied for respirable coal mine dust
exposures in the West. Therefore, using Table X, the relative risk of
NMRD mortality, after a 45-year occupational lifetime of exposure to
(low-rank) western respirable coal mine dust at a concentration
averaging 2.0 mg/m\3\, is estimated to be:
RR = e-0.00709 (45 x 2.0) = 1.89
This means that the risk of NMRD mortality is estimated to be 89
percent greater for a miner who has been exposed to 90 mg-year/m\3\ of
respirable coal mine dust than for an unexposed miner of the same age,
region, and smoking history. At a 45-year occupational lifetime average
respirable coal mine dust concentration of 1.5 mg/m\3\, the estimated
relative risk is:
RR = e0.00709(45x1.5) = 1.61
Therefore, for respirable coal mine dust exposures in the West-
region (where the coal is low-rank), increasing the lifetime average
from 1.5 mg/m\3\ to 2.0 mg/m\3\ increases the estimated relative risk
by 28 percentage points (i.e., (1.89-1.61)*100). According to Attfield
and Kuempel (2008), the coefficient giving rise to this increase
(0.00709) is statistically significant at a confidence level exceeding
99 percent. Therefore, contrary to the commenters' assertions, the
Attfield-Kuempel analysis shows an increased risk of NMRD mortality
associated with increasing respirable coal mine dust exposures in the
region with lowest rank coal. Multiplying these relative risks by 0.75
(the regional factor for Mid-west coal) attenuates but does not
eliminate, the estimated exposure-response relationship.
For exposures to the higher rank respirable coal mine dust in East
Appalachia, the corresponding relative risks are:
RR = e0.2187+0.00709(45x2.0) = 2.36
at 2.0 mg/m\3\ and
RR = e0.2187+0.00709(45x1.5) = 2.01
at 1.5 mg/m\3\.
Therefore, increasing the cumulative exposure from 67.5 mg-year/
m\3\ to 90 mg-year/m\3\ increases the estimated relative risk by an
estimated 35 percentage points (i.e., (2.36-
[[Page 24843]]
2.01)*100).\25\ This shows that the estimated exposure-response
relationship is steeper (positive slope) in East Appalachia than in the
West, as reflected by the positive regional coefficient. For the
Anthracite region, where coal has the highest rank, the estimated
coefficient is substantially larger (Table X: 1.4844), so the slope of
the estimated exposure-response relationship is far steeper than in
East Appalachia or any of the other regions. Therefore, the commenters'
interpretation that the Attfield-Kuempel 2008 study suggests that there
is no increased risk associated with the lower-than-anthracite ranks of
coal is not correct.\26\
---------------------------------------------------------------------------
\25\ The mg-year/m\3\, 45-yr occupational lifetime average, is
calculated from the mg/m\3\ dust concentration. Where 67.5 mg-year/
m\3\ = 1.5 mg/m\3\ x 45 yr occupational lifetime average and 90 mg-
year/m\3\ = 2.0 mg/m\3\ x 45 yr occupational lifetime average.
\26\ The commenters also stated that the exposure estimates used
by Attfield and Kuempel (2008) are biased in such a way as to
``increase the exposure response slope.'' This comment is discussed
in Section III.B.2.c.
---------------------------------------------------------------------------
In the QRA for the proposed rule, all work locations are classified
as ``Low/Medium Rank,'' ``High Rank Bituminous,'' or ``Anthracite'' by
a procedure described in Footnote 40 of that QRA. Appendix K of the QRA
states that work locations included in the Anthracite and High Rank
Bituminous categories are assigned coal rank coefficients of 1.4844 and
0.2187 (Table X), respectively. All other work locations are assigned a
coefficient of zero. The resulting relative risk estimates for NMRD
mortality under current exposure conditions are shown, by occupation,
in Table 68 of the QRAs for the proposed and final rules. The fact that
the underlying Attfield-Kuempel exposure-response model shows relative
risk as increasing with increasing exposure levels--even for low/medium
rank coal--can be seen by comparing relative risks in the QRAs' Table
68 to the corresponding exposure levels in the QRAs' Table 12.
As shown above and in Appendix K of the QRAs for the proposed and
final rules, the Attfield-Kuempel exposure-response analysis does
exactly what some of the commenters said is needed: Using geographic
location as a proxy, it stratifies the analysis of NMRD mortality risk
by coal rank. Though it may be prone to misinterpretation, that
analysis identifies statistically significant and substantial NMRD
mortality hazards not only for anthracite, but also for regions
identified with high rank bituminous and lower rank coal.
2. Exposure-Response Models and Possible Threshold Effects
For each of the three adverse health conditions covered by the QRAs
for the proposed and final rules (CWP, severe emphysema, and NMRD
mortality), a previously published exposure-response model was used to
quantify the excess risk associated with specified respirable coal mine
dust exposures averaged over a 45-year occupational lifetime.
Appendices I, J, and K in both QRAs describe the three models and
explain, mathematically, how the models were applied to calculate
risks. Some commenters objected to the use of these models for a
variety of reasons. These objections will be addressed in the following
subsections: (a) Attribution of Risk, (b) Bias due to Errors in
Diagnosis, (c) Bias due to Errors in Exposure Estimates, (d) Threshold
Effects, and (e) Model Consistency and Coherence.
a. Attribution of Risk
A commenter stated that regression equations do not necessarily
express causal relationships and objected to the characterization in
the QRA for the proposed rule of its underlying formulas as exposure-
response relationships.
Although the misuse or misinterpretation of regression analysis can
lead to groundless imputations of causal relations, regression analysis
can properly be used to quantify a causal relationship that is known or
believed to exist. As shown in the Health Effects section of the
preambles to the proposed rule and in this final rule, there is ample
toxicological and epidemiologic evidence to support a causal
relationship between respirable coal mine dust exposures and the
adverse health outcomes that have been identified. MSHA believes
regression analysis was properly used and interpreted in the published
studies on which the QRAs for the proposed and final rules rely. MSHA
also believes that the resulting regression models express useful
estimates of causal exposure-response relationships. In addition, while
some commenters questioned the strength or shape of the exposure-
response relationships, one commenter challenged the premise of a
causal connection between respirable coal mine dust exposure and
adverse health effects. The commenter provided a simple hypothetical
regression analysis example. The example illustrates both (1) the
danger of misidentifying a causal relationship by misinterpreting a
regression result and (2) why MSHA believes the regression models used
to quantify excess risk in the QRAs for the proposed and final rules
express exposure-response relationships rather than spurious, non-
causal associations.
In the commenter's example, the underlying basis of causal
relationships is represented by two equations:
Risk = Age - Exposure
and
Exposure = 0.5 x Age
The first equation specifies that in the hypothetical universe of
this example, aging causes risk to increase, while exposure is
protective and causes risk to decrease. The second equation expresses a
causal relationship between age and exposure: Each year of aging causes
an increase of 0.5 exposure units.\27\ Combining these two equations,
risk can be expressed as either,
---------------------------------------------------------------------------
\27\ Aging might be said to cause exposure if exposure
accumulates unavoidably as time passes. Exposure to cosmic radiation
is a possible example.
---------------------------------------------------------------------------
Risk = Age - (0.5 x Age) = 0.5 x Age
or, as the commenter chose to do for the sake of example,
Risk = (2 x Exposure) - Exposure = Exposure
Now, if a researcher were to compile data on risk and exposure in
this hypothetical universe, and then perform a regression analysis on
these data (ignoring age), the result would be, as indicated by the
commenter, a spurious (i.e., non-causal but mathematically correct)
relationship of the form
Risk = 1 x Exposure
where ``1'' is derived from the analysis as the estimated regression
coefficient. Because of this, and the fact that the QRA relies on
regression models, the commenter concluded that MSHA's projected
changes in risk are meaningless.
The commenter, however, did not present a full analysis in the
example. If the researcher suspected that Age (but not exposure) was
causally connected to Risk, then this would presumably motivate the
researcher to compile data on Age and perform the regression analysis
on that variable. The result would properly express the causal
exposure-response relationship:
Risk = 0.5 x Age
In this case, the regression analysis would yield ``0.5'' as the
estimated coefficient of Age, thereby correctly determining the slope
of the causal exposure-response relationship. A researcher might also
perform an exploratory, multiple regression analysis using all of the
available data, including both Age and Exposure as candidate predictor
variables. In this event, calculation of the regression coefficients
would be computationally intractable if the data contained
[[Page 24844]]
absolutely no measurement errors.\28\ If, more realistically, the data
did contain measurement errors, then the regression analysis would
yield a relationship with estimated coefficients of the following form:
---------------------------------------------------------------------------
\28\ This is because it would not be possible to invert the so-
called X'X matrix, given the unvarying interdependence of Age and
Exposure.
---------------------------------------------------------------------------
Risk = a1 x Age + a2 x Exposure
where the regression estimates, a1 and a2, would
generally be close to +1 and -1, respectively, but could differ from
these values by amounts dependent on the error structure. So, rather
than showing that regression invariably produces spurious
relationships, the commenter's example illustrates the importance of
taking all relevant variables into account. When properly executed on
the relevant data, regression analysis provides a valid means of
estimating the parameters of causal exposure-response relationships.
MSHA believes that the exposure-response models on which the QRAs
for the proposed and final rules rely were derived from regression
analyses properly executed on the relevant data. The causal connections
with respirable coal mine dust exposure are supported by evidence from
independent studies,\29\ and the effects of age and other correlates
(such as coal rank and smoking history when available) were
simultaneously estimated. All three studies (Kuempel et al., 2009a,
2009b; Attfield and Kuempel, 2008) found both age and cumulative
respirable coal mine dust exposure to be statistically significant
factors in predicting the probability of adverse health effects. Other
factors (such as smoking history, coal rank, and race) were
incorporated into the exposure-response models when they were found to
be statistically significant.
---------------------------------------------------------------------------
\29\ See the Health Effects Section of the preamble to the
proposed rule.
---------------------------------------------------------------------------
The commenter disagreed with MSHA about the utility of the specific
regression models on which the QRA for the proposed rule relied, and
the relative importance of possibly relevant factors that were not
included--either because the factors were not deemed relevant by the
studies' authors or because the necessary data were unavailable. The
commenter proposed that socioeconomic and demographic factors that may
affect exposure or risk (such as age, seniority, education, income, and
access to medical care) be included in the models and used in the
calculation of partial attributable risks. The commenter suggested that
neglecting such variables could lead to spuriously high estimates of
health risks due to exposure.
As indicated above, age was accounted for in all of the models used
in the QRAs for the proposed and final rule). Some socioeconomic
factors may have been represented, to an unknown extent, by coal mining
region in the CWP and NMRD mortality studies and by race in the
emphysema study. Risks in the CWP and emphysema studies were attributed
to exposure based on internal comparisons with miners in the same
cohort experiencing relatively little or no exposure. Variation in
respirable coal mine dust exposure among miners within mining regions
is unlikely to be related to socioeconomic differences. Therefore,
socioeconomic differences among miners within regions are unlikely to
explain the risk attributed to exposure (i.e., the difference between
risk expected with and without the exposure, after adjustment for age
and coal mining region or race). MSHA recognizes that the regression
models may have been improved by explicit consideration of various
socioeconomic factors. However, no such studies have been published,
and the commenter provided no evidence that including such variables
would have a significant impact on the estimated effects of respirable
coal mine dust exposure.
Similarly, other commenters identified a number of factors that
were not modeled in the regression analyses but could potentially
contribute to the observed frequency of adverse health effects. These
included silica content of the respirable coal mine dust, coal rank,
mine size, and seam height.
Coal rank was not considered in the emphysema study, but it was
represented by a surrogate mdash;coal mining region--in the CWP and
NMRD mortality studies. Mine size may, to some degree, be correlated
with socioeconomic characteristics, but the only evidence of its
relevance pertains to its correlation with exposure levels: As shown in
their comment, exposures tend to be greater at smaller mines.
Therefore, accurate exposure estimates should include the contribution
of mine size to health risks.\30\ Similarly, seam height may be related
to socioeconomic characteristics, but the only known effect it has on
respiratory health arises through its impact on silica content of the
respirable coal mine dust: As pointed out in their comment, thin seams
require mining a higher proportion of stone than thick seams. This
leaves silica content of respirable coal mine dust as a potentially
important variable that was not included in the regression models used
in the QRA.
---------------------------------------------------------------------------
\30\ Potential biases in the exposure estimates are addressed in
Section III.B.2.c below.
---------------------------------------------------------------------------
MSHA agrees that including silica exposures as a covariate would
have improved the credibility of these models. There are no alternative
studies on U.S. exposures that do so. However, Miller et al. (2007),
using data from British coal mines, conducted two separate analyses on
mortality due to CWP and mortality due to COPD, both of which
simultaneously examined silica exposures and respirable coal mine dust
exposures as candidate predictor variables. Both of these analyses
showed a stronger association with respirable coal mine dust than with
quartz, and including both variables in the models, resulted in
approximately the same regression coefficient for respirable coal mine
dust exposure as when silica exposure was excluded.\31\ Furthermore,
the models containing both silica and respirable coal mine dust
exposures resulted in estimated regression coefficients for silica
exposure that were not statistically significant. In contrast, the
estimated coefficients for respirable coal mine dust exposure were
statistically significant at a high confidence level (>99.9 percent)
regardless of whether silica exposure was included. These analyses were
used in the QRAs for the proposed and final rules to confirm the
significance of respirable coal mine dust exposures below the existing
standard. (See Figures 12 and 15 in both QRAs.)
---------------------------------------------------------------------------
\31\ Though remaining approximately the same, the estimated
regression coefficients for respirable coal mine dust exposure
actually increased slightly when silica exposure was included in the
model. For CWP mortality, the regression coefficient for respirable
coal mine dust exposure was 0.0058 when quartz exposure was excluded
and 0.0060 when quartz exposure was included (Miller et al. (2007),
Table 5.9). For COPD mortality, the coefficient for respirable coal
mine dust exposure was 0.0016 when quartz exposure was excluded and
0.0019 when quartz exposure was included. (Miller et al. (2007),
Table 5.18). Exposure units for both respirable coal mine dust and
silica were g-hr/m\3\. Predicted effects are on the natural
logarithm of relative risk.
---------------------------------------------------------------------------
Although the possible confounding effects of tobacco smoking were
addressed in all of the studies used in the QRAs for the proposed and
final rules, one commenter objected to the use of ``smoking patterns
that held decades ago'' in formulating exposure-response relations
applicable to current or projected conditions. This commenter stated
that because of curvature in the joint exposure-response relationship
for severe emphysema (described in Appendix J of the QRA), part of the
risk of severe emphysema attributed to respirable dust exposure
[[Page 24845]]
depended on smoking patterns that no longer exist.
MSHA addressed this issue in both QRAs by basing its estimates of
excess risks of severe emphysema attributed to respirable coal mine
dust exposure only on the results obtained for never-smokers.\32\ This
was done partly to avoid the amplification effect of smoking noted by
the commenter. Likewise, the estimated excess risks of CWP and NMRD
mortality attributed to respirable coal mine dust exposure are
independent of smoking effects.
---------------------------------------------------------------------------
\32\ See the QRA for the proposed rule, pp. 53, 74, 131-132,
captions to Tables 15, 24, and footnote to Table 28.
---------------------------------------------------------------------------
The commenter also used the relatively large regional background
effect estimated by one of the models to suggest that a causal
interpretation of the QRA's regression models is not justified. One of
the exposure-response models used in the QRAs for the proposed and
final rules, namely the Attfield-Kuempel NMRD mortality model, does
assign a ``background'' relative risk of 4.4 to miners in the
Anthracite region (Attfield and Kuempel (2008), Table IX).
As stated in the QRA for the proposed rule, Appendix K (p. 135),
``This suggests that the regional effects [as estimated using the
model] are primarily due to geographic factors other than coal rank.''
However, it does not undercut a causal interpretation of the model's
result for respirable coal mine dust exposure. Study demographics
affirm that only 5.6 percent of the study group resided in the
Anthracite region (Table III-7). Furthermore, a causal interpretation
is supported by the results for NMRD mortality vs. respirable coal mine
dust exposures found by Miller et al. (2007, Table 5.10), in which the
regional and/or coal rank issue did not arise. Attfield and Kuempel
(2008) recognized that in their analysis, ``variations in lifestyle,
health care, and non-coalmine exposures across geographical regions are
. . . confounded with coal rank. . . .'' Nevertheless they concluded
that ``the findings confirm and enlarge upon previous results showing
that exposure to coal mine dust leads to increased mortality, even in
the absence of smoking.'' After consideration of the commenters' views,
MSHA continues to agree with these conclusions from Miller et al.
(2007) and Attfield and Kuempel (2008).
b. Bias due to Errors in Diagnosis
Other commenters stated that inaccuracies in diagnosing CWP and PMF
by means of chest X-rays during the fourth Round of the NCWHSP
invalidate the exposure-response relationships used in the QRA for the
proposed rule. These commenters also stated that the adjusted summary
prevalence for the percentage of combined opacities in the original
readings for Round 4 using ILO 1980 was 2.3% for category 1+ and 0.3%
for category 2+ and that the re-readings using ILO 1980 were 22.5% and
0.91% for categories 1+ and 2+, respectively. From this, they inferred
that the results from re-reading the NCWHSP x-rays were no more
reliable or valid than the original readings and therefore do not
represent prevalence of disease.
Accuracy of the Round 4 X-ray readings pertains only to the
exposure-response relationships used for CWP and not for severe
emphysema or NMRD mortality. Furthermore, imprecision in the readings
would not bias the logistic regression results for CWP used in the QRAs
for the proposed and final rules, since the readers were unaware of
respirable coal mine dust exposures for the miners whose X-rays they
were reading. Therefore, errors in the readings due to imprecision
would have been uncorrelated with exposure and so should not have
appreciably affected the regression estimates. In addition, imprecision
of the readings was reduced by using the median category assigned by
three specially selected B-readers. Potential bias was mitigated by
specifically selecting the three readers to be ``representative of B-
readers in general (i.e., avoiding extremes of interpretation)''
(Attfield and Seixas, 1995). The commenters present no evidence of any
bias in these readings.
MSHA believes that disagreement between results from the original
readings of Round 4 x-rays and the re-readings does not imply that the
re-readings were ``no more reliable or valid than the original
readings. . . .'' The team of three B-readers who performed the re-
readings were selected because they were highly experienced (having
read at least 500 films during Round 4) and, based on a preliminary
reading trial, were the least likely to give extreme interpretations
among readers meeting the other selection criteria. More importantly,
the opacity prevalences shown by the commenters are for ``combined
opacities,'' a category that includes both rounded and irregular
opacities. Unlike small rounded opacities, small irregular opacities
are not generally associated with simple CWP; and for small rounded
opacities, much closer agreement was reported between the original
readings and the re-readings. For CWP1+, prevalence was 1.3% in the
original Round 4 readings and 2.1% in the re-readings of the same Round
4 X-ray films (Goodwin and Attfield, 1998).
Furthermore, Attfield and Seixas (1995) reported good agreement in
the prevalences of CWP1+ found by the three readers used in their
analysis of the Round 4 data: 7%, 7%, and 9%. They also reported that
``this similarity persisted when the data were tabulated by deciles of
estimated dust exposure. . . .''
As reported in Attfield et al. (1997), a randomly selected subset
of 2,380 x-rays from Round 1 of the NCWHSP were re-read by three
readers who were selected to be representative of reader participants
in the surveillance program. The median determinations of these re-
readings were used to re-estimate exposure-response relationships for
comparison with the corresponding results reported in Attfield and
Morring (1992a). Although the intercepts (i.e., the predictions of
background risk at no respirable coal mine dust exposure) were
significantly different, ``the logistic [regression] coefficients from
the two studies for cumulative exposure were almost identical (0.008
for the original study and 0.010 for the re-readings)'' (Attfield et
al., 1997, p. 343). Consequently, estimates of excess risk attributable
to respirable coal mine dust exposure (obtained by subtracting the
intercept from the risk predicted at a specified exposure level
according to the same analysis) would be similar regardless of whether
the original readings or the re-readings were used.\33\
---------------------------------------------------------------------------
\33\ Because of the upward curvature in the logistic regression
model, estimated excess risk would be slightly higher using the
analysis yielding a higher intercept than if the two analyses
yielded identical regression coefficients for respirable coal mine
dust exposure.
---------------------------------------------------------------------------
c. Bias Due to Errors in Exposure Estimates
Biases in respirable coal mine dust exposure estimates could enter
into the analyses in the QRAs for the proposed and final rules in a
variety of ways. Bias may enter either into the exposure estimates used
in the epidemiologic studies on which both QRAs rely or into the QRAs'
estimates of current exposures. Since the QRAs' projections of
exposures under the proposed and final rules are formed by modifying
the estimates of current exposures, biases in current exposure
estimates would also affect the projections.
The estimates of current exposures in the QRAs for the proposed and
final rules are formulated primarily from MSHA inspector samples, but
they are supplemented by operator samples for
[[Page 24846]]
work locations where fewer than two (i.e., only one or zero) valid
inspector sample is available for the base year, 2008. The current
exposures estimates are also adjusted upwards for certain work
locations where there is some evidence that relatively high respirable
coal mine dust levels have been temporarily reduced in the presence of
an MSHA inspector.\34\ The procedure used to form the adjusted,
supplemented (AS) estimates, and the rationale behind it, are described
in the QRA for the proposed rule on pages 24-25 and in Appendix F. The
effect of these adjustments on exposure estimates is discussed on page
26 of the QRA for the proposed rule and summarized in Figures 8 and 9
of the QRAs for the proposed and final rules, which compare the AS
estimates against the generally lower unadjusted estimates drawn
entirely from inspector samples. As explained in the QRA for the
proposed rule Footnotes 26 and 28, and supported by the statistical
analysis in Appendix E(c) of the QRAs for the proposed and final rules,
MSHA believes that the adjustments do not introduce bias into the AS
exposure estimates, but rather compensate for pre-existing downward
biases in both the inspector and operator sampling data.
---------------------------------------------------------------------------
\34\ Some commenters mistakenly stated that MSHA did not adjust
the AS estimates when the inspector samples are higher. However,
whenever only one valid MSHA sample was available for a work
location, operator samples were used in addition to the MSHA sample,
regardless of whether the MSHA measurement was higher or lower than
the operator average. As to other aspects of the AS estimates, these
commenters recognized that MSHA's ``approach was motivated by the
concern that dust levels are temporarily lowered when MSHA
inspectors are present . . . '' but stated that ``when the operator
data are higher than the inspector data, MSHA has no real evidence
that this is because of extra control efforts during the inspector
sampling.'' MSHA's objective in using the AS estimates is to
estimate conditions on all shifts, not just shifts that were sampled
by MSHA or operators or both. Since evidence of bias exists in both
the inspector and the operator samples (see the QRAs for the
proposed and final rules, pp. 24-25 and Appendix E), the AS
estimation procedure was deliberately designed to compensate for
bias in samples from both sources.
---------------------------------------------------------------------------
Some commenters disagreed with MSHA's AS estimates stating that the
QRA's adjustment process systematically overestimates exposures, even
when the original exposure estimates are unbiased.'' According to this
commenter, the AS procedure ignores or denies ``the obvious possibility
that the operator samples may sometimes be too high''.
It is not MSHA's objective in using the AS estimation procedure to
derive unbiased estimates for individual work locations. Instead, the
objective is to improve the accuracy of the estimated mean for a group
of related work locations (e.g., all continuous mining machine
operators or all continuous mining machine operators at high rank
bituminous coal mines). MSHA agrees that the adjustments may result in
overestimates of exposure at individual work locations, but it is only
the mean exposure, estimated across an entire group, that is included
in the risk calculations in the QRAs for the proposed and final rules.
Based on evidence cited in the QRAs, MSHA believes that mean
exposure levels, across groups of work locations, are underestimated by
both the inspector and the operator sampling data. The commenter did
not address this evidence and suggested instead that the adjustments
were made ``unjustifiably . . . to correct for possible occasional
underestimation of true exposures . . . but without performing any
symmetrical adjustments to correct for equally possible occasional
overestimation of true exposures.'' MSHA does not agree that respirable
coal mine dust samples, whether they are collected by inspectors or by
operators, are equally likely to overestimate or underestimate mean
exposure levels. Instead, MSHA believes that the unadjusted means are
biased downward precisely because respirable coal mine dust
concentrations on sampled shifts are more likely to be below the mean
than to exceed it. This was a principal motivating factor behind
development of the continuous personal dust monitor.
Moreover, MSHA made corrections for occasional overestimation of
exposures. For example, the QRAs for the proposed and final rules
exclude repeated inspector samples at work locations exhibiting high
Day-1 measurements and adopt a weighting procedure designed to avoid
biasing the estimates toward work locations targeted for more frequent
dust inspections because of their relatively high respirable coal mine
dust measurements. These adjustments resulted in reducing estimates of
respirable coal mine dust concentrations more than the AS procedure
increased them.
In addition to evidence of underestimation cited in the QRAs, Boden
(1986) noted that mine- and job-specific distributions of respirable
coal mine dust concentrations compiled from operator compliance samples
in 1970 to 1977 contained greater than expected numbers of low
measurements compared to fitted lognormal distributions. Attfield and
Morring (1992a) reported the same general tendency. These findings are
further support of the QRAs' use of the AS estimation procedure.
MSHA agrees with the commenter that there may be work locations
where inspector samples are perfectly representative, statistically, of
normal conditions. However, MSHA believes that making a relatively
small upward adjustment for roughly half of any such work locations
hardly compensates for other work locations at which inspector samples
and operator samples are both biased downward. Figures 8 and 9 in the
QRAs for the proposed and final rules show that the impact of these
adjustments on estimated means is not excessive compared to the
downward biases that have been reported. As stated in Footnote 28 of
the QRA for the proposed rule,
MSHA recognizes that the AS estimates may be biased relative to
mean exposure levels . . . on those shifts sampled by MSHA
inspectors . . .. However, the objective is to obtain the best
possible estimate of mean exposure across all shifts within groups
of related work locations, and not just those shifts that are
sampled by an MSHA inspector. Accordingly, MSHA believes that its
use of operator data in the AS estimation procedure as applied to
specific work locations serves to reduce rather than increase the
potential for overall bias.
Systematically increasing exposure estimates is not the same thing
as systematically over-estimating exposures. These increases may well
be insufficient to fully compensate for the downward bias in respirable
coal mine dust samples as a representation of respirable coal mine dust
concentrations.
Commenters stated that another limitation of the AS estimation
procedure was that there was no symmetrical counter-adjustment in the
estimated effects of exposure used in the QRA's exposure-response
models. The commenter stated that when exposure estimates are adjusted
upward, then potency estimates should be symmetrically counter-adjusted
downward to avoid biasing risk estimates upward.
The commenters assumed that a downward bias in exposure
measurements was not accounted for in estimating the exposure-response
relationships. As described in Seixas et al. (1991), respirable coal
mine dust concentration measurements obtained at the mining face were,
for the NCWHSP, adjusted upward by 13 percent to compensate for a
downward bias judged to exist in the operator sampling data used.\35\
These adjusted exposure values
[[Page 24847]]
were then applied to both the pre- and post-1970 exposures used in the
development of cumulative exposure estimates for all of the exposure-
response relationships on which the QRA for the proposed rule relies.
---------------------------------------------------------------------------
\35\ Other adjustments described in Seixas et al. (1991) were
designed to compensate for specific biases introduced, at the time
of the NCWHSP, by MSHA's analytical and data processing procedures
for determining respirable coal mine dust concentrations from
gravimetric samples. These biases have long since been eliminated,
as documented in the Federal Register notice MSHA published jointly
with DHHS on July 7, 2000 (65 FR 42068). Therefore, corresponding
adjustments are not necessary for the 2004-2008 data used in the
QRAs.
---------------------------------------------------------------------------
In response, MSHA notes that since respirable coal mine dust
concentrations measured at the face are generally far higher than those
measured at other work locations, they dominate in determining
regression estimates of the exposure effects. Hence, the 13-percent
upward adjustment in exposures resulted in a corresponding reduction of
estimated potency, just as the commenter suggested. This 13-percent
adjustment correlates well with the overall impact of applying the AS
estimation procedure (see Figures 8 and 9 in the QRAs for the proposed
and final rules).
After cautioning that errors in estimated exposures could
(theoretically) bias the QRA's estimates of risks attributable to the
exposures, the commenters suggested that ``an unknown fraction (up to
100%) of the risk attributed to differences in exposures may in reality
be due to unmodeled errors in exposure estimates and covariates . . .
.''
MSHA recognizes that any unknown fraction may be as high as 100
percent or as low as zero percent. However, the commenters did not
submit any calculations showing how large or widespread the measurement
errors would need to be to account for a significant portion of the
differences in prevalence of adverse health effects observed for study
subjects having categorically different estimated exposures. Nor did
the commenters provide any evidence that any errors in the estimated
exposures used to establish the exposure-response models in the QRA for
the proposed rule were of a type that would increase, rather than
occlude, the estimated effects of respirable coal mine dust
exposure.\36\
---------------------------------------------------------------------------
\36\ Errors due to imprecision of the sampling device (cyclone,
pump, and weight gain determination) are not of a type that would
increase estimated effects of respirable coal mine dust exposure.
Since they are independent of the underlying exposures, having more
errors of this type merely raises the threshold on how steep the
response must be for the relationship to be detectable.
---------------------------------------------------------------------------
Other commenters stated that there was a specific systematic error
in estimates of pre-1970 exposures that tend to exaggerate the effects
of respirable coal mine dust exposure in the Kuempel pulmonary response
model for severe emphysema, the Attfield-Kuempel NMRD mortality model,
and (to a lesser extent) the Attfield-Seixas CWP models.
In response to commenters' concern, MSHA notes that the
epidemiologic studies that produced these models relied on estimates of
pre-1970 exposure levels for specific jobs. These estimates were formed
by combining exposure measurements collected in 1968-1969 by the U.S.
Bureau of Mines (BOM) with measurements collected by mine operators in
1970-1972. The U.S. BOM dataset contained data for certain jobs at the
mining face but little or no data for most other underground jobs and
no data at all for any surface jobs. Therefore, in order to compile
lifetime cumulative exposures for each miner included in the
epidemiologic studies, job-specific mean respirable coal mine dust
concentrations observed in the 1970-1972 operator data were multiplied
by a factor of 2.3. This factor ``was obtained averaging ratios of job-
specific BOM dust means to 1970-1972 MSHA concentrations for every
occupation where there were sufficient U.S. BOM data (n > 10 samples)''
(Attfield and Morring, 1992a). All exposures for miners after 1972 were
estimated using the job-specific means calculated each year from the
operator data.
According to these commenters, the estimates of each miner's pre-
1970 exposures are biased relative to the U.S. BOM data and elevate the
slope of the exposure-response curve and reduce thresholds of effect,
thereby spuriously overestimating risk. Since they were based on an
average ratio rather than job-specific ratios, pre-1970 exposures were
generally underestimated in high-exposure jobs and overestimated in
low-exposure jobs. According to the commenters, this resulted in
underestimating total cumulative exposure for the most highly exposed
miners and overestimating total cumulative exposure for the least
exposed miners, thereby giving rise to a ``spuriously steeper slope''
in the estimated exposure-response relationships derived from these
data.
The use of the mean ratio to estimate job-specific occupational
exposure averages prior to 1970 was justified by Attfield and Morring
(1992a) by four factors. First, a large part of the job-to-job
variation in the ratio of pre-1970 BOM exposure data to 1970-1971 mine
operator exposure data is probably of random origin, especially for
jobs with relatively few BOM samples. Based on standard errors for the
ratios' numerators, 95% confidence intervals included the value 2.3
(i.e., the mean ratio used in the back-extrapolation) for 13 of the 25
ratios for the jobs shown in Table I of Attfield and Morring (1992a).
Second, for some of the remaining jobs, the mean of 2.3 was
believed to be more valid than the actual, observed, job-specific
ratios. For example, BOM data show pre-1970 dust levels were less than
or equal to levels shown by the 1970 and 1971 data for the supply man
and utility man jobs. In the opinion of Attfield and Morring, this did
not seem reasonable.
Third, the necessity of pooling individual MSHA jobs into the
broader Lainhart categories for matching with the work histories
resulted in reduced variation of dust levels across Lainhart job groups
compared to individual MSHA jobs. This brought the job-specific ratios
based on Lainhart categories (which Attfield and Morring considered to
be of more practical relevance than the individual MSHA jobs cited by
the commenters) closer to the mean of 2.3 used in the exposure
derivation.
The last of the four factors proposed by Attfield and Morring
concerns the results of attempting to derive exposure estimates based
on variable ratios. The actual BOM job means were used directly to
estimate the exposures, with MSHA data being used only to fill in the
gaps. The resulting exposure estimates had a mean and standard
deviation of 100 and 79 g-hr/m\3\, respectively, and were highly
correlated with those developed by using the common ratio (Pearson
correlation = 0.95). Use of these data in exposure-response analyses
did not realize any advantages. In another attempt, a set of pre-1970
dust exposure estimates was generated by using variable ratios derived
from a nonlinear regression model. The resulting exposure estimates did
not correlate better with medical indexes in analyses of exposure-
response.
MSHA agrees with Attfield and Morring that the first three factors
support their use of the common average ratio. However, their fourth
factor may support the position taken by commenters that use of this
constant ratio artificially inflates the slope of the exposure-response
regression line. This would be the case if the criterion for
``realizing any advantages'' and correlating ``better'' is simply that
the estimated slope is steeper (and therefore more evident) than the
slope obtained using the constant ratio. It is not clear from Attfield
and Morring (1992a) what the criterion actually is.
[[Page 24848]]
MSHA believes that both the commenters and Attfield and Morring
(1992a) overlooked an important factor mitigating any bias introduced
into cumulative exposure estimates by use of the common ratio: Namely,
that miners generally did not continue to work in a single occupation
for their entire lifetimes. In another context, Attfield and Morring
(1992a) state: ``. . . few miners spent all of their working life in
the dustiest jobs, hence heavy exposures received while performing
those jobs were usually diluted by the exposures caused by work in less
dusty jobs'' (op cit, p. 252). Likewise, some of a miner's occupations
would have a below-average ratio while others would have an above-
average ratio. Therefore, job-related exposure biases introduced into
the exposure history of an individual miner would tend to compensate
for one another; and estimates of overall cumulative exposure would be
expected to approach the correct value as the number of individual jobs
held increased. For this reason, along with those provided by Attfield
and Morring, MSHA believes that bias due to use of a common ratio for
back-extrapolation had only a minor impact, if any, on the estimated
exposure-response relationships.
Some commenters also stated that the Attfield and Kuempel (2008)
NMRD mortality study had another bias, related to incomplete work
history data, that could potentially bias exposure-response
associations by under-estimating exposure and over-estimating risk.
After acknowledging that ``up to 23 years of exposure may have been
omitted from a miner's exposure,'' Attfield and Kuempel (2008)
addressed potential impact of exposure misclassification on their
results. According to Attfield and Kuempel, any such impact was
mitigated by several factors. First, dust exposure levels in U.S. mines
were mandated to be much lower after 1969; data indicates that levels
had dropped by 1975 to less than one-third to one-quarter of pre-1969
levels, with most of the drop happening in the period 1970-1972
[Attfield and Morring, 1992b]. A miner's post-1970 exposure would
generally have contributed a relatively small percentage of total
exposure. Second, the workforce had an average age of 44.5 at the start
of follow-up, meaning that many in the study cohort would be likely to
retire early in the follow-up period, again limiting the potential for
misclassification. Third, although younger miners have the most
potential for misclassification in their exposures since their tenure
during follow-up may have been as long, or longer than, their pre-
follow-up tenure, very few NMRD deaths occurred in younger miners. Only
6% of the total NMRD deaths occurred in miners younger than 45 years of
age at start of follow-up, while 19% occurred in miners younger than
age 50. The impact of exposure misclassification during follow-up was
assessed by restricting the analysis to miners aged 50 years or older
at start of follow-up. Use of the proportional hazards model on NMRD on
this subgroup gave rise to a relative risk of 1.006 per mg-year/m\3\
(p<0.0001), which is similar, but slightly smaller than that for all
workers (relative risk=1.007). According to Attfield and Kuempel, these
findings do not absolve the results from the effects of exposure
misclassification, but the findings do indicate that any effect is
limited and ``much less than might be suggested by first appearances.''
Although Attfield and Kuempel characterize the issue as one of
``exposure misclassification,'' this is somewhat misleading, since the
missing exposures are systematically set to the lowest possible value
(zero) rather than to various values randomly drawn from the
distribution of exposure levels. Consequently, the effect is not
``possible attenuation of the exposure-response relationship,'' as
Attfield and Kuempel suggest, but, to the contrary, an inflation of the
relative risk associated with each unit of exposure, as suggested by
these commenters. The three mitigating factors cited by Attfield and
Kuempel reduce the effect of this bias, but they do not completely
eliminate it.
Only part of the impact of excluding exposures experienced after
1970 is revealed by restricting analysis to workers aged 50 or greater
at the start of follow-up, as described by Attfield and Kuempel above.
Although these workers were older than the average age of the cohort,
it can reasonably be presumed that many of them still accumulated
significant exposures after 1970. Therefore, the restricted analysis
does not show the full impact of the bias. Nevertheless, even the
partial impact is greater than Attfield and Kuempel suggest by
comparing the relative risks estimated for a single mg-yr/m\3\ of
exposure. Over a 45-year occupational lifetime, exposure to low rank
(West region) respirable coal mine dust at an average concentration of
2.0 mg/m\3\ produces an estimated relative risk =
e90x0.00709 = 1.89 based on the full analysis and relative
risk = e90xLoge (1.006) = 1.71 based
on the partial analysis.\37\ This discrepancy of over 10 percent
demonstrates a substantial overestimate of the risk attributable to
respirable coal mine dust exposure. Eliminating the bias entirely would
almost certainly reduce the estimated relative risk even further.\38\
---------------------------------------------------------------------------
\37\ The average respirable coal mine dust concentration of 90
mg-yr/m\3\ is calculated by multiplying 2.0 mg/m\3\ by 45 yr
occupational life.
\38\ All of the discussion and calculations in this paragraph
pertain to estimated NMRD mortality risks.
---------------------------------------------------------------------------
MSHA agrees that setting all exposures experienced after 1970 to
zero has inflated the Attfield-Kuempel estimates of NMRD mortality risk
attributable to respirable coal mine dust exposure. However, based on
the discussion above, MSHA sees no evidence that this bias is entirely
or even mostly responsible for the observed relationship between
respirable coal mine dust exposure and NMRD mortality risk. Still, the
bias may help explain why the Attfield-Kuempel relative risk estimates
are so much greater than corresponding estimates based on the research
reported by Miller et al. (2007), as shown in Figure 15 for COPD
mortality in the QRAs for the proposed and final rules. Accordingly,
MSHA is reducing the coefficient of respirable coal mine dust exposure
used to estimate NMRD mortality relative risk (hazard ratios) by one-
third. This brings the coefficient down to a value of 0.0048, which is
halfway between the original Attfield-Kuempel estimate of 0.00709 and
the Miller estimate of 0.0025.\39\
---------------------------------------------------------------------------
\39\ The Attfield-Kuempel estimate is shown in Table X of
Attfield and Kuempel (2008) and Appendix K of the QRA for the
proposed rule. The Miller estimate was derived by multiplying 0.0013
(i.e., the coefficient of respirable coal mine dust exposure shown
in Model NMRD/05 of Miller et al. (2007) by 1,920 hr/yr and dividing
by 1,000 mg/m\3\.
---------------------------------------------------------------------------
d. Threshold Effect
One commenter suggested that the majority of cases of respirable
coal mine dust-related disease observed in miners is due to high
multiples of average exposures (perhaps 5 to 10 times). The commenter
stated that miners in this upper end of the exposure distribution
contribute disproportionately, and perhaps exclusively to the number of
observed cases. Since current average respirable coal mine dust
concentrations exceed 0.5 mg/m\3\ for nearly all underground face
occupations (see Figure 7 in the QRAs for the proposed and final
rules), the commenter considered concentrations of 2.5 mg/m\3\ or less
(i.e., anything less than a five-fold multiple of the average) to be
generally benign. However, the
[[Page 24849]]
commenter cited no toxicological or epidemiological evidence to support
this hypothesis with respect to respirable coal mine dust exposures.
The commenter suggests that only respirable coal mine dust
concentrations above a threshold level can cause adverse respiratory
health effects, and that exposure-response relationships for
respiratory diseases must model a threshold effect. The commenter was
correct in noting the QRA's exclusive reliance on threshold-free risk
models. However, the commenter cited no alternative, empirically-
derived threshold models applicable to risks specifically due to
respirable coal mine dust exposures, and provided no evidence to
support the premise that respirable coal mine dust is toxic only when
exposures exceed a threshold level.\40\ Although the QRA did not
discuss the evidence for or against thresholds, the applicability of
threshold models to respirable coal mine dust exposures has been
investigated in the published literature.
---------------------------------------------------------------------------
\40\ The research cited by the commenter does not apply
specifically to respirable coal mine dust exposures.
---------------------------------------------------------------------------
The possibility of an exposure threshold for CWP response was
investigated and rejected in Attfield et al. (1997). In the explanation
from the Attfield article below, TLV represents a possible threshold
limit value.
Determination of the existence of a threshold effect, through
use of the transformation
CE - (CE-TLV) [middot] H(CE-TLV),
Where CE is cumulative exposures and H(CE-TLV) = 0 if CE < TLV, and
1 otherwise, was examined using the [chi]\2\ value for the
coefficient for transformed exposure variable.
Figure 1 shows a plot of this statistic for three outcomes:
category 1+, category 2+ and PMF for a range of TLV from 0.0 to 2.0
mg[middot]m-\3\. It is clear from this figure that there
was little convincing indication of a threshold. For category 1+ and
PMF, [chi]\2\ peaked close to 0 mg[middot]m-\3\, while
for category 2+ the peak was near to 1.0 mg[middot]m-\3\
but the curve was virtually flat, suggesting great uncertainty in
the location of any threshold. Use of the log-likelihood value in
place of [chi]\2\ suggested even less evidence for a threshold. In
other analyses . . ., rather than a threshold, there was evidence of
a non-zero baseline of response at zero dust exposure.
Figure III-1 is reproduced from Figure 1 of Attfield et al. (1997)
and shows why the authors concluded that the evidence failed to support
a threshold effect (no threshold effect existed at or above 1.0 mg/
m\3\).
[GRAPHIC] [TIFF OMITTED] TR01MY14.002
Figure III-1--Examination of threshold. Plot of [chi]2 statistics
against candidate threshold limit values for category 1 +, category 2+
and PMF, reproduced from Figure 1 of Attfield et al. (1997). PMF was
mislabeled as ``PFM'' in the original Figure
Bailer et al. (1997) examined several alternative models, including
threshold models, for describing exposure-response relationships
between respirable coal mine dust and FEV1 deficits among
miners who participated in Round 1 of the NCWHSP. For FEV1
less than 80% of the predicted normal value, a threshold was suggested
at a cumulative exposure of 22.0 mg-yr/m\3\.\41\ This corresponds to
exposure at an average respirable coal mine dust concentration of 0.5
mg/m\3\ over a 45-year occupational lifetime.\42\
---------------------------------------------------------------------------
\41\ The 95-percent confidence interval reported for this
estimate was 0 to 55 mg-yr/m\3\, so the evidence for a threshold was
not statistically significant at a 95-percent confidence level.
\42\ The average respirable coal mine dust concentration of 0.5
mg/m\3\ is calculated by multiplying 22 mg-yr/m\3\ by 45 yr
occupational life.
---------------------------------------------------------------------------
Based on its review of the available evidence included in the QRAs
for the proposed and final rules and the Health Effects section of the
preamble to the proposed rule, MSHA has determined that the best
available epidemiological evidence fails to support a threshold model
for either CWP or clinically significant pulmonary effects due to
respirable coal mine dust exposures. The evidence indicates that if an
exposure threshold does exist, it is likely to occur at respirable coal
mine dust concentrations below not only the existing standard, but also
the final standard, assuming a 45-year lifetime of occupational
exposure. Due to the nonlinear nature of the models, much of the reason
for stratifying the exposures by occupation and work location was to
account for higher exposures in certain job categories.
Regardless, the mean respirable coal dust concentration for each
coal mining occupation in the QRAs for the proposed and final rules is
documented in accordance to the MSHA's job coding based on single
distinct occupation. Attfield and Morring (1992a) determined that the
average tenure
[[Page 24850]]
worked for the Lainhart job coding scheme was different for each
occupation group. Therefore, the occupational category decomposition
for respirable coal dust is needed in the QRA, as was done in both
QRAs.
e. Model Consistency and Coherence
One commenter also stated that the Attfield-Kuempel exposure-
response model for NMRD mortality used in the QRA for the proposed rule
exhibited inconsistencies that do not pass basic consistency checks for
yielding valid risk predictions. As an example, this commenter cited
the Attfield-Kuempel model for NMRD mortality risk, which, even with
cumulative exposure set to zero, produces relative risk estimates of
4.4 and 1.2 for miners regionally associated with anthracite and high
rank bituminous coal, respectively. The commenter did not describe or
enumerate the ``basic consistency checks'' considered necessary for
validating risk predictions or identify any other examples of purported
inconsistencies in any exposure-response models used in the QRA.
As discussed in Section III.B.2.c. of this preamble, the commenters
did not recognize that the model does not attribute a relative risk of
4.4 to coal in the absence of any exposure. Instead, as explained in
the QRA for the proposed rule, Appendix K, the model estimates a
relative risk of 4.4 ``for miners regionally associated with anthracite
. . .'' and ``[t]his suggests that the regional effects are primarily
due to geographic factors other than coal rank . . . .'' (QRA, Appendix
K, p. 135). The relative risk estimate of 4.4 represents background
risk in the Anthracite region, which is not associated by the model
with coal. The same background risk is present in both the estimate of
risk under current exposure conditions and the reduced risk projected
to remain under the final rule. Therefore, background risk associated
with the Anthracite region is canceled out when projected risk is
subtracted from existing risk to estimate the final rule's impact.
MSHA does not regard the relative risk estimated for exposure in
the Anthracite region as an inconsistency. As emphasized above, the
Attfield-Kuempel model yields a background relative risk or intercept
of 4.4 for occupationally unexposed miners in the Anthracite region.
The effect of anthracite exposure is modeled by the slope of the
exposure-response curve, rather than its intercept. The model predicts
(a) that the background rate of NMRD mortality in the anthracite region
is 4.4 times what it is in the West region; and (b) that the slope of
the exposure-response relationship is also greater (by a factor of 4.4)
for anthracite exposures than for exposures to western coal.\43\
---------------------------------------------------------------------------
\43\ At a specified mean respirable coal mine dust exposure
concentration, [micro] mg/m\3\, experienced over a 45-year
occupational lifetime in the Anthracite region, the slope (i.e.,
rate of change) of the Attfield-Kuempel exposure-response model for
relative risk of NMRD mortality is:
45[beta] x exp([alpha] + 45[beta][micro]) = exp([alpha]) x
45[beta] x exp(45[beta][micro])
where [beta] = 0.00709, [alpha] = 1.4844 for the Anthracite
region, and [alpha] = 0 for the West region. Therefore, for any
specified value of [micro], the slope for anthracite exposures is
exp (1.4844) = 4.4 times the slope for West region exposures. Note
that for reasons explained in Section III.B.2.c, MSHA is reducing
the Attfield-Kuempel estimate of [beta] by a factor of one-third,
from 0.00709 down to 0.0048.
---------------------------------------------------------------------------
Furthermore, MSHA believes that it is appropriate to attribute
improvements in predicted risk (obtained by subtraction within coal
mining regions) with reductions in the exposures expected under the
final rule. The commenter listed several factors, unrelated to
respirable coal mine dust exposure, that could account for the
predicted improvements, including model specification errors, unmodeled
interactions among variables, omitted covariates and confounders, etc.
However, these possibilities do not arise from inconsistencies in the
particular exposure-response models used in the QRA. Such factors may
contribute to the uncertainty of any epidemiological analysis. The fact
that the commenter ``could'' account for the predicted improvements
does not contradict MSHA's view that the predicted improvements are
rationally attributable to reductions in respirable coal mine dust
exposure.
Despite their shortcomings, the exposure-response models used in
the QRA comprise the best available means of quantifying risks
attributable to respirable coal mine dust exposures. Therefore they
satisfy both the requirements of Sec. 101(a)(6)(A) of the Mine Act
requiring the Secretary to set health standards ``on the basis of the
best available evidence'' and the Office of Management and Budget's
(OMB) 2002 data quality guidelines, Guidelines for Ensuring and
Maximizing the Quality, Objectivity, Utility, and Integrity of
Information Disseminated by Federal Agencies (36 FR 8452, February 22,
2002). None of the commenters cited alternative quantitative models
that they thought MSHA should use instead.
2. Reliance on Mean and Cumulative Exposures
Some commenters, in accounting for possible threshold effects,
objected to the reliance in the QRA for the proposed rule on mean
respirable coal mine dust concentrations at work locations and lifetime
cumulative respirable coal mine dust exposures. In addition, the
commenters disagreed with the QRA's application of exposure-response
models to mean exposures within groups of occupationally,
geographically, and environmentally related work locations.\44\ The
commenters explained that there are two related problems with the QRA's
exposure metric: (1) Its use of cumulative exposures (ignoring peaks,
and the fact that a higher concentration for a shorter time may cause
diseases even though the same cumulative exposure spread over more
years would not); and (2) its focus on mean exposures, ignoring the
variance of exposure and the occurrence of exceptionally high (far
above the mean) cumulative exposures.
---------------------------------------------------------------------------
\44\ In the present context, ``environmentally related'' refers
to work locations in the same overexposure recurrency class as
defined in the QRA. ``Geographically related'' refers to work
locations assigned to the same coal rank category.
---------------------------------------------------------------------------
The commenters' concern about relying on average exposures depends
partly on the premise of threshold effects noted in Section III.B.2.d.
of this preamble. If this premise were true, then attributing risks to
average respirable coal mine dust concentrations and cumulative
exposures could both mask threshold effects and assign risks to a
broader population than warranted. The existing epidemiological data,
however, do not appear to support the premise of significant threshold
effects. Furthermore, as mentioned in the QRA, no exposure-response
models have been published that would enable MSHA to account for peak
respirable coal mine dust exposures when quantifying health risks.
The commenters are also concerned that masking can occur when
different exposures are averaged together. MSHA agrees, and the QRA for
the proposed rule states this in the justification for stratifying its
analysis:
Applying an exposure-response model to an occupational average
exposure level fails to account for risks in more specific
environments where the exposure is above the occupational average.
(QRA, p. 41.)
. . . Therefore . . . exposure response models for CWP, severe
emphysema, and NMRD mortality are applied to dust concentration
averages for clusters of work locations whose dust conditions pose
similar risks. (QRA, p. 42.)
Work locations with respirable coal mine dust conditions posing
similar risks are identified in the QRA not only by occupation, but
also by the recurrence of exposure measurements exceeding 1.0 mg/m\3\
and 2.0 mg/m\3\
[[Page 24851]]
(``recurrency class'') and by the rank of coal at the work location.
Accordingly, the QRA's analysis is stratified into 306 cells, shown in
the Tables 12 and 20 in the QRA. Although this complicates presentation
of the QRA's results, it was done precisely to avoid distorting risk
estimates by averaging essentially different exposures. The QRA
provides separate analyses for strata ranging between work locations
showing average exposure to low rank respirable coal mine dust at 0.11
mg/m\3\ and work locations showing average exposure to high rank
respirable coal mine dust at 2.94 mg/m\3\. (See Table 12 in the QRAs
for the proposed and final rules.)
These same commenters stressed the importance of quantifying not
just the mean exposure concentration before and after a rule is
implemented, but how the frequency distribution of exposures will
change. To illustrate, a hypothetical example was provided to show that
a rule that decreases mean exposure can increase risk. A key feature of
this example was that the rule reduces the mean exposure concentration,
through rigorous dust control measures that result in lower exposures
for most workers, but in higher exposures for workers in locations
where implementation or compliance fail.
The commenters presented no discussion of where, how, or why the
proposed rule would cause exposures for any miners to increase, and
MSHA sees no reason why failures of implementation or compliance would
do so. Furthermore, the projections in the QRA for the proposed rule of
respirable coal mine dust concentrations under the proposed and final
rules do exactly what the commenter advocates as being important: The
frequency distribution of exposures, before and after implementation of
the rule, is projected before estimating any risks. The QRA does this
by projecting the expected impact of the rule separately onto each of
the individual respirable coal mine dust measurements used to
characterize the exposure distribution for each work location (See the
QRA for the proposed rule, Appendix H(c), p.128). Mean projected
exposure concentrations are calculated, for each work location and then
for the whole cluster of similar work locations comprising each stratum
of the analysis, only after the frequency distribution of respirable
coal mine dust concentrations on a shift has been projected.
MSHA did not rely on mean exposures, and as further justification
for stratifying its analysis, the QRA for the proposed rule points out
that when exposure-response relationships are curved upwards (as in the
QRA), ``evaluating risk at the average exposure level will always
underestimate average risk.''
The commenters also stated that MSHA's QRA did not quantify
relatively high (disease-relevant) exposures, nor model how they would
change if the proposed rule is finalized.
As indicated above, the QRA for the proposed rule separately
evaluates current and projected risks in 306 different exposure strata,
including five in which average exposure exceeds the existing standard
(QRA, Table 12). In addition, the QRA for the proposal quantifies the
prevalence of individual excursions (QRA, Tables 6 and 9 and Figures 5
and 6) and explicitly projects the impact of reducing these excursions
to the final standard (QRA, p. 64 and Footnote 55). MSHA agrees that
further research on the effects of excursions would be beneficial, but
there have been no studies providing exposure-response models sensitive
to measures of exposure excursion frequency and intensity. MSHA
believes that by modeling the elimination of all shift exposures above
the final standard in its projections of risk under the final rule, the
QRA for the final rule has accounted for excursions to the greatest
extent possible.
3. Projected Exposures and Risk Reductions
MSHA believes that it is not only important to quantify the mean
exposure concentration before and after a final rule is implemented,
but also how the frequency distribution of exposures will change. This
is why the QRAs for the proposed and final rules address each work
location separately in their projections of exposures, estimating the
job-specific effect on relatively low exposures separately from the
effect on exposures that currently exceed the standard. Some commenters
used a very different method of predicting how exposures would have
changed under the proposed rule. According to their method, respirable
coal mine dust concentrations under the proposed rule would follow the
same distributional form as current exposures, but with the mean
shifted lower by an amount sufficient enough to force nearly all of the
high concentrations down below the proposed standard. To reduce dust
concentrations sufficiently while maintaining the same distributional
form, a substantially greater reduction in the mean is required than
what the QRA for the proposed rule projects.
The QRA for the proposed and final rules formulate projections by
reducing current exposures by various amounts, depending where they are
relative to the applicable standard, and then calculating the resulting
mean for each stratum in the analysis. Since the QRA assumes
(conservatively) that respirable coal mine dust concentrations on
relatively dusty shifts will be reduced only as far as necessary to
achieve compliance, the distribution of projected concentrations
generally bears little resemblance to the current distribution of
concentrations. It is anticipated that the continuous personal dust
monitor will eventually enable mine operators to maximize production
while keeping dust concentrations at or below the permissible standard
on every shift. The projected change in exposure distributions is
schematically illustrated by Figure III-2.
[[Page 24852]]
[GRAPHIC] [TIFF OMITTED] TR01MY14.003
Figure III-2--Schematic diagram of change in distribution of respirable
coal mine dust concentrations (RCMD) at an individual work Location as
projected by QRA for the proposed rule. Vertical line represents the
final respirable coal mine dust concentration standard
In contrast, other commenters' method constructs its projections by
computing the mean of a theoretical distribution in which individual
respirable coal mine dust concentrations would rarely exceed the final
standard. This calculation is based on the premise that in achieving
compliance with the final standard on every shift, the distribution of
concentrations would compress but retain the same general shape as
before. Their method assumes that the shape of the respirable coal mine
dust distribution (i.e., the relative variance) remains unchanged. The
type of change predicted by the commenters is shown in Figure III-3.
The underlying difference between these two approaches is that the
commenters state that MSHA's analysis in the QRA for the proposal of
the required respirable coal mine dust reductions needed to meet the
proposed respirable coal dust standard is not adequate because it
substantially underestimates the necessary reductions. Under the final
rule, operators will only need to make reductions on shifts on which
the 1.5 mg/m\3\ standard is exceeded. Additional reductions may occur
and were included in the QRA's projections to the extent suggested by
empirical evidence (Table 19 and Appendix H(b) of the QRAs for the
proposed and final rules), but neither the proposed and final rules
require these reductions. The theoretical model used by the commenters
would require larger reductions to satisfy the theoretical constraint
of a constant relative variance.
[GRAPHIC] [TIFF OMITTED] TR01MY14.004
Figure III-3--Schematic diagram of projected change in distribution of
respirable coal mine dust (RCMD) concentrations according to the
commenters approach. Vertical line represents final respirable coal mine
dust concentration standard
These commenters expressed concern about the difficulty of
reproducing MSHA's analysis of the inspector sampling data cited in the
QRA for the proposed rule (U.S. Department of Labor, MSHA (2010).
Quantitative Risk Assessment, Dust Data Files, InspSamp.txt). Before
discussing the evidence the commenters present in support of their
theoretical model, it is helpful to clarify a source of some confusion.
The commenters are correct when they state that a total of 146,917
valid, Day-1 inspector samples \45\ were used by MSHA in the QRA, as
shown in Tables 1 and 3 of the QRA for the proposal. These commenters
noted that this subset of 146,917 was obtained from the total of
181,767 non-voided samples by excluding (a) 14,016 samples collected
within 21 days after ``Day 1'' of an MSHA dust inspection, (b) 10,927
Day-1 samples not associated with an occupation, and (c) 9,906 Day-1
intake air samples. One additional sample (d) was excluded ``because
the dust concentration measurement appears to have resulted from a
coding error.'' These subtotals (a, b, c, and d) are all shown in
Appendix B of the QRAs for the proposed and final rules and fully
account for the 34,850 valid samples excluded from the analysis
[[Page 24853]]
(181,767-34,850 = 146,917). The apparent source of confusion was that
the summary formula provided at the bottom of page 93 in the QRA for
the proposed rule did not include the 9,906 excluded intake air
samples.\46\ This has been corrected in Appendix B of the QRA for the
final rule.
---------------------------------------------------------------------------
\45\ A ``Day-1'' inspector sample is an MSHA inspector sample
that was collected more than 21 days after the initial day of a
prior MSHA inspection in the same production area of a specified
mine.
Samples are deemed to have been obtained in the ``same
production area'' of a specified mine when the samples are coded
with the same mine ID and the same 2nd and 3rd digits of MSHA's 4-
digit entity code. For example, entity codes 0010 and 9011 represent
the same production area within a specified mine.
\46\ These commenters also requested clarification of the 4-
digit entity code provided in the sampling data files. Leading zeros
and blanks should be treated as equivalent when interpreting the
first two characters. As stated in Footnote 12 on pages 5 and 14
respectively of the QRAs for the proposed and final rules, samples
collected at the same work location within a mine or processing
facility are identified by sharing the same 2nd and 3rd characters
of the entity code, along with the same mine ID and job
classification code.
---------------------------------------------------------------------------
These commenters also were concerned with the QRA's stated reasons
for excluding the 2004-2007 inspector samples from its estimates of
current and projected exposure levels. After noting the temporal
changes in samples per work location shown by Table 5 in the QRA for
the proposed rule, and substantial right-skewing of the respirable coal
mine dust concentration data, they stated that a downward trend in the
average [respirable coal mine dust] level per work location is expected
due to increasing sampling error associated with decreasing sample size
for the right-skewed data, absent any real change in respirable coal
mine dust distributions over that period.\47\ Furthermore, the
commenters expressed concern with MSHA's finding of a downward trend in
inspectors' measurements because their assessment of a temporal trend
by job category in the MSHA inspector Day-1 sample data shows no
meaningful temporal trend in any category or for the aggregated data.
According to the commenters, some trends reached nominal statistical
significance, but they explained virtually zero percent of the variance
of the natural-log-transformed respirable coal mine dust data.
---------------------------------------------------------------------------
\47\ These commenters also questioned MSHA's use of a study
predating the 2004-2008 data, and of miners' anecdotal evidence, to
justify the assumption of downward bias in MSHA's respirable coal
mine dust measurements. MSHA acknowledges that it is inherently
difficult, if not impossible, to fully quantify bias due to
selective reductions of dust levels in the presence of an MSHA
inspector. However, MSHA finds the anecdotal evidence for such bias,
confirmed over many years of miners' testimony at public hearings,
to be persuasive. The 1993 study represented an attempt to quantify
some part of this bias, and no similar study of later sampling data
is available. It was cited in the QRA for the proposed rule, along
with the anecdotal evidence, only to support MSHA's assessment that
such bias exists. Neither it, nor the anecdotal evidence, was used
in any attempt to quantify the extent of the bias (U.S. Dept. of
Labor, MSHA, 1993, Report of the Statistical Task Team of the Coal
Mine Respirable Dust Task Group).
---------------------------------------------------------------------------
For both underground and surface measurements, MSHA's analyses
(summarized in Appendix D(c), Tables 39 and 41, in both QRAs for the
proposed and final rules) show a statistically significant downward
time-trend in respirable coal mine dust concentrations obtained from
inspector samples, at confidence levels exceeding 99.9 percent. Unlike
the non-peer reviewed analysis submitted by these commenters, MSHA's
peer-reviewed analyses account for specific mines, specific work
locations within mines, and applicable standards. Although, in MSHA's
analysis, the percentage of variance explained by the time-trend
(represented by ``sampling date'' in the ANCOVA tables) is small
compared to that explained by occupational differences, it is larger
than the amount explained by mine-to-mine differences or differences
between production areas within the same mine, and even the applicable
standard. It may be that in the commenters' analysis, temporal effects
were partially masked by aggregating across work locations and ignoring
differences and/or changes in the applicable standard in effect at
specific work locations. As mentioned on page 102 of the QRA for the
proposed rule, the ANCOVA method used adjusts for variability in the
number of samples obtained in each year at each location. Furthermore,
lack of statistical symmetry in the data (and associated heterogeneity
of sampling errors) is addressed by application of the maximum-
likelihood Box-Cox transformation \48\ (Box and Cox, (1964)). The
commenters' objections to MSHA's analyses are not supported by the
available data.
---------------------------------------------------------------------------
\48\ This enables valid analysis of data exhibiting a much wider
array of error structures than what these commenters assume, and
permits the logarithmic transformation (appropriate when standard
deviation is proportional to the mean concentration measurement) as
a special case. In the analysis of surface data (QRA for the
proposal, Table 41), the transformation (Box-Cox [lambda]=0) is
identical to the logarithmic transformation favored by these
commenters. In the analysis of underground data (QRA, Table 39), the
transformation (Box-Cox [lambda]=0.1) is close to logarithmic but
reflective of data that is slightly less skewed than the Lognormal
assumption would predict.
---------------------------------------------------------------------------
These commenters performed an analysis of the Log-transformed
inspector data and reported that when each Mine ID and work location-
specific set of untransformed data was normalized (divided) by its
corresponding applicable dust standard, the resulting log-transformed
data sets aggregated by job category were, in each, either
approximately normally distributed (for 9 of 33 job categories), or
otherwise approximately distributed as a mixture of two normal
distributions for the remaining job categories.
From this analysis, the commenters concluded that mixed lognormal
distributions provided a more accurate and simpler basis for performing
statistical analysis with the coal mine dust data set. However, they
presented no evidence that the logarithmic transformations they used
were ``more accurate'' than the Box-Cox transformations used by MSHA in
the QRA for the proposed rule (which include the logarithmic
transformation as a special case). It is simpler to analyze the data
(and explain results) when all mines and work locations within mines
are combined into an undifferentiated pool. However, the finding in the
QRA for the proposed rule \49\ that ``. . . work locations exhibit a
wide variety of distributional forms . . . that cannot adequately be
approximated by a lognormal model'' did not refer to the combined data.
These commenters presented no evidence suggesting that it was more
accurate to combine data from all work locations associated with the
same occupation than to differentiate among work locations at different
mines or mine areas. Tables 39 and 41 of the QRA for the proposal show
that these differences are statistically significant, so not including
them would not yield more accurate results.
---------------------------------------------------------------------------
\49\ Appendix G(b), p. 125.
---------------------------------------------------------------------------
Approximate log-normality across work locations was never
questioned or disputed in the QRA for the proposed rule. For purposes
of estimating the impact of the final rule on expected risk, the
important questions are whether the distributions should be assumed
lognormal within work locations and, far more important, whether they
would retain, within work locations, the same coefficient of variation
and distributional form under the final rule regardless of their
distribution. MSHA expects the final rule to have its greatest impact
on work locations currently exhibiting the highest dust concentrations,
with relatively little impact on work locations already in compliance
with the final standard on every shift.
According to the commenters, full compliance with the rule as
proposed would have required a 92% reduction in the mean respirable
coal mine dust concentration for longwall tailgate operators, from 1.39
mg/m\3\ (their estimate of the current mean) to 0.11 mg/m\3\ (their
estimate of the mean level required to meet the proposed 1.0 mg/
[[Page 24854]]
m\3\ standard with a 99% compliance rate). This calculation relies on
the following unfounded assumptions that MSHA responds to below.
(i) That variability in dust concentrations for a specified
occupation, pooled across all mines and mine sections, is similar to
the variability at the individual work locations where exposure
occurs and the final standard would actually be implemented.
The values of [sigma]1 and [sigma]2 shown in
the commenter's calculations represent the pooled variability in
respirable coal mine dust concentrations across all work locations for
each occupation. Thus, the measure of variability these commenters use
in their analysis combines (1) the average variability observed within
work locations and (2) the variability in the mean levels observed
between work locations of the same occupational type. This inflates the
estimates of variability within work locations--where the mandated
reductions would actually have to occur. Furthermore, individual work
locations may have widely differing degrees of variability in
respirable coal mine dust concentrations. Therefore, pooled estimates
of variability within work locations (even if properly calculated so as
to eliminate the effects of variability between work locations) could
merely be averages of significantly divergent exposure patterns at
individual work locations. The calculations that the commenters present
in their comments apply only to work locations where variability in
respirable coal mine dust concentrations is approximately equal to
variability observed across the entire population of work locations
associated with longwall tailgate operators.
(ii) That within occupational categories, the shift-to-shift
dust concentration at each work location is lognormally distributed.
Although the assumption of universally lognormal exposure
distributions is widespread and perhaps entrenched in the occupational
hygiene literature, it is not always supported by coal mine dust
concentration measurements at individual work locations. (See Appendix
G(b), QRA for the proposed rule.) Multimodal, or even unimodal right-
skewed distributions, are not necessarily well-approximated by a
lognormal model. Although these commenters correctly suggest that
multimodal distributions can often be adequately represented as
mixtures of lognormal distributions, they present no evidence that such
distributions provide good, predictive models for the distribution of
respirable coal mine dust concentrations within work locations. The
fact that pooled exposures are lognormally distributed does not imply
that exposures at individual work locations are lognormally
distributed.
(iii) That the distributional form (i.e., shape) of each
occupational exposure distribution, as represented by the lognormal
parameters shown in their comments, would not change after
successful implementation of the final rule.
As illustrated by Figure III-3, it is this assumption of shape-
retention that is primarily responsible for the extreme reductions in
mean exposure that these commenters conclude are necessary for
compliance with the proposed rule. The commenters did not present
empirical evidence directly supporting this assumption, but they did
offer the following justification after MSHA questioned the assumption
at a public hearing: (1) Empirical evidence for each job category was
shown to be consistent with contributing log-normal components; (2)
evidence was based on an analysis of dust concentration measurements
that had already been ``normalized'' as a result of dividing them by
compliance level specific to each job location and job category; and
(3) the underlying pre-normalized data aggregated across each job
category also exhibit mixed log-normal distributions. According to the
commenters, this demonstrates that compliance resulted in job-specific
multiplicative shifts of the type assumed in their subsequent analysis.
They also argued that if more complex types of shifts had arisen due to
compliance, such as those projected in the QRA, then the pre-normalized
data would not be expected to exhibit the degree of consistency with
mixed log-normal distributions that is summarized in the comments.
Although all three of the commenters' premises summarized above are
true, they do not support the commenters' conclusion that the effect of
applying job-type-specific control measures to comply with new
regulations will be to induce a leftward (downward) multiplicative
shift in the mixed log-normal distribution that the commenters
estimated to be consistent with empirical data for that job category.
Furthermore, the commenters' three premises apply only to the
distributions of respirable coal mine dust concentration measurements
aggregated across all work locations of a given occupational type.
Their analysis models a static distribution for each occupational
aggregate and does not address the response to compliance with more
stringent standards. Despite the ``normalization'' procedure described,
the commenters' analysis provides no information on how individual work
locations have responded to reductions in their exposure limits. For
most work locations, the applicable standard did not even change
appreciably during the data period. The fact that these aggregated
distributions are consistent with mixed lognormal assumptions
demonstrates nothing about how individual work locations will respond
to the reduced standard.
4. Uncertainty Analysis
As indicated above, a difference in assumptions as to how
respirable dust exposures would have changed under the proposed rule
led some commenters to project exposures for longwall tailgate
operators that are quantifiably different from those projected by MSHA.
Although MSHA believes that Figure III-2 provides a much better picture
than Figure III-3 of how dust concentrations in individual work
locations will change under either the proposed or final rule, MSHA
fully acknowledges that its predictions of future exposure
distributions are not certain. This uncertainty was expressed in the
QRA for the proposal by a statement of the major assumptions involved
in MSHA's projections (QRA, p. 80). However, MSHA has no empirical data
basis for quantifying the degree of uncertainty attached to these
assumptions. This illustrates a more general point: Although it may be
possible to quantify and compare the results of competing models, it
may not be possible (in the absence of appropriate experimental data)
to provide a valid quantitative assessment of uncertainty in regard to
competing assumptions.
Several commenters stated that the QRA for the proposal lacked
sufficient discussion of the uncertainty surrounding its estimates of
current and projected exposures and health risks, and of the reductions
in risk expected to result from implementation of the proposed rule.
Although the QRA for the proposed rule contained qualitative
discussions of its major assumptions and their implications with
respect to both current and projected risks (pp. 58-59 and p. 80,
respectively), it did not present much quantitative information on
statistical uncertainties related to the estimates it used. In part,
this was because such quantification often overlooks far greater and
more important uncertainties in the underlying assumptions.
Nevertheless, in response to comments, the QRA for the final rule
provides additional information on uncertainty of the estimates
wherever possible. In
[[Page 24855]]
addition, the QRA for the final rule contains a comprehensive
uncertainty analysis for MSHA's estimates of current and projected
exposures (QRA for the final rule, Section 4).
MSHA agrees with some commenters that a purely quantitative
approach has the potential to underestimate uncertainty due to its lack
of incorporation of model uncertainty. Therefore, although MSHA
believes that the QRAs for the proposed and final rules have employed
the best available models for estimating existing and future health
risks, MSHA's presentation of quantitative uncertainty measures should
be tempered by the realization that such measures depend heavily on
acceptance of the underlying assumptions of the models used in the both
QRAs.
One commenter stated that the two mortality studies cited in the
QRA for the proposal (Miller et al., 2007; and Attfield and Kuempel,
2008, Figure 15) yield what appear to be quite different estimates of
relative risk for COPD mortality attributable to respirable coal mine
dust exposure. However, the commenter did not mention the main point of
the QRA's discussion of the difference between these estimates on page
40: ``. . . even the lower estimate shows a significant increase in
COPD mortality attributable to the dust exposure.'' More importantly,
the difference in relative risk reported from the two studies (Miller
et al., 2007; Attfield and Kuempel, 2008) is not statistically
significant. Table III-8 contains 90-percent confidence intervals for
the relative risks at mean concentrations of 1.0, 1.5, and 2.0 mg/m\3\.
The lack of any statistically significant difference is shown by the
extensive overlap between corresponding intervals. Therefore, contrary
to the commenter's suggestion, the difference in estimated relative
risks may well reflect normal sampling variability rather than a
fundamental disagreement between models.
In addition, Table III-8 presents 90-percent confidence intervals
for relative risks of COPD mortality based on MSHA's revision of the
Attfield-Kuempel estimate, which is intended to mitigate bias due to
underestimation of exposure, as explained in the last paragraph of
Section III.B.2.c.\50\
---------------------------------------------------------------------------
\50\ As in the case of NMRD mortality risk discussed earlier,
the revised estimate of the coefficient of cumulative respirable
coal mine dust exposure for estimating COPD Relative Risk lies
halfway between the Attfield-Kuempel estimate of 0.00648 and the
Miller COPD/17 estimate of 1.92 x 0.0016 = 0.00307 (i.e., (0.00648 +
0.00307)/2 = 0.00478). Therefore, relative risk (RR) in the revised
model is given by: RR = exp (0.00478 x 45 x [mu]), where [mu] is the
mean respirable coal mine dust concentration experienced over a 45-
year occupational lifetime. Standard errors for the revised
coefficient were obtained by applying the standard propagation of
errors formula for the average of two independent random variables
(i.e., the 1.92-adjusted Miller and the Attfield-Kuempel estimates
of the coefficient).
Table III-8--90-Percent Confidence Intervals for Relative Risk (RR) of COPD Mortality Attributable to Respirable
Coal Mine Dust Exposure Averaged Over 45-Year Occupational Lifetime, According to Three Different Exposure-
Response Models
----------------------------------------------------------------------------------------------------------------
Attfield/
Miller et al. Attfield/ Kuempel
Mean respirable coal mine dust conc. mg/m\3\ (2007) model Kuempel (2008) revised by
COPD/17 MSHA
----------------------------------------------------------------------------------------------------------------
1.0............................................................. 1.10-1.20 1.12-1.61 1.13-1.36
1.5............................................................. 1.16-1.31 1.18-2.03 1.20-1.58
2.0............................................................. 1.22-1.43 1.25-2.58 1.28-1.84
----------------------------------------------------------------------------------------------------------------
The commenter also suggested that mortality data obtained after
implementation of the Mine Act contradict predictions from the
exposure-response models on which the QRA relies. Citing Bang et al.
(1999) and Mazurek et al. (2009), the commenter stated that mean
respirable coal mine dust concentrations have been reduced in the past,
yet health risks have increased in some age categories. According to
the commenter, this conflicts with the predictions of the QRA's risk
modeling, and shows that the model predictions are not certain, and may
be incorrect. For reasons explained below, MSHA believes the commenter
misinterpreted the results of both studies. Bang et al. (1999) computed
annual age-specific mortality rates for three age groups (15-44, 45-64,
and 65 or older), and for the aggregate, among decedents for whom CWP,
asbestosis, or silicosis was identified as either an underlying or
contributing cause of death. The overall age-adjusted CWP-related
mortality rate declined steadily over the 1985-1996 study period,
``from 8.32 per million in 1985 to 3.20 per million in 1996.'' CWP-
related mortality rates also declined significantly within the 45-64
and >= 65 age groups, but not in the 15-44 age group. The authors
concluded that ``the reduction of CWP mortality could be related to
enforcement of and compliance with dust-control measures adopted in
1969.'' With respect to the lack of a statistically significant
downward trend in the 15-44 age group, the authors noted not only that
``this observation may have resulted in part from lack of power due to
smaller annual numbers of deaths at younger ages; '' but also that--
The continued occurrence of pneumoconiosis deaths in young
adults may reflect recent overexposures. High levels of exposure are
associated with much shorter latency and more rapid disease
progression, resulting in early death [Bang et al., 1999].
Mazurek et al. (2009) examined annual CWP mortality rates and years
of potential life lost (YPLL),\51\ based on 28,912 decedents from 1968
through 2006 for whom CWP was identified as the underlying cause of
death. The overall finding was that:
---------------------------------------------------------------------------
\51\ The term ``years of potential life lost (also known as
``potential years of life lost'') is a measure of the relative
impact of various diseases and lethal forces on society (see Last,
John M., ed. 2001. A Dictionary of Epidemiology, Fourth Edition. New
York: Oxford University Press, Inc.).
YPLL is computed by estimating the years that people would have
lived if they had not died prematurely due to disease or other
causes. YPLL is an important measure of premature mortality. YPLL is
equal to the numerical difference between a predetermined endpoint
age (i.e., 75, 85, etc.) and the age at death for a death or deaths
that occurred prior to that endpoint age. In addition, the YPLL Rate
is equal to the (Number of YPLLs divided by the population under
endpoint age) x 100,000.
. . . CWP deaths among U.S. residents aged >=25 years declined
73%, from an average of 1,106.2 per year during 1968-1972 to 300.0
per year during 2002-2006. . . . Age-adjusted death rates among
residents aged 25-64 declined 96%, from 1.78 per million in 1968 to
0.07 in 2006; age-adjusted death rates among residents aged >=65
years declined 84%, from 6.24 per million in 1968 to 1.02 in 2006 .
---------------------------------------------------------------------------
. . [Mazurek et al., 2009].
[[Page 24856]]
Annual CWP-attributable YPLL before age 65 years was also reported
to have declined, ``from a high of nearly 1,800 in 1970 to a low of 66
in 2001.'' However, YPLL before age 65 years was found to have been
increasing between 2002 and 2006. Unlike the commenter, the authors did
not associate the observed increase in YPLL from 2002 and 2006 with any
supposed decrease in exposures over that time period. Instead, the
authors noted that the
. . . annual CWP-attributable YPLL before age 65 years also have
decreased, from a high of nearly 1,800 in 1970 to a low of 66 in
2001. However, the findings in this report indicate that YPLL before
age 65 years have been increasing since 2002. This is consistent
with the observed increase in the percentage of underground coal
miners identified with CWP, in particular among younger workers.
The report did not examine historical changes in the age-
composition of the mining population or analyze the effects that the
changes would have on historical changes in YPLL. However, contrary to
the commenter's implicit assumption of a progressive decline in
exposures in the latter years of the study period, Mazurek et al. did
pose the following possible explanations for the observed increase in
YPLL:
One cause of the increased YPLL in recent years might be greater
exposure of workers to coal dust . . . Increased coal production per
shift can make dust suppression more difficult. . . . Larger, more
powerful machines generate larger quantities of dust in shorter
periods, potentially exposing workers to higher concentrations of
dust. . . In addition, the total number of hours worked in
underground coal mines increased 25.6%, from an annual average of
1,671 per miner during 1978-1982 to 2,099 per miner during 2003-
2007. Increased hours of work can result in increased inhaled dust,
which might exceed the lungs' ability to remove dust. . . Finally,
another cause of increased CWP-attributable YPLL could be missed
opportunities by miners for early disease screening, which could
exacerbate disease progression. [Mazurek et al., 2009].
None of these potential explanations invokes any decrease in mean
cumulative exposure to explain the relatively recent increase in YPLL.
Neither the results reported in Mazurek et al. (2009) nor the possible
explanatory factors it discusses conflict in any way with ``the
predictions of the QRA's risk modeling'' or show ``that the model
predictions . . . may be incorrect.''
Some measure of the uncertainty implicit in the estimates of
exposure under current conditions in the QRA for the proposed and final
rules is given by QRA Figures 7, 8, and 9, along with the discussion of
underlying assumptions in the Section 2 of the QRA for the final rule.
In conjunction with new projections of exposures and residual excess
risks under a 1.5 mg/m\3\ respirable coal mine dust concentration final
standard, Section 4b of the QRA for the final rule discusses
uncertainty in the exposures expected under the final standard and
enforcement policies. In the remainder of this section, MSHA addresses
uncertainty in the exposure-response models used in the QRAs for the
proposed and final rules. Confidence bands graphically representing
this source of uncertainty are provided in Section 4c of the QRA for
the final rule.
a. CWP, Including PMF
Table 65 (in Appendix I) in the QRA for the final rule (Table 53 in
the QRA for the proposed rule) provides the standard errors of all
estimated coefficients used in the exposure-response models for CWP1+,
CWP2+ and PMF. Nevertheless, some commenters objected to the absence of
confidence bands in the graphic displays of these models (Figures 10
and 11 of both QRAs). In response to these commenters, 90-percent
confidence intervals for the estimated excess risks attributable to
respirable coal mine dust are shown for 73-year-old miners at three
different exposure levels in Tables III-9 and III-10. Table III-9
pertains to geographic regions associated with low/medium rank coal and
Table III-10 pertains to geographic regions with high rank coal.
Assuming, as MSHA does, that the Attfield-Seixas models are reasonably
accurate, there is a chance of approximately 1 in 20 that 45 years of
occupational exposure at the specified level would result in fewer
adverse outcomes, per thousand, than the left interval endpoint.
Similarly, the chance is approximately another one in twenty that
exposure at the specified level would result in adverse outcomes at a
rate exceeding the upper confidence limit. For example, according to
the Attfield-Seixas model, the likelihood is approximately 95 percent
that 45 years of occupational exposure to high rank respirable coal
mine dust at an average concentration of 1.5 mg/m\3\ would result in
more than 53 excess cases of PMF per 1,000 miners at age 73 years.
Table III-9--Maximum Likelihood Estimates and 90-Percent Confidence Intervals for Excess Risk of CWP
Attributable to Respirable Coal Mine Dust Exposure, Based on Attfield-Seixas Model for 73-Year-Old Miners After
45-Years of Occupational Exposure at Low to Medium Rank Coal Mines
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Excess cases per thousand exposed miners
-----------------------------------------------------------------------------------
Mean respirable coal mine
dust conc. mg/m\3\ CWP 1+
CWP 2+
PMF
----------------------------------------------------------------------------------------------------------------
1.0......................... 98.3 73.0-125.6 57.5 29.7-92.3 20.0 5.7-63.3
1.5......................... 163.5 119.4-211.7 100.8 48.9-170.7 50.2 8.8-121.2
2.0......................... 238.2 172.2-309.5 156.0 71.6-273.0 77.0 12.1-203.0
----------------------------------------------------------------------------------------------------------------
Table III-10--Maximum Likelihood Estimates and 90-Percent Confidence Intervals for Excess Risk of CWP
Attributable to Respirable Coal Mine Dust Exposure, Based on Attfield-Seixas Model for 73-Year-Old Miners After
45-Years of Occupational Exposure at High Rank Coal Mines
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Excess cases per thousand exposed miners
-----------------------------------------------------------------------------------
Mean respirable coal mine
dust conc. mg/m\3\ CWP 1+
CWP 2+
PMF
----------------------------------------------------------------------------------------------------------------
1.0......................... 177.7 118.2-244.4 141.0 69.8-237.6 96.8 30.6-208.9
1.5......................... 303.1 198.6-413.7 271.4 125.0-459.1 196.9 53.2-444.9
2.0......................... 437.3 290.3-572.9 433.6 196.5-672.7 338.6 82.2-688.2
----------------------------------------------------------------------------------------------------------------
[[Page 24857]]
b. Severe Emphysema
Standard errors for all estimated coefficients in the Kuempel
pulmonary impairment model are shown in Table 66 of Appendix J in the
QRA for the final rule (Table 54 in the QRA for the proposed rule).
Table III-11 below provides 90-percent confidence intervals for
estimated excess risks of severe emphysema attributed by the model to
respirable coal mine dust exposures at 45-year occupational lifetime
average concentrations of 1.0, 1.5, and 2.0 mg/m\3\. As in Tables 16,
24, and 28 of both QRAs, these risks apply to never-smoking miners at
age 73. According to this model, the likelihood is approximately 95
percent, for example, that white miners exposed to respirable coal mine
dust at an average concentration of 1.5 mg/m\3\ will, at age 73 years,
experience severe emphysema at a rate exceeding 49 cases per thousand
exposed miners. Similarly, the likelihood is approximately 95 percent
that this rate will be less than 156 cases per thousand.
Table III-11--Maximum Likelihood Estimates and 90-Percent Confidence Intervals for Excess Risk of Severe
Emphysema Attributable to Respirable Coal Mine Dust Exposure, Based on Kuempel Pulmonary Impairment Model for 73-
Year-Old Never-Smoking Miners After 45-Years of Occupational Exposure
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Excess cases of severe emphysema
Mean respirable coal mine dust conc. mg/m\3\ per thousand exposed miners
---------------------------------------------------------------
Racially ``white'' miners
Racially ``non-white'' miners
----------------------------------------------------------------------------------------------------------------
1.0............................................. 61.0 31.6-94.3 94.3 50.3-141.0
1.5............................................. 98.7 49.6-156.3 147.0 77.5-220.7
2.0............................................. 141.2 69.0-227.4 202.1 105.8-301.7
----------------------------------------------------------------------------------------------------------------
c. Mortality Due to NMRD
Attfield and Kuempel (2008) did not provide standard errors or
other measures of uncertainty for the model of NMRD mortality risk
presented in their Table X (reproduced in Appendix K of the QRAs as
Table 67 for the final rule and Table 55 for the proposed rule).
However, in a communication from Dr. Attfield (U.S. Department of
Labor, MSHA, Memorandum for the Record: Email from Michael Attfield,
2011), MSHA has obtained standard errors for the estimated coefficients
pertaining to cumulative respirable coal mine dust exposure and
geographical coal mining region. These are presented in Table III-12
below.
Table III-12--Standard Errors of Estimated Coefficients Related to
Respirable Coal Mine Dust Exposure in Attfield-Kuempel NMRD Mortality
Model
------------------------------------------------------------------------
Standard error
Variable of estimated
coefficient
------------------------------------------------------------------------
Anthracite.............................................. 0.16557
East Appalachia......................................... 0.18853
West Appalachia......................................... 0.16335
Midwest................................................. 0.21121
------------------------------------------------------------------------
Cumulative respirable coal mine dust Exposure (mg-yr/ 0.00128
m\3\)..................................................
------------------------------------------------------------------------
Miller et al. (2007) presented estimates and standard errors for
the coefficients specified in 18 candidate models of NMRD mortality
risk associated with respirable coal mine dust exposures in the United
Kingdom (Miller et al., 2007, Table 5.12). In the model that best fits
the data (NMRD/17), the estimated coefficient of cumulative exposure
and its standard error were 0.0014 and 0.0001997, respectively, for
respirable coal mine dust exposures expressed in units of mg-hr/m\3\.
For exposures expressed in units of mg-yr/m\3\, the corresponding
values are 0.0027 and 0.000383, assuming, as in the QRA, an average
work-year of 1,920 hours.
Because of bias in the Attfield-Kuempel estimates due to
underestimation of respirable coal mine dust exposure for the study
cohort, as explained in the last paragraph of Section III.B.2.c. above,
MSHA is using a model of NMRD mortality risk in which the Attfield-
Kuempel coefficient of respirable coal mine dust exposure has been
reduced by averaging it with the coefficient estimated from the NMRD/17
model. The modified coefficient is (0.00709 + 0.0027)/2 = 0.0049, with
a standard error of
[GRAPHIC] [TIFF OMITTED] TR01MY14.005
Table III-13 contains maximum likelihood estimates and 90-percent
confidence intervals for the relative risk of NMRD mortality
attributable to respirable coal mine dust exposure according to the
Attfield-Kuempel model, the Miller NMRD/17 model, and MSHA's modified
version of the Attfield-Kuempel model. All the risks shown in Table
III-13 are relative to unexposed workers with identical smoking
histories in the same coal mining region. A relative risk of 1.0 would
indicate no expected effect of exposure, and values deviating from 1.0
describe predicted multiplicative effects.\52\ For example, according
to the modified Attfield-Kuempel model (refer to Table III-13, last
column, below), 45 years of occupational exposure at an average
respirable coal mine dust concentration of 1.5 mg/m\3\ increases the
risk of NMRD mortality by an
[[Page 24858]]
amount probably between 29 and 50 percent--with a 5-percent chance that
the increase is less than 29 percent and a 5-percent chance that the
increase is greater than 50 percent.
---------------------------------------------------------------------------
\52\ Relative Risk Interpretation: The relative risk is the risk
of the exposed group compared to risk of a control group (unexposed
workers with identical smoking histories in the same coal mining
region). If the relative risk is equal to one, then the risk of
developing disease for the exposed group is the same as the risk for
the comparison group. This would indicate no association between
exposure and the risk of disease. If the relative risk is greater
than one, there is a strong positive association (risk of disease
increases with increased exposure); whereas if the relative risk is
less than one, there is a strong negative association (risk of
disease decreases with increased exposure). If the confidence
interval (CI) for relative risk contains the number one, this
implies lack of statistically significant evidence for an
association.
---------------------------------------------------------------------------
Table III-14 translates the relative risks shown in Table III-13
into excess risks (expected cases per thousand exposed miners)
attributable to respirable coal mine dust exposure. As explained in
Appendix K of the QRA for the final rule, this translation was based on
a competing risk life-table analysis.\53\ As before, these excess risks
should be interpreted relative to unexposed workers with identical
smoking histories in the same coal mining region. For miners exposed
for 45 years to respirable coal mine dust at an average concentration
of 1.5 mg/m\3\, the modified Attfield-Kuempel model (see Table III-14,
last column) predicts between 6.4 and 11.0 excess cases of NMRD
mortality by age 73, per thousand exposed miners. By definition of the
90-percent confidence interval, there is (again according to the
modified Attfield-Kuempel model) approximately a 5-percent chance that
the excess NMRD mortality rate would be below 6.4 cases per thousand,
and another 5-percent chance that it would be above 11.0 cases per
thousand, for miners exposed at this level.\54\
---------------------------------------------------------------------------
\53\ To obtain the values in Table III-14, relative risks
calculated in the QRA for 162 different clusters of work locations
were paired with the corresponding life-table determination of
excess risk of NMRD mortality. These 162 pairs were then arranged in
order of increasing relative risk, thereby forming a look-up table.
Each relative risk in Table III-13 was then assigned an excess risk
corresponding to that in the matched pair of the look-up table.
Intermediate values were calculated using linear interpolation. The
162 matched pairs of relative and excess risks are shown in the
corresponding cells of Tables 17 and 68 of the QRA for the final
rule.
\54\ The 90% confidence interval indicates the range within
which there is approximately a 90% probability that the excess NMRD
mortality rate lies. In the example, there is a 10% chance that the
true excess NMRD mortality rate lies outside of the range of 6.4-
11.0. Therefore, there is approximately a 5% chance that the true
rate would be below 6.4 cases per thousand and another 5% chance
that it would exceed 11.0 cases per thousand.
Table III-13--Maximum Likelihood Estimates and 90-Percent Confidence Intervals for Relative Risk (RR) of NMRD
Mortality Attributable to Respirable Coal Mine Dust Exposure Averaged Over 45-Year Occupational Lifetime,
According to Three Alternative Exposure-Response Models
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Relative risk of NMRD mortality
-----------------------------------------------------------------------------------
Mean respirable coal mine
dust conc. mg/m\3\ Attfield/Kuempel
Miller et al. (2007)
Attfield/Kuempel modified
(2008)
NMRD/17
by MSHA
----------------------------------------------------------------------------------------------------------------
1.0......................... 1.38 1.25-1.51 1.13 1.10-1.16 1.25 1.19-1.31
1.5......................... 1.61 1.40-1.86 1.20 1.15-1.25 1.39 1.29-1.50
2.0......................... 1.89 1.57-2.29 1.27 1.20-1.35 1.55 1.41-1.71
----------------------------------------------------------------------------------------------------------------
Table III-14--Maximum Likelihood Estimates and 90-Percent Confidence Intervals for Excess Risk of NMRD Mortality
Attributable to Respirable Coal Mine Dust Exposure Averaged Over 45-Year Occupational Lifetime, According to
Three Alternative Exposure-Response Models
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Excess cases of NMRD mortality by age 73 years, per thousand exposed miners
-----------------------------------------------------------------------------------
Mean respirable coal mine
dust conc. mg/m\3\ Attfield/Kuempel
Miller et al. (2007)
Attfield/Kuempel modified
(2008)
NMRD/17
by MSHA
----------------------------------------------------------------------------------------------------------------
1.0......................... 8.5 5.5-11.6 2.9 2.2-3.5 5.5 4.2-7.2
1.5......................... 13.3 8.8-19.2 4.4 3.4-5.5 8.9 6.4-11.0
2.0......................... 19.4 13.0-28.3 5.9 4.4-7.9 12.0 9.4-15.9
----------------------------------------------------------------------------------------------------------------
C. Feasibility
1. Pertinent Legal Requirements
Section 101(a)(6)(A) of the Federal Mine Safety and Health Act of
1977 (Mine Act), 30 U.S.C. 811(a)(6)(A), requires the Secretary of
Labor, in setting health standards, to consider the feasibility of the
standards. Section 101(a)(6)(A) of the Mine Act states that the
Secretary, in promulgating mandatory standards dealing with toxic
materials or harmful physical agents under the Mine Act, shall set
standards to assure, based on the best available evidence, that no
miner suffer material impairment of health from exposure to toxic
materials or harmful physical agents over his working life. (30 U.S.C.
811(a)(6)(A)). In developing these standards, the Mine Act requires the
Secretary to consider the latest available scientific data, the
feasibility of the standards, and experience gained under other laws.
Id.
Thus, the Mine Act requires that the Secretary, in promulgating a
standard, based on the best available evidence, attain the highest
degree of health and safety protection for the miner with feasibility a
consideration.
In relation to feasibility, the legislative history of the Mine Act
contemplates technology-forcing standards and standards that may
include some financial impact. The legislative history states that:
* * * While feasibility of the standard may be taken into
consideration with respect to engineering controls, this factor
should have a substantially less significant role. Thus, the
Secretary may appropriately consider the state of the engineering
art in industry at the time the standard is promulgated. However, as
the circuit courts of appeals have recognized, occupational safety
and health statutes should be viewed as ``technology forcing'', and
a proposed health standard should not be rejected as infeasible
``when the necessary technology looms on today's horizon.'' AFL-CIO
v. Brennan, 530 F.2d 109 (3d Cir. 1975); Society of Plastics
Industry v. OSHA, 509 F.2d 1301 (2d Cir. 1975), cert. denied, 427
U.S. 992 (1975). * * *
Similarly, information on the economic impact of a health
standard which is provided to the Secretary of Labor at a hearing or
during the public comment period, may be given weight by the
Secretary. In adopting the language of section 102(a)(5)(A), the
Committee wishes to emphasize that it rejects the view that cost
benefit ratios alone may be the basis for depriving miners of the
health protection which the law was intended to insure. The
committee concurs with the judicial
[[Page 24859]]
constitution that standards may be economically feasible even though
from the standpoint of employers, they are ``financially burdensome
and affect profit margins adversely'' (I.U.D. v Hodgson, 499 F.2d
647 (D.C. Cir. 1974)). Where substantial financial outlays are
needed in order to allow industry to reach the permissible limits
necessary to protect miners, other regulatory strategies are
available to accommodate economic feasibility and health
considerations. These strategies could include delaying
implementation of certain provisions or requirements of standards in
order to allow sufficient time for engineering controls to be put in
place or a delay in the effective date of the standard. S. Rep. No.
95-181, at 21-22 (1977), reprinted in 1977 U.S.C.C.A.N. 3421-22.
Courts have interpreted the term ``feasible'' as meaning ``capable
of being done, executed, or effected,'' both technologically and
economically. See Kennecott Greens Creek Mining Co. v. MSHA and
Secretary of Labor, 476 F.3d 946, 957 (D.C. Cir. 2007) (citing American
Textile Mfrs. Inst. v. Secretary of Labor (OSHA Cotton Dust), 452 U.S.
490, 508-09 (1981)). In order for an agency's rules to be deemed
feasible, the agency must establish ``a reasonable possibility that the
typical firm will be able to develop and install engineering and work
practice controls that can meet the [permissible exposure limit] in
most of its operations.'' Kennecott Greens Creek, 476 F.3d at 957
(quoting American Iron & Steel Inst. v. OSHA, 939 F.2d 975, 980 (D.C.
Cir. 1991)).
In promulgating standards, hard and precise predictions from
agencies regarding feasibility are not required. The ``arbitrary and
capricious test'' is usually applied to judicial review of rules issued
in accordance with the Administrative Procedure Act. See American
Mining Congress v. Secretary of Labor, 671 F.2d 1251, 1254-55 (10th
Cir. 1982) (applying the arbitrary and capricious standard of review to
MSHA rulemaking challenges). The legislative history of the Mine Act
further indicates that Congress explicitly intended that the
``arbitrary and capricious test'' be applied to judicial review of
mandatory MSHA standards. ``This test would require the reviewing court
to scrutinize the Secretary's action to determine whether it was
rational in light of the evidence before him and reasonably related to
the law's purposes.'' S. Rep. No. 95-181, 95th Cong., 1st Sess. 21
(1977). In achieving the Congressional intent of feasibility under the
Mine Act, MSHA may also consider reasonable time periods of
implementation. Id. at 21.
Feasibility determinations involve complex judgments about science
and technology. Therefore, in analyzing feasibility, an agency is not
required to provide detailed solutions to every problem. Rather, it is
sufficient that the agency provides ``plausible reasons for its belief
that the industry will be able to solve those problems in the time
remaining.'' Kennecott Greens Creek, 476 F.3d at 957 (quoting National
Petrochemical & Refiners Ass'n v. EPA, 287 F.3d 1130, 1136 (D.C. Cir.
2002)). MSHA's feasibility determinations in this rulemaking are
buttressed by its statistical findings that many mines are already in
compliance with the requirements of the final rule. See Kennecott
Greens Creek, 476 F.3d at 959; American Iron & Steel Institute v. OSHA
(AISI-II), 939 F.2d 975, 980 (D.C. Cir. 1991). The fact that ``a few
isolated operations within an industry will not be able to comply with
the standard does not undermine a showing that the standard is
generally feasible.'' 476 F.3d at 957 (quoting AISI-II, 939 F.2d at
980).
Finally, MSHA has authority to promulgate technology-forcing rules.
When a statute is technology-forcing, the agency ``can impose a
standard which only the most technologically advanced plants in an
industry have been able to achieve-even if only in some of their
operations some of the time.'' Kennecott Greens Creek, 476 F.3d at 957
(citing United Steelworkers of America v. Secretary of Labor, 647 F.2d
1189, 1264 (D.C. Cir. 1980) and quoting AISI v. OSHA, 577 F.2d 825,
832-35 (3d Cir. 1978)).
Economic feasibility presents different issues from that of
technological feasibility. In the OSHA Cotton Dust case, the Supreme
Court stated that a standard would not be considered economically
feasible if an entire industry's competitive structure was threatened.
According to the Court, the appropriate inquiry into a standard's
economic feasibility is whether the standard is capable of being
achieved. 452 U.S. at 508-509. To establish economic feasibility, MSHA
is not required to produce hard and precise estimates of cost. Rather,
MSHA must provide a reasonable assessment of the likely range of costs
of its standard, and the likely effects of those costs on the industry.
See United Steelworkers of America v. Secretary of Labor, 647 F.2d at
1264. The courts have further observed that granting companies
reasonable time to comply with new exposure limits may enhance economic
feasibility. Id. at 1264.
MSHA evaluated the technological and economic feasibility of
meeting the requirements of the final rule. The technological
feasibility of the final rule includes two determinations. MSHA
determined that it is feasible to use the continuous personal dust
monitor (CPDM) as a compliance device to sample coal miners' exposures
to respirable coal mine dust. MSHA also determined that it is feasible
for operators to achieve the 1.5 mg/m\3\ standard (0.5 mg/m\3\ for
intake air and part 90 miners) using existing and available engineering
controls and work practices. The final rule provides a reasonable
amount of time of 18 months after the effective date of the final rule
to implement the requirements concerning the use of CPDMs. It also
provides a reasonable amount of time of 24 months after the effective
date of the final rule to implement the standards. In addition, MSHA
determined that the final rule is economically feasible.
2. Technological Feasibility of Using the CPDM as a Compliance Device
To Sample Coal Miners' Exposures
This preamble discusses the development of the CPDM over the last
20 years. Development began in the 1990s following a 1992 report issued
by MSHA's Coal Mine Respirable Dust Task Group (Task Group) and the
1996 Dust Advisory Committee Report in which both recommended the
development of continuous personal dust monitor technology for use in
underground coal mines. Prototypes were developed prior to the proposed
Plan Verification rulemaking in the mid-2000s. The pre-commercial CPDM
is the specific prototype that NIOSH and MSHA, along with input from
the mining industry, decided to complete and test in 2006. The
commercial CPDM was made available after MSHA's intrinsic safety
approval of the pre-commercial CPDM in September 2008 and subsequent
NIOSH approval in September 2011 following promulgation of revisions to
30 CFR part 74. Discussion on the development and testing of this
technology is summarized below along with comments on the proposed
rule.
a. Background Information on the Coal Mine Dust Personal Sampler Unit
(CMDPSU) and Continuous Personal Dust Monitors (CPDM)
Since the 1970s, mine operators and MSHA inspectors have used the
approved coal mine dust personal sampler unit (CMDPSU) to determine the
concentration of respirable dust in coal mine atmospheres. The CMDPSU,
which consists of a battery-powered pump unit, a cyclone (a type of
particle-size selector) and filter assembly, is either worn or carried
by the miner and, under MSHA's existing standards, remains operational
during the entire shift or for 8 hours, whichever time is
[[Page 24860]]
less. The CMDPSU samples the mine atmosphere by drawing dust-laden mine
air, at a flow rate of 2 liters per minute (L/min) through a 10-mm
nylon cyclone that removes non-respirable dust particles from the
airstream, allowing respirable dust particles to be deposited on the
filter surface. The collection filter is enclosed in an aluminum
capsule which is sealed in a protective plastic enclosure, called a
cassette, to prevent contamination. After completion of sampling, the
filter cassette is capped and sent to MSHA for processing, where it is
disassembled to remove the filter capsule for weighing under controlled
conditions to determine the amount of dust that was collected on the
filter. The measured weight gain is used to determine the average
concentration of respirable coal mine dust in the work environment of
the affected miners.
Because samples are typically transmitted through the mail to MSHA
for processing, results of sampling are often not known to mine
operators, miners, and MSHA for at least a week or more. Consequently,
if results indicate the presence of excessive dust concentrations, any
corrective action taken to lower dust levels would only impact miners'
exposure a week or more after sampling has been completed. The ability
to continuously monitor and give mine operators and miners real-time
feedback on dust concentrations in the work environment has been an
MSHA goal for nearly three decades.
MSHA's commitment to advanced sampling technology, specifically
technology that measures coal mine dust concentration continuously, is
noted in the preamble to 30 CFR part 70 dust rules that became
effective in April 1980 (45 FR 23990). In response to comments during
that rulemaking regarding the machine-mounting of sampling devices that
would give a continuous readout of dust concentrations, the Agency
agreed that every effort should be made to advance sampling technology.
In addition, MSHA stated that the Agency had embarked on an intensive
program to develop a reliable machine-mounted continuous dust monitor.
At that time, prototypes of such monitors had been developed and were
being tested in several mines. Additionally, MSHA noted that the U.S.
Bureau of Mines, now NIOSH, was pursuing research in this area. While
found to be useful as an engineering tool to monitor the effectiveness
of dust controls, those monitors, which were based on light-scattering
technology, proved to be unsuitable for enforcement purposes at that
time.
The health benefits of continuous monitoring were recognized by
MSHA's Coal Mine Respirable Dust Task Group, established in 1991, and
the Dust Advisory Committee. In 1992, the Task Group issued a report
that concluded that continuous monitoring of the mine environment and
dust control parameters offered the best long-term solution for
preventing occupational lung disease among coal miners. It specifically
recommended development of monitoring technology capable of providing
both short-term as well as full-shift concentration measurements.
Similarly, the Dust Advisory Committee unanimously recommended in its
report issued in 1996 that continuous personal dust monitoring (CPDM)
technology, once verified as reliable, be broadly used by MSHA for
assessing operator compliance efforts in controlling miners' dust
exposures and for compliance purposes.
In response to the recommendations by the Task Group and Dust
Advisory Committee, NIOSH undertook an aggressive research and
development program in the 1990s to produce a prototype technology for
a new type of personal dust monitor that would provide a direct
measurement of respirable coal mine dust levels in the mine atmosphere
on a real-time basis, unlike the existing sampling system used since
1970. The new technology would eliminate the delay in obtaining an
offsite laboratory analysis which, on average, requires a week or more
before the results are known to the mine operator and MSHA. Such
technology, which is referred to generically as a ``continuous personal
dust monitor'' (CPDM), would enable a mine operator to be more
proactive in taking corrective measures to avoid miners' exposure to
excessive respirable coal mine dust levels and in optimizing mining
procedures and dust control parameters to continuously maintain
respirable coal mine dust concentrations at or below the dust standard.
NIOSH's efforts to advance the technology for directly measuring
and displaying the amount of respirable coal mine dust contained in
mine air in real-time resulted in the development of a prototype CPDM
in 2003. The prototype CPDM represented the first significant advance
in respirable coal mine dust sampling technology in more than 30 years.
This prototype dust monitor consisted of a respirable dust sampler, a
gravimetric analysis device, and an on-board computer that was
incorporated into the miner's cap lamp battery case as a single package
located on the belt. The cap lamp battery case contained all the
components, including two separate batteries, to enable the dust
monitor and cap lamp to operate independently. The CPDM was configured
to have dimensions and weight similar to those of the current lead-acid
type miner's cap lamp battery. Air from a miner's work environment
entered the sampling device through an inlet located adjacent to the
lens of the cap light on the miner's hard hat and flowed via a flexible
tube that ran parallel to the lamp cord to the belt-mounted device. The
air stream was first coursed through a size selector, a Higgins-Dewell
(HD) cyclone, at a flow rate of 2.2 L/min to separate the non-
respirable dust, so that only airborne particles that could penetrate
to the lung were analyzed by the device. From there, the air stream
flowed through: (1) A heater that removed excess moisture; (2) a 14-mm
diameter glass fiber filter; (3) a flow rate sensor; and (4) a
computer-controlled pump.
The prototype CPDM employed a unique inertial mass sensor system
called the Tapered Element Oscillating Microbalance (TEOM[supreg]
system). The TEOM system consists of a hollow tapered tube called the
tapered element, which is clamped at its base and free to oscillate at
its narrow or free end on which an exchangeable filter cartridge is
mounted. Electronics positioned around the TEOM system cause the
tapered element to oscillate (or resonate) at its natural frequency.
When dust particles are deposited on the collection filter, the mass of
the collection filter increases, causing the natural oscillating
frequency of the tapered element to decrease. Because of the direct
relationship between mass and frequency change, the amount of
respirable coal mine dust deposited on the filter can be determined by
measuring the frequency change. The concentration of respirable coal
mine dust in the mine atmosphere was then determined by a computer
incorporated in the CPDM prototype. The computer divided the mass of
dust collected by the volume of mine air that passed through the
monitor during the sampled period. The result was reported on the
monitor's digital display. The data were retained for downloading onto
any personal computer using accompanying software. To accommodate
monitoring over a full shift, the prototype monitor was designed to
operate continuously for up to 12 hours. The display on the device
continuously showed: (1) The average concentration from the beginning
of the shift; (2) the percent of the respirable dust standard that had
been reached; and (3) the respirable dust concentration calculated at
distinct 30-minute
[[Page 24861]]
intervals. Through the display, both the miner wearing the device and
the mine operator were aware of the concentration of respirable coal
mine dust at any time during the shift. This information could be used
to validate whether dust control parameters were working as intended to
ensure that miners were not being exposed to excessive dust
concentrations.
While the performance of the prototype CPDM to accurately and
precisely measure respirable coal mine dust in the mine environment and
its durability under in-mine conditions had not been extensively
evaluated when MSHA published its proposed Plan Verification rule (68
FR 10784, March 6, 2003), preliminary indications from the limited
testing performed by NIOSH suggested that the prototype CPDM had the
potential to provide timely information on dust levels. Although MSHA
had confidence in this technology, a final determination of the
applicability and suitability of CPDMs under conditions of use being
proposed was not expected until after completion of the scheduled
laboratory and in-mine testing and evaluation at the end of 2003. MSHA
recognized that to be accepted by the mining community, the new CPDM
must reliably monitor respirable dust concentrations in the mine
environment with sufficient accuracy to permit exposures to dust
concentrations to be effectively controlled on each shift. As part of
the comprehensive dust control program in the proposed Plan
Verification rule, MSHA proposed a new standard to permit, but not
require, the use of such monitors to encourage the use of CPDM
technology.
Public hearings on the proposed Plan Verification rule, together
with MSHA's proposed Single Sample rule (68 FR 10940, March 6, 2003),
were held in Pennsylvania, West Virginia, Indiana, Kentucky, Alabama,
and Colorado in May 2003. Commenters expressed concern that the
proposed sampling program did not incorporate the new CPDM technology.
After reviewing the favorable performance of the prototype CPDM in
initial in-mine tests, MSHA announced in July 2003 and August 2003,
respectively, that it would suspend all work to finalize the proposed
dust rules published in March 2003, and the proposed single sample rule
published in July 2000, to pursue accelerated research on the new CPDM
technology being tested by NIOSH. NIOSH research verifying the CPDM
technology, as reliable under in-mine conditions, was being conducted.
The comment period was extended indefinitely to assemble the best
information available on CPDM technology and its application in coal
mines. On successful completion of in-mine performance verification
testing of the new technology, MSHA would move forward with a final
rule to incorporate new requirements for monitoring exposures that
reduce miners' risk of black lung disease.
After enlisting the collaboration of various stakeholders
representing industry and organized labor in the final testing of the
pre-commercial CPDM, MSHA and NIOSH purchased 25 units for the
collaborative study, which was initially conducted in 10 underground
mines. This was followed by extended testing at 4 additional mines.
Additional test data were also collected by MSHA at the request of
NIOSH at 180 randomly-selected mechanized mining units across 10 MSHA
coal districts for the purpose of evaluating the equivalency of the
CPDM compared to using the then approved CMDPSU.
In September 2006, NIOSH published the results of the collaborative
research effort designed to verify the performance of the pre-
commercial CPDM in laboratory and underground coal mine environments.
According to the NIOSH Report of Investigations 9669, ``Laboratory and
Field Performance of a Continuously Measuring Personal Respirable Dust
Monitor,'' (Volkwein et al., NIOSH, 2006), the testing of the pre-
commercial CPDM under a broad range of test conditions verified it to
be accurate and precise in providing end-of-shift dust concentration
information. It also stated that the device was acceptable to miners
from an ergonomic standpoint, and when worn by miners during normal
work, the device demonstrated durable performance with about a 90%
availability rate, which is similar to existing sampling devices. This
study demonstrated that the pre-commercial CPDM technology was suitable
for use in coal mines to monitor and prevent overexposures to
respirable coal mine dust.
In September 2008, the commercial model of the CPDM successfully
passed MSHA's intrinsic safety tests permitting the device to be
purchased for use in coal mines as an engineering tool.
Based on the results of the collaborative study, MSHA published a
Request for Information (RFI) on October 14, 2009 (74 FR 52708) on the
feasibility of using the commercial CPDM technology to more effectively
monitor and control miners' exposure to respirable coal mine dust
during a working shift. Most commenters generally agreed that requiring
the use of a CPDM would enhance the protection of miners' health.
On April 6, 2010 (75 FR 17512), MSHA and NIOSH published a final
rule that revised the approval requirements for the CMDPSU and
established new performance-based requirements for the CPDM to permit
the Secretaries of HHS and Labor to approve dust monitoring devices for
use in coal mines based on new designs and technology capable of
continuously monitoring and reporting concentrations of respirable coal
mine dust during and at the end of a work shift.
On September 6, 2011, NIOSH approved a commercial CPDM as meeting
the CPDM requirements of 30 CFR part 74. Sampling devices, such as the
CPDM, can be used for compliance purposes only if they meet the
specific performance criteria defined in 30 CFR part 74 and have been
approved by the Secretaries of Labor and HHS for use as a compliance
sampling device. The performance criteria in 30 CFR part 74 establish
the requirements for bias, precision, and reliability that must be met
for direct-reading devices such as the CPDM. The results of published
NIOSH studies demonstrate that the CPDM meets these performance
criteria.
The use of an approved CPDM, which affords real-time respirable
coal mine dust exposure measurements, will significantly improve health
protection for current and future coal miners by reducing their
cumulative coal mine dust exposure and reducing their risk of
developing and dying from occupational lung diseases. The approved CPDM
is demonstrated to be accurate, precise, reliable, and durable under
in-mine use conditions, and is commercially available.
The CPDM is capable of being used in a shift mode, in which the
device is programmed by certified persons to operate for specific shift
lengths (e.g., 8, 10, 12 hours) to monitor a Designated Occupation (DO)
or another sampling entity's exposure, or in an engineering mode for
short-term evaluations. If the device is operated in an engineering
mode, the person would operate it for short periods of time within the
shift to record respirable dust levels during specific mining
activities or at specific dust-generation sources in the mine. The
display has various screens that show the: (1) Time of day; (2) elapsed
time since beginning of the shift; (3) total amount of respirable dust
accumulated on the filter since the start of sampling, which is stored
in an internal memory for analysis; (4) dust concentrations; and (5) a
bar graph of the respirable dust concentration during the entire
sampling period. On the bar
[[Page 24862]]
graph, each bar represents the average concentration value for each
previous 30-minute interval, with a new bar added to the graph every 30
minutes. Also displayed and stored are sampling status conditions that
have occurred during sampling. The terminology ``sampling status
conditions'' is explained elsewhere in the preamble related to Sec.
70.210. This, along with other information, is stored in the CPDM and
can be accessed and downloaded with a personal computer at the end of
the shift for analysis, recordkeeping, and posting.
The final rule, like the proposal, requires mine operators to use
an approved CPDM to sample designated occupations (DOs) and other
designated occupations (ODOs) in each MMU and each part 90 miner. In
addition, it permits them to use the approved CPDM or CMDPSU to sample
designated areas (DAs) and designated work positions (DWPs). However,
the proposal would have required all underground coal mine operators to
use approved CPDMs 12 months after the effective date of the final rule
to sample DOs on each production shift and part 90 miners on each
shift, seven calendar days per week (Sunday through Saturday), 52 weeks
per year. The final rule differs from the proposed requirements in that
mine operators are required to use the CPDM on consecutive production
shifts to collect 15 valid representative samples from each DO and ODO
and 5 valid representative samples from each part 90 miner every
calendar quarter. In addition, the final rule permits operators of
underground anthracite mines to continue to use the approved CMDPSU
after the 18-month period. Specific details regarding the change in the
period from the proposed 12 months to 18 months after the effective
date of the final rule, the option to use CMDPSUs in underground
anthracite mines instead of CPDMs, and the reduction in the CPDM
sampling frequency, are discussed elsewhere in this preamble under
final Sec. Sec. 70.201, 70.208, 90.201, and 90.207.
b. Technological Feasibility Determination on the Use of the CPDM
MSHA concluded in the Preliminary Regulatory Economic Analysis to
the proposed rule (PREA) that requiring the use of the CPDM to sample
miner exposures to respirable coal mine dust was technologically
feasible. NIOSH, through an informal partnership with MSHA, industry,
and organized labor, conducted extensive testing of the CPDM in a
variety of underground coal mines.\55\ The in-mine testing verified the
new sampling device to be accurate and reliable, ergonomically
acceptable to miners, and sufficiently durable to withstand the rigors
of the underground environment. This testing demonstrated that the CPDM
is suitable for use in coal mines to monitor and prevent overexposure
to respirable coal mine dust (Volkwein et al., 2004, NIOSH RI 9663;
Volkwein et al., 2006, NIOSH RI 9669).
---------------------------------------------------------------------------
\55\ Section 501(a)(1) of the Mine Act, 30 U.S.C. 951(a)(1),
provides that NIOSH shall conduct studies and research to improve
working conditions and prevent occupational diseases in the coal
mining industry.
---------------------------------------------------------------------------
In the PREA, MSHA stated that the CPDM is a new technology and that
there are only a few hundred of these devices currently in use.
However, MSHA determined that the proposed 12-18 month phase-in period
would allow sufficient time to manufacture the necessary quantity of
CPDMs. It would also provide sufficient time for operators to conduct
training on the use and care of the device.
Many commenters expressed support for using the CPDM as an
engineering tool to identify dust sources and reduce dust exposure
during a miner's work shift. Some of the commenters were opposed to
using it for compliance purposes. Some commenters suggested that MSHA
conduct a data-gathering study along with NIOSH and other interested
parties using both the gravimetric and CPDM before requiring use of the
CPDM. Other commenters suggested that MSHA delay requiring the use of
the CPDM until further field testing in coal mines is conducted to
address technical concerns about the readiness of the CPDM, its
measurement accuracy, and its reliability for long-term use in coal
mines. These commenters also suggested that ergonomic improvements be
incorporated into the CPDM design to make it more worker-friendly since
they believe its weight would cause serious harm to the musculoskeletal
system of the miner.
Specifically, some commenters cited results of coal mine operator
field testing involving side-by-side sampling in underground mines
using the approved CMDPSU and the commercial CPDM. These commenters
stated that the sampling results varied greatly and demonstrated that
additional development of, and improvement on, the CPDM is needed to
provide accurate results in underground mine environments. These
commenters also claimed that their independent testing of the CPDM
found the devices to be unreliable in typical underground conditions.
When tested under the same environmental conditions, the commenters
stated that multiple CPDMs reported a wide range of airborne dust
concentrations, particularly when operating in elevated temperatures
and humidity levels. For example, one commenter stated that only 554 of
the 955 (58%) concentrations measured with the CPDM were within 25% of
the concentrations measured with the CMDPSU. This commenter concluded
that, since the NIOSH definition of accuracy is that the sampling
device be accurate to within 25% of the actual concentration 95% of the
time, the CPDM does not meet the NIOSH accuracy definition.
NIOSH reviewed the commenters' data regarding the sampling
performance of the CPDM. In its comments on the proposed rule, NIOSH
stated that it questioned the commenters' interpretation of the data
for three reasons.
The analytical methodology used by the commenters was inappropriate
for the conditions to which it was applied; several of the commenters
inappropriately referred to their data by using a scientific term that
could be interpreted in different ways; and none of the commenters'
data included statistically representative samples that fully reflect
the conditions observed nationwide in underground coal mines.
Regarding the comments that the CPDM did not meet the NIOSH
Accuracy Criterion (Kennedy et al., 1995), NIOSH commented that this
criterion is designed primarily this criterion is designed primarily
for evaluating the accuracy of a sampling and analytical method under
controlled laboratory conditions. Although the NIOSH Accuracy Criterion
does not require field testing, it recognizes that field testing ``does
provide further test of the method.'' However, in order to provide a
valid basis for assessing accuracy and avoid confusing real differences
in dust concentrations with measurement errors when testing is done in
the field, precautions have to be taken to ensure that all samplers are
exposed to the same concentrations. If not carried out correctly, field
testing yields invalid comparisons and erroneous accuracy conclusions
as it did in the commenters' limited field study.
In addition, NIOSH stated that the commenters did not properly
define the term ``accuracy'' in their analysis. ``Accuracy'' is defined
by referencing two statistically independent and fundamental parameters
known as ``precision'' and ``bias.'' Precision refers to consistency or
repeatability of results, while bias refers to a systematic error
[[Page 24863]]
that is present in every measurement. Since the NIOSH Accuracy
Criterion requires that measurements consistently fall within a
specified percentage of the concentration, the criterion covers both
precision and uncorrectable bias. NIOSH's experimental design was
developed such that the precision and bias of the CPDM could be
estimated by regression analysis of data obtained in field
environments. Regression analysis is a statistical methodology that
uses the relationship between two or more quantitative variables so
that one variable can be predicted from the other, or others. The CPDM
performance was then compared to the defined and accepted reference
standard within the mining industry, which is the gravimetric CMDPSU.
In its comment, NIOSH stated that when evaluating the performance
of the CPDM, it collected and analyzed samples that were statistically
representative of the nation's underground coal mining industry. The
sample set was selected using the Survey Select procedures from the SAS
statistical analysis software package. The samples were collected by
MSHA inspectors at approximately 20 percent of active mechanized mining
units. Statistically representative samples are critical for correctly
estimating the bias of the CPDM relative to the gravimetric method of
the CMDPSU. Bias may not be properly estimated from studies conducted
in a limited number of mines or regions, regardless of the number of
samples obtained. The methodology used by NIOSH to collect data was
reviewed and approved by various members of the mining community.
In addition, NIOSH noted that none of the commenters' data sets
were statistically representative of the entire underground coal mining
industry. The largest data set MSHA received came from a commenter who
collected 955 samples from 6 of its mines by having miners wear a CPDM
and a CMDPSU (gravimetric sampler) concurrently. Unlike the commenter's
data, NIOSH data were collected from over 100 mines. Therefore, the
NIOSH data set is more representative of the underground mining
environment and is more appropriate for evaluating the accuracy and
precision of the CPDM and its use as a compliance instrument.
In terms of bias, NIOSH reviewed the results presented by the
commenter and concluded that those results support those published by
NIOSH. They show that the average concentration measured by the CMDPSU,
0.83 mg/m\3\, was virtually identical to the CPDM average value of 0.82
mg/m\3\. NIOSH further concluded, from reviewing both the commenter's
and NIOSH's data sets, that there was no statistically significant
difference between the data sets, and that the bias between the CPDM
and the approved CMDPSU is zero. In so concluding, NIOSH noted that, to
be strictly correct, dust concentration data are lognormally
distributed and, therefore, a simple arithmetic average cannot be
calculated from these data. The appropriate method is to average the
logarithms of the numbers, followed by un-transformation of the
logarithmic averages. This method yields average concentrations that
are typically lower than simple arithmetic averages. However, the
relative difference between the averages will remain the same in either
case.
Regarding the comment that the CPDM variability was too large for
it to be used as a compliance instrument, NIOSH commented that there
will be no imprecision or variability in the regression if there is
total control of all parameters in any given test. In addition,
imprecision in a regression is a direct estimate of the degree to which
there are unknown and uncontrolled parameters at work during the test.
The variability reported by the commenter was primarily due to large
sample variability, which was due to uncontrolled variables known to
exist in field samples, even when two identical samplers were placed
side-by-side. Because the commenter's experimental design did not
control for the variability resulting from the samplers themselves, it
was not an appropriate estimate of the CPDM's precision. Instead, the
data introduced by the commenter included uncontrolled variability
potentially caused by significant dust gradients known to exist,
sampler inlet location differences, and the nature of mine ventilation.
Ventilation currents found in mines can produce widely varying results
or seemingly poor precision between two identical side-by-side
instruments, even though their inlets may be separated by only a few
inches. To correctly estimate the precision of the CPDM, an
experimental design must minimize the uncontrolled variables in the
sampling. Here, the commenter's data and analysis were based on a
flawed experimental design and analysis.
In addition, spatial variability, or the differences in
concentration related to location, while sometimes substantial, does
not contribute to measurement error. As stated in Sec. 72.800 of this
preamble regarding a single, full-shift measurement of respirable coal
mine dust, the measurement objective is to accurately measure average
atmospheric conditions, or concentration of respirable dust, at a
sampling location over a single shift. The average respirable coal mine
dust concentration on a specific shift is being measured at the
sampling location.
NIOSH has conducted the necessary scientific studies with approved
methods and the results were published in a peer-reviewed document.
Through years of work, NIOSH has demonstrated that the CPDM is an
accurate instrument that meets the NIOSH Accuracy Criterion and,
therefore, can be used as a compliance instrument. (Volkwein et al.,
NIOSH RI 9669, 2006). The recent NIOSH approval of the commercial CPDM,
under 30 CFR part 74, further demonstrates that the CPDM is an accurate
compliance sampling device for determining the concentration of
respirable dust in coal mine atmospheres.
Some commenters expressed concerns regarding the reliability of the
CPDM for long-term compliance use in mines based on their experience
using the device. These commenters cited on-site voiding characterized
in comments as reported instantaneous errors of samples as a persistent
problem. They also stated that 35 to 80 percent of the units in use
were returned for service and that the repair time was lengthy. One
commenter stated that of the 40 CPDMs purchased, 14 units, or 35
percent, were returned to the manufacturer for repair over a 10-month
period, while 5 of the units were returned for repair multiple times,
suggesting the devices were less than mine-ready. According to this
commenter, 20 percent of the 1,000 samples collected indicated that an
error had occurred during sampling and over 6 percent indicated
multiple errors. In addition, the analysis encountered numerous
diagnostic failures with the CPDM units. Another commenter reported
similar equipment and diagnostic issues, as well as failures when
exposed to certain radio frequencies. According to this commenter, the
failures were not reported by the CPDM and, as a result, may have
produced false concentration measurements.
According to NIOSH's comment, these commenters relied on the
analysis of data collected by the CPDM at multiple mines without an
appropriate experimental protocol to control for data quality. Given
that these commenters did not control critical variables like the level
of operator training, sampling methodology, and sample size and
distribution across mines, the data generated do not provide an
appropriate estimate of the CPDM's reliability. In addition, these
commenters misunderstood the CPDM error
[[Page 24864]]
messages received during their testing, believing that the messages
indicated failure of the CPDM. The CPDM, as currently programmed,
monitors its performance during sampling and registers any status
conditions (errors) logged during the sample run. These messages are
not indicative of a failure of the CPDM, rather they provide the user
with valuable constructive feedback in real-time concerning sample
validity. The frequency and type of these error messages are logged
during sample collection. They will be used by MSHA to determine
whether samples are valid or should be voided.
In its comment, NIOSH has identified several parameters currently
being used as validation criteria. These are based on the existing list
of sample validation criteria for the CMDPSU developed over time. Based
on MSHA's previous experience, defining the final validation criteria
requires routine use of the approved CPDM as a compliance instrument.
Given the limited data set, including error messages, from only five
mines cited by the commenters as evidence of CPDM failure, both NIOSH
and MSHA consider the cited failure rate of 41 errors per 1,000 hours
to be invalid. The NIOSH published data remains the most appropriate
data set to assess the failure rate of the CPDM.
In addition to proper interpretation of the error messages, NIOSH
commented that it used an experimental design in their study that
controlled critical variables needed to ensure the quality of data
collected. Two factors related to reliability were evaluated, critical
repairs and remedial repairs. Critical repairs were considered those
that required factory service while remedial repairs were those capable
of being performed in the field. Using this experimental design, the
critical repair rate of the pre-commercial devices was calculated to be
1.24 repairs per 1,000 hours, with a total rate of 4.75 repairs per
1,000 hours. These repair rates are an order of magnitude less than the
failure rates suggested by some commenters due to their inappropriate
analysis of the CPDM's error messages as described above. Furthermore,
repair rates are expected to improve in general due to the quality
control systems required for certification by 30 CFR part 74.
As of June 2011, the CPDM's manufacturer had reported improvements
in repair rates. According to this manufacturer, 77 different units,
representing 28.8 percent of the total units shipped, were returned a
total of 115 times for repair in the previous two years. Repair rates
decreased, quarter over quarter, after the first six to eight months of
shipments due to process improvements. Also, repair turnaround times,
which averaged 26 days per repair the first year following the product
launch in May 2009, averaged 15.1 days between July 2010 and June 2011.
The average turnaround time in 2011 was 4.7 days. Reliability of the
CPDM has improved based on these data, the increasing population of
CPDMs in the field, and the reduction in the number of units being
returned for servicing, and the actions taken by the manufacturer to
address reported field performance.
Some commenters expressed concerns about the CPDM operating
reliably, when used in underground mining environments that have
elevated temperatures and humidity levels, under certain laboratory
conditions, and when exposed to certain radio frequency signals or
electromagnetic interference (EMI). These commenters provided
supplemental information and analysis of laboratory testing indicating
that the CPDM does not respond reliably under all controlled conditions
like those that can be encountered in an underground coal mine.
As discussed earlier, the CPDM was initially tested in 10 mines and
then further tested in 4 other mines that included a variety of coal
types, equipment types, and mining methods, operating conditions,
geographic locations, and seam heights. Consequently, the CPDM was
subjected to the typical temperature and humidity conditions normally
encountered at an underground coal mine. Additionally, sampling
packages that included one CPDM and two CMDPSUs were exposed to the
full range of environmental conditions encountered at over 100 mines, a
good representation of the entire underground mining sector. To be
approved under 30 CFR part 74, the CPDM must operate reliably and
accurately at any ambient temperature and varying temperatures ranging
from -30 [deg]C to + 40 [deg]C; at any atmospheric pressure from 700 to
1,000 millibars; at any ambient humidity from 10% to 100% RH; while
exposed to water mists generated for dust suppression; and while
monitoring atmospheres including such water mists which is common at
longwall mining operations. The differences resulting from temperature
and humidity testing reported by a commenter are below the minimum
detection limit of the commercial CPDM, which is 0.2 mg/m\3\.
Therefore, the commenter's conclusions, which are based on these test
results, are inaccurate. In addition, the CPDM has a user-selected
temperature operating range to optimize performance. The commenter's
test procedures did not specify the selected operating range and did
not indicate that this range was modified for different temperature
ranges.
In addition, the commenter's laboratory testing involved a settling
dust test under controlled conditions, which included the application
of an outdated U.S. Department of Defense, Military Standard MIL-STD-
810F, Method 510.4, Procedure III (January 1, 2000). This laboratory
testing was not designed to evaluate the accuracy and precision of
airborne dust sampling instruments. Therefore, the accuracy and
precision conclusions are inaccurate. The conclusions are also
inaccurate because the testing involved talc as a surrogate for
respirable coal mine dust. Talc has a size distribution ranging from
0.8 to 1.3 [micro]m and is not representative of respirable coal mine
dust, which has a size distribution of 10 [micro]m or less.
Furthermore, because the dust chamber did not establish a uniform
distribution of respirable dust within the chamber, the reported
differences between the CPDMs and between the CPDMs and the CMDPSU
would be expected. Since only one CMDPSU was used during testing, an
estimate of sampler variability could not be obtained. Lastly, only 7
tests were completed and each test was of limited duration. As a
result, the dust settling chamber results submitted by the commenter
are flawed and not representative of the actual underground coal mining
environment.
Some commenters stated that pre-programming of temperature range
selection is difficult in areas such as Alabama which has unseasonable
weather. These commenters also stated that high temperature or high
humidity causes higher CPDM readings and that the 2006 NIOSH study did
not discuss the effect of high temperatures or high humidity.
Certified persons pre-program the CPDMs with environmental
conditions that the units are expected to be exposed to on the sampled
shift. Temperature and humidity in underground coal mines are fairly
uniform and stable and there is little variability experienced on a
daily basis. Even when there are seasonal changes, the operators know
the temperature and humidity ranges that apply to their mines; the
values used to program the CPDMs need to be reasonable but not exact.
Regarding concern expressed about the reliability of the CPDM when
exposed to certain radio frequency (RF) signals or electromagnetic
interference (EMI), the commercial CPDM meets the
[[Page 24865]]
electromagnetic interference requirements of 30 CFR part 74. In
addition, MSHA and NIOSH intend to modify 30 CFR part 74 to incorporate
approval requirements on electro-static discharge and radiated RF
susceptibility. The CPDM manufacturer has redesigned and incorporated
changes to the commercial CPDM to ensure that it passes electro-static
discharge and radiated RF tests before the CPDM is required to be used
for compliance sampling. Testing by an independent lab will provide
verification. These changes should eliminate the commenter's concerns.
Some commenters stated that CPDM calibration is too complex and
difficult and operators will need to have two units ready for each
person to be sampled in case a unit does not properly calibrate.
CPDMs are calibrated by certified persons approximately one to two
times per year depending on the number of hours the unit has operated.
In the event that a unit were to fail the pre-operational check during
the pre-shift warm-up period, the operator would either use another
CPDM for sampling, or notify the District Manager orally and in writing
that sampling will not occur because a CPDM is not available.
Some commenters stated that the CPDM is not designed to perform in
the wet, foggy, and misty atmosphere on the longwall face. They also
stated that wetting of the dust inlet due to rain or roof sweats, water
head bolters, shearers and jacksetters, and shoveling under the belt
will prevent accurate measurement of respirable dust.
The CPDM is designed to perform in such mining environments and
uses the cyclone and heating element to prevent moisture affecting the
CPDM's determination of respirable dust concentration. This was one of
the parameters considered when NIOSH tested the CPDM in underground
mine environments, such as at the longwall face, for part 74 approval.
The CPDM was found to produce accurate results in accordance with
NIOSH's Accuracy Criterion.
One commenter stated that the CPDM collects different dust particle
size than the CMDPSU making it inconsistent with prior definitions of
hazardous respirable dust that supports the underlying risk and benefit
research.
The CPDM and CMDPSU collect essentially the same dust particle size
distribution, with the CPDM almost matching the CMDPSU. This is
illustrated by the low 1.05 constant factor used by the manufacturer
for programming the CPDM to automatically provide an MRE-equivalent
concentration, compared with the 1.38 constant factor used for the
CMDPSU. Both samplers are designed with the same type of cut points
with each sampler using a different cyclone. Each sampler also runs at
a different flowrate, which makes the cyclones behave similarly,
resulting in the CPDM and CMDPSU capturing almost identical dust
particle sizes. This was also a consideration when NIOSH tested the
CPDM for part 74 approval.
Some commenters stated that there is no blank cassette analysis to
protect against the known deficiencies in the filter system that cause
false weight gains.
For a CPDM, there is no need to pre-weigh a filter or to perform a
blank cassette analysis to check the filter. During the unit's 30-
minute warm-up period, the device zeroes the filter to set a baseline
at the beginning of the shift. Anything on the filter or any deficiency
in the filter is eliminated as a potential false weight gain. The CPDM
then registers any net change in weight of the filter during the shift
to correlate the change to a respirable dust concentration measurement.
Some commenters stated that repeated, current lab quality control
procedures, audits and checks to help reduce error are not employed for
the CPDM. One commenter stated, for example, that lab examinations to
determine sample discoloration or evidence of rock dust or other
contaminants are eliminated, increasing the probability of inaccurate
exposure assessments. Other commenters stated that MSHA currently
employs procedures in the sample analytical lab to prevent
contamination-induced false results, such as ``oversized,''
nonrespirable particles or sample contamination from other sources.
These commenters expressed concern that such protections will no longer
be available if the CPDMs are adopted as a compliance mechanism. The
commenters stated that CPDMs use an electronic vibration measurement to
determine sample weight and the collection filters are not examined by
any laboratory for reasons that void large numbers of current samples.
There are no such laboratory examination procedures because the
CPDM filters will not be sent to laboratories. The CPDM recognizes when
contamination is entering the system (e.g., when water enters the unit,
or the unit is overloaded when dropped into a dust powder) and then
triggers sampling status condition codes (referred to as error codes in
the proposed rule). MSHA's experience is that a relatively small number
of samples are voided for contamination or oversize particles. The most
common reason that samples are voided is for excess samples that are
sent by the operator. For example, of the 41,701 operator CMDPSU
samples submitted to MSHA in 2009, approximately 15.6% were voided. Of
those voided samples, approximately 5.48% were voided for submission of
excess samples, 0.11% for oversize particles, and 0.50% for
contaminated samples (U.S. Department of Labor, MSHA, 2012a).
Some commenters stated that, based on limited experimentation, a
new but suspect conversion factor (1.05 CPDM vs. 1.38 CMPDSU) is used
to relate CPDM results to the British MRE sampler on which U.S. health-
based dust risks, benefits, and limits were based.
As noted in the preamble to the proposed rule, NIOSH researchers
(Page et al., 2008) determined that measurements of respirable dust
concentrations using the CPDM and CMDPSU are comparable. The MRE was
used as the basis for the existing coal mine respirable dust standards
and had been designed specifically to match the United Kingdom British
Medical Research Council (BMRC) criterion. The CMDPSU is used with a
1.38 multiplier to convert readings to the BMRC criterion.
In order to compare CPDM measurements with those of the CMDPSU,
NIOSH conducted field research. Researchers used a stratified random
sampling design that incorporated a proportionate allocation strategy
to select a sample of MMUs representative of all U.S. underground coal
mines. A sample of 180 MMUs was chosen, representing approximately 20%
of the MMUs in production at the time the sample was selected
(September 2004). Dust concentrations were monitored concurrently by
both CMDPSUs and CPDMs for a full shift. A total of 129 valid CPDM/
CMDPSU dust sample sets were obtained. A weighted linear regression
analysis of this database shows that, in comparison with the CMDPSU,
the CPDM requires a mass equivalency conversion multiplier of 1.05 [95%
Confidence Interval (1.03 to 1.08)] to produce a concentration that is
an MRE-equivalent concentration similar to the CMDPSU. This research
shows that the two types of sampling units are very comparable due to
this linear relationship.
One commenter stated that the CPDM does not distinguish between
coal dust, rock dust, or any other dust that may be in the air.
[[Page 24866]]
No approved sampling device distinguishes between types of
respirable dust measured at coal mines. The respirable dust standards
in Parts 70, 71, and 90 are environmental standards that apply to
respirable coal mine dust in the mine atmosphere. Any respirable dust
in the mine atmosphere is considered respirable coal mine dust to which
miners are exposed and, when measured, is counted for determining
compliance with the respirable dust standards.
Some commenters stated that requiring miners to frequently read the
CPDM monitor is a safety concern because it distracts miners while
doing their job. One commenter noted that use of the CPDM interfered
with shuttle car operator's running of the shuttle car.
MSHA recognizes that anything new has the potential to attract
attention. However, it is the certified person, not the miner, who is
required under final Sec. 70.205(c) to monitor the dust concentration
being reported by the device at mid-shift or more frequently as
specified in the operator's approved mine ventilation plan. Under final
Sec. 70.201(h), miners will be provided training on the various types
of information displayed on the CPDM screen. At that time, operators
can stress that miners should only make such observations when it is
safe to do so.
Some commenters pointed to studies that show that carrying a load
can result in both physiological and biomechanical changes, discomfort,
higher rates of musculoskeletal disorders (MSDs) and increased risk of
falls. For example, a NIOSH study, Information Circular (IC) 9501-
Miners' Views about Personal Dust Monitors (Peters et al., 2008),
provided limited insight into ergonomic issues associated with wearing
a CPDM. Commenters noted that the NIOSH study followed a previous
model, which found that perceived negative features or barriers could
affect an individual's actions regarding the use of the CPDM to assess
and reduce his or her dust exposures. Commenters stated that, for the
NIOSH report, 30 miners were interviewed and that some miners reported
issues with sitting in equipment due to the limited space in operator
compartments and with the CPDM getting bumped when working in confined
areas. In addition, some miners said when the CPDM was attached to the
belt with no clips, it sometimes falls off the belt, and when pouches
were provided to hold the CPDM, sometimes there was not enough room on
the belt for the pouch because of the other pouches already on the
belt. Commenters noted that 11 miners who had worn the CPDM responded
to a questionnaire and that 82 percent had problems that included
discomfort, weight issues, difficulty wearing it on the miner's belt,
being in the way when interfacing with equipment, and many errors
occurring.
The 2008 NIOSH study (Peters et al., 2008) cited by commenters was
based on a pre-commercial model of the CPDM. Since that time, the
manufacturer has improved the unit's design, incorporating a better
means of attaching the unit to the miner's belt and providing a shorter
cap lamp cord. These improvements allow better positioning of the CPDM
on the miner. NIOSH evaluated the commercial CPDM model and, in
September 2011, determined that it met the CPDM approval requirements
of 30 CFR part 74, which include that the CPDM be designed and
constructed so that miners can wear and operate the CPDM without
impeding their ability to perform their work safely and effectively.
In addition, many commenters expressed concern about the weight of
the CPDM and the size and stiffness of the sampling hose and light cord
assembly. Some commenters stated that requiring miners to wear the
CPDM, many of whom have become accustomed to wearing the smaller and
lighter cap light compared to the lead acid battery, will suffer
serious musculoskeletal disorders, which have been on a decline.
MSHA notes that under the final rule, miners will wear the CPDM
less since the frequency of required sampling is significantly reduced
from the proposal, which would have required 24/7 sampling of the DO
and the part 90 miner. This is discussed elsewhere in the preamble
under final Sec. Sec. 70.201, 70.208, and 90.207.
Also, NIOSH commented that when the configuration of the CPDM was
conceived in 1999 at the urging of the mining community, miners
typically wore both a self-contained self-rescuer (SCSR) on their
mining belt and a battery to power their cap lamp. Integrating the CPDM
with the cap lamp battery reflected the available technology at that
time. The current CPDM integrates the dust sampler and cap lamp
battery, with a total weight that is within 8 ounces of the traditional
lead acid cap lamp battery alone, a power source that is still in use.
According to an MSHA survey of 418 coal mines in October 2010,
which was completed after publication of the proposed rule, 47 percent
of the cap lamps in use were being powered by lead-acid batteries. In
its comment, NIOSH noted that traditional lead acid cap lamp batteries
weigh over 5 pounds. The total relative increase in the weight of the
miner's belt is low given that only 8 ounces is added by combining the
CPDM with the cap lamp battery. Not only is the marginal weight change
of the miner's ensemble an important factor regarding biomechanical
loading, but the resultant weight distribution characteristics
(especially height and anterior-posterior of center of mass) are
important with respect to balance issues. Studies, by Lin et al. (1996)
and Dempsey et al. (1996), show that user preferences and biomechanics
of different loading configurations are complex but, the least
problematic configuration was the placement of two symmetric loads
below hip level with two shoulder straps and a waist belt. Although
this configuration used criss-crossed straps, it was otherwise similar
to a typical miner's belt configuration. A miner's belt may be more
effective at reducing shoulder loads because it transfers the load to
the hips, which reduces the risk of injury to the shoulders and back.
Commenters suggested that, because recent advances in cap lamp
technology have reduced the size and weight of the battery, the CPDM
should not be used as a compliance instrument until it accommodates
this new technology. Other commenters suggested separating the dust
sampler from the cap lamp. Ultimately, the existing design of the CPDM
may be modified to accommodate the change in cap lamp technology. The
CPDM manufacturer has reported plans to improve the ergonomic design of
the unit. Changes include a shorter cap lamp cord to minimize tangling,
especially in low coal; removal of the cap lamp due to recent approvals
of wireless cap lamps; and possible reduction in weight.
Some commenters stated that the CPDM should not be required until
it can measure silica exposures.
Neither the CMDPSU nor the CPDM is able to measure quartz in
respirable coal mine dust samples. MSHA will continue to collect
respirable dust samples to analyze for quartz to establish applicable
respirable dust standards and limit miners' quartz exposure. Also, as
discussed elsewhere in the preamble related to Sec. 70.101, the final
rule does not change the existing respirable dust standard when quartz
is present.
Some commenters expressed concern that there is only one CPDM
manufacturer and, therefore, requiring use of the CPDM results in
guaranteed sales regardless of price, performance, or quality of
service, and there will be little incentive for the manufacturer to
address issues limited to a small
[[Page 24867]]
segment of customers. Based on its experience with the CPDM
manufacturer, MSHA does not anticipate the concerns expressed by the
commenters. The Agency anticipates a continuation of the same high
level of cooperation that the manufacturer of the CPDM has shown to
date.
Some commenters stated that there should be a 24-month interim
period before a new standard becomes effective. The commenters
suggested that during this period the gravimetric sampler should be
used while a joint labor, industry, MSHA, and NIOSH committee consider
problems that may arise as the CPDM and new standards are integrated
into underground mining. As the mining industry knows, MSHA and NIOSH
jointly approved the CPDM for use in underground coal mines, and
determined that the device was accurate, precise, reliable, and durable
under in-mine conditions. MSHA intends on taking the lead in conducting
a retrospective study beginning February 1, 2017. MSHA also intends to
evaluate the data collected using CPDMs to determine whether (1) the
1.5 mg/m\3\ respirable dust standard should be lowered to protect
miners' health; (2) the frequency of CPDM sampling should be increased;
(3) engineering controls and work practices used by mine operators
achieve and maintain the required respirable coal mine dust levels; and
(4) samples taken on shifts longer than 8 hours should be converted to
an 8-hour equivalent concentration to protect miners who work longer
shifts. Using the results of this study, MSHA intends to identify best
practices that can be shared with the mining community. Under the
Department's Plan for Retrospective Analysis of Existing Rules, MSHA
intends to consult with industry, labor, NIOSH, and other stakeholders
to determine how these best practices can be replicated throughout
mines to achieve similar results.
This retrospective study will be conducted in accordance with the
Department of Labor's Plan for Retrospective Analysis of Existing Rules
which complies with Executive Order (E.O.) 13563 ``Improving Regulation
and Regulatory Review'' (76 FR 3821). E.O. 13563 requires agencies to--
develop and submit to the Office of Information and Regulatory
Affairs a preliminary plan, consistent with law and its resources
and regulatory priorities, under which the agency will periodically
review its existing significant regulations to determine whether any
such regulations should be modified, streamlined, expanded, or
repealed so as to make the agency's regulatory program more
effective or less burdensome in achieving the regulatory objectives.
[76 FR 3822]
The Department of Labor's Plan for Retrospective Regulatory
Review--
is designed to create a framework for the schedule and method
for reviewing its significant rules and determining whether they are
obsolete, unnecessary, unjustified, excessively burdensome,
counterproductive or duplicative of other Federal regulations.
Sections 70.201 and 90.201 of the final rule provide that operators
must use CPDMs 18 months after the effective date of the rule. In the
event of any logistical or feasibility issues involving the
availability of the CPDM, MSHA will publish a notice in the Federal
Register to continue to use an approved CMDPSU to conduct sampling. In
addition, assuming no technological issues arise concerning the use and
manufacture of CPDMs, and depending on manufacturer projections, if
CPDMs are not available in sufficient quantities, MSHA will accept, as
good faith evidence of compliance with the final rule, a valid, bona
fide, written purchase order with a firm delivery date for the CPDMs.
3. Technological Feasibility of Achieving the Required Dust Standards
MSHA concluded, in the PREA, that compliance with the respirable
dust standards in the proposed rule was feasible on each shift because
the sampling data indicated that mine operators are keeping miners'
average exposures at or below the levels required under the existing
standards, and dust exposures at most operations average less than the
proposed standards of 1.0 mg/m\3\ for underground and surface coal
mines, and 0.5 mg/m\3\ for part 90 miners and intake air. MSHA
acknowledged, however, that some of the proposed requirements regarding
the use of single full-shift samples to determine noncompliance on each
shift and changes to the definition of normal production shift would
result in higher exposure measurements when compared to the existing
sampling program. MSHA concluded that existing engineering controls
including ventilation, water sprays and environmentally controlled cabs
along with changes in work practices can be used to further reduce dust
levels. Engineering controls are the primary means used to control
respirable coal mine dust exposures. Work practices may be used to
further reduce dust levels. In addition, MSHA acknowledged that in rare
instances, some operators, after taking these actions, may encounter
implementation issues as they attempt to comply with the proposed
requirements and need to take additional measures to comply with the
proposed standards. To allow mine operators adequate time to comply
with the proposed respirable dust standards, MSHA included a two-year
phase-in period for the 1.0 mg/m\3\ proposed standard for underground
and surface coal mines, and a six-month phase-in period for the 0.5 mg/
m\3\ proposed standard for part 90 miners and intake air.
Many commenters expressed concern with complying with the proposed
1.0 mg/m\3\ standard for underground and surface coal mines on each
shift. They stated that they have incorporated all available
engineering and administrative dust controls and that they cannot lower
respirable dust levels any lower than the existing 2.0 mg/m\3\
standard. In addition, several commenters stated that MSHA incorrectly
assessed the feasibility of the proposed 1.0 mg/m\3\ standard for
underground coal mines. These commenters stated that the vast majority
of operators cannot meet the proposed 1.0 mg/m\3\ standard on a single
shift sampling basis at any single mine over any substantial period of
time. They stated that operators may be able to meet the proposed
standard some of the time, but will not be able to meet the proposed
standard all of the time, as would have been required by the proposed
rule. Other commenters stated their calculations showed that, as
opposed to less than 200 citations per year for violations of the
current 2.0 mg/m\3\ standard, a 1.0 mg/m\3\ standard based on a single,
full-shift measurement could result in more than 230,000 citations
annually. In addition, some commenters stated that each violation would
require abatement, a penalty, and mine plan amendments, and would
likely result in mine interruptions until plan approvals can be
obtained and abatement accomplished. These commenters stated that by
averaging results from the current dust sampling system and not using
the latest 2010 database of single shift sample results to determine
compliance impacts under the proposed rule, MSHA improperly masked the
feasibility of the proposal. Lastly, some commenters stated that MSHA
did not support its conclusion that existing engineering controls and
changes in work practices can be used to further reduce dust levels.
These commenters, however, did not provide any definitive data to
support their statements.
During the development of the final rule, MSHA evaluated the
rulemaking record, including public comments, and the potential impacts
of alternatives to
[[Page 24868]]
the proposed rule. As a result of this evaluation, the final rule
addresses the commenters' concerns in several ways. First, the final
rule includes a respirable dust standard of 1.5 mg/m\3\ for underground
and surface coal mines. MSHA's rationale for the 1.5 mg/m\3\ standard
is discussed elsewhere in this preamble under Sec. Sec. 70.100 and
71.100. MSHA's analysis of the technological feasibility of the 1.5 mg/
m\3\ standard for underground and surface coal mines and the 0.5 mg/
m\3\ standard for part 90 miners and intake air on each shift is
discussed below.
Second, the final rule requires sampling of designated occupations
(DOs) on 15 consecutive shifts each quarter. The proposal would have
required sampling of DOs on each and every shift.
Third, the final rule provides that noncompliance with the
respirable dust standard is demonstrated during the sampling period
when either two or more samples out of five operator samples or three
or more samples out of fifteen operator samples meet or exceed the
applicable excessive concentration value (ECV), or the average for all
operator samples meets or exceeds the applicable ECV.\56\ A detailed
discussion on the ECVs is in Appendix A of this preamble. MSHA
constructed the ECVs to ensure that a citation is issued when the
respirable dust standard is exceeded. The ECVs ensure that MSHA is 95
percent confident that the applicable respirable dust standard has been
exceeded. Each ECV accounts for the margin of error between the true
dust concentration measurement and the observed dust concentration
measurement when using the CMDPSU or the CPDM.
---------------------------------------------------------------------------
\56\ In the final rule, compliance determinations are also based
on single full-shift MSHA inspector samples. MSHA inspectors sample
a small fraction of a mine's production shifts to ensure that dust
levels are at or below the standard.
---------------------------------------------------------------------------
Under the proposal, noncompliance determinations would have been
made on an operator's single full-shift sample that met or exceeded the
ECV or a weekly accumulated exposure that exceeded the weekly
permissible accumulated exposure.
Finally, MSHA has revised the methodology used to assess the
technological feasibility of meeting the respirable coal mine dust
standards. To evaluate the impact of the final rule, MSHA retained the
adjustment factor used in the PREA for normal production. MSHA did not
retain the adjustment factor to estimate an equivalent 8-hour
concentration for work shifts longer than 8 hours. Like the proposal,
MSHA's feasibility analysis is based on sampling data from samples
collected in 2008 and 2009. Rather than using both operator and
inspector samples as was done for the proposal, this final analysis is
based solely on MSHA inspector samples. MSHA has more confidence in
MSHA inspector samples for the reasons discussed in Section 1(a) of the
QRA for the final rule.
As in the PREA, these data reflect measurements under the existing
sampling program. The definition in the final rule for a normal
production shift will result in higher exposure measurements when
compared to the existing sampling program. Therefore, as in the PREA,
each individual sample is adjusted to account for normal production as
defined by the final rule.
Even without an adjustment for work shifts longer than eight hours,
the final rule results in more representative measurement of dust
concentrations to which miners are being exposed on a daily basis in
the active workings. Under final Sec. Sec. 70.201(c), 71.201(b), and
90.201(b), sampling is conducted over the entire work shift. Since the
work shift for many miners normally extends beyond eight hours, the
reported sampling results for the 2008 and 2009 period likely
understate miners' everyday coal mine respirable dust exposures. MSHA
anticipates an increase initially in the observed dust concentrations
under the final rule.
To evaluate the impact of the proposed rule for feasibility
purposes, MSHA applied two adjustment factors to the 2008-2009 data.
The first factor adjusted the 2008-2009 sample data to estimate an
equivalent 8-hour concentration for work shifts longer than eight
hours. The second factor adjusted the sample data for normal
production. After consideration of the comments and relevant data, MSHA
is not including in the final rule the provision that adjusts
respirable coal mine dust measurements for shifts longer than 8 hours.
The rationale for not including this provision is discussed elsewhere
in the preamble discussion of the equivalent concentration definition
under Sec. 70.2.
To evaluate the impact of the final rule for feasibility purposes,
MSHA retained the adjustment factor for normal production that was
applied to the 2008-2009 data. In deriving the normal production
adjustment factor for underground mines, MSHA applied a conservative
method using production data for the previous 30 production shifts
collected from mine operators during the Agency's enforcement
activities in October 2009. First, the average shift length was
calculated for underground operations. Using 2009 shift length
information for each mine stored in the MSHA Standardized Information
System (MSIS) database, MSHA determined that the average shift length
for longwall MMUs was 10 hours and the average for non-longwall MMUs
was 9 hours. The 30-shift average production was calculated for each of
the 193 MMUs that were inspected. These production values were then
averaged across all non-longwall and longwall MMUs, yielding estimated
overall 30-shift averages of 921 tons and 7,355 tons, respectively.
These averages were then divided by the average shift length for the
MMU type established earlier to estimate average production rate in
tons per hour. For example, to estimate the overall longwall MMU
production rate, 7,355 tons, which represents the full-shift
production, was divided by 10 hours, yielding an estimated production
rate of 736 tons/hour. The same calculation was performed for non-
longwall MMUs resulting in a production rate of 102 tons/hour (921 tons
/ 9 hrs).
Next, the production reported for each MSHA inspector and operator
sample collected during CY 2009 was averaged across all non-longwall
and longwall MMUs. This yielded overall 8-hour averages of 672 tons and
5,537 tons, respectively, for MSHA inspector samples, and 703 tons and
5,398 tons, respectively, for operator compliance samples. These
averages were then divided by 8 hours, yielding estimates of the
average production rate across the respective MMU types. For example,
the production rate for operator samples was estimated at 88 tons/hour
(703 tons/8 hr) for non-longwall MMUs and 675 tons/hour (5,398 tons/8
hr) for longwall MMUs.
These estimates of average production rates were used to derive the
industry-wide production factors by dividing the estimated overall 30-
shift average production rate by the overall CY 2009 average production
rate. In the case of non-longwall MMUs, each operator DO concentration
was multiplied by 1.16 (102/88 tons/hr). And, each longwall MMU sample
was multiplied by 1.09 (736/675 tons/hr).
Although some commenters stated that MSHA's feasibility assessment
of the proposed rule was based solely on historical averages, that
assessment was based on the mean (or average) concentrations, the
average deviation of sample concentrations from standards, and the
percentage of observations above the standard. For the final rule, MSHA
presents these summary statistics for more detailed occupations than
were presented for the proposal
[[Page 24869]]
and also presents the median. MSHA also calculated the average
deviations in a slightly different manner than was done for the
proposal. Rather than computing the deviation from the existing
standards as was done for the proposal, the deviation in this analysis
is the deviation from the final standard or the existing standard,
whichever is lower.
The means and medians of the detailed occupations and locations are
measures of central tendency and help to answer the question of whether
typical dust levels in each operation/location currently meet the
standards. If both the mean and median of the inspector samples
collected in various mines over the two-year period are less than the
final standard, then MSHA concludes that typical dust levels for that
occupation/location currently meet the standard. The percentage of
observations currently above the final standards for each occupation/
location indicates the probability that an MSHA inspector will find a
violation for a single full-shift sample exceeding the standard in the
final rule.\57\ The average deviation of the sample concentrations from
the existing standard or final standard provides an indication of the
degree to which mine operators are currently meeting the standards in
the final rule. In addition, the average deviation takes into account
the reduced standards below 1.5 mg/m\3\. A negative average deviation
indicates how much exposures average below the 1.5 mg/m\3\ standard and
any reduced standard below 1.5 mg/m\3\ that was in effect at the time
the samples were taken.
---------------------------------------------------------------------------
\57\ For this analysis, MSHA used the standard even though a
sample would have to meet or exceed the ECV for there to be a
violation under the final rule.
---------------------------------------------------------------------------
Summary data for various types of coal mining are presented in the
following sections. After each presentation, MSHA also discusses the
currently available dust control technology which can be used to reduce
exposures that exceed the final standard. As was noted in the PREA,
these technologies are also discussed in several NIOSH publications
available at: http://www.cdc.gov/niosh/mining/topics/RespirableDust.html. In response to comments, the discussions of the
control technologies are more extensive in this assessment than those
presented in the assessment of the proposed rule.
MSHA reviewed MMU data where an inspector collected a respirable
dust sample that, after adjustments to represent the normal production
on that shift, would have exceeded a concentration of 1.5 mg/m\3\.
Specifically, MSHA looked at all longwall and approximately 20% of non-
longwall MSHA MMU dust surveys collected during the fourth quarter of
calendar year 2009 where the adjusted concentrations would have
exceeded 1.5 mg/m\3\. MSHA reviewed measurements of the engineering
controls in use on the day each sample was collected to assess whether
using additional engineering controls would have likely reduced the
dust concentration to levels at or below 1.5 mg/m\3\. Every survey
indicated that additional control measures are available that would be
likely to reduce the respirable dust concentration to 1.5 mg/m\3\ or
less. MSHA determined that many MMUs could: Increase air quantity, air
velocity, the number of water sprays, and the water pressure; balance
the quantity of air delivered to the face with the scrubber air
quantity; and/or change from blowing face ventilation to exhausting
face ventilation. Changing one or more dust controls is an option at
all MMUs that MSHA reviewed. On nearly all MMUs that used blowing face
ventilation and a scrubber, the air quantity provided was less than the
scrubber air quantity, causing an imbalanced system and the potential
for respirable dust overexposures. Many MMUs using exhausting face
ventilation had air quantities that would produce Mean Entry Air
Velocities (MEAV) of less than 100 feet per minute (fpm), which
indicates that the air provided could be increased to provide greater
protection of miners' health. The number of water sprays, while
important, is not the only spray variable affecting dust control; the
location, flow rate, spray pattern, and droplet size are variables that
impact dust levels where miners work. The dust control data that MSHA
reviewed is contained in two spreadsheets titled ``MSHA Longwall
Surveys with Adjusted Concentrations of 1.5 mg/m\3\ Dust Controls, Oct-
Dec 2009'' and ``MSHA Random Non-Longwall Surveys with Adjusted
Concentrations of 1.5 mg/m\3\ Dust Controls, Oct-Dec 2009'' (U.S.
Department of Labor, MSHA, 2012b and 2012c). Detailed discussions of
these dust control technologies follow.
Some commenters expressed concern with the phase-in periods in
proposed Sec. Sec. 70.100, 71.100, and 90.100 regarding the respirable
dust standards, Sec. 70.101 regarding the respirable dust standard
when quartz is present, and Sec. 75.350 regarding the respirable dust
standard in the belt air course. The final rule is changed from the
proposal. It includes a 24-month implementation date in each of these
sections to provide an appropriate amount of time for mine operators to
comply with the standards in the final rule. Comments on the proposed
phase-in periods and MSHA's rationale for the 24-month period in the
final rule are discussed elsewhere in this preamble under final
Sec. Sec. 70.100, 70.101, 71.100, 75.350, and 90.100.
a. Surface Coal Mines and Facilities
Table IV-1 presents a summary of the 2008-2009 sampling data for
surface coal mines and facilities by selected occupations. Of the more
than 4,500 samples taken by MSHA inspectors at surface coal operations
and facilities during 2008 and 2009 approximately 5% exceeded the
standard and the average deviation was 0.69 mg/m\3\ below the standard.
The mean and median of the samples were 0.47 mg/m\3\ and 0.26 mg/m\3\,
respectively. MSHA believes that these data overstate the exposures at
surface coal operations and facilities because, rather than conducting
random sampling, MSHA inspectors tend to sample operations where they
believe respirable coal mine dust levels are high. Based on these data,
MSHA concludes that most operations at surface mines and facilities can
meet the 1.5 mg/m\3\ standard without significant changes on each
shift.
Table IV-1--Summary of 2008-2009 Sampling Data for Surface Coal Mines and Facilities, by Selected Occupations
----------------------------------------------------------------------------------------------------------------
Number of Pct. > Avg. deviation
Occupation samples Mean mg/m\3\ Median mg/m\3\ standard * mg/m\3\
----------------------------------------------------------------------------------------------------------------
Bulldozer Operator.............. 1,118 0.28 0.16 1 -0.50
Cleaning Plant Operator......... 175 0.75 0.59 13 -0.75
Cleanup Man..................... 108 0.55 0.44 2 -0.95
Crusher Attendant............... 104 0.62 0.35 12 -0.71
[[Page 24870]]
Fine Coal Plant Operator........ 177 0.84 0.71 14 -0.66
Highlift Operator/Front End 160 0.28 0.12 1 -1.08
Loader.........................
Highwall Driller................ 797 0.43 0.24 4 -0.44
Laborer/Blacksmith.............. 179 0.52 0.34 8 -0.90
Mechanic........................ 194 0.49 0.37 4 -1.00
Other **........................ 799 0.47 0.28 5 -0.83
Refuse Truck Driver/Backfill 162 0.30 0.24 0 -1.13
Truck Driver...................
Utility Man..................... 386 0.71 0.44 12 -0.76
Welder (NonShop)................ 188 0.69 0.24 10 -0.81
-------------------------------------------------------------------------------
Total....................... 4,547 0.47 0.26 5 -0.69
----------------------------------------------------------------------------------------------------------------
* 1.5 mg/m\3\ or a reduced standard below 1.5 mg/m\3\.
** Occupations with fewer than 100 samples.
Source: Tabulation of MSHA MSIS Data.
The highest mean and median exposures and the greatest percentage
of samples exceeding the standard were for the cleaning plant and fine
coal plant operators. As MSHA stated in the PREA, workers in surface
facilities can be protected by enclosing the dust-generating processes,
placing the operator in an environmentally controlled booth, using dust
collectors to limit the amount of dust that becomes airborne, ensuring
that the equipment is being maintained and functioning properly, and
following good work practices.
As MSHA noted in the PREA, engineering controls and work practices
are also available to reduce the dust concentrations at other surface
work locations. According to NIOSH's Best Practices for Dust Control in
Coal Mining (Best Practices), most of the dust generated at surface
mines is produced by mobile earth-moving equipment such as drills,
bulldozers, trucks, and front-end loaders, excavating silica-bearing
rock and minerals. There exist four practical areas of engineering
controls to mitigate surface mine worker exposure to all airborne
dusts, including silica. Those are drill dust collection systems
including wet suppression, enclosed cab filtration systems, controlling
dust on unpaved haulage roads, and controlling dust at the primary
hopper dump. (Colinet et al., 2010 NIOSH Information Circular 9517,
Best Practices for Dust Control in Coal Mining, (``NIOSH IC 9517''),
pp. 65-72.)
MSHA concludes that it is technologically feasible for surface coal
mines and facilities to comply with the 1.5 mg/m\3\ standard in the
final rule on each shift.
In addition, a review of the 2008-2009 operator-submitted
respirable coal mine dust samples used for the proposed rule shows 97
surface mines operating on reduced standards of 0.5 mg/m\3\ or less.
Many mines submitted respirable dust samples that routinely indicate
the mine is able to operate and still control dust at or below the 0.5
mg/m\3\ level. For operator-submitted respirable dust samples for 2008
and 2009, 65% of all valid samples were at or below 0.5 mg/m\3\. The
engineering controls and work practices available to reduce quartz
exposure at surface mines are the same as those described above for
reducing dust levels at surface coal mines and facilities.
b. Intake Air at Underground Coal Mines
Table IV-2 presents a summary of the 2008-2009 inspector intake air
samples at underground coal mines. Of the more than 8,200 samples taken
by MSHA inspectors in underground coal operations during 2008 and 2009,
less than 6% exceeded 0.5 mg/m\3\ and the average deviation was 0.33
mg/m\3\ below the 0.5 mg/m\3\ standard. The mean and median of the
samples were 0.17 mg/m\3\ and 0.11 mg/m\3\, respectively. Based on
these data, MSHA concludes that most intake air can meet the 0.5 mg/
m\3\ standard without significant changes on each shift.
According to NIOSH's Best Practices, maintaining this concentration
is not usually difficult, but it requires attention from mine operators
to address activities that can raise intake air dust levels. Typically,
high levels of intake air dust are sporadic and brief in nature due to
activities in the intake air entries that may take place over the
course of a working shift. These sporadic activities include delivery
of supplies and/or personnel, parking equipment in the intake, rock
dusting, scoop activity, and construction activity. (NIOSH IC 9517,
2010, p. 61.)
Table IV-2--Summary of 2008-2009 Inspector Intake Air Samples at Underground Coal Mines
----------------------------------------------------------------------------------------------------------------
Number of Pct. > 0.5 mg/ Avg. deviation
Location samples Mean mg/m\3\ Median mg/m\3\ m\3\ mg/m\3\
----------------------------------------------------------------------------------------------------------------
Not Belt Air.................... 7,655 0.15 0.10 3.5 -0.35
Belt Air........................ 613 0.43 0.35 28.1 -0.07
-------------------------------------------------------------------------------
Total....................... 8,268 0.17 0.11 5.3 -0.33
----------------------------------------------------------------------------------------------------------------
Source: Tabulation of MSHA MSIS Data.
The highest mean and median exposures and the greatest percentage
of intake air samples exceeding 0.5 mg/m\3\ were taken in belt entries.
The average deviation for the belt air samples was less than 0.1 mg/
m\3\ below the 0.5 mg/
[[Page 24871]]
m\3\ standard. One commenter specifically supported respirable dust
control and reduction in dust levels for intake air because intake air
goes straight to the face.
According to NIOSH's Best Practices, when belt air is used for face
ventilation, dust generated in the belt area should be controlled. Dust
controls at the belt head helped maintain low dust levels in the belt
entry. Automated water sprays were used to suppress dust at the
section-to-main belt transfer point. A belt scraper equipped with water
sprays controlled dust by cleaning the outside surface of the belt
after the coal had been transferred to the main belt. (NIOSH IC 9517,
2010, p. 61.)
In addition, because the potential for dust from the belt entry to
contaminate the face area has increased in recent years due to the
increased quantity of coal being transported by the belt, NIOSH states
that the following practices can help control respirable dust levels in
the belt entry: Belt maintenance, wetting the coal product during
transport, belt cleaning by scraping and washing, use of a rotary brush
that cleans the conveying side of the belt, and wetting dry belts.
(NIOSH IC 9517, 2010, pp. 18-19.)
MSHA concludes that it is technologically feasible for mine
operators to meet the 0.5 mg/m\3\ standard for intake air on each
shift. As noted in the PREA, many of the high dust concentrations for
intake air represented samples taken while belt entries were being used
as intake air courses. Dust concentrations in the belt entry, when used
as an intake air course, can be consistently maintained at or below the
final standard by employing currently available engineering controls
such as water sprays at transfer points to adequately wet the conveyor
belt and transported coal, combined with regular belt maintenance and
cleaning of the belt entry. Moreover, no mine is required to use belt
entries as intake air courses and relatively few do (less than 40 mines
in 2009). If maintaining the belt entries is burdensome, an operator
has the option of using another entry for intake air.
c. Part 90 miners
Table IV-3 presents a summary of the 2008-2009 sampling data for
part 90 miners. Of the 500 samples taken by MSHA inspectors for part 90
miners during 2008 and 2009, approximately 23% exceeded 0.5 mg/m\3\ and
the average deviation was 0.13 mg/m\3\ below the applicable standard.
The mean and median of the samples were 0.37 mg/m\3\ and 0.24 mg/m\3\,
respectively. These data indicate that current dust levels for the part
90 miners meet the final 0.5 mg/m\3\ standard. In addition, dust levels
for part 90 miners will likely decline under the final rule after
operators implement controls to reduce the dust levels in the intake
airways and active workings. Further, there are currently fewer than 70
part 90 miners out of an underground coal work force of approximately
50,000 miners. A mine operator may further reduce the dust levels of a
part 90 miner by limiting the time that the part 90 miner spends in
high dust areas, such as at the face for underground miners; on the
surface, for example, an operator can move a part 90 miner to a less
dusty job or place the miner in an environmental cab. Finally, part 90
miners can avoid areas of the mine that are under a reduced dust
standard due to the presence of quartz. Therefore, MSHA concludes that
it is technologically feasible for mine operators to meet the final 0.5
mg/m\3\ standard for part 90 miners on each shift.
Table IV-3--Summary of 2008-2009 Sampling Data for Part 90 Miners
----------------------------------------------------------------------------------------------------------------
Pct. > 0.5 mg/ Avg. deviation
Number of samples Mean mg/m\3\ Median mg/m\3\ m\3\ mg/m\3\
----------------------------------------------------------------------------------------------------------------
502............................................. 0.37 0.24 23 -0.13
----------------------------------------------------------------------------------------------------------------
Source: Tabulation of MSHA MSIS Data.
d. Non-Longwall Underground Mining Operations
Table IV-4 presents a summary of the adjusted 2008-2009 sampling
data for non-longwall operations in underground coal mines by selected
occupations. Of the nearly 38,000 samples taken by MSHA inspectors at
non-longwall operations in underground coal mines during 2008 and 2009,
after adjustment, approximately 9% exceeded the standard and the
average deviation was 0.68 mg/m\3\ below the standard. The mean and
median of the samples were 0.75 mg/m\3\ and 0.59 mg/m\3\, respectively,
approximately half of the 1.5 mg/m\3\ standard.
Table IV-4--Summary of Adjusted 2008-2009 Sampling Data for Non-Longwall Operations in Underground Coal Mines,
By Selected Occupations
----------------------------------------------------------------------------------------------------------------
Number of Pct. > Avg. deviation
Occupation Samples Mean mg/m\3\ Median mg/m\3\ Standard * mg/m\3\
----------------------------------------------------------------------------------------------------------------
Coal Drill Operator............. 194 0.75 0.61 8 -0.73
Continuous Mining Machine Helper 656 0.79 0.64 8 -0.63
Continuous Mining Machine 7,595 0.99 0.81 17 -0.44
Operator.......................
Cutting Machine Operator........ 185 1.14 0.91 25 -0.35
Electrician..................... 949 0.40 0.31 2 -0.98
Laborer......................... 257 0.40 0.30 5 -1.03
Loading Machine Operator........ 284 0.36 0.30 0 -1.12
Mechanic........................ 406 0.56 0.45 4 -0.86
Mobile Bridge Operator.......... 1,283 0.80 0.67 9 -0.69
Other **........................ 407 0.59 0.41 6 -0.82
Roof Bolting Machine Operator... 8,651 0.74 0.60 8 -0.70
Scoop Car Operator.............. 3,574 0.69 0.53 8 -0.74
Section Foreman................. 385 0.64 0.50 7 -0.78
Shuttle Car Operator............ 11,867 0.68 0.54 7 -0.74
Tractor Operator/Motorman....... 275 0.53 0.41 3 -0.91
[[Page 24872]]
Utility Man..................... 775 0.63 0.51 5 -0.79
-------------------------------------------------------------------------------
Total....................... 37,743 0.75 0.59 9 -0.68
----------------------------------------------------------------------------------------------------------------
* 1.5 mg/m\3\ or a reduced standard below 1.5 mg/m\3\.
** Occupations with fewer than 100 samples.
Source: Tabulation of MSHA MSIS Data.
The highest mean, median exposures, the greatest percentage of
samples exceeding the applicable standard, and the smallest average
deviation below the applicable standard were for the cutting machine
and continuous mining machine operators. These data are consistent with
NIOSH's findings that the greatest source of respirable dust at
continuous mining operations is the continuous mining machine. NIOSH's
Best Practices states that, at most continuous mining operations, the
DO is the continuous mining machine operator and that dust generated by
the continuous mining machine has the potential to expose the
continuous mining machine operator and anyone working downwind of the
active mining. (NIOSH IC 9517, 2010, p. 41.)
In the PREA, MSHA stated that dust levels at non-longwall
operations could be controlled using currently available engineering
controls, implementing well-designed face ventilation systems and
controls, and following good maintenance and work practices. This is
consistent with NIOSH's Best Practices, which states that ventilating
air to a continuous mining section, whether blowing or exhausting, is
the primary means of protecting workers from overexposure to respirable
dust. In addition, proper application of water spray systems,
ventilation, and mechanical equipment (scrubbers) provides the best
overall means of respirable dust control. Also, the maintenance of
scrubbers, water sprays, cutting bits and/or drill bits is basic to any
effective dust control strategy and must be routinely practiced.
Furthermore, suppression of dust is the most effective means of dust
control. Suppression is achieved by the direct application of water to
wet the coal before and as it is broken to prevent dust from becoming
airborne.
Once dust is airborne, NIOSH states that other methods of control
must be applied to dilute it, direct it away from workers, or remove it
from the work environment. For example, redirection of dust is achieved
by water sprays that move dust-laden air in a direction away from the
operator and into the return entry or behind the return ventilation
curtain. In addition, capture of dust is achieved either by water
sprays that impact with the dust in the air to remove it or by
mechanical means such as fan-powered dust collectors. Ventilating air
dilutes and directs dust away from workers. Either blowing or
exhausting ventilation is used on continuous mining sections. A cut
sequence should be adopted so that cut-throughs are made from intake to
returns when practical to prevent return air from blowing back over the
operator. Handheld remote control of the continuous mining machine has
made it possible for operators to stay outby the continuous mining
machine while operating the machine; however, operator positioning is
crucial depending on the ventilation system being used. The velocity
and quantity of face ventilating air are important factors for
controlling respirable dust exposure of the continuous mining machine
operator. A good ventilation plan consists of sufficient mean entry air
velocity to confine dust near the face and/or direct it toward the
return entry with a high enough quantity of air for diluting generated
respirable dust. (NIOSH IC 9517, 2010, pp. 41, 48, 54.)
Roof bolting machines are another source of dust at non-longwall
underground coal mine operations. Most roof bolting machines are
equipped with MSHA-approved dry dust collection systems to remove dust
during drilling. However, roof bolting machine operators can be
overexposed to dust from drilling, cleaning the dust collector, not
maintaining the dust collector, or working downwind of the continuous
mining machine. According to NIOSH, the largest source of operator dust
exposure can occur from working downwind of the continuous mining
machine. NIOSH states that if the dry dust collector is properly
maintained and if the roof bolting machine is not working downwind of
the continuous mining machine, very little dust should be measured in
the roof bolting machine operator's work environment.
According to NIOSH, there are three major roof bolting respirable
dust problem areas: (1) Filter leaking or plugging, (2) accumulation of
dust in the collection system, and (3) low airflow at the bit due to
hose, fitting, and relief valve leaks. NIOSH's best practices can help
reduce dust exposure to the roof bolting machine operator by
maintaining the dust collector system, cleaning the dust box, using
dust collector bags, routing miner-generated dust to the return, and
not working downwind of the continuous mining machine. (NIOSH IC 9517,
2010, p. 57).
Some commenters stated that MSHA's technological feasibility
assessment of the proposed rule did not take into consideration that
mine operators had optimized the dust controls in their operations to
achieve compliance with the current 2.0 mg/m\3\ standard. These
commenters further stated that there is no new technology that will
allow mine operators to generally comply with the proposed 1.0 mg/m\3\
standard.
Under its existing dust standards, MSHA has found numerous
instances involving mine operators using dust control technologies that
were not in proper working order. For example, ventilation at the face
is sometimes insufficient because of lost air due to inadequate or
missing line curtains and stoppings. In addition, water sprays are
sometimes inadequate because of insufficient pressure or improper or
clogged nozzles. MSHA has also found scrubbers not properly maintained
with clean filters or miners not being positioned in fresh air.
MSHA has also found numerous instances involving mine operators
using dust control technologies together with improper work practices.
The following information from NIOSH's Best Practices shows how work
practices (e.g., miner and equipment positioning, and maintenance) can
reduce a miner's exposure to respirable coal mine dust.
The velocity and quantity of face ventilating air are important
factors for controlling respirable dust exposure of the continuous
mining machine
[[Page 24873]]
operator. When blowing ventilation is used, the continuous mining
machine operator should be positioned in the clean discharge air at the
end of the blowing curtain or tubing with intake air sweeping from
behind. The continuous mining machine operator should not proceed past
the end of the line curtain. If the continuous mining machine operator
must be on the return side of the curtain, some of the intake air
should be bled over the line brattice to provide fresh air to the
continuous mining machine operator. In addition, scrubber discharge
must be on the opposite side of the line brattice to allow scrubber
exhaust to discharge directly into return air. The air quantity
provided at the end of the line curtain should be limited to 1,000 cfm
over the scrubber capacity. Air quantities exceeding 1,000 cfm over the
scrubber capacity can overpower the scrubber and push dust-laden air
past the scrubber inlets. (NIOSH IC 9517, 2010, pp. 54-55.) MSHA has
found miners working in the return air with scrubber exhaust not
discharging directly into the return air and air quantities exceeding
1,000 cfm over the scrubber capacity.
When exhausting ventilation is used, intake air is delivered to the
face in the working entry. The clean air sweeps the face, and the dust-
laden air is then drawn behind the return curtain or through the
exhaust tubing to the return entries. This type of system will keep
mobile equipment in fresh air. It affords the continuous mining machine
operator more freedom of movement than a blowing ventilation system. In
addition, it allows more visibility around the loading area so that
shuttle car operators can easily determine where the continuous mining
machine operator is located when entering the face area.
Another advantage of exhausting ventilation is that shuttle car
operators are always positioned in fresh air. The end of the
ventilation curtain or tubing must be kept within 10 feet of the face
when not using a scrubber to ensure that air reaches and effectively
sweeps the face. The continuous mining machine operator should not
proceed inby the end of the line curtain since this will expose the
operator to dust-laden return air. If continuous mining machine
operator dust levels are too high, the first thing to check is whether
the operator is standing parallel to or outby the end of the line
curtain. Scrubber exhaust must be on the same side of the entry as the
line curtain to allow scrubber exhaust to discharge directly into
return air. (NIOSH IC 9517, 2010, pp. 55-56.) MSHA has found instances
of the exhaust curtain or tubing farther than 10 feet from the face
when not using a scrubber, continuous mining machine operators standing
parallel to or outby the end of the line curtain, and scrubber exhaust
being recirculated rather than being discharged into the return air.
Bit type and bit wear can adversely affect respirable dust
concentrations. Routine inspection of bits and replacement of dull,
broken, or missing bits improve cutting efficiency and help minimize
dust generation. (NIOSH IC 9517, 2010, p. 52.)
High-pressure sprays are recommended for redirecting of dust.
However, care must be taken when determining location and direction
because high pressure can cause turbulence, leading to rollback of dust
laden air. Operators should examine, clean, or replace sprays if
necessary before each cut. (NIOSH IC 9517, 2010, p. 47.) MSHA has found
instances where water sprays different from those specified in the
approved mine ventilation plan were being used and where some of the
sprays were not operating properly.
Scrubbers lose as much as one-third of their airflow after just one
cut. The most common cause of efficiency loss is filter panel clogging.
Pitot tubes should be used to obtain air velocity readings as a measure
of scrubber performance. When the dust is excessive, cleaning of the
filter panel, the demister, and the scrubber ductwork, is required more
often. Also, the spray nozzles in the ductwork should be checked to
ensure they are completely wetting the entire filter panel and not just
the center. In some mines, filters should be cleaned with water at
least after each place change. In addition, inlets and ductwork may
require more frequent cleaning. (NIOSH IC 9517, 2010, pp. 49-51.) MSHA
has found instances where scrubbers were operating with clogged
filters. MSHA has also found that some operators use less efficient
filters. A less efficient filter traps fewer dust particles, but is
used by some mine operators because it requires less frequent
maintenance than an efficient filter which traps more dust.
In addition to dust created by the roof bolting machine itself,
roof bolting machine operators can be exposed to continuous mining
machine-created dust when bolting is required downwind of the
continuous mining machine. According to NIOSH, regardless of the type
of ventilation being used, the cutting sequence must be designed to
limit the amount of time the roof bolting machine operator works
downwind of the continuous mining machine. Properly sequenced cuts with
double-split ventilation can eliminate the need to work downwind of
dust concentrations created by the continuous mining machine. (NIOSH IC
9517, 2010, pp. 59-60.)
Because MSHA has found numerous instances involving mine operators
using dust control technologies that were not in proper working order
and improper work practices, both of which have contributed to miners'
exposure to respirable coal mine dust in excess of the existing
permissible levels, it is reasonable to conclude that mine operators
have not optimized all existing dust controls. MSHA concludes that it
is technologically feasible for mine operators to meet the 1.5 mg/m\3\
standard for non-longwall underground coal mining operations using
existing engineering controls along with proper work practices on each
shift.
e. Underground Coal Mining Longwall Operations
Longwall coal mining operations generally have the highest
respirable coal mine dust levels. In the PREA, MSHA stated that, in
rare instances, some operators may encounter implementation issues as
they attempt to comply with the proposed dust standards. Under the
final rule, implementation issues are greatly reduced for longwall
operators.
Table IV-5 presents a summary of the adjusted 2008-2009 sampling
data for longwall operations in underground coal mines by selected
occupations. Of the more than 2,000 samples taken by MSHA inspectors
during 2008 and 2009, after adjustment, approximately 21% exceeded the
standard and the average deviation was 0.39 mg/m\3\ below the standard.
The mean and median of the samples were 1.09 mg/m\3\ and 0.98 mg/m\3\,
respectively. These data indicate that, after adjustment, typical dust
levels at longwall operations are below the 1.5 mg/m\3\ standard. The
longwall operator on the tailgate side is the only occupation/location
where more than 30 percent of the adjusted samples exceeded the
standard.
[[Page 24874]]
Table IV-5--Summary of Adjusted 2008-2009 Sampling Data for Longwall Operations in Underground Coal Mines, By
Selected Occupations
----------------------------------------------------------------------------------------------------------------
Number of Pct. > Avg. deviation
Occupation samples Mean mg/m\3\ Median mg/m\3\ standard * mg/m\3\
----------------------------------------------------------------------------------------------------------------
Headgate Operator............... 352 0.74 0.60 8 -0.74
Jack Setter (Longwall).......... 726 1.16 1.04 22 -0.32
Longwall Operator (Headgate 337 1.20 1.11 24 -0.27
Side)..........................
Longwall Operator (Tailgate 371 1.39 1.22 35 -0.09
Side)..........................
Other **........................ 253 0.76 0.58 11 -0.71
-------------------------------------------------------------------------------
Total....................... 2,039 1.09 0.98 21 -0.39
----------------------------------------------------------------------------------------------------------------
* 1.5 mg/m\3\ or a reduced standard below 1.5 mg/m\3\.
** Occupations with fewer than 100 samples.
Source: Tabulation of MSHA MSIS Data.
As MSHA stated in the PREA, existing technologies are available to
reduce dust levels in longwall operations. Ventilation is the most
effective control. The amount of ventilation reaching the face can be
increased by better maintenance and positioning of the line curtains
and stoppings, increasing the amount of air delivered to the longwall
face, and reducing the restrictions in the intake entries. Under some
circumstances, mine operators may have to develop additional airways.
In addition, efficient and better positioned water spray nozzles as
well as increased water pressure and volume can be used. Work
practices, such as proper positioning of the miner as well as the
cleaning and maintenance of the dust controls further reduce dust
levels. The use of CPDMs will enable operators to ascertain the effects
of these practices and how to combine their use most effectively.
NIOSH noted many areas where improvements could be made to reduce
current dust levels in longwall operations. These areas include: (1)
Reducing dust in the intake air entries by decreasing air velocities in
the intake entries; (2) controlling dust generated by the shearer by
ensuring sufficient wetting of the coal; (3) maintaining the cutting
drum bits by promptly replacing damaged, worn, or missing bits; (4)
controlling dust generated by the stageloader/crusher by fully
enclosing the stageloader/crusher, wetting the coal in the stageloader
and crusher area, and using scrubber technology to create negative
pressure; (5) using a high-pressure water-powered scrubber; and (6)
installing and maintaining gob curtains. (NIOSH IC 9517, 2010, pp. 17-
26.)
Some commenters stated that, like non-longwall operations, dust
controls for longwall operations have been optimized and there were no
additional controls available to further reduce coal mine dust levels.
In response to these comments, MSHA notes that the Agency has found
that improvements have been made in respirable dust control at longwall
operations since the 1990s. According to NIOSH, approximately 25% of
the active longwall faces in the United States were surveyed to
quantify dust generation from major sources and determine the relative
effectiveness of the different control technologies. NIOSH found that
the average face velocities increased by 28% (0.71 m/sec or 140 ft/min)
when compared to air velocities reported in a mid-1990s longwall study.
NIOSH also found that water to the shearer increased in an effort to
control dust liberated from the face. Headgate splitter arm directional
spray systems were observed on 90% of the surveyed longwalls. The exact
type, number and location of these sprays varied significantly between
mines, but all were operating on the principle of splitting the
ventilating air as it reaches the headgate side of the shearer and
holding the dust-laden air near the face. (Rider et al., 2011, pp. 2-
3.) NIOSH stated that although average shift production rates rose
approximately 53%, dramatic reductions in average dust levels, between
20% and 58%, were realized at each face sampling location when dust
levels were compared to a 1990s study. (Rider et al., 2011, p. 7.)
However, despite these improvements, like non-longwall operations,
MSHA has found that there are numerous instances involving mine
operators using dust control technologies that were not in proper
working order and using improper work practices, both of which have
contributed to miners' exposure to excessive respirable coal mine dust.
For example, MSHA has found instances where air being directed into the
mine is lost before it reaches the face due to inadequate curtains and
stoppings, miners were improperly positioned in the return air, and
inadequate maintenance resulted in excessive dust levels.
NIOSH has also found instances involving mine operators using dust
control technologies that were not in proper working order or improper
work practices, both of which have contributed to miners' exposure to
excessive respirable coal mine dust. NIOSH observed: (1) Longwall
operations with improperly maintained brattice curtain behind the
hydraulic support legs resulting in large voids with air escaping into
the gob; (2) shearer operators located inby, rather than outby, the
headgate drum exposed to elevated dust levels when the headgate drum
cut into the headgate entry; and (3) an improperly angled hydraulically
adjustable splitter arm allowed dust to migrate over the top of the
splitter arm and into the walkway. (NIOSH IC 9517, 2010, pp. 23-24,
30.)
In addition, NIOSH notes that unidirectional cutting may allow for
greater flexibility to place workers upstream of the dust sources than
bidirectional cutting. Depending on roof conditions, this may allow the
operators to modify the cut sequence so that shields are only advanced
downwind of the shearer. Activating shield advance as close to the
tailgate drum as possible and keeping jack setters upwind of the
advancing shields may protect the jack setters from elevated dust
levels by keeping them in a clean air envelope created by the shearer's
directional spray system. (NIOSH IC 9517, 2010, p. 34.)
Based on MSHA's experience with and NIOSH's analysis of dust
control techniques, MSHA concludes that it is technologically feasible
for mine operators to meet the 1.5 mg/m\3\ standard for longwall
underground coal mining operations using existing engineering controls
along with proper work practices on each shift.
f. Underground Coal Mining in the Presence of Silica
Some commenters expressed concern about the feasibility of meeting
reduced
[[Page 24875]]
dust standards due to the presence of silica. The available dust
controls discussed previously are effective in reducing the amount of
respirable coal mine dust, including silica, in the mine atmosphere. In
addition, NIOSH recommends that if roof rock must be cut, it is often
beneficial to cut the coal beneath the rock first and then back the
continuous mining machine up to cut the remaining rock. This method of
cutting leaves the rock in place until it can be cut out to a free,
unconfined space, which creates less respirable dust (especially silica
dust). (NIOSH IC 9517, 2010, p. 53.) NIOSH also notes that if the
continuous mining machine operator works downwind of the roof bolting
machine, as much as 25% of the continuous mining machine operator's
quartz dust exposure can be attributed to dust from the bolting
operation. NIOSH notes that the problem is usually a lack of
maintenance of the dust controls on the roof bolting machine. (NIOSH IC
9517, 2010, p. 60.)
4. Economic Feasibility of Complying with the Final Rule
MSHA has traditionally used a revenue screening test--whether the
yearly costs of a rule are less than 1 percent of revenues, or are
negative (i.e., provide net cost savings)--to establish presumptively
that compliance with the regulation is economically feasible for the
mining industry. Recent Census Bureau data show that mining in general
has operating profits greater than 17 percent of sales and
corresponding after tax profits of approximately 10 percent.\58\ The
Agency believes that with these average profit levels, when the cost of
a regulation has less than a 1 percent impact on the affected
industry's revenues, it is generally appropriate to conclude that the
regulation is feasible.
---------------------------------------------------------------------------
\58\ Most recent Census Bureau data can be found at http://www2.census.gov/econ/qfr/current/mmw1.xls on the line for Mining.
---------------------------------------------------------------------------
In estimating costs of a rule, it is important to distinguish
between compliance costs (costs that the affected industry incur to
comply with the rule) and transfer payments. As a result of additional
citations that MSHA estimates will be issued under the final rule,
operators will incur penalty payments. Penalty payments are considered
transfer payments from the affected party to the Federal government
resulting from violations of the final rule; transfer payments are not
considered compliance costs. However, transfer payments are important
for describing the distributional effects of a rule. Therefore, to
determine whether the final rule is economically feasible, MSHA has
included as total costs the estimated compliance costs and penalty
payments.
Using the screening test noted above, MSHA has concluded that the
requirements of the final rule are economically feasible. MSHA
estimates that the annualized costs of the final rule, including
transfer payments, to underground coal mine operators is $27.1 million
($26.2 million of compliance costs and $0.9 million of penalty
payments), which is approximately 0.13 percent of total annual revenue
of $20.2 billion ($27.1 million/$20.2 billion) for all underground coal
mines.
MSHA estimates that annualized costs of the final rule, including
transfer payments, to surface coal mine operators is $4.02 million
($4.0 million of compliance costs and $24,900 of penalty payments),
which is approximately 0.02 percent of total annual revenue of $17.9
billion ($4.02 million/$17.9 billion) for all surface coal mines.
5. Conclusion
MSHA has concluded that the final rule is technologically feasible
both in terms of sampling respirable dust concentrations with the CPDM
and the availability of engineering controls to meet the respirable
coal mine dust standards of 1.5 mg/m\3\ and 0.5 mg/m\3\ for intake air
and part 90 miners. The CPDM is accurate, reliable, and ergonomically
correct. In addition, current dust levels for most sampled occupations
and locations were typically found to be below the applicable
standards. Existing engineering controls including ventilation, water
sprays and environmentally controlled cabs along with proper work
practices can be used to further reduce dust levels. Mine operators are
not maintaining optimal dust controls at all times. MSHA and NIOSH both
have found instances where air being directed into the mine is lost
before it reaches the face due to operators' failing to maintain
ventilation controls with proper curtains and stoppings, miners are
improperly positioned in the return air, and there is inadequate
maintenance, all resulting in excessive dust levels. Correcting
existing problems will allow mine operators to further reduce dust
levels without having to make substantial additional expenditures in
dust controls.
Since the compliance cost estimates for both underground and
surface coal mines are below one percent of their estimated annual
revenue, MSHA concludes that compliance with the provisions of the
final rule will be economically feasible for the coal industry.
IV. Section-by-Section Analysis
A. 30 CFR Part 70--Mandatory Health Standards--Underground Coal Mines
1. Section 70.1 Scope
Final Sec. 70.1, like the proposal, states that part 70 sets forth
mandatory health standards for each underground coal mine subject to
the Federal Mine Safety and Health Act of 1977, as amended.
MSHA received several comments requesting that the Agency extend
the scope of the rule to various facilities, contractors, and contract
employees. The final rule, like existing Sec. 70.1, applies to all
underground coal mine operators and protects the health of all miners
working in underground coal mines.
2. Section 70.2 Definitions
The final rule does not include the proposed definitions for Weekly
Accumulated Exposure and Weekly Permissible Accumulated Exposure that
would have applied when operators use a CPDM to collect respirable dust
samples under proposed part 70. These two definitions are not needed
since the proposed weekly sampling requirements are not included in the
final rule.
Act
The final rule, like the proposal, defines Act as the Federal Mine
Safety and Health Act of 1977, Public Law 91-173, as amended by Public
Law 95-164 and Public Law 109-236.
Active Workings
Final Sec. 70.2, like the proposal, makes no change to the
existing definition of active workings.
Approved Sampling Device
The final rule, like the proposal, defines an approved sampling
device as a sampling device approved by the Secretary and Secretary of
Health and Human Services (HHS) under part 74 of this title. Whenever a
sampling device is used by operators to comply with the requirements of
part 70, the device must be approved for use in coal mines under part
74 (Coal Mine Dust Sampling Devices). MSHA did not receive any comments
on the proposed definition and the definition is finalized as proposed.
Certified Person
Final Sec. 70.2 makes nonsubstantive changes to the existing
definition of certified person. It does not include the
[[Page 24876]]
parenthetical text following the references to Sec. Sec. 70.202 and
70.203.
Coal Mine Dust Personal Sampler Unit (CMDPSU)
The final rule, like the proposal, defines a coal mine dust
personal sampler unit (CMPDSU) as a personal sampling device approved
under 30 CFR part 74, subpart B. This definition is included to
distinguish between the two types of coal mine dust monitoring
technology approved under part 74 and to clarify the applicability of
the final rule to each approved sampling device. The existing
gravimetric sampling device used by operators is a CMDPSU. MSHA did not
receive any comments on the proposed definition and the definition is
finalized as proposed.
Concentration
Final Sec. 70.2, like the proposal, makes no change to the
existing definition of concentration.
Continuous Personal Dust Monitor (CPDM)
The final rule, like the proposal, defines a continuous personal
dust monitor as a personal sampling device approved under 30 CFR part
74, subpart C. This definition is included to distinguish between the
two types of coal mine dust monitoring technology approved under part
74 and to clarify the applicability of the final rule to each approved
sampling device. MSHA did not receive any comments on the proposed
definition and the definition is finalized as proposed.
Designated Area (DA)
The final rule is similar to the proposal. It defines designated
area (DA) as a specific location in the mine identified by the operator
in the mine ventilation plan under Sec. 75.371(t) of this title where
samples will be collected to measure respirable dust generation sources
in active workings; approved by the District Manager; and assigned a
four-digit identification number by MSHA. The proposal would have
defined the DA as an area of a mine identified by the operator in the
mine ventilation plan. The final definition includes a specific
reference to Sec. 75.371(t). This is consistent with the existing
definition. In addition, like the proposal, the definition includes
language from existing Sec. 70.208(e) regarding how DAs are denoted.
MSHA did not receive any comments on the proposed definition.
Designated Occupation
Final Sec. 70.2 includes a nonsubstantive change to the existing
definition of designated occupation. It includes the abbreviation MMU
for mechanized mining unit.
District Manager
Final Sec. 70.2, like the proposal, makes no change to the
existing definition of District Manager.
Equivalent Concentration
The final rule is changed from the proposal. Under the final rule,
equivalent concentration is defined as the concentration of respirable
coal mine dust, including quartz, expressed in milligrams per cubic
meter of air (mg/m\3\) as measured with an approved sampling device,
determined by dividing the weight of dust in milligrams collected on
the filter of an approved sampling device by the volume of air in cubic
meters passing through the filter (sampling time in minutes (t) times
the sampling airflow rate in cubic meters per minute), and then
converting that concentration to an equivalent concentration as
measured by the Mining Research Establishment (MRE) instrument. When
the approved sampling device is:
(1) The CMDPSU, the equivalent concentration is determined by
multiplying the concentration of respirable coal mine dust by the
constant factor prescribed by the Secretary.
(2) The CPDM, the device shall be programmed to automatically
report end-of-shift concentration measurements as MRE-equivalent
concentrations.
Like the proposal, the introductory paragraph in the definition
under the final rule provides that dust concentration measurements from
an approved sampling device will be converted to MRE-equivalent
concentrations. Unlike the proposal, the final rule includes quartz in
the definition as that is also an adjusted MRE-equivalent
concentration. Also, the final definition, unlike the proposal, does
not adjust the MRE-equivalent concentration for shifts longer or
shorter than 8 hours to an 8-hour equivalent concentration.
Final paragraph (1), like the proposal, applies when the approved
sampling device is the CMDPSU and is derived from existing Sec. 70.206
which describes converting a concentration of respirable dust as
measured with the CMDPSU. For the CMDPSU, the constant factor is 1.38.
This compensates for the difference in the dust collection
characteristics and makes the measurements equivalent to what would be
obtained using an MRE instrument.
Final paragraph (2) of the definition applies when the approved
sampling device is the CPDM. It states that when using the CPDM, the
device must be programmed to automatically report end-of-shift
concentration measurements as MRE-equivalent concentrations.
The manufacturer's programming will use the constant factor
determined by the Secretary for HHS specific to this approved sampling
device to provide an MRE-equivalent concentration.
MSHA acknowledges that working conditions for miners have changed
in recent decades with the result that miners, on average, work longer
hours over the course of a shift, week, year and/or lifetime. In an
attempt to address the additional exposure that comes from such a
change in working conditions, the proposal would have required the
respirable coal mine dust sample results to be expressed in terms of an
8-hour equivalent concentration for shifts longer than 8 hours,
regardless of how many hours the miners worked over the course of a
week, a month, or a lifetime to capture the effect of longer shifts. In
addition, MSHA requested comment on the recommendation in the 1995
NIOSH Criteria Document to lower exposure to 1.0 mg/m\3\ for up to a
10-hour work shift over a 40-hour workweek.
Some commenters stated that the effect of the 8-hour conversion
would be that, for miners working the same number of hours per week,
miners who worked 8 hours could be exposed to more respirable dust than
miners who worked longer shifts. One commenter pointed out that, for
the same 40-hour week, a miner working five 8-hour shifts could be
exposed to more dust than a miner working four 10-hour shifts. Some of
the commenters expressed concern that the 8-hour conversion, when
applied to shift lengths of 10 or 12 hours, would result in
concentration limits well below the 8-hour concentration limit. They
stated that this would force them to reduce the lengths of their shifts
in order to comply with the limit, decreasing the efficiency of their
mines. Another commenter stated that the 8-hour conversion formula was
too complicated and confusing for miners who work extended shifts and
that miners would not be able to figure out their exposure limits. The
commenter stated that they appreciated the Agency taking into account
the fact that most miners work more than an 8-hour shift, but urged
MSHA to adopt a simplified approach.
MSHA reviewed its data on shift length and hours worked. The data
show that the majority of miners currently work longer than 40 hours
per
[[Page 24877]]
week, whether they are working 8-hour shifts or longer shifts. The data
also show that some miners are working 8-hour shifts 6 days per week,
while some miners are working 10-hour shifts 4 or 5 days per week.
MSHA also reviewed the available data on health outcomes as a
function of the respirable dust dose over a single shift. As stated
above in the discussion regarding the QRA, the data show disease
causation with long-term exposures. As noted in NIOSH's CIB, ``although
no epidemiologic data exists that implicate longer hours as a
contributory causative factor for CWP, working longer hours leads to
the inhalation of more dust into the lungs.'' However, as stated above,
shift length cannot predict the number of hours miners are exposed to
respirable coal mine dust in the long-term. While it is possible that
shift length could contribute to disease, the available evidence is
insufficient to support a linkage at this time. As such, MSHA believes
that the link between longer shifts and resulting disease requires
further examination and study. MSHA did not receive comments to support
this linkage.
After consideration of the relevant data and in response to
comments, MSHA believes a concentration limit, with sampling performed
for a full shift, is the most appropriate approach to account for the
longer total exposure to which miners now on average are exposed. MSHA
believes that this approach, which captures increased exposures
regardless of shift length, accomplishes some of the purpose of the 8-
hour equivalent concentration. Accordingly, MSHA has not included the
conversion to an 8-hour concentration in the final ``equivalent
concentration'' definition. By not including the 8-hour conversion in
the final rule, MSHA is preserving the status quo. However, the final
rule requires operators to sample during the entire shift that a miner
works and is exposed to respirable coal mine dust, even if the shift
exceeds 8 hours. Full-shift sampling will provide additional health
protection over and above what is currently provided for miners who
work longer than 8-hour shifts.
In the future, MSHA intends to evaluate samples taken on shifts
longer than 8 hours, additional studies, data, literature, and any
other relevant information to determine whether an 8-hour equivalent
concentration is necessary to protect miners who work longer shifts.
Mechanized Mining Unit (MMU)
The final definition of a mechanized mining unit (MMU) is clarified
from the proposal. It is defined as a unit of mining equipment
including hand loading equipment used for the production of material;
or a specialized unit which uses mining equipment other than specified
in Sec. 70.206(b) or in Sec. 70.208(b) of this part. It further
provides that each MMU will be assigned a four-digit identification
number by MSHA, which is retained by the MMU regardless of where the
unit relocates within the mine. It also provides that when:
(1) Two sets of mining equipment are used in a series of working
places within the same working section and only one production crew is
employed at any given time on either set of mining equipment, the two
sets of equipment shall be identified as a single MMU.
(2) Two or more sets of mining equipment are simultaneously engaged
in cutting, mining, or loading coal or rock from working places within
the same working section, each set of mining equipment shall be
identified as a separate MMU.
Several commenters stated that the proposed definition was
confusing and unclear or that it conflicted with the requirements of
proposed Sec. 75.332 pertaining to working sections and working
places. In response to these comments, the final definition includes
several clarifications. The definition includes references to final
Sec. 70.206(b) concerning bimonthly sampling and Sec. 70.208(b)
concerning quarterly sampling to clarify when a specialized unit is an
MMU, i.e., when directed by the District Manager in accordance with
Sec. Sec. 70.206(b) or 70.208(b). The proposed definition included a
reference to Sec. 70.207(b), which is redesignated in the final rule.
The definition also includes the statement that the four-digit
identification number is retained by the MMU ``regardless of where the
unit relocates in the mine.'' This language is similar to the existing
sampling requirements for MMUs under Sec. 70.207(f)(1), which contains
identical language.
Paragraphs (1) and (2) further clarifies that two sets of equipment
will be identified as a single MMU when only one production crew is
employed ``at any given time on either set of mining equipment'' or
when two sets of mining equipment are ``simultaneously engaged in
cutting, mining, or loading coal or rock from working places.''
Paragraphs (1) and (2) are similar to the existing sampling
requirements for MMUs under Sec. 70.207(f)(2), which contains similar
language.
MRE Instrument
Final Sec. 70.2, like the proposal, makes no change to the
existing definition of MRE instrument.
MSHA
Final Sec. 70.2, like the proposal, makes no change to the
existing definition of MSHA.
Normal Production Shift
The final rule is changed from the proposal. It defines normal
production shift as a production shift during which the amount of
material produced by an MMU is at least equal to 80 percent of the
average production recorded by the operator for (1) the most recent 30
production shifts or (2) for all production shifts if fewer than 30
shifts of production data are available.
The proposal would have defined normal production shift as the
amount of material produced by an MMU that is at least equal to the
average production recorded by the operator for the most recent 30
production shifts or for all production shifts if fewer than 30 shifts
of production data are available.
Several commenters supported the proposed definition, agreeing that
exposure monitoring should be conducted during shifts that represent
typical production levels. One commenter added that the proposed
definition would fix a loophole that permits operators to sample for
compliance with the respirable dust standard when production is very
low. The commenter added that sampling under the proposed definition
would result in a better understanding of the exposures occurring under
normal operating conditions.
Other commenters expressed a variety of concerns, most related to
the variability of production and feasibility of reaching the minimum
production level contained in the proposal. They indicated that the
proposed production level was too high and, as a result, more operator
samples would be considered invalid and voided, and more sampling would
be needed. Some of these commenters noted that dynamic factors such as
equipment breakdowns or variable mining conditions could cause
fluctuations in production, resulting in the sampled shifts not meeting
the proposed definition. One commenter stated that the number of needed
samples would probably double as a result of the averaging period and
the required tonnage. Another commenter stated that 50 percent of the
company's production shifts would not meet the
[[Page 24878]]
proposed definition. This same commenter recommended that ``normal
production shift'' be defined as 80 percent of the prior 30-shift
average production, while another commenter suggested that MSHA should
consider using 75 percent of the prior 30 days' average to reduce the
number of invalid samples.
MSHA has considered all comments received and the concerns
expressed regarding the feasibility of reaching the proposed minimum
production level. In response, MSHA has changed the production level in
the final normal production shift definition to 80 percent. The purpose
for defining normal production shift is to achieve reliable
measurements of miners' day-to-day exposures to respirable coal mine
dust that occur during production under normal mining conditions. It is
important for miner health and safety that operator sampling occur
during shifts that represent typical production and mining conditions
on the MMU. The level of coal production has a significant impact on
dust generation. As production increases, the amount of generated
respirable coal mine dust also increases. Samples that are collected on
shifts when production is much less than what generally occurs cannot
reflect typical dust concentration levels to which miners are exposed
or normal mining activity on the MMU. Such measurements underestimate
miners' typical dust exposures. Under the existing definition,
operators are required to sample when production is at least 50 percent
of the average production reported during the operator's last sampling
period (i.e., last set of five valid samples). The existing 50 percent
production level is not representative of typical dust concentration
levels under normal mining conditions.
The Dust Advisory Committee recommended that respirable dust
samples be taken when production is sufficiently close to normal
production, which it stated should be defined as 90 percent of the
average production of the last 30 production shifts.
In its 1995 Criteria Document, NIOSH recommended that, consistent
with standard industrial hygiene practice (which requires exposure
measurements be collected during typical work shifts), for a production
shift to be considered a ``normal production shift,'' it must produce
at least 80 percent of the average production over the last 30
production shifts. NIOSH further stated that a production-level
threshold should ensure that exposure conditions are comparable between
sampled and unsampled shifts.
The final 80 percent production level responds to commenters'
concerns, is the same as the recommendation in the 1995 NIOSH Criteria
Document, and is consistent with the 1996 Dust Advisory Committee
Report. It is also consistent with MSHA's longstanding practice that
MSHA inspectors' respirable dust samples be collected when production
is at least 80 percent of the average of the previous 30 production
shifts. The 80 percent production level under the final definition
reflects typical conditions under which miners work, particularly in
combination with the final rule's requirement that operators sample
miners during the entire time that miners work, which is discussed
elsewhere in the preamble related to Sec. 70.201(c). The final
definition is more protective of miners than the existing definition.
Like the existing operator sampling program, if a ``normal
production shift'' is not achieved, MSHA may void the sample collected
during that shift. MSHA recognizes that under the final rule, the total
number of required operator samples to be collected on the MMU will
increase from that required under the existing standards. However, as
discussed elsewhere in the preamble related to Sec. 70.206(d), a valid
equivalent concentration measurement that exceeds the standard by at
least 0.1 mg/m\3\, even when production is lower than the 80 percent
threshold, will be used to determine the equivalent concentration for
that MMU.
Under existing practice, if an operator encounters unique mining
conditions that reduce production, such as when the coal seam narrows
due to a rock intrusion running through the coal bed, MSHA allows the
operator to submit any relevant information to the District Manager so
that average production levels can be adjusted to ensure samples are
considered valid in that they represent current, normal mining
conditions. This practice provides sufficient flexibility to account
for unique fluctuations in the mining process. Under the final rule,
MSHA will continue this practice.
Like the proposal, the final rule retains the proposed time period,
that is, the most recent 30 production shifts, in determining whether a
production shift is considered a normal production shift.
During the comment period, MSHA requested comment from the mining
community on whether the average of the most recent 30 production
shifts would be representative of dust levels to which miners are
typically exposed. This request was made in the preamble to the
proposed rule, the Agency's opening statements at the public hearings,
and a Federal Register notice (76 FR 12649, March 8, 2011). MSHA did
not receive any comments on this proposal.
MSHA considers the time frame in the existing definition, which
requires samples to be collected for the ``last 5 valid samples,'' to
be inadequate and not a representative period that reflects typical
production. MSHA's existing practice for inspector sampling is to use
30 production shifts as a time period for establishing typical
production. Based on agency experience and as stated in the proposed
rule, using 30 production shifts provides sufficient historical data to
give a reliable representation of an MMU's typical production.
Averaging production over the 30 production shifts, instead of the last
5 valid samples, accounts for any fluctuations in mining cycles,
including those in which production is higher than usual. In addition,
both the 1995 NIOSH Criteria Document and 1996 Dust Advisory Committee
Report recommended that the last 30 production shifts be used as the
benchmark to gauge production levels.
Also, the final definition, like the proposal, requires that when
an MMU has operated for fewer than 30 production shifts, the average
production of all production shifts would be considered to determine a
``normal production shift.'' MSHA did not receive comments on this
proposed provision and it is finalized as proposed. MSHA believes it is
essential to use records from all of an MMU's production shifts when it
has operated for fewer than 30 shifts because this would result in the
most reliable determination of the MMU's production and a miner's
exposure.
One commenter who did not support the proposed definition expressed
concern that operators would have to track more production shifts in
order to meet the required production level. Comments on the production
records required to be made to establish a ``normal production shift''
are discussed elsewhere in the preamble related to final Sec.
70.201(g).
Finally, some commenters suggested that the definition of ``normal
production shift'' could be eliminated by using personal samples to
measure miner's actual exposure since it would not matter what the
production was during the sampling period. Comments on personal
sampling are discussed elsewhere in the preamble related to final Sec.
70.201.
Other Designated Occupation (ODO)
The final rule includes nonsubstantive changes from the
[[Page 24879]]
proposal. It defines other designated occupation (ODO) as an occupation
on a mechanized mining unit (MMU) that is designated for sampling
required by part 70 in addition to the DO. It further provides that
each ODO will be identified by a four-digit identification number
assigned by MSHA.
MSHA received one comment related to the proposed definition. The
commenter requested that MSHA consider personal sampling of miners in
lieu of sampling the ODOs. MSHA has addressed this comment elsewhere in
the preamble under final Sec. 70.201. The final rule, consistent with
the Mine Act, requires environmental sampling to accomplish the
objective of controlling respirable dust to protect the health of
miners. The definition of ODO is finalized as proposed.
Production Shift
Final Sec. 70.2 includes nonsubstantive changes to the existing
definition of production shift. It includes the abbreviations MMU for
mechanized mining unit and DA for designated areas.
Quartz
The final rule is changed from the proposal. It retains the
existing definition of quartz, which is defined as crystalline silicon
dioxide (SiO2) not chemically combined with other substances
and having a distinctive physical structure.
The proposal would have defined quartz to mean crystalline silicon
dioxide (SiO2) as measured by: (1) MSHA Analytical Method P-
7: Infrared Determination of Quartz in Respirable Coal Mine Dust; or
(2) Any method approved by MSHA as providing a measurement of quartz
equivalent to that obtained by MSHA Analytical Method P-7.
MSHA received one comment on the proposed definition. The commenter
expressed concern regarding notice of any analytical measurement method
that MSHA could approve as equivalent to Analytical Method P-7. In
response, MSHA has concluded that a change in the proposed definition
is not necessary because the existing Analytical Method P-7 used in
determining the amount of quartz in respirable coal mine dust (U.S.
Department of Labor, MSHA, 2011) is sufficient.
Representative Sample
The final rule defines representative sample as a respirable dust
sample, expressed as an equivalent concentration, that reflects typical
dust concentration levels and (1) with regard to an MMU, normal mining
activities in the active workings during which the amount of material
produced is equivalent to a normal production shift; or (2) with regard
to a DA, when material is produced and routine day-to-day activities
are occurring.
The proposed rule would have defined ``representative sample'' as a
respirable dust sample that reflects typical dust concentration levels
and normal mining activity in the active workings during which the
amount of material produced is equivalent to a normal production shift.
The final definition differs from the proposed definition in two ways.
First, the final definition adds the language, ``expressed as an
equivalent concentration'' to clarify that each respirable dust sample
measurement must be converted to an MRE-equivalent concentration as
defined under this final Sec. 70.2. Second, similar to the existing
definition of ``production shift'' in Sec. 70.2, the final definition
distinguishes between a representative sample for an MMU and a
representative sample for a DA. To avoid confusion and to distinguish a
representative sample on an MMU from one in the DA, the final
definition clarifies that, for a DA, the representative sample is based
on a shift during which material is produced and routine day-to-day
activities are occurring in the DA. The definition for a DA is the same
as the existing definition which does not take into account the amount
of material produced.
MSHA received one comment related to the proposed definition. The
commenter stated that there was no need to define representative
samples and that MSHA should modify its sampling methodology such that
personal samples, rather than occupational samples, are taken.
With respect to the commenter's recommendation that MSHA replace
the occupational sampling methodology with personal sampling, MSHA
addresses this comment elsewhere in the preamble under final Sec.
70.201. In addition, the definition for representative sample ensures
that respirable dust samples accurately reflect the amount of dust to
which miners are exposed. Without a definition, operators could perform
sampling at times that do not represent typical production which would
under-represent, or bias, miners' dust exposures. Operator sampling
must be conducted when miners are in positions and physical locations
performing the same tasks that they perform on non-sampling days to
constitute representative samples. To be considered a representative
sample, operators should ensure that sampling occurs when mining
activities, such as production methods, reflect that of non-sampling
days (e.g., when approved cut sequences are followed, and the sequence
of mining includes the turning of multiple crosscuts). The final
definition of representative samples will provide protection for
miners' health by allowing MSHA to accurately evaluate the functioning
of operators' dust controls and the adequacy of operators' approved
plans.
Respirable Dust
The final rule makes a nonsubstantive change to the existing
definition of respirable dust. It defines respirable dust as dust
collected with a sampling device approved by the Secretary and the
Secretary of HHS in accordance with part 74 (Coal Mine Dust Sampling
Devices) of this title. The final definition deletes from the existing
definition, ``Sampling device approvals issued by the Secretary of the
Interior and Secretary of Health, Education, and Welfare are continued
in effect,'' because it is not needed. Approved sampling devices are
approved by MSHA and NIOSH under 30 CFR part 74.
Secretary
The final rule makes a nonsubstantive change to the existing
definition of Secretary. It defines Secretary as the Secretary of Labor
or a delegate. It includes the gender neutral term ``a'' delegate
rather than the existing term ``his'' delegate.
Valid Respirable Dust Sample
For clarification, the final rule revises the definition under
existing Sec. 70.2 for a valid respirable dust sample to mean a
respirable dust sample collected and submitted as required by this
part, including any sample for which the data were electronically
transmitted to MSHA, and not voided by MSHA.
The final definition adds language to clarify that for CPDM
samples, the data files are ``electronically'' transmitted to MSHA, and
not physically transmitted like samples collected with the CMDPSU. The
proposed rule did not include this clarification.
3. Section 70.100 Respirable Dust Standards
Final Sec. 70.100(a) is changed from the proposal. It requires
that each operator continuously maintain the average concentration of
respirable dust in the mine atmosphere during each shift to which each
miner in the active workings of each mine is exposed, as
[[Page 24880]]
measured with an approved sampling device and expressed in terms of an
equivalent concentration, at or below: (1) 2.0 milligrams of respirable
dust per cubic meter of air (mg/m\3\); and (2) 1.5 mg/m\3\ as of August
1, 2016.
Final paragraph (a)(1) is the same as proposed paragraph (a)(1). It
retains the existing standard of 2.0 mg/m\3\ on the effective date of
this final rule. Final paragraph (a)(2) is redesignated from proposed
paragraph (a)(3) and changes the date on which the 1.5 mg/m\3\ standard
is effective from the proposed 12 months to 24 months after the
effective date of the final rule.
Unlike proposed paragraph (a)(2) and (a)(4), the final rule does
not require that the standard be lowered to 1.7 mg/m\3\ 6 months after
the effective date of the final rule, or to 1.0 mg/m\3\ 24 months after
the effective date of the final rule.
MSHA proposed the 1.0 mg/m\3\ standard in accordance with Section
101(a)(1) of the Mine Act, 30 U.S.C. 811(a)(1). Section 101(a)(1) of
the Mine Act requires that the Secretary take certain action when a
recommendation to issue a rule, accompanied by a Criteria Document, is
received from NIOSH. The Secretary must refer the recommendation to an
advisory committee, or publish the recommendation as a proposed rule,
or publish in the Federal Register the determination and reasons not to
do so.
In 1995, NIOSH published and submitted to MSHA a Criteria Document
on Occupational Exposure to Respirable Coal Mine Dust. Consistent with
Section 101(a)(1) of the Mine Act, the Secretary referred the NIOSH
Criteria Document to an advisory committee (Dust Advisory Committee).
In the Criteria Document, NIOSH recommended that respirable dust
exposures be limited to 1.0 mg/m\3\ as a TWA concentration for up to 10
hours per day during a 40-hour work week as measured according to
existing MSHA methods. This recommended exposure level (REL) was based
on exposure-response studies of U.S. coal miners participating in the
National Coal Workers' Health Surveillance Program (NCWHSP) and
sampling data collected by the Bureau of Mines from 1969-1971 and MSHA
from 1985-1988. NIOSH used an average concentration of 0.5 mg/m\3\ of
respirable dust in its disease risk estimates because, at that time, it
constituted the lower range of the exposure data. NIOSH determined that
extrapolations beyond the range of the existing exposure data would
have carried considerable uncertainty. NIOSH found that, at a mean
concentration of 0.5 mg/m\3\, the excess risk of morbidity from
progressive massive fibrosis at age 65 exceeded 1/1,000 for all
durations of exposure and coal ranks evaluated, including 15 years of
exposure to medium/low-rank coal, believed to be least toxic. NIOSH
expected that long-term average dust concentrations would be below 0.5
mg/m\3\ if miners' daily exposures were kept below the recommended
exposure limit (REL) of 1.0 mg/m\3\ (NIOSH 1995). NIOSH also
recommended that the 1.0 mg/m\3\ REL should apply to surface coal
mines.
In 1996, the Dust Advisory Committee also recognized that
overexposure to respirable coal mine dust remained a problem and
recommended unanimously that MSHA consider lowering the allowable level
of exposure to coal mine dust. The Committee reviewed MSHA monitoring
data and scientific studies provided by NIOSH, including the NIOSH 1995
Criteria Document. The Committee concluded that
there is substantial evidence that either a significant number of
miners are currently being exposed to coal mine dust at levels well
in excess of 2.0 mg/m\3\ or that the current exposure limit for coal
mine dust is insufficiently protective.
MSHA's QRA to the proposed rule used respirable dust exposure data
collected from 2004 through 2008 and published quantitative studies on
coal workers' morbidity from black lung (Attfield and Seixas, 1995),
mortality from nonmalignant respiratory diseases (Attfield and Kuempel,
2008) and severe emphysema (Kuempel et al., 2009a) to estimate excess
disease risks in U.S. miners. The QRA estimated disease risks after 45
years of single-shift occupational exposure at exposure levels under
the existing standard. The QRA results indicated that, in every
exposure category, exposure under the existing standards places miners
at a significant risk of material impairment of health. In addition,
MSHA found that average dust concentrations exceed the proposed
respirable dust standard of 1.0 mg/m\3\ at a number of work locations
in every occupational category. The percentage of work locations that
would exceed the proposed respirable dust standard of 1.0 mg/m\3\
ranges from less than 1 percent for a few surface occupations to more
than 70 percent for miners working on the longwall tailgate. The
percentages are generally greater for underground occupations than for
surface occupations. A statistically significant percentage of surface
work locations (generally cleaning plant operations and surface
drilling) have average dust concentrations exceeding the proposed
exposure standard. For part 90 miners, the average dust concentration
exceeds the proposed standard of 0.5 mg/m\3\ at more than 20 percent of
the work locations.
On March 8, 2011, MSHA issued a Federal Register notice (76 FR
12648) requesting comments on the proposed respirable dust
concentration limits and requested alternatives. In addition, MSHA
stated that the Agency received comments that some aspects of the
proposed rule may not be feasible for particular mining applications
and that MSHA is interested in comments.
MSHA received many comments on the proposed 1.0 mg/m\3\ standard
and the proposed phase-in periods of 24 months for the proposed 1.0 mg/
m\3\ standard and 12 months for the proposed 1.5 mg/m\3\ standard. Many
commenters supported the proposed 1.0 mg/m\3\ standard. Other
commenters suggested that MSHA, NIOSH, industry, and labor conduct a
nationwide study using the CPDM to determine what dust concentrations
are protective and achievable. MSHA intends to conduct a retrospective
study that evaluates the 1.5 mg/m\3\ respirable dust standard to
determine if the standard should be further lowered to protect miners'
health.
The final rule responds to commenters' concerns by establishing
feasible dust standards and a uniform, longer 24-month implementation
date for the final respirable coal mine dust standards. In addition,
the final 1.5 mg/m\3\ standard affirms MSHA's initial determination,
set out in the proposal, that exposures at existing respirable dust
levels are associated with coal workers' pneumoconiosis (CWP), chronic
obstructive pulmonary disease (COPD) including severe emphysema, and
death due to non-malignant respiratory disease (NMRD). All of these
outcomes constitute material impairments to a miner's health or
functional capacity. However, the final 1.5 mg/m\3\ standard comports
with MSHA's initial conclusion in the preamble to the proposed rule
that some mine operators may encounter engineering control
implementation issues as they attempt to comply with the proposed 1.0
mg/m\3\ standard.
The final 1.5 mg/m\3\ standard is projected to have a greater
impact on risk for underground miners than for surface miners.
Surveillance and exposure data have been collected on U.S. underground
coal miners for over 40 years; there are few comparable studies on
surface coal miners. The QRA to the final rule shows that surface work
locations exceed the final 1.5 mg/m\3\ standard on relatively few
shifts and that the final 1.5 mg/m\3\ standard is
[[Page 24881]]
projected to have relatively little impact for surface workers who are
exposed to average concentrations below 0.5 mg/m\3\. However, the data
also show that certain surface occupations are exposed to
concentrations of respirable dust exceeding the final 1.5 mg/m\3\
standard. Table 28 of the QRA for the final rule contains more details
on the projected reduction in the health risks for each occupational
category.
The final 1.5 mg/m\3\ and 0.5 mg/m\3\ standards and single shift
sampling evaluated in the QRA for the final rule, and other
requirements of the final rule will reduce respirable dust levels for
miners. These other requirements include: (1) Sampling for a full
shift, (2) changing the definition of normal production shift, (3)
requiring the use of CPDMs for sampling, (4) revising the sampling
program, (5) requiring more timely corrective action on a single, full-
shift operator sample, (6) changing the averaging method to determine
compliance on operator samples, and (7) requiring records of on-shift
examinations and corrective actions taken to assure compliance with the
respirable dust control parameters. Collectively, MSHA expects these
requirements will reduce respirable dust levels that miners face,
further protect miners from the debilitating effects of occupational
respiratory disease, and result in improvements that would be greater
than those shown in Table 28.
MSHA will continue to examine closely the 1.5 mg/m\3\ standard.
This will include evaluation of miners' exposure to respirable coal
mine dust under exposure hours that are in excess of 8 hours per shift,
changes to the definition of normal production shift, and while using a
CPDM. MSHA intends to work closely with all segments of the mining
community in its continuing assessment of the 1.5 mg/m\3\ standard to
determine whether the final rule achieves MSHA's goals to lower and
maintain respirable dust levels to protect miners' health.
MSHA gave serious consideration to establishing a 1.0 mg/m\3\
standard, as proposed, based on its determination that there is a
significant risk to miners of material impairment of health when
exposures meet or exceed the proposed standard. MSHA has concluded,
however, that additional sampling and experience may be warranted for
underground coal mines while other provisions of the final rule are in
effect, including full-shift sampling, the revised definition of normal
production shift, and use of the CPDM, and that comparable experience
is warranted for surface coal mines, before considering a standard
lower than 1.5 mg/m\3\.
MSHA's technological feasibility analysis of the 1.5 mg/m\3\
standard and comments on the technological feasibility of the proposed
1.0 mg/m\3\ standard are discussed elsewhere in this preamble under
Section III.C., concerning the Technological Feasibility of Achieving
the Required Dust Standards.
Some commenters stated that the proposed 1.0 mg/m\3\ standard is
not based on the best available evidence but rather is based on faulty
science and medical data. These comments and the underlying evidence,
science, and medical data in support of the final 1.5 mg/m\3\ standard
are addressed in Section III.A. of this preamble, concerning Health
Effects.
Some commenters stated their calculations showed that, as opposed
to fewer than 200 citations per year for violations of the current 2.0
mg/m\3\ standard, a 1.0 mg/m\3\ standard based on a single, full-shift
measurement could result in more than 230,000 citations annually. In
addition, some commenters stated that MSHA failed to consider that each
violation would require abatement, a penalty, and mine plan amendments,
and would likely result in mine interruptions until plan approvals can
be obtained and abatement accomplished. Some commenters also stated
that MSHA overestimated the number of citations for excessive dust that
would be issued under the proposed rule. They anticipated that a
citation would be issued for every sample that met or exceeded the ECV
and for every sample that met or exceeded the WPAE (weekly permissible
accumulated exposure). As clarified by MSHA at the final public
hearing, it was never the Agency's intent to issue multiple citations
for excessive dust on single samples taken for the same entity and also
issue a citation when the WPAE was exceeded. Based on MSHA's evaluation
of public comments and changes included in the final rule, MSHA has
revised its projections for the number of citations that will be issued
for excessive dust as a result of the final rule; these projections are
discussed in Appendix A of the REA.
Regarding the proposed phase-in periods, some commenters stated
that if black lung is a problem, then the Agency needs to act quickly.
Other commenters stated that lowering the standard within these time
periods was not achievable and asked for more time. The 24-month
implementation date for the final 1.5 mg/m\3\ standard will allow the
mining community the opportunity to identify and implement feasible
engineering controls; train miners and mine management in new
technology and control measures; and improve their overall dust control
program. The Dust Advisory Committee unanimously recommended a phase-in
period for any reduction to the existing standard. MSHA believes that
24 months will provide an appropriate amount of time for mine operators
to feasibly come into compliance with the final respirable dust
standard.
A few commenters stated that the results of respirable dust
sampling suggest that the average dust concentration in many District 1
mines is under the proposed 1.0 mg/m\3\ standard. These commenters
requested that anthracite mines be exempt from the final rule since
overexposure to respirable dust above 1.0 mg/m\3\ is not a problem in
these mines for various reasons: Low production, work shifts over 7
hours/day are not common, and the mines are very wet.
In response, MSHA's QRA for the final rule identifies NMRD
mortality hazards not only for anthracite, but also for regions
identified with high rank bituminous and low rank coal. Therefore,
anthracite mines are not exempt from the dust standards in the final
rule. Additional discussion on the health effects from exposure to
respirable coal dust in anthracite mines is in Section III.B. of this
preamble concerning the QRA.
Final Sec. 70.100(b), is substantially the same as proposed Sec.
70.100(b). It requires that each operator must continuously maintain
the average concentration of respirable dust within 200 feet outby the
working faces of each section in the intake airways, as measured with
an approved sampling device and expressed in terms of an equivalent
concentration at or below: (1) 1.0 mg/m\3\, and (2) 0.5 mg/m\3\ as of
August 1, 2016.
Final paragraph (b)(1), like the proposal, requires that each
operator maintain the concentration of respirable coal mine dust at or
below 1.0 mg/m\3\. This standard is consistent with existing Sec.
70.100(b).
Final paragraph (b)(2), like the proposal, requires that each
operator maintain the concentration of respirable coal mine dust at or
below 0.5 mg/m\3\ but, in response to comments, MSHA changed the
implementation period from the proposed 6-month period to 24 months
after the effective date of the final rule.
Proposed Sec. 70.100(b)(2) would have provided a 6-month period
for lowering the respirable dust standard in intake airways. MSHA
proposed a 6-month period for the 0.5 mg/m\3\ standard because, based
on Agency data for these
[[Page 24882]]
areas of the mine, MSHA believed this period would have provided an
appropriate amount of time for mine operators to feasibly come into
compliance. The proposed 6-month period for the proposed 0.5 mg/m\3\
standard was independent of proposed Sec. 70.100(a)(2) regarding a 6-
month period for the proposed 1.7 mg/m\3\ interim standard.
During the public comment period, MSHA solicited comment on the
proposed phase-in period for lowering the dust standard for intake air
courses. Commenters expressed concern that the proposed 6-month period
was not sufficient for mine operators to develop, implement, and assess
control measures necessary to meet the proposed 0.5 mg/m\3\ standard.
In response to these comments, in the final rule MSHA changed the
proposed 6-month period to 24 months after the effective date of the
rule. The 24-month period is consistent with the period in final
paragraph (a)(2). Like the 24-month period in final paragraph (a)(2),
it will allow mine operators sufficient time to comply with the final
0.5 mg/m\3\ standard in paragraph (b)(2).
One commenter stated that sampling within 200 feet outby the
working face is too close to locate the measuring point and that the
best location to sample intake air is in the intake air course opposite
the loading point.
MSHA has historically required that a lower dust standard be
maintained in intake airways within 200 feet of the working faces (45
FR 23990, April 8, 1980). The purpose of the existing respirable dust
standard for intake air is to ensure that the air ventilating working
faces is sufficiently uncontaminated to assist in controlling
respirable dust at the working faces (45 FR 23994). The final 0.5 mg/
m\3\ standard will ensure that intake air ventilating the working faces
is sufficiently clean before it reaches the working faces where major
dust generating sources are located and where miners work. The required
location of the sampling point, within 200 feet of the working face, is
consistent with existing Sec. 70.100, which has been in existence
since 1980. The location provides an accurate sampling point for
measuring respirable dust in intake airways. Similarly, under the final
rule, maintaining the average concentration of respirable dust within
200 feet outby the working faces of each section in the intake airways
at or below 0.5 mg/m\3\ ensures that relatively clean air is used to
ventilate the face and where miners work. The lower standard will
improve health protection for miners. Also, maintaining the lower dust
level using available engineering controls makes it more likely that an
operator can maintain compliance with respirable dust standards in the
MMU.
One commenter stated that the proposed 0.5 mg/m\3\ standard is
unattainable. MSHA has concluded that this standard is feasible. Of the
more than 8,200 samples taken by MSHA inspectors in underground coal
operations during 2008 and 2009, less than 6% exceeded 0.5 mg/m\3\. The
feasibility of the 0.5 mg/m\3\ standard is discussed in more detail
elsewhere in this preamble under Section III. C., concerning the
Technological Feasibility of Achieving the Required Dust Standards.
One commenter suggested that the rock dust application requirements
of the Emergency Temporary Standard published in September 2010 (75 FR
57849) and finalized in June 2011 (76 FR 35968) affect the levels of
respirable dust in the intake airway to which miners are exposed and
would make compliance with the proposed standard problematic. This
comment is addressed elsewhere in this preamble under Sec. 70.101.
4. Section 70.101 Respirable Dust Standard When Quartz is Present
Final Sec. 70.101(a), like proposed Sec. 70.101(a), requires that
each operator must continuously maintain the average concentration of
respirable quartz dust in the mine atmosphere during each shift to
which each miner in the active workings of each mine is exposed at or
below 0.1 mg/m\3\ (100 micrograms per cubic meter of air or [mu]g/m\3\)
as measured with an approved sampling device and expressed in terms of
an equivalent concentration.
Final Sec. 70.101(b), like proposed Sec. 70.101(b), requires that
when the equivalent concentration of respirable quartz dust exceeds 100
[mu]g/m\3\, the operator must continuously maintain the average
concentration of respirable dust in the mine atmosphere during each
shift to which each miner in the active workings is exposed as measured
with an approved sampling device and in terms of an equivalent
concentration at or below the applicable respirable dust standard. It
also states that the applicable dust standard is computed by dividing
the percent of quartz into the number 10. It further requires that the
application of this formula must not result in an applicable dust
standard that exceeds the standard established by Sec. 70.100(a).
Some commenters stated that they supported a separate standard for
silica to better protect miners. One commenter suggested that MSHA
develop a program to reduce miners' exposures to silica that would
include training, engineering and administrative controls, and
respiratory protection. Some commenters who supported a separate silica
standard did not support the proposal which would reduce the respirable
coal mine dust standard when silica is present. Some of these
commenters stated that the proposed formula should be changed and
should be based on the percentage of quartz as a percentage of the
standard rather than a percentage of the total weight of the sample. In
addition, some of these commenters stated that it may not be feasible
for certain mining operations to continue to operate if they are on a
reduced respirable dust standard that could be as low as, or lower
than, 0.5 mg/m\3\.
Final Sec. 70.101(a) and (b), like the proposal, do not change the
existing respirable dust standard when quartz is present and is
consistent with existing Sec. 70.101. Existing Sec. 70.101 protects
miners from exposure to respirable quartz by requiring a reduced
respirable dust standard when the respirable dust in the mine
atmosphere of the active workings contains more than 5 percent quartz.
Existing Sec. 70.101 is based on a formula that was prescribed by the
Department of Health, Education and Welfare (now DHHS). The formula,
which applies when a respirable coal mine dust sample contains more
than 5.0 percent quartz, is computed by dividing 10 by the
concentration of quartz, expressed as a percentage. The formula results
in a continuous reduction in the respirable dust standard as the quartz
content of the respirable dust increases over 5 percent (i.e., the
higher the percentage of quartz, the lower the reduced respirable dust
standard).
The standard in final paragraph (a) is based on the formula in
existing Sec. 70.101. Final paragraph (a), like existing Sec. 70.101,
is designed to limit a miner's exposure to respirable quartz to 0.1 mg/
m\3\ (100 [mu]g/m\3\-MRE), based on the existing 2.0 mg/m\3\ respirable
dust standard.
The question of revising the existing respirable dust standard when
quartz is present by establishing a separate standard for silica will
be considered for a separate rulemaking. In addition, comments on the
feasibility of meeting reduced respirable coal mine dust standards due
to the presence of silica are discussed elsewhere in this preamble
under Section III.C. regarding Feasibility.
Some commenters suggested that the rock dust application
requirements of the Emergency Temporary Standard
[[Page 24883]]
published in September 2010 (75 FR 57849) and finalized in June 2011
(76 FR 35968) affect the levels of silica to which miners are exposed
and would make compliance with the proposed standard problematic. These
commenters stated that applying rock dust introduces quartz into the
sampling air stream thereby contributing to the total amount of
respirable dust being measured and is a major source of weight gain in
many samples.
If the rock dust used to maintain the incombustible content of the
combined coal dust, rock dust, and other dust, meets the definition of
rock dust under Sec. 75.2, the applied rock dust does not need to
contain a large portion of respirable dust and is allowed to contain a
limited amount of silica. Mine operators can work with their suppliers
to ensure the rock dust purchased contains a low percentage of
respirable dust and very little, if any free silica. Limiting the
percentage of respirable material and exercising care in the
application of rock dust to limit the exposure of miners working
downwind will reduce or eliminate the potential impact on respirable
coal mine dust levels.
5. Section 70.201 Sampling; General and Technical Requirements
Final Sec. 70.201 addresses general and technical sampling
requirements concerning operator sampling. It includes requirements for
sampling with the CPDM. Final Sec. 70.201 is consistent with the Dust
Advisory Committee's unanimous recommendation that CPDM technology,
when verified, be broadly used along with other sampling methods for
evaluation of dust controls at all MMUs and other high risk locations.
The Committee further recommended that once verified as reliable, MSHA
should use CPDM data for assessing operator compliance in controlling
miner exposures and should consider use of CPDM data in compliance
determinations. NIOSH has conducted the necessary scientific studies,
whose results were published in a peer-reviewed document, which
adequately demonstrated the CPDM to be an accurate instrument by
meeting the long-standing NIOSH Accuracy Criterion. The recent MSHA and
NIOSH approval of the CPDM, as meeting the intrinsic safety and
accuracy requirements of 30 CFR part 74, shows that the CPDM is ready
to be used as a compliance sampling device in coal mines.
Some commenters stated that operator sampling is not credible and
that MSHA should be responsible for all compliance sampling.
The Dust Advisory Committee recommended that MSHA secure adequate
resources to carry out compliance sampling but, in the interim,
operator compliance sampling should continue with substantial
improvement to increase credibility of the program.
In 2009, MSHA conducted a targeted enforcement initiative that
focused on miners' exposures to respirable coal mine dust at selected
underground coal mines. As a result of the lessons MSHA learned during
this initiative, MSHA instructed underground coal mine operators to
conduct audits of their respirable dust monitoring and control programs
and address any deficiencies. A mine operator is responsible for
providing a safe and healthful mining workplace and must design an
adequate plan, implement and monitor it, and revise it, as needed. MSHA
prepared specific information for miners and mine operators to use as a
tool for ending black lung disease. The information provided specific
instructions on actions that could be taken to respond to MSHA's
program, End Black Lung Act--Now!
Following the 2009 enforcement initiative, MSHA conducted a
weeklong dust control emphasis program. During this program, every coal
mine inspector dedicated a part of each inspection to health-related
activities and applied the lessons learned during the enforcement
initiative. Based on these lessons learned, MSHA reviewed the quality
of dust controls stipulated in approved ventilation plans, focusing on
the primacy of engineering controls and evaluated respirable dust
practices during regular inspections. In addition, MSHA training
specialists monitored the quality of training provided by industry
personnel on the risks of, and methods to prevent, black lung. MSHA is
continuing its dust emphasis program in order to increase surveillance
of operator sampling and take appropriate action to ensure that an
effective system is in place to investigate practices or actions which
would cause unrepresentative dust samples to be submitted. MSHA is also
continuing to use a national group of MSHA health specialists to
conduct focused health inspections. These inspections emphasize the
importance of maintaining dust controls to protect miners.
Some commenters stated that existing sampling procedures do not
reflect accurate measurements of miners' exposure to respirable coal
mine dust. The accuracy of the CMDPSU and the CPDM is discussed in the
section-by-section analysis concerning Sec. 72.800 Single, Full-shift
Measurement of Respirable Coal Mine Dust and Section III.C.,
Feasibility, respectively, of this preamble.
Some commenters stated that only the miner needs to be sampled to
get a miner's exposure. This comment is addressed elsewhere in this
preamble under Sec. 70.201(c).
Final paragraph (a) is changed and clarified from the proposal. It
requires that an approved CMDPSU be used to take bimonthly samples of
the concentration of respirable coal mine dust from the designated
occupation (DO) in each MMU until January 31, 2016. It also requires
that, effective February 1, 2016, DOs in each MMU must be sampled
quarterly with an approved CPDM as required by this part and an
approved CMDPSU must not be used, unless notified by the Secretary to
continue to use an approved CMDPSU to conduct quarterly sampling.
Final paragraph (a) changes the proposed implementation period for
using the CPDM from 12 to 18 months after the final rule is effective.
Paragraph (a) clarifies that during the 18-month period, an operator
must take bimonthly samples of the DO in each MMU using a CMDPSU. It
further clarifies that, after the 18-month period, bimonthly sampling
will cease and the DO in each MMU must be sampled quarterly with an
approved CPDM instead of a CMDPSU, unless the Secretary provides
notification to continue using a CMDPSU for quarterly sampling.
On October 14, 2009, MSHA published a request for information (74
FR 52708) on the use of the CPDM as a sampling device to measure a
miner's exposure to respirable coal mine dust. All commenters generally
agreed that the required use of a CPDM would enhance the protection of
miners' health.
On March 8, 2011, MSHA issued in the Federal Register a request for
comments (76 FR 12648) and stated that in the proposal, MSHA also
planned to phase in the use of CPDMs to sample production areas of
underground mines and part 90 miners. MSHA solicited comments on the
proposed phasing in of CPDMs, including time periods and any
information with respect to their availability. MSHA requested
commenters to provide the rationale if they recommended shorter or
longer time frames (76 FR 12649).
Some commenters suggested that the proposed 12-month period should
be lengthened; others suggested that it be shortened. A few commenters
suggested that MSHA should extend the phase-in
[[Page 24884]]
period and allow the use of both, the CMDPSU and the CPDM, during the
phase-in period because limiting the type of equipment when there is a
new technology available can result in problems.
In response to the comments, final paragraph (a) extends the time
after which only a CPDM can be used to conduct operator sampling, from
12 to 18 months to allow operators additional time to obtain CPDMs and
train miners in the use of these devices. In addition, the requirement
that a CMDPSU be used to conduct sampling during the 18 months
following the effective date of the final rule addresses commenters'
concerns that the proposed sampling provisions were too confusing.
Final paragraph (a) simplifies the proposed sampling requirements by
requiring that all operators continue to sample production areas
bimonthly with the CMDPSU for the first 18 months after the effective
date of the rule and that the operators stop sampling bimonthly and
switch to quarterly sampling with the CPDM after the 18-month period.
Additionally, maintaining operators' existing bimonthly sampling with a
CMDPSU during the 18 months following the effective date of the rule
allows operators time to concentrate on their dust control systems,
train miners on the new sampling requirements, and learn how to operate
the CPDM and certify persons to handle the CPDM.
MSHA is aware that the CPDM will be in demand and there is
currently only one manufacturer of the device. MSHA has contacted the
manufacturer and discussed the amount of time needed to produce the
necessary quantity of CPDMs. In addition, MSHA considered the amount of
time it would take for the Agency and operators to train necessary
personnel in the use and care of the device. An 18-month period after
the effective date of the final rule should be a sufficient amount of
time for production of the CPDM and training on the use of the CPDM.
Under the final rule, the amount of sampling and, thus, the number of
CPDMs needed are significantly reduced from what the proposal would
have required. However, if MSHA determines that there are logistical or
feasibility issues concerning availability of the CPDM, MSHA will
publish a notice in the Federal Register to continue to use an approved
CMDPSU to conduct quarterly sampling. In addition, assuming no
technological issues arise concerning the use and manufacture of CPDMs,
and depending on manufacturer projections, if CPDMs are not available
in sufficient quantities, MSHA will accept, as good faith evidence of
compliance with the final rule, a valid, bona fide, written purchase
order with a firm delivery date for the CPDMs.
Some commenters stated that MSHA underestimated the number of CPDMs
needed to comply with the proposal. In the development of the final
rule, MSHA discovered an error in MSHA's estimates for the number of
CPDMs that would have been required to sample ODOs under the proposed
rule. Chapter IV of the REA for the final rule discusses MSHA's
underestimation and provides a revised calculation of the number of
CPDMs that would have been needed under the proposal.
Final paragraph (b) is changed from the proposal. It requires that
an approved CMDPSU be used to take bimonthly samples of the
concentration of respirable coal mine dust from each designated area
(DA) as required by this part until January 31, 2016. The proposal
would have required quarterly sampling of the DA on the effective date
of the final rule. The bimonthly sampling requirement of DAs for the
first 18 months after the effective date of the final rule is
consistent with the bimonthly sampling required by existing Sec.
70.201. Continuing the existing bimonthly sampling of DAs during the
18-month period is also consistent with the bimonthly sampling of DOs
in each MMU required by final paragraph (a). As discussed above, the
18-month period, after which the use of CPDMs is required, will provide
sufficient time for manufacturers to produce the necessary quantity of
units and for MSHA and operators to train personnel in the use and care
of the CPDM. On February 1, 2016, final paragraph (b)(1) requires that
DAs associated with an MMU be redesignated as Other Designated
Occupations (ODO). Paragraph (b)(1) clarifies that ODOs must be sampled
quarterly with an approved CPDM as required by this part and an
approved CMDPSU must not be used, unless notified by the Secretary to
continue to use an approved CMDPSU to conduct quarterly sampling. Final
paragraph (b)(1) is derived from proposed paragraphs (b) and (c).
A few commenters stated that requiring existing DAs associated with
an MMU to be redesignated as ODOs will not result in any increased
protection for miners because the DO is the occupation that is most
exposed to respirable dust. These commenters stated that the additional
sampling is too burdensome and costly especially on small mine
operators.
Existing DAs associated with an MMU are to be designated as ODOs
because the sampling would be used to measure respirable dust exposure
of occupations on an MMU rather than areas associated with an MMU.
Examples of DAs associated with an MMU that would be designated as ODOs
and an explanation of the frequency of sampling ODOs are in final Sec.
70.208(b) concerning quarterly sampling. The final rule will help
ensure that the sample reflects an accurate measurement of the
occupation monitored and will provide comparable protection for ODOs
and DOs. For example, ODOs identified by the District Manager would be
based on MSHA's historical sampling data on the MMU. Sampling of ODOs
such as shuttle car operators on MMUs using blowing face ventilation
would be required because MSHA's data show that sampling only the DOs
does not always adequately protect other miners in the MMU. In response
to commenters' concerns, under Sec. 70.208 of the final rule,
operators will sample each DO and each ODO each calendar quarter until
15 valid representative samples are collected for each. The total
number of samples required from the DO and ODO is less than the total
proposed 24/7 sampling of the DO and sampling of the ODO for 14 shifts.
The required sampling for a typical MMU using blowing face ventilation
will have 1 DO and 2 ODOs and, under the final rule, will require
sampling until 15 valid representative samples are collected each from
that DO and each ODO during the calendar quarter. Sampling of an ODO
must follow completion of sampling for the DO, and sampling of a second
ODO must follow completion of sampling for the first ODO. Additional
discussion of sampling ODOs that are redesignated from existing DAs is
provided in Sec. 70.208 regarding quarterly sampling of MMUs.
Final paragraph (b)(2) is similar to proposed paragraph (d). On
February 1, 2016, final paragraph (b)(2) requires that DAs identified
by the operator under Sec. 75.371(t) of this chapter be sampled
quarterly with an approved CMDPSU as required by part 70, unless the
operator notifies the District Manager in writing that an approved CPDM
will be used for all DA sampling at the mine. The notification must be
received at least 90 days before the beginning of the quarter in which
CPDMs will be used to collect the DA samples.
Paragraph (b)(2) clarifies that the quarterly sampling of the DAs
applies to those DAs that are identified by the operators under Sec.
75.371(t). In addition, paragraph (b)(2) clarifies that the operators
may use the CMDPSU while conducting DA sampling but, if operators plan
to conduct DA sampling using the CPDM rather than the
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CMDPSU, operators must notify MSHA of their intent to do so. This
clarification ensures that operators do not switch between sampling
devices on successive quarterly sampling periods, or use both sampling
devices during the same sampling period. The 90-day notification period
allows MSHA sufficient time to modify MSHA's health computer system to
accept CPDM electronic records for all DAs located at the mine.
One commenter stated that DA sampling should be eliminated because
MSHA stated that using the CPDM is not the best use for sampling a DA.
DA sampling provides important information needed to evaluate the dust
controls used in the DA so that the mine operator can ensure that
miners working in these areas are protected. Because the CMDPSU reports
of sample results provide the necessary information for these area
samples, and because the CPDM is designed to be worn, the final rule
provides that a mine operator must use CMDPSUs for sampling DAs.
However, a mine operator may, upon notifying the District Manager, use
CPDMs for sampling all DAs in a mine.
Final paragraph (c) is the same as proposed paragraph (e). Like the
proposal, it requires that sampling devices be worn or carried directly
to and from the MMU or DA to be sampled and be operated portal-to-
portal. In addition, it requires that sampling devices remain with the
occupation or DA being sampled and be operational during the entire
shift, which includes the total time spent in the MMU or DA and while
traveling to and from the mining section or area being sampled.
Several commenters supported the proposal that sampling devices be
operational while traveling to and from the mining section or area
being sampled. Paragraph (c) clarifies the existing requirement that
the sampling device be operated portal-to-portal. Miners are exposed to
respirable dust while traveling to and from the working section or area
being sampled. Many miners ride mantrips onto the section, some for as
long as an hour, during which time miners are exposed to respirable
dust. Sampling during travel time provides an accurate measurement of
respirable dust exposures during usual work conditions because it
accounts for all the time that a miner works and is exposed to
respirable coal mine dust.
Many commenters expressed support for full-shift sampling. Some of
these commenters indicated that it is not uncommon today for miners to
work longer than the traditional 8-hour work shift and agreed that it
is appropriate to determine miners' respirable dust exposure based on
their full work shift. Other commenters acknowledged that turning off a
sampler after 8 hours is not representative of the time that miners
work and the respirable dust conditions in which they work.
MSHA agrees with commenters and believes that it is more
appropriate to determine miners' daily exposures based on their full
work shift. Full-shift sampling will provide operators with the
opportunity to manage miners' exposure to coal mine dust so that miners
will be adequately protected. MSHA estimates that the average work
shift on active mining units is approximately 9 hours for non-longwall
mining and 10 hours for longwall mining. Working shifts longer than 8
hours increases exposure to respirable coal mine dust, resulting in
increased health risks to miners, both in terms of incidence and
severity. In addition, limiting the sampling duration to 8 hours, when
a miner's work shift may be 10 hours, 12 hours, or longer, does not
provide an adequate assessment of the respirable dust exposure during
the full shift. According to NIOSH's Current Intelligence Bulletin 64
(``CIB 64''), Coal Mine Dust Exposures and Associated Health Outcomes--
A Review of Information Published Since 1995 (2011): ``U.S. coal miners
are working longer hours, which leads to the inhalation of more
respirable coal mine dust into the lungs.''
Final paragraph (c) is consistent with the 1996 Advisory
Committee's Report, the 1995 NIOSH Criteria Document, and the
conclusions of the 1992 Coal Mine Respirable Dust Task Group Report.
This final provision is also consistent with generally accepted
industrial hygiene principles today, which take into consideration all
of the time a worker is exposed to an airborne contaminant, even if it
exceeds 8 hours a day.
Therefore, final paragraph (c) requires operators to sample during
the entire shift as discussed above, portal to portal, rather than a
maximum of 8 hours. This will account for all the time that a miner
works and allow more representative measurement of miners' exposures to
respirable coal mine dust.
Final paragraph (c), like the proposal, continues the area sampling
requirement of existing Sec. 70.201(b). Under the final rule, the
sampling device must remain with the occupation or DA being sampled
during the entire shift to ensure that respirable dust concentration
levels are continuously being monitored. If a miner in an occupation
being sampled changes from one occupation to another during the
production shift, the sampling device must remain with the occupation
designated for sampling. For example, if using a CPDM to sample a DO
(continuous mining machine operator) on a continuous mining section and
the duties of the machine operator are divided equally between Miner 1
and Miner 2, the dust sampler must be worn for half the shift by Miner
1 and the other half by Miner 2, while each is operating the continuous
mining machine. Similarly, a dust sampler must remain at the DA during
the entire shift. Once sampling results are available, mine operators
and MSHA would analyze the data to determine if adjustments need to be
made (e.g., re-designating DOs or modifying dust control parameters).
In the March 8, 2011, request for comments (76 FR 12650), MSHA
stated that some commenters suggested during the rulemaking hearings
that, for compliance purposes, respirable dust samples should be taken
only on individual miners in underground coal mines. MSHA further
stated that, under the existing rule, MSHA enforces an environmental
standard, that is, the Agency samples the average concentration of
respirable dust in the mine atmosphere. MSHA also stated that the
proposed rule would continue the existing practice that samples be
collected from designated high-risk occupations associated with
respirable dust exposure and from designated areas associated with dust
generation sources in underground mines. MSHA solicited comments on the
sampling strategy in the proposed rule, any specific alternatives,
supporting rationale, and how such alternatives would protect miners'
health.
Some commenters supported the continuation of area sampling. One of
these commenters preferred area sampling over personal sampling stating
that personal sampling would necessitate that every miner be sampled.
This commenter also stated that a miner's activities, e.g., lunch
break, should be considered as part of his normal activity and count
towards normal exposure. Another commenter stated that area sampling
makes sense only when using the CMDPSU.
Many commenters stated that they preferred personal sampling,
particularly when using the CPDM, because the CPDM provides an accurate
measurement of an individual miner's exposure rather than potential
exposure at a single work location. Many of these commenters stated
that the CPDM was designed and tested for personal sampling and
personal exposure and that using it for area sampling defeated
[[Page 24886]]
its designated purpose because it was not designed to be hung and left
unattended. These commenters also stated that the CPDM was designed to
provide immediate information to the miner so that the miner could make
immediate adjustments in behavior, tactical positioning in relation to
dust sources, or mining procedures. A few commenters stated that not
conducting personal sampling hinders an operator's ability to rotate
miners to reduce exposures. Some commenters suggested that full-shift
personal sampling of the highest risk miner on all production shifts
would provide a valuable data base for researchers to use to pinpoint
areas in need of improvement and provide miners with real time data
that they could use to prevent overexposure resulting in reduced
exposure to dust concentrations without any need to reduce the existing
permissible level. Some commenters stated that area sampling is an
antiquated practice and adds to sampling complexity by requiring new
plan approvals and irrelevant details. Other commenters stated that
passing the pump from miner to miner as is required during area
sampling causes measurement errors and does not result in a true
representation of the miner's exposure. A few commenters stated that
individual sampling is preferred by industrial hygienists, and one
commenter noted that personal sampling is consistent with the NIOSH
recommendation and OSHA's sampling approach. A number of commenters
stated that the final rule should provide for sampling underneath a
respirator, in the miner's immediate breathing zone, instead of
requiring atmospheric sampling.
The Advisory Committee recommended a mix of samples--personal,
occupational, and area--to be a reasonable, systematic approach for the
determination of miners' respirable dust exposure and subsequent
control of exposure. The NIOSH Criteria Document stated that personal
sampling is preferable and that area sampling should be substituted for
personal sampling only where area sampling has been shown to measure an
equivalent or higher concentration. However, the NIOSH Criteria
Document also stated area sampling is sufficient under Section 202(b)
of the Mine Act.
An area sample is one taken at a fixed location. It measures the
concentration of respirable dust in that location and not necessarily
the exposure of any individual. Area sampling under existing Sec.
70.201(b) involves sampling the occupation or DA and has been in use by
MSHA since 1970. Section 202(b)(2) of the Mine Act requires an operator
to ``. . . continuously maintain the average concentration of
respirable dust in the mine atmosphere during each shift to which each
miner in the active workings is exposed. . . . '' The purpose of this
provision, as set forth in Section 201(b) of the Mine Act, is to ensure
that ``the working conditions in each underground coal mine are
sufficiently free of respirable dust concentrations in the mine
atmosphere to permit each miner the opportunity to work underground
during the period of his entire adult working life without incurring
any disability from pneumoconiosis or any other occupation-related
disease during or at the end of such period.'' 30 U.S.C. 841(b). The
area sampling requirement of the final rule is consistent with sections
201(b) and 202(b)(2) of the Mine Act. Rather than measuring the
exposure of any individual miner for the duration of a shift, area
sampling allows an operator to monitor the mine atmosphere with the
greatest concentration of respirable dust in the areas where miners are
working or traveling and to take corrective measures that protect each
miner working or traveling in the area. For example, based on the
various dust generating sources and the manner in which the face is
ventilated, the area by the continuous mining machine operator on a
continuous mining MMU is the area on a continuous mining MMU with the
greatest concentration of respirable dust. Since miners are required to
work in this area, operators are required to maintain the mine
atmosphere in this area or location in compliance with the dust
standard on each shift. By doing so, other miners in less risky
occupations are protected from excessive dust concentrations.
While area sampling does not show a particular miner's dust
exposure, the area sampling results will show whether miners are
exposed to excessive dust concentrations. The objective of area
sampling is to control the concentration of respirable dust to which
miners are exposed in the workplace. In American Mining Congress v.
Secretary of Labor, 671 F.2d 1251 (10th Cir. 1982), the Court found
that area sampling was reasonable and consistent with the Mine Act.
If placed in a fixed location, the CPDM will provide an accurate
measurement of the respirable dust in the atmosphere where miners work
or travel. In addition, it will provide immediate information to the
miners working in that location so that the mine operator could make
immediate adjustments in controls in relation to dust sources to reduce
dust generation or suppress, dilute, divert, or capture the generated
dust. Compared with administrative controls or respirators, well-
designed engineering controls provide consistent and reliable
protection to all workers because the controls are less dependent on
individual human performance, supervision, or intervention to function
as intended. Area sampling with the CPDM will also provide information
on miners' exposure in areas with the highest concentration of dust.
This will give the mine operator and MSHA valuable data to pinpoint
areas in need of improvement.
Passing the CPDM from miner to miner will not cause measurement
errors because passing the CPDM is done in conjunction with a certified
person. The certified person will ensure that the CPDM is properly
handled when passed from one miner to the next. In addition, MSHA has
not received any notification on dust data cards indicating any
significant issues encountered during the switching of the existing
CMDPSU since 1981. Area sampling effectively achieves the purpose of
the Mine Act to protect the health of miners by requiring operators to
maintain good air quality in the mine.
Final paragraph (c)(1) is the same as proposed paragraph (e)(1). It
requires that when using a CMDPSU and the work shift to be sampled is
longer than 12 hours, the operator must switch-out the unit's sampling
pump prior to the 13th hour of operation.
Final paragraph (c)(2) is the same as proposed paragraph (e)(2). It
requires that the operator switch-out the CPDM with a fully charged
device prior to the 13th hour of operation, if the work shift to be
sampled is longer than 12 hours.
In the March 8, 2011, request for comments (76 FR 12649), MSHA
stated that the Agency understands that some work shifts are longer
than 12 hours, and that dust sampling devices generally last for
approximately 12 hours. MSHA solicited comments on appropriate time
frames to switch-out sampling devices, CMDPSUs or CPDMs, to ensure
continued operation and uninterrupted protection for miners for the
entire shift.
Some commenters stated that switching out the pump prior to the
13th hour is financially burdensome to the operator because it will
require purchasing additional pumps. Other commenters stated that until
the CPDMs are available, the CMDPSU should only be used for 8 hours
because mechanical problems may require a miner to work over 12 hours
and additional samplers may not be readily available. Some
[[Page 24887]]
commenters stated that it would probably be best to change the sampling
device after the end of an eight-hour shift to make certain the unit
has enough battery life to cover the number of hours a miner works and
the results of the samples could then be combined.
The CMDPSU manufacturer's instructional manual states that the
typical battery-pack service life varies from a minimum of 8 hours to a
maximum of 11.5 hours. However, the manufacturer's testing parameters
are more rigorous than the conditions in the mine. The pumps are tested
in extreme levels of coal mine dust which cause large amounts of dust
to accumulate on the filter. This leads to high back pressure,
requiring the pump to work harder, and resulting in a shorter battery
life. With the use of proper dust controls, the pump will not have to
work as hard, thereby prolonging the battery life. To address shifts
greater than 12 hours, the final rule requires that the unit be
switched-out prior to the 13th hour to prevent disruption in operation
and to provide continued protection for miners. Mine operators who have
knowledge that their sampling pumps will not last more than 12 hours
should change them out sooner to ensure the full sampling period is
covered. If the battery is depleted before the end of the shift, the
sample would be voided.
NIOSH's Report of Investigations 9669, Laboratory and Field
Performance of a Continuously Measuring Personal Respirable Dust
Monitor (Volkwein et al., NIOSH (2006) suggests that 12 hours of
battery power be provided to the CPDM. In addition, 30 CFR 74.7(i)
requires the CPDM to have sufficient battery capacity to operate for 12
hours. The final rule is consistent with NIOSH's report and the
existing CPDM approval requirements in 30 CFR part 74. It requires that
the CPDM be switched-out prior to the 13th hour to prevent disruption
in operation and to provide continued protection for miners.
Final paragraph (d) is substantially the same as proposed paragraph
(f). It requires that, if using a CMDPSU, one control filter be used
for each shift of sampling. Each control filter must: (1) Have the same
pre-weight date (noted on the dust data card) as the filters used for
sampling; (2) Remain plugged at all times; (3) Be used for the same
amount of time, and exposed to the same temperature and handling
conditions as the filters used for sampling; and (4) Be kept with the
exposed samples after sampling and in the same mailing container when
transmitted to MSHA. MSHA did not receive comments on the proposed
control filter requirements.
Final paragraph (d), which requires an operator to use control
filters when sampling, is consistent with accepted industrial hygiene
principles and practice. A control filter is an unexposed filter of the
same design as the filter used for sampling and is pre- and post-
weighed on the same day as the filter used for sampling. MSHA first
began using control filters in its enforcement program in May 1998 and
continues this practice today. Control filters improve measurement
accuracy by eliminating the effect of differences in pre- and post-
exposure laboratory conditions, or changes introduced during storage
and handling of the filter cassettes. The final rule extends the
program in effect since July 2007, which allows operators to use
control filters in the optional quartz sampling program, to the entire
sampling program. The control filter must be used for all operator
sampling to adjust the resulting weight gain obtained on each exposed
filter by subtracting any change in the weight of the control filter
from the change in weight of each exposed filter. This is especially
important since the filter cassettes to be used by operators would be
pre-weighed by the manufacturer and post-weighed by MSHA. To ensure the
precision and accuracy of the pre-weight of filters, MSHA audits the
daily production of filter cassettes. The program conforms to ANSI/ASQ
Z1.4-2008, ``Sampling Procedures and Tables for Inspection by
Attributes,'' which defines the criteria currently used to monitor the
quality of the operator bimonthly sampling program.
Since the control filter would be used to adjust the resulting
weight gain obtained on each exposed filter cassette, the control
filter must have the same pre-weight date as the filter cassette to be
used for sampling on the same shift. The pre-weight date is noted on
the dust data card. To prevent exposure to the mine environment, the
plugs attached to the inlet and outlet side of the cassette must not be
removed. Also, it is important that the control filter be used for the
same amount of time, and exposed to the same temperature and handling
conditions as the ones that are used for sampling, i.e., carry the
control filter in a shirt or coverall pocket while underground. While
the control filter can be carried by any miner assigned to the MMU
being sampled, it would be preferable if that miner performed the job
of the DO. Finally, the control filter cassette must be kept together
with the exposed samples after sampling and should be treated in the
same manner as the exposed filters prior to being transmitted to MSHA.
Failure to follow these instructions would be cause for voiding the
sampling results.
Final paragraph (d)(4) requires that the control filter must be in
the same mailing container as the exposed samples when transmitted to
MSHA. This provision is new and will ensure that the control filter and
the sample are linked during processing of the sample that is being
submitted to MSHA.
Final paragraph (e) is the same as proposed paragraph (g). It
requires that records showing the length of each production shift for
each MMU be made and retained for at least six months and be made
available for inspection by authorized representatives of the Secretary
and the representative of miners, and submitted to the District Manager
when requested in writing.
One commenter stated that production shift records should be
retained for 12 months. A few commenters stated that the production
shift records are unnecessary and excessively burdensome.
Under the final rule, mine operators need to know the length of the
production shift to enter this information into the CPDM or record it
on the CMDPSU dust card. The information is also necessary for MSHA to
verify that an operator is accurately recording the production shift
lengths for sampling. The 6-month retention period will give MSHA
adequate time to review the records. Although some commenters suggested
longer retention periods for production records, the Agency does not
believe that a longer period is justified in light of the record's
purpose.
Final paragraph (f) is the same as proposed paragraph (h). It
requires that upon request from the District Manager, the operator must
submit the date and time any respirable dust sampling required by this
part will begin, and that this information be submitted at least 48
hours prior to scheduled sampling.
One commenter supported the proposal. Another commenter stated that
the proposed requirement to submit information to MSHA 48 hours prior
to scheduled sampling creates a burden on MSHA. One commenter suggested
that less than 48 hours notice should be allowed for legitimate reasons
provided the District Manager is notified of the change. The 48-hour
notification requirement does not create a burden on MSHA; rather it
provides MSHA with the opportunity to observe and monitor operator
sampling to ensure that both operating conditions and sampling
requirements are met. MSHA will consider mitigating circumstances if
[[Page 24888]]
conditions or activities outside the operator's control interfere with
meeting the 48-hour requirement. Under those circumstances, however,
the mine operator would need to notify the District Manager of any
changes to the sampling schedule as soon as possible.
Final paragraph (g) is the same as proposed paragraph (i). It
requires that to establish a normal production shift, the operator
record the amount of run-of-mine material produced by each MMU during
each shift to determine the average production for the most recent 30
production shifts, or for all the production shifts if fewer than 30
shifts of production data are available. It further requires that
production records be retained for at least six months and be made
available for inspection by authorized representatives of the Secretary
and the miners' representative.
The final rule is consistent with the Dust Advisory Committee's
recommendation that MSHA require the mine operator to maintain the
appropriate production records. MSHA currently relies on production
information provided by the operator to determine at what production
level the mine ventilation plan should be evaluated. No production
records are required for each MMU. Although operators must submit
production data on a quarterly basis, the data are compiled for the
entire mine. In addition, quarterly reports provide information on the
amount of clean coal produced, which is much lower than the tonnage of
total run-of-mine material produced, and is not useful for establishing
what constitutes a normal production shift for each MMU for sampling.
MSHA will use the production records to establish a normal
production level. If there were no records indicating typical
production levels in the mine, MSHA would be unable to determine
whether an operator's sampling of dust concentrations occurred during a
shift that reasonably represented typical production levels and mining
conditions.
One commenter stated that production records to establish a normal
production shift would not be necessary once operators were required to
sample with CPDMs every production shift, 7 days per week, 52 weeks per
year. The final rule does not require 24/7 continuous sampling. This
commenter also stated that, under the revised definition of an MMU, it
would be difficult to separate production between two sets of equipment
because shuttle cars may pull coal from different continuous mining
machines.
The MMU production is associated with the amount of material cut
and loaded by the mining machine (continuous mining machine, loading
machine, etc.). The mine operator must relate the production of
material to the MMU. Which shuttle cars are pulling from a specific MMU
does not determine the amount of material produced by each MMU. MMU-
specific information is available through various methods and MSHA
believes that the majority of mines currently track production on a
per-MMU basis.
One commenter requested a 12-month record retention period. The 6-
month period will allow MSHA sufficient time to review the production
records and, therefore, a longer retention period is not necessary. The
6-month time allows MSHA adequate time to be at the mine and have
access to sampling data to determine if the samples are representative
samples.
Final paragraph (h) is substantially similar to proposed paragraph
(j). It requires that mine operators using CPDMs provide training to
all miners expected to wear a CPDM. The training must be completed
prior to a miner being required to wear a CPDM, and then every 12
months thereafter. This training must be provided to each miner working
in a position as a DO or ODO. In addition, if a CPDM is used for DA
sampling, and the DA location for the sample is on the miner performing
specific tasks, the training must be provided to the miner that will be
wearing the CPDM.
Many commenters supported initial and annual retraining
requirements on the CPDM and indicated that the knowledge was necessary
to help reduce dust exposure. One commenter generally stated that the
proposed training requirements are burdensome for the mine operator.
One commenter recommended that refresher CPDM training be provided
every 6 months. A few commenters indicated that the 12-month retraining
requirement is extensive and does not achieve any safety benefit for
miners who only wear the CPDM and do not set it up.
The Mine Act recognizes the importance of miner training and
education in the prevention of injury and disease. In accordance with
Section 115(b) of the Mine Act, training must be provided during normal
working hours and miners must be paid at their normal rate of pay while
they take such training. In addition, if the training is provided at a
location other than the normal place of work, miners must be
compensated for the additional costs they may incur in attending such
training sessions. 30 U.S.C. 825.
Initial training is appropriate to ensure miners wearing CPDMs
understand the function and purpose of the equipment they are wearing
and the importance of monitoring dust concentrations. Although
certified persons set up the CPDMs, a miner who is trained on the use
and operation of the sampler and information displayed on the CPDM is
more likely to recognize potential problems and respond to them
appropriately. Based on MSHA's experience and consistent with other 30
CFR training requirements, training is most effective when provided
close to the time when the miner is expected to wear the CPDM and then
reinforced every 12 months. It is essential that miners who wear a CPDM
have a fundamental understanding of its operation even if they are not
setting up the CPDM for sampling. Usage of the CPDM by miners, such as
accessing information and collecting short-term samples, is discussed
below concerning paragraphs (h)(3) and (h)(4).
MSHA received several comments both for and against including CPDM
training in part 48 training. Several commenters suggested that the
training should be included in part 48 new miner training, experienced
miner training and annual refresher training. Other commenters stated
that the initial and annual CPDM training should not be incorporated
into part 48 training, generally stating that part 48 training already
includes too much information, making it difficult for miners to retain
all that is given. They indicated that it is important to give miners
the needed time to learn about the CPDM.
After reviewing all the comments, MSHA determined that additional
training should not be added to part 48 training. MSHA considered
whether training on the operation and use of the CPDM could be
adequately covered under part 48 training, taking into account the
other subjects that part 48 is required to address. MSHA determined
that it is impractical to include the proposed comprehensive training
on CPDMs within the prescribed time limits under part 48. Additional
time should be allotted for CPDM training under part 48. However,
operators may choose to provide CPDM training separately from training
under part 48, or may provide CPDM training on days that part 48
training is held as long as additional time is designated to ensure
that training on the CPDM required under the final rule is sufficient.
Final paragraphs (h)(1)-(4) are similar to proposed paragraphs
(j)(1)-(5). Proposed paragraph (j)(2) would have required all miners to
be instructed on
[[Page 24889]]
how to set up the CPDM for compliance sampling. Some commenters stated
this was unnecessary and were concerned that it could lead to persons
who are not certified performing functions that require certification.
In response to the comments, the final rule requires mine operators
to have certified persons set up the CPDM for compliance. Therefore, it
is not necessary to train miners on the set up of the CPDM. Miners who
are not certified persons are, however, required to be trained on
topics that pertain to shift sampling under final paragraph (h). Final
paragraph (h)(1) is similar to proposed (j)(5). It requires that the
training include the importance of monitoring dust concentrations and
properly wearing the CPDM. Final paragraph (h)(1) includes a conforming
change. The proposal would have required training on the importance of
``continuously'' monitoring dust concentrations. Since continuous
monitoring is not required by the final rule, the term ``continuously''
is not included in paragraph (h)(1). Commenters generally agreed that
miners need to be trained on the importance of monitoring dust and how
to wear the CPDM.
Final paragraph (h)(2) is the same as proposed (j)(1). It requires
that training include explaining the basic features and capabilities of
the CPDM. One commenter indicated that training miners in all functions
of the CPDM may result in an uncertified person activating functions
that only a person certified in sampling, maintenance, and calibration
should be able to access. Most commenters supported the proposed
requirement, noting that miners have a right to know the features and
functions of the equipment, and its capabilities, as well as what the
collected information means.
It is vital that miners are properly trained on the operation of
CPDMs to ensure the integrity and credibility of the sampling process.
For the sampling program to be effective, miners must understand the
proper use of the CPDM and its operation. Well-informed miners are more
likely to make the most of the capabilities of the new CPDM technology.
Final paragraph (h)(3) is similar to proposed paragraph (j)(3).
Like the proposal, it requires that training include discussing the
various types of information displayed by the CPDM and how to access
that information. This training will provide a miner with an
understanding of how to use the displayed data to assess any concerns
of overexposure to respirable dust. Several commenters expressed
concern about training on how to access information on a CPDM. One
commenter stated that only persons certified in sampling, maintenance,
and calibration should be able to access data that are not readily
displayed during use. The commenter added that if miners access data,
it would have negative effects on the sampling process.
To clarify, this training is limited to accessing information that
is readily available by pushing a button located on the CPDM. This only
changes the information provided on the display screen and does not
affect programming of the CPDM to collect a full-shift sample. The
training is necessary to provide users with an understanding of how to
access the various screens and data displayed on these screens, but not
to change the settings on the CPDM.
Final paragraph (h)(4) is the same as proposed paragraph (j)(4). It
requires that training include how to start and stop a short-term
sample run during compliance sampling. A short-term sample is an
engineering evaluation, which runs for a term shorter than the full-
shift sampling, and provides information on respirable dust levels in a
particular location.
One commenter stated that it is not necessary to train a miner, who
simply is going to wear the unit for sampling, on how to start, stop,
reset, or to do any function that is required to be performed by a
certified person.
It is important that miners be able to conduct, access, and view
short-term sampling. This would not interfere with an ongoing
compliance sampling run and would not change any programmed settings
entered by a certified person. Short-term samples can provide a miner
with immediate information regarding the real-time dust levels in his
work location. As changes are made in dust controls on the MMU, or in
the miner's physical location, short-term sampling will provide data
concerning the miner's exposure to respirable dust. These data will be
useful to the miner in making adjustments to his work practices. Miners
do not need to be certified in sampling to be able to conduct the short
term sampling.
Final paragraph (i) is similar to proposed paragraph (k). It
requires that an operator keep a record of training at the mine site
for 24 months after completion of the training. It also provides that
an operator may keep the record elsewhere if the record is immediately
accessible from the mine site by electronic transmission. It further
requires that, upon request by an authorized representative of the
Secretary, Secretary of HHS, or representative of miners, the operator
must promptly provide access to any such training records. Final
paragraphs (i)(1)-(3) require the record to include the date of
training, the names of miners trained, and the subjects included in the
training.
Final paragraph (i) makes a non-substantive change by replacing the
proposed term ``2 years'' with ``24 months.''
Final paragraphs (i)(1)-(3) are new; they were added to clarify
that the record must contain sufficient information for an authorized
representative of the Secretary, Secretary of HHS, or miners'
representative to determine that the operator has provided CPDM
training in accordance with requirements in paragraph (h). This is the
type of information that is generally required for all training records
to establish that the training has occurred.
One commenter stated that the proposed requirement to keep records
is burdensome. Another commenter favored the proposed retention period.
Record retention for the 24-month period is important so that MSHA can
determine that the required initial and retraining has been provided.
Final paragraph (j) is new. It provides that an anthracite mine
using the full box, open breast, or slant breast mining method may use
either a CPDM or a CMDPSU to conduct the required sampling. It requires
that the mine operator notify the District Manager in writing of its
decision to not use a CPDM. Final paragraph (j) is added in response to
comments that the CPDM will be damaged or destroyed by miners going up
and down the pitch in an anthracite mine. In addition to damage to the
unit, MSHA has concluded from its experience with anthracite mines,
that miners may also be injured due to the particular configuration of
such mines. Therefore, final paragraph (j) allows operators to use
either sampling device due to the potential hazards to the miner
associated with mining in such confined spaces with extremely pitching
coal seams.
Final paragraph (k) is similar to proposed Sec. 70.209(h) and
moved to this final Sec. 70.201. It provides that MSHA's approval of
the dust control portion of the operator's mine ventilation plan may be
revoked based upon samples taken by MSHA or in accordance with this
part 70. Paragraph (k) is consistent with existing Sec. 70.208(f) and
is moved to final Sec. 70.201 to clarify that, consistent with
existing enforcement policy, its provisions apply to all underground
sampling entities and not just DAs.
One commenter stated that proposed Sec. 70.209(h), which stated
that MSHA
[[Page 24890]]
approval of the operator's ventilation system and methane and dust
control plan may be revoked based on samples taken by MSHA or the
operator, is excessive. The commenter stated that a ventilation plan is
not inadequate because a sample exceeds the proposed ECV or the WAE
exceeds the WPAE. The commenter further stated that the District
Manager should be required to follow the procedures in MSHA's Program
Policy Manual, Volume V, page 6, MSHA Initiated Plan Changes, to revoke
the ventilation plan. Another commenter stated that mine operators have
no effective remedy in plan disputes. This commenter stated that MSHA
opposes expedited hearings before the Federal Mine Safety and Health
Review Commission on this sort of issue, and that the backlog of cases
precludes actual expedited consideration.
In response to comments, paragraph (k) clarifies that MSHA may
revoke the respirable dust control portion of the ventilation plan
based on sample results, but not the entire ventilation plan. MSHA
intends to notify the operator, in the citation issued for excessive
dust, of the revoked dust control portion of the approved ventilation
plan. Final paragraph (k) ensures that respirable dust controls are
updated timely to ensure miners' exposures to excessive respirable dust
are controlled on each and every shift.
6. Sections 70.202 Certified Person; Sampling and 70.203 Certified
Person; Maintenance and Calibration
Final Sec. Sec. 70.202 and 70.203, like the proposal, retain the
requirements in existing Sec. Sec. 70.202(a) and 70.203(a) that
respirable dust sampling be performed by a person certified to collect
dust samples and handle dust samplers while they are in operation, and
that maintenance and calibration of approved samplers be performed by a
person certified to perform such tasks.
Although the proposal did not include revisions to the existing
requirements in Sec. Sec. 70.202(a) and 70.203(a), one commenter
recommended that MSHA eliminate the requirement that dust sampling and
maintenance and calibration of approved sampling devices be performed
by certified persons. The commenter stated that restricting dust
sampling collection to certified persons does nothing to further the
quality of the sampling process and that certification does not ensure
that dust sampling is any better than if conducted by a non-certified
person.
Certification ensures the validity of collected samples and the
integrity of the dust sampling program. The collection of respirable
dust samples by untrained persons, or with sampling devices that are
not maintained as approved or calibrated in accordance with required
procedures, would significantly affect the accuracy and quality of dust
samples. Under that scenario, the entire dust program would be
undermined and the protections from dust exposure afforded coal miners
under the standards would be reduced. To maintain the integrity of
MSHA's dust program, there must be competency standards for those
entrusted with administering the program.
One commenter questioned the need for certified industrial
hygienists to become MSHA-certified in sampling, stating that certified
industrial hygienists are qualified to conduct respirable dust sampling
and do not need further instruction or a separate certification. The
commenter also pointed out that MSHA certification in such cases is
costly.
MSHA recognizes that industrial hygienists have to meet certain
educational and experience-based thresholds to become professionally
certified and maintain certification as industrial hygienists. However,
an independent MSHA certification process is needed for MSHA's dust
sampling program. In general, industrial hygienists must demonstrate a
basic technical understanding of industrial hygiene practices in a
broad number of subject matters in order to become certified. However,
the comprehensive nature of the industrial hygienist certification
examination does not ensure that the individual has knowledge of MSHA-
specific requirements that are necessary to carry out MSHA's dust
monitoring program. A certification process specifically directed at
evaluating familiarity with the intricacies of the dust sampling
requirements is needed to maintain the quality of MSHA's dust program.
For example, MSHA's certification process tests knowledge of key dust-
related standards contained in 30 CFR; sampling and calibration
equipment to be used; and procedures used for maintenance and
calibration of this equipment. It also requires satisfactory completion
of hands-on demonstrations of certain performance criteria. Each
certification applicant must be explicitly aware of the
responsibilities and the importance associated with sampling and
maintenance and calibration certification, as well as the potential for
civil and criminal sanctions that may apply if certified persons do not
perform their duties properly. These specific requirements and issues
are not part of the certification process for industrial hygienists.
Final Sec. Sec. 70.202(b) and 70.203(b), like the proposal, retain
the existing requirements that candidates for certification pass an
MSHA-administered examination to demonstrate competency in respirable
dust sampling procedures and in maintenance and calibration procedures,
as appropriate. Also like the proposal, final Sec. Sec. 70.202(b) and
70.203(b) add new provisions that require candidates for certification
to complete an MSHA course of instruction prior to examination and
certification. The instructional course requirements under final
Sec. Sec. 70.202(b) and 70.203(b) are consistent with the
recommendation of the 1992 Coal Mine Respirable Dust Task Group.
MSHA received a number of comments on this provision. One commenter
expressed support for the proposed requirement that persons complete a
course of instruction prior to becoming certified. Another commenter
recommended that the final rule include a provision requiring each mine
to have a minimum of two persons trained in sampling at any given time.
Mine operators are in the best position to determine how many
persons should be trained and certified in sampling and in maintenance
and calibration to ensure the continuity of their operations given the
operational demands of the mine, as well as the number of miners
employed by the operator. Accordingly, the final rule does not specify
how many persons that a mine operator must have trained or certified.
One commenter suggested that a single certification should permit a
person to collect dust samples and perform maintenance and calibration
of approved sampling devices.
Given the differences in duties between persons certified in
sampling and those certified in maintenance and calibration, separate
certifications are necessary.
One commenter found the exception in proposed Sec. 70.203(b) that
would allow maintenance of CMDPSU sampling head assemblies to be
performed by persons certified either in sampling or maintenance and
calibration to be confusing. As MSHA explained in the proposal,
``maintenance of the head assembly does not require a person to open,
handle, disassemble, or reassemble the sampling device's internal
components.'' As such, maintenance of the head assembly would not
affect
[[Page 24891]]
electrical components and other intrinsic safety features that must be
maintained in order for the CMDPSU to retain its approval under part
74. Therefore, the final rule, like the proposal, continues to reflect
that necessary head assembly maintenance may be performed by persons
certified in sampling, as well as those certified in maintenance and
calibration.
Some commenters recommended a requirement that certified persons
take regular refresher training. One of these commenters stated that
certified persons should be required to receive training on sampling or
maintenance and calibration of the CPDM every 6 months. Other
commenters stated that certified persons should be retrained if they
are unable to pass the recertification exam required every three years
by proposed Sec. Sec. 70.202(c) and 70.203(c). One of these commenters
added that retraining should also be mandated when necessitated by
equipment or procedural modifications. An additional commenter stated
that the final rule should restrict certified persons' sampling or
maintenance and calibration certification to the specific CPDM model on
which the person received classroom instruction and examination.
To become certified under final Sec. Sec. 70.202(b) and 70.203(b),
each person seeking initial certification will have to complete both an
MSHA course of instruction and pass an MSHA examination for the
certification that the person is seeking. As explained in the proposal,
it is essential for each person seeking initial certification in
accordance with this rule to take classroom training prior to taking
the MSHA competency examination. These requirements also strengthen the
overall certification process. Like the proposed rule, final Sec. Sec.
70.202(b) and 70.203(b) do not include provisions that would mandate
periodic retaking of the applicable MSHA course of instruction once a
person has received certification or has failed a subsequent competency
examination. MSHA does not believe that there would be added value to
require candidates for recertification to periodically retake the
instructional course. They are able to review procedures and regulatory
requirements on their own and will have had the benefit of regular,
hands-on experience in either sampling, or maintenance and calibration
procedures. Their competency will be adequately evaluated by whether
they pass or fail the examination. To maintain certification in the
tasks the certified person performs, every three years, a person must
pass the applicable MSHA examination demonstrating competency in
sampling procedures under final Sec. 70.202(c) or competency in
maintenance and calibration under final Sec. 70.203(c). Accordingly,
there is a continuing obligation that certified persons have to remain
proficient in the use, handling, and/or maintenance and calibration
practices of the approved device in use at their mine.
In addition, MSHA expects that any equipment or procedural
modifications to the CPDM would be minor and would not necessitate
requiring a certified person to repeat the instructional course. Given
the expectation that CPDM design developments will be occasional and
are unlikely to be drastic, there is no need to require retraining due
to equipment or procedural modifications. For example, in MSHA's
experience, design changes over the years to the CMDPSU, the approved
respirable dust sampling device currently used in coal mines, has not
necessitated limiting the person's certification to a particular CMDPSU
model. Furthermore, MSHA does not anticipate technological advances in
respirable dust sampling instrumentation so frequently or to such a
degree that would warrant limiting certification to a particular CPDM
model. MSHA understands that the current approved CPDM manufacturer
offers various training opportunities for those in need of training on
its products. Finally, MSHA believes that the periodic re-examinations
required by final Sec. Sec. 70.202(c) and 70.203(c) will ensure that
certified persons are knowledgeable and maintain competency on the
device in use at their particular mine. For this reason, final
Sec. Sec. 70.202(b) and 70.203(b) do not require persons seeking
recertification to retake the courses of instruction prior to taking
the periodic competency examinations required under final Sec. Sec.
70.202(c) and 70.203(c).
To maintain certification, final Sec. Sec. 70.202(c) and
70.203(c), like the proposal, require persons certified in dust
sampling procedures or maintenance and calibration procedures to pass
the applicable MSHA examination demonstrating competency in sampling
procedures or maintenance and calibration procedures every three years.
A certified person who fails the MSHA examination is no longer
certified and is not permitted to perform the duties of a certified
person. Also, a person who is certified on the effective date of the
final rule will be required to retake and pass the applicable MSHA
examination within three years of that date.
Commenters varied in opinion as to the need and practicality of re-
examination. One commenter stated that the three-year re-examination
frequency is too long a period of time, while other commenters believed
it was too onerous. One of these commenters suggested that a five-year
interval would be more appropriate, while another suggested allowing
continuing education units as a more desirable alternative to re-
examination.
After considering these comments, MSHA continues to believe that
the proposed three-year re-examination interval is reasonable. MSHA
recognizes the importance of routinely demonstrating, without too much
passage of time, that certified persons remain competent in performing
the essential skills required of them. Requiring persons to be re-
examined at regular intervals as a condition of maintaining a valid
certification will ensure that certified persons have a minimum
threshold of proficiency at all times, as familiarity with proper
procedures is integral to protecting the health of miners. To allow
more than three years to pass, however, before re-testing certified
persons could permit an inordinate period to elapse during which
inadvertent, improper or erroneous sampling or maintenance and
calibration practices might occur and go unchecked. MSHA also believes
that testing more frequently than at three-year intervals could be
unreasonably burdensome on operators and certified persons.
Another commenter recommended elimination of the re-examination
provision. This commenter stated that certified persons should simply
be permitted to sign an annual ethics statement. MSHA has not included
this suggestion because merely signing an ethics statement does nothing
to objectively demonstrate that a person maintains the proficiency
needed to conduct respirable dust sampling or maintain and calibrate
approved sampling devices. An annual self-certification pledge is akin
to certifying persons for life, the very practice that MSHA has found
to be deficient in ensuring that certified persons are qualified to
perform the required sampling, and maintenance and calibration tasks.
Certifying persons for life can result in diminished aptitude or
proficiency in skills that can affect a person's competence to perform
required tasks. It is absolutely critical that persons who are
designated to perform dust sampling and maintenance and calibration of
dust sampling equipment maintain the necessary competency to do so.
Periodic re-
[[Page 24892]]
examination under final Sec. Sec. 70.202(c) and 70.203(c) will ensure
that certified persons maintain their knowledge, skills, and abilities
to competently perform their duties.
Another commenter stated that it would be administratively
impossible for MSHA to schedule and provide the number of re-
examinations that would be required by proposed Sec. Sec. 70.202(c)
and 70.203(c). The commenter expressed concern that MSHA does not
currently have the staff to instruct and administer tests to this many
people and with such recurring frequency. Although MSHA understands the
commenter's concern, the Agency will make arrangements to assemble and
prepare the needed resources to carry out its administrative functions
under the final rule.
Final Sec. Sec. 70.202(d) and 70.203(d) are derived and clarified
from the proposal. They provide that MSHA may revoke a person's
certification for failing to properly carry out required sampling
procedures or maintenance and calibration procedures, as appropriate.
These final provisions are consistent with the Dust Advisory
Committee's recommendation that MSHA consider a retraining and/or
decertification procedure for certified persons who fail to perform
their duties properly.
Final Sec. Sec. 70.202(d) and 70.203(d) do not include the
proposed provision that MSHA may revoke a person's certification for
failing to pass the MSHA examination. The proposed provisions would
have given MSHA discretion to revoke a person's certification for
failing to pass the examination which is inconsistent with final
Sec. Sec. 70.202(c) and 70.203(c) which require that, to maintain
certification, a person must pass the examination every three years.
MSHA received two comments on this provision. One commenter
suggested that revocation should be mandatory in those cases where
certified persons execute their duties improperly. MSHA has not adopted
the suggestion. Because of the seriousness of decertification, each
case should be judged on a case-by-case basis. In certain
circumstances, decertification, or even criminal referral, may be
appropriate. In other cases, however, decertification may not be
warranted. In any event, it is important to permit the certified person
the opportunity to present mitigating circumstances or otherwise rebut
any evidence that MSHA would use in order to justify the person's
decertification.
The second commenter suggested that, because MSHA seldom uses its
decertification authority, MSHA should eliminate the revocation
provisions. This commenter also suggested that MSHA should perform all
respirable dust sampling in lieu of certifying and decertifying
persons. MSHA has not adopted these suggestions. The authority to
decertify a person is a significant factor in safeguarding the
integrity of the sampling and maintenance and calibration processes,
providing a healthful environment for miners, and maintaining miners'
confidence and support for the dust program. MSHA's current
decertification procedures and procedures regarding appeals of
revocation are addressed in MSHA's Program Policy Letter (PPL) No. P12-
V-01, March 8, 2012 (Reissue of P09-V-08--Procedures for Revoking MSHA
Certifications to Take Respirable Dust Samples or to Maintain and
Calibrate Approved Dust Sampling Devices). In addition, as explained
elsewhere in this preamble, the responsibility to provide a safe and
healthful environment for miners is primarily the operator's
obligation.
Final Sec. Sec. 70.202 and 70.203, like the proposal, does not
include paragraph (c) in both existing Sec. Sec. 70.202 and 70.203,
which permit MSHA to temporarily certify a person to collect respirable
dust samples or to maintain and calibrate approved sampling devices if
the person has received specific instruction from an authorized
representative of the Secretary. MSHA is not including the existing
temporary certification provisions because MSHA's experience has been
that people seek permanent certification, rather than temporary
certification. MSHA received no comment on the proposed deletions of
paragraphs(c) in existing Sec. Sec. 70.202 and 70.203.
7. Section 70.204 Approved Sampling Devices; Maintenance and
Calibration
Final Sec. 70.204(a), like the proposal, requires that approved
sampling devices be maintained as approved under 30 CFR part 74 and
calibrated in accordance with MSHA Informational Report IR 1240 (1996)
``Calibration and Maintenance Procedures for Coal Mine Respirable Dust
Samplers'' or in accordance with the manufacturer's recommendations, if
using a CPDM.
Final paragraph (a) is similar to the proposal and clarifies that
only persons certified in maintenance and calibration can perform
maintenance work on ``the CPDM or the pump unit of the CMDPSU'' rather
than ``the pump unit of approved sampling devices'' because the CPDM is
a sealed unit. MSHA's experience with the CMDPSU is that maintenance
and calibration of the pump unit requires a person to open, handle,
disassemble, or reassemble the sampling device's internal components.
Additionally, maintenance of the pump unit could affect the electrical
components or other intrinsic safety features that must be maintained
for the device to retain its approval and not become a source of
possible ignition of a methane and oxygen atmosphere. Persons trained
and certified in maintenance and calibration procedures on the CMDPSU
have been determined to be competent and knowledgeable to properly
perform pump unit maintenance on the CMDPSU. Final paragraph (a)
clarifies that only persons certified in maintenance and calibration
can perform maintenance on the CPDM. The CPDM is a new sampling device
which is a sealed unit. To ensure proper performance of the CPDM and
the integrity of the samples, it is critical that only persons trained
and certified in maintenance and calibration be allowed to perform
maintenance work on the CPDM.
One commenter generally supported the proposed provision; another
one did not. The latter commenter questioned whether requiring
maintenance and calibration be done according to the manufacturer's
instructions was equivalent to open-ended incorporation by reference.
As required in other 30 CFR provisions, it is prudent and
reasonable to require that the CPDM be calibrated according to
manufacturer's recommendations. The CPDM is a new sampling device and
the manufacturer has the knowledge and expertise to determine how the
unit is to be calibrated. Maintaining the CPDM according to the
manufacturer's recommendations will ensure that it is maintained as
approved under 30 CFR part 74.
Final Sec. 70.204(b) is substantially similar to proposed Sec.
70.204(b). It requires that sampling devices be calibrated at the
flowrate of 2.0 liters of air per minute (L/min) if using a CMDPSU, or
at 2.2 L/min if using a CPDM, or at a different flowrate recommended by
the manufacturer, before they are put into service and, thereafter, at
time intervals recommended by the manufacturer or prescribed by the
Secretary or Secretary of HHS. As a clarification regarding the
calibration of flowrate, final paragraph (b) includes the phrase ``if
using a CMDPSU, or at 2.2 L/min if using a CPDM,'' and does not include
the phrase ``or prescribed by the Secretary or Secretary of HHS for the
particular device.'' Calibration is determined by approval of the
sampling device based
[[Page 24893]]
on the performance of the unit. The manufacturer must establish, for a
device meeting part 74 requirements, the flowrate that produces a
sample that measures respirable coal mine dust. In addition, like the
proposal, final paragraph (b) allows the time intervals between
calibrations to be performed according to the manufacturer's
recommendations, as well as prescribed by the Secretary or Secretary of
HHS. This will allow the Secretaries to establish a different
calibration schedule when necessary to address problems associated with
a particular sampling unit.
One commenter understood the flowrate provision in proposed
paragraph (b) to mean that the manufacturer could change the flowrate
and it would change the concentration measured. MSHA clarified at a
public hearing that the flowrate is recommended by the manufacturer and
approved by MSHA and NIOSH. Calibration of the sampling device is done
following the manufacturer's specifications, but how the sampler is
used in the field to collect samples is specified by NIOSH and MSHA.
Final paragraph (c), like the proposal, requires that if a CMDPSU
is used to sample, it must be examined and tested by a person certified
in sampling or in maintenance and calibration within 3 hours before the
start of the shift on which the approved sampling devices will be used
to collect respirable dust samples. This will ensure that the sampling
device is clean and in proper working condition prior to use.
One commenter suggested that the preshift check could be done
anytime before the start of the shift, not within 3 hours of the shift
as specified in the proposed rule.
The requirement to examine and test the CMDPSU within 3 hours
before the start of the shift is consistent with MSHA's existing
policy. Since the 1980s, MSHA has interpreted the language
``immediately before each sampling shift'' required by existing
Sec. Sec. 70.204(d), 71.204(d), and 90.204(d) as being equal to no
more than 3 hours (U.S. DOL, MSHA, MSHA Policy Memorandum No. 81-17 C,
1981; U.S. DOL, MSHA Program Information Bulletin No. P09-31, 08/25/
2009). The 3-hour time frame in the final paragraph (c) provides
operators transparency regarding their responsibilities for testing and
examining sampling devices, flexibility, and assurance that the
sampling devices work effectively during the next shift. This time
frame also ensures that the sampling device is not assembled and
exposed for extended periods to possible contamination and mishandling
on coal mine property.
The examination and testing requirements for a CMDPSU are specified
in paragraphs (c)(1) through (c)(5). Final paragraphs (c)(1) through
(c)(4) are identical to the proposed rule. Final paragraph (c)(1)
requires a thorough examination of all components of the cyclone
assembly, including the interior of the connector barrel, vortex
finder, cyclone body, and grit pot, to assure that they are clean and
free of dust and dirt. Final paragraph (c)(2) requires the examination
of the inner surface of the cyclone body to assure that it is free of
scoring or scratch marks on the inner surface of the cyclone where the
air flow is directed by the vortex finder into the cyclone body. Final
paragraph (c)(3) requires examination of the external hose connecting
the pump unit to the sampling head assembly to assure that it is clean
and free of leaks. Final paragraph (c)(4) requires examination of the
clamping and positioning of the cyclone body, vortex finder, and
cassette to assure that they are rigid, in alignment, firmly in
contact, and airtight. Final paragraph (c)(5), like the proposal,
requires testing the voltage of each battery while under actual load to
assure the battery is fully charged. This requires that a fully
assembled and examined sampling head assembly be attached to the pump
inlet with the pump unit running when the voltage check is made. The
final requirement in (c)(5) is simplified by modifying the proposed
language related to CMDPSU batteries. The proposal would have required
that the voltage for nickel cadmium cell batteries must not be lower
than the product of the number of cells in the battery multiplied by
1.25, and the voltage for other than nickel cadmium cell batteries must
not be lower than the product of the number of cells in the battery
multiplied by the manufacturer's nominal voltage per cell value. The
final provision requires that the voltage for the batteries used in the
CMDPSU must not be lower than the product of the number of cells in the
battery multiplied by the manufacturer's nominal voltage per cell
value. This revision allows replacement batteries of different designs
to be used once approved. No comments were received on paragraphs
(c)(1) through (c)(5).
Final paragraph (d)(1) requires that if using a CPDM, the person
certified in sampling or in maintenance and calibration must follow the
pre-operational examinations, testing, and set-up procedures, and
perform necessary maintenance recommended by the manufacturer to assure
its operational readiness within 3 hours before the start of the shift
on which the device will be used to collect respirable dust samples.
Final paragraph (d)(2) requires the certified person to perform other
required scheduled examinations and maintenance procedures recommended
by the manufacturer.
Final paragraphs (d)(1) and (2) are similar to proposed Sec.
70.206(b)(2), (5), and (6). Proposed Sec. 70.206 would have provided
requirements for a CPDM Performance Plan. Proposed Sec. 70.206(b)(2),
(5) and (6) would have required the approved CPDM Performance Plan to
include the names or titles of the responsible mine officials who are
designated by the operator and the following information: The pre-
operational examinations, testing and set-up procedures to verify the
operational readiness of the sampling device before each sampling
shift; the routine daily and other required scheduled maintenance; and
procedures or methods for verifying the calibration of each CPDM. The
proposed CPDM Performance Plan has not been included in this final
rule. Additional discussion is provided in Sec. 70.206 of this
preamble concerning ``Bimonthly sampling; mechanized mining units.''
One commenter on the proposed CPDM Performance Plan requirements
pointed out that proposed Sec. 70.206(b)(5) would have required
scheduled maintenance procedures but that those procedures come with
the CPDM from the manufacturer and should not need to be submitted to
MSHA as part of a plan. MSHA agrees and has not included this operator
submission requirement in the final rule. Existing Sec. 74.10 requires
that manufacturers include operating and storage instructions and a
maintenance and service life plan with each new CPDM device sold. Final
paragraph (d) requires that such operating, maintenance, and
calibration instructions be followed. The certified person must perform
scheduled examinations and maintenance procedures recommended by the
manufacturer.
Furthermore, final paragraphs (d)(1) and (2) are parallel to those
requirements for the CMDPSU under final paragraph (c), except the
certified person needs to follow the manufacturer's specifications for
sampling or for maintenance and calibrations. Mine operators are in the
best position to maintain equipment, tools, and instruments that they
use to comply with the Mine Act and related standards. Under the
existing standards, operators are responsible for ensuring that their
CMDPSUs are properly maintained, and MSHA believes
[[Page 24894]]
application of this practice to the CPDM is reasonable.
Final paragraph (e), like the proposal and existing standard,
incorporates by reference MSHA Informational Report IR 1240 (1996)
referenced in final paragraph (a) of these sections. This incorporation
by reference was approved by the Director of the Federal Register in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. A copy is available
on the MSHA Web site at http://www.msha.gov and may be inspected or
obtained at MSHA, Coal Mine Safety and Health, 1100 Wilson Blvd., Room
2424, Arlington, Virginia 22209-3939 and at each MSHA Coal Mine Safety
and Health District Office. Copies may be inspected at the National
Archives and Records Administration (NARA). For information on the
availability of this material at NARA, call 202-741-6030, or go to:
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. No comments were received on the
proposal.
8. Section 70.205 Approved Sampling Devices; Operation; Air Flowrate
Final Sec. 70.205(a) requires that approved sampling devices be
operated at the flowrate of 2.0 L/min if using a CMDPSU, or at 2.2 L/
min if using a CPDM, or at a different flowrate recommended by the
manufacturer. The language was changed from the proposal to be
consistent with final Sec. 70.204(b), and the language ``if using a
CMDPSU, or at 2.2 L/min if using a CPDM,'' was added to the final
provision.
One commenter understood the flowrate provision to mean the
manufacturer could change the flowrate and this would change the
concentration measured. This comment is addressed elsewhere in the
preamble under Sec. 70.204(b).
Final paragraph (b), like the proposal, requires that if a CMDPSU
is used, each device be examined during each sampling shift by a person
certified in sampling. Like the existing standards, the purpose of the
on-shift CPDM examinations required by final paragraph (b) is to verify
that the device remains in the proper location and continues to operate
properly.
Final paragraph (b)(1), like the proposal, requires that the CMDPSU
be examined during the second hour of a sampling shift to assure it is
in the proper location, operating properly, and at the proper flowrate.
It further requires that if the proper flowrate is not maintained, the
certified person must make the necessary corrective adjustments. In
addition, final paragraph (b)(1), similar to the proposal, provides
that the examination is not required if the approved CMDPSU is being
operated in an anthracite coal mine using the full box, open breast, or
slant breast mining method. Proposed paragraph (b)(1) would not have
required the examination if the sampling device was operated in a
breast or chamber of an anthracite coal mine where only the full box
mining method was used.
One commenter questioned whether the on-shift examination of the
sampling device should be required for anthracite mines. Based on
MSHA's experience with anthracite mines, MSHA has determined that in
the full box mining method, as well as open breast and slant breast
mining methods, which are used only in certain anthracite mines, there
is limited space for the certified person and that conducting this
examination is potentially unsafe. Under the final rule, operators of
anthracite coal mines are not required to perform the examination of
the sampling device during the second hour of operation when the device
is operated where these mining methods are used.
Final paragraph (b)(2), like the proposal, requires that the
certified person check the CMDPSU during the last hour of operation to
assure that it continues to operate properly, including at the proper
flowrate. This provision also requires that, if the proper flowrate is
not maintained, the respirable dust sample must be transmitted to MSHA
with a notation on the back of the dust data card stating that the
proper flowrate was not maintained. It further requires that other
events occurring during the collection of the respirable dust sample
that may affect the validity of the sample, such as dropping of the
sampling head assembly onto the mine floor, must be noted on the back
of the dust data card. No comments were received on the proposal.
Final paragraph (c) is changed from the proposal. It is similar to
proposed Sec. 70.206(b)(1) and (7). It requires that if a CPDM is
used, the person certified in sampling must monitor the dust
concentrations and the sampling status conditions being reported by the
CPDM at mid-shift or more frequently as specified in the approved mine
ventilation plan to assure that: The sampling device is in the proper
location and is operating properly; and the work environment of the
occupation or DA being sampled remains in compliance with the standard
at the end of the shift. The language ``status conditions'' as it
relates to CPDM sampling is terminology used in the approved CPDM
manufacturer's literature.
Proposed Sec. 70.206(b)(1) and (7) relating to the proposed CPDM
Performance Plan would have required identifying information on the
occupations, locations, and miners being sampled, and that the
designated mine official monitor the frequency with which dust
concentrations are reported by the CPDM during each sampling shift.
Under the proposal, monitoring intervals would have been determined, in
part, based on considerations such as the occupation being monitored,
geologic conditions, the location in the mine from which the sample
would have been taken, production levels, past exposure levels and
similarity to current conditions, and mine experience.
The majority of comments on the proposed CPDM Performance Plan
stated that another mine plan was not necessary. MSHA has determined
that the CPDM Performance Plan would have been duplicative of many
requirements in existing mine ventilation plans. Therefore, the
proposed CPDM Performance Plan is not included in the final rule.
Additional discussion on the proposed CPDM Performance Plan is located
under final Sec. 70.206 of this preamble.
Final paragraph (c) is similar to proposed Sec. 70.206(b)(7) which
would have required the CPDM Performance Plan to include reasonable
monitoring intervals based on the conditions at each mine. Routine
monitoring of dust concentrations during the sampling shift is
important. It ensures that MSHA, mine operators, and miners know the
dust concentrations where samples were taken so that timely corrective
action can be taken as necessary. As such, final paragraph (c) requires
that when a CPDM is in use, the certified person must monitor the dust
concentration being reported by the device at mid-shift or more
frequently as specified in the operator's approved mine ventilation
plan. Mid-shift means the middle of the shift for whatever specific
shift length worked. In addition, specifying the monitoring frequency
as part of the approved ventilation plan will also allow the District
Manager to assess the need, if any, for more frequent monitoring of
dust concentrations on a mine-by-mine basis. For example, the District
Manager may require the operator to more frequently monitor dust
concentrations during the shift when CPDM sampling at the DO has shown
repeated overexposures.
For the same reason discussed under final paragraph (b), final
paragraph (c) does not require on-shift monitoring under this section
when CPDMs are
[[Page 24895]]
operated in certain anthracite mining operations.
9. Section 70.206 Bimonthly Sampling of Mechanized Mining Units
Final Sec. 70.206 regarding bimonthly sampling of mechanized
mining units (MMUs) is similar to proposed Sec. 70.207 regarding
sampling of MMUs when using a CMDPSU. Unlike proposed Sec. 70.206, the
final rule does not include requirements for a CPDM Performance Plan.
Proposed Sec. 70.206 would have required each operator to develop and
submit for approval a CPDM Performance Plan prior to sampling with the
CPDM. The Plan would have required specific information on CPDMs and
approval procedures for the Plan.
MSHA received many comments on the proposed CPDM Performance Plan.
The majority of comments stated that another mine plan was not
necessary. MSHA has determined that the CPDM Performance Plan would
have been duplicative of many of the requirements in existing mine
ventilation plans. In addition, the information that is needed to
ensure the proper use of a CPDM is addressed by other provisions of
this final rule or will be incorporated into each operator's
ventilation plan. For example, certain provisions that would have been
required under the CPDM Performance Plan are included in final
Sec. Sec. 70.204(d)(1) and (d)(2), and 70.205(c) and are discussed
elsewhere in this preamble. As many of the requirements in the proposed
CPDM Performance Plan are redundant with existing mine ventilation
plans and most of the requirements of this final rule, MSHA determined
that the CPDM Performance Plan is unnecessary. Miners will be
adequately protected by the requirements of a mine's ventilation plan
and this final rule. Accordingly, the proposed CPDM Performance Plan is
not included in this final rule.
The title of Sec. 70.206 is changed from proposed Sec. 70.207. It
does not include the term ``CMDPSU'' to avoid confusion with the
sampling device required for bimonthly sampling of MMUs under this
section and quarterly sampling of MMUs under final Sec. 70.208. Final
Sec. 70.201(a) addresses the required sampling devices.
Final Sec. 70.206 includes language that bimonthly sampling of
MMUs is required until January 31, 2016 . This change clarifies that
bimonthly sampling ceases 18 months after the effective date of the
final rule.
Final paragraph (a) is redesignated from proposed Sec. 70.207(a)
and, like the proposal, requires that each operator take five valid
representative samples from the DO in each MMU during each bimonthly
period. The term ``representative samples'' replaces the term
``respirable dust samples'' that is used in the existing standard. The
term ``valid representative samples'' used here and throughout the
preamble and rule is a short form reference to the terms ``valid
respirable dust sample'' and ``representative samples.'' Requiring
``valid representative samples'' ensures that samples taken by the
operator reflect typical dust concentrations and conditions at the mine
during normal mining activity. MSHA received one comment on the
definition of representative samples. That comment is discussed
elsewhere in this preamble under Sec. 70.2.
Paragraph (a) further requires that DO samples be collected on
consecutive normal production shifts or normal production shifts each
of which is worked on consecutive days. This is consistent with the
existing standard. MSHA received several comments on the definition of
``normal production shift.'' Those comments are addressed elsewhere in
this preamble under Sec. 70.2.
Final paragraph (a), like the proposal, provides that the bimonthly
sampling periods are: (1) January 1--February 28 (29); (2) March 1--
April 30; (3) May 1--June 30; (4) July 1--August 31; (5) September 1--
October 31; and (6) November 1--December 31. The bimonthly sampling
periods are identical to the existing standard.
Some commenters suggested that MSHA include a provision addressing
malfunctions, suspected tampering and environmental conditions that
could affect measurement of respirable dust levels. These commenters
stated that mine operators should not be required to commit to long-
term ventilation plan approvals for short-term issues due to
environmental conditions when those conditions are not representative
of the normal mining conditions used in the development of ventilation
plans.
Mine operators have always had the opportunity to submit
information on the back of dust data cards when they knew that a
respirable dust sample collected to fulfill the requirements of part
70, 71, or 90 was not representative of normal conditions. The
information submitted has been and will continue to be used to
determine if the sample submitted by the operator is a valid sample. To
clarify the responsibilities of the certified person responsible for
collecting respirable dust samples, MSHA has included requirements for
the submission of information on the back of dust data cards in final
Sec. Sec. 70.205(b)(2), 71.205(b)(2) and 90.205(b)(2).
Final paragraph (b) is redesignated from proposed Sec. 70.207(b)
and, like the proposal, requires that unless otherwise directed by the
District Manager, the DO samples must be taken by placing the approved
sampling device as specified in paragraphs (b)(1) through (10) of this
section. The DOs specified in paragraphs (b)(1) through (10) are
unchanged from the existing standard.
On March 8, 2011, MSHA issued in the Federal Register a request for
comments (76 FR 12648, 12650) and stated that the proposed rule
addresses: (1) Which occupations must be sampled using CPDMs, and (2)
which work positions and areas could be sampled using either CPDMs or
CMDPSUs. MSHA solicited comments on the proposed sampling occupations
and locations, and on whether there are other positions or areas where
it may be appropriate to require the use of CPDMs. MSHA also requested
comments on whether the proposed CPDM sampling of ODOs on the MMU is
sufficient to address different mining techniques, potential
overexposures, and ineffective use of approved dust controls. MSHA did
not receive comments on proposed Sec. 70.207(b).
Final Sec. 70.206(c) is redesignated from proposed Sec.
70.207(c). It requires that when the applicable dust standard changes
in accordance with final Sec. 70.101 (Respirable dust standard when
quartz is present), the standard will become effective 7 calendar days
after the date of notification of the change by MSHA. The rationale for
paragraph (c) is discussed elsewhere in this preamble under Sec.
70.208(c).
Final paragraph (c) does not include the requirements in proposed
Sec. 70.207(c)(1) and (c)(2). Proposed Sec. 70.207(c)(1) would have
required that if all samples from the most recent bimonthly sampling
period do not exceed the new standard, the operator would begin
sampling on the affected MMU on the first production shift during the
next bimonthly period following receipt from MSHA of the change in the
standard. Proposed Sec. 70.207(c)(2) would have required that if any
sample from the most recent bimonthly sampling period exceeds the new
standard (reduced due to the presence of quartz), the operator would
have to make necessary adjustments to the dust control parameters in
the mine ventilation plan within three days, and then collect samples
from the affected MMU on consecutive normal production shifts until
five valid representative samples are collected. It further provided
that the samples collected would be treated as normal bimonthly samples
under this part.
[[Page 24896]]
One commenter stated that one overweight sample was not an
indication of a problem and that the ventilation plan did not need to
be changed when one sample was high or the average of five samples was
over the concentration standard. Other commenters stated that an
operator cannot make ventilation plan changes without MSHA approval and
that three days was too short a time period for the operator to
resubmit the ventilation plan for changes.
After reviewing the comments, MSHA has determined to not include
proposed paragraphs (c)(1) and (c)(2) in the final rule. The proposal
would have required additional sampling requirements before the
operator became aware of the new reduced standard. For consistency
between the sampling requirements of the final rule, final paragraph
(c) is the same as final Sec. 70.207(b) regarding bimonthly sampling
of DAs, Sec. 70.208(c) regarding quarterly sampling of MMUs, Sec.
70.209(b) regarding quarterly sampling of DAs, Sec. 71.206(b)
regarding quarterly sampling, and Sec. 90.207(b) regarding quarterly
sampling.
Final paragraph (d) is redesignated from proposed Sec. 70.207(d)
and makes non-substantive changes. Like the proposal, it requires that
if a normal production shift is not achieved, the DO sample for that
shift may be voided by MSHA. It further requires that any sample that,
regardless of production, exceeds the standard by at least 0.1 mg/m\3\
must be used in the determination of the equivalent concentration for
that MMU. Paragraph (d) is similar to and consistent with final Sec.
70.208(d) regarding quarterly sampling of MMUs.
One commenter stated that it was unfair for MSHA to count a sample
that was over the standard when normal production was not achieved
without giving the operator some credit for a sample that was below the
standard when normal production was not achieved. The commenter also
stated that if production is not met on a given shift and the sample is
under the standard, it is still an indication of the miner's exposure.
Final paragraph (d) ensures that respirable dust sampling is
representative of the activities that occur when sampling is not being
conducted and dust generation sources are active. If normal production
is not achieved, the samples can be expected to reflect an
unrealistically lower reading of respirable dust levels in the mine
atmosphere than what would be expected during typical mining conditions
at the location where the miner is working. Without normal production,
an accurate determination of the effectiveness of the dust control
parameters in the approved ventilation plan cannot be established. If
samples collected are in compliance with the respirable dust standard
when normal production levels are achieved and the ventilation plan is
followed, miners have a reasonable expectation that on shifts when
samples are not collected, the respirable dust levels are in compliance
with the respirable dust standard. Any sample that exceeds the standard
while production is less than normal should be used to determine the
respirable dust concentration of the MMU since operating at a higher
production would likely increase miners' respirable dust exposure even
more.
The above rationale is consistent with the 1995 NIOSH Criteria
Document, the 1996 Dust Advisory Committee Report, and the 1992 Coal
Mine Respirable Dust Task Group Report, all of which emphasized the
need for mine operators to achieve normal production levels when
evaluating the respirable dust parameters contained in the approved
ventilation plan.
Another commenter expressed concern that MSHA would use an overly
restrictive approach in evaluating samples, adding that, in the past,
MSHA refused to void samples with oversized particles if there was a
specific weight gain. To illustrate, the commenter stated that a
sampling device could be dropped and filled with non-respirable dust
from the mine floor and MSHA would not void the sample because it had a
specific weight gain.
MSHA will continue to use the criteria listed in MSHA Method P-19
for evaluating samples for oversized particles (U.S. Department of
Labor, MSHA Method P-19, 2012). Samples with net weight gains greater
than 1.4 mg are opened and visually inspected for oversized particles.
If this examination reveals the presence of foreign materials or other
abnormalities, the sample is voided as contaminated. Any sample with a
net weight gain of 6.0 mg or greater is subjected to further
examination. The procedures used by MSHA's Pittsburgh Safety and Health
Technology Center in MSHA Method P-19 are available on request. It is
the operator's responsibility to submit samples that are collected
according to the requirements of Title 30 of the CFR. As stated
earlier, the operator has always had the opportunity to note on the
back of the dust data card events that may make a sample non-
representative. MSHA has incorporated the requirements for the operator
to make notations on the back of the dust data card in final Sec. Sec.
70.205(b)(2), 71.205(b)(2) and 90.205(b)(2).
Another commenter suggested that the word ``may'' in the proposal
ought to be changed to ``must'' in the final rule so that DO samples
would always be voided if a normal production shift is not achieved.
MSHA is using ``may'' instead of ``must'' to allow samples that exceed
the standard to be included in the average of samples submitted to
fulfill the sampling requirements of final Sec. 70.206. If normal
production levels are not achieved and the sample collected
nevertheless exceeds the standard by at least 0.1 mg/m\3\, MSHA will
use the sample to determine the equivalent concentration.
Final paragraph (e) is similar to proposed Sec. 70.207(g) and (i).
It requires that when a valid representative sample taken in accordance
with this section meets or exceeds the excessive concentration value
(ECV) in Table 70-1 that corresponds to the applicable standard and
particular sampling device used, the operator must: (1) Make approved
respiratory equipment available; (2) Immediately take corrective
action; and (3) Record the corrective actions. The actions required by
paragraph (e) are similar to those in proposed Sec. 70.207(g) and (i).
Proposed Sec. 70.207(g) would have required that, during the time
for abatement fixed in a citation, the operator: (1) Make approved
respiratory equipment available to affected miners in accordance with
Sec. 72.700; (2) submit to the District Manager for approval proposed
corrective actions to lower the concentration of respirable dust to
within the standard; and (3) upon approval by the District Manager,
implement the proposed corrective actions and then sample the
environment of the affected occupation in the MMU in the citation on
each normal production shift until five valid representative samples
are taken.
Proposed Sec. 70.207(i) would have required that when the
equivalent concentration of one or more valid samples collected by the
operator exceeds the standard but is less than the ECV in proposed
Table 70-1, the operator would have to: (1) Make approved respiratory
equipment available to affected miners in accordance with proposed
Sec. 72.700; (2) take corrective action to lower the respirable dust
concentration to at or below the standard; and (3) record the
corrective actions taken in the same manner as the records for
hazardous conditions required by existing Sec. 75.363.
In the March 8, 2011, request for comments (76 FR 12648), MSHA
stated that the Agency received comments that
[[Page 24897]]
the proposed rule should not require mine operators to record
corrective actions or excessive dust concentrations as Sec. 75.363
hazardous conditions. MSHA further stated that it ``would like to
clarify that the proposal would require that operators record both
excessive dust concentrations and corrective actions in the same manner
as conditions are recorded under Sec. 75.363'' and that ``MSHA would
not consider excessive dust concentrations or corrective actions to be
hazardous conditions, since the proposed requirement is not a section
75.363 required record'' (76 FR 12650).
Some commenters supported the requirements of proposed Sec.
70.207(i) and some did not. Most commenters stated that a 1.0 mg/m\3\
dust concentration is not a hazardous condition and a single shift
sample should not require an operator to take action under proposed
Sec. 70.207(i).
In response to the comments, final paragraph (e) is changed from
the proposal. It does not require action if the dust sample exceeds the
standard but is less than the ECV in Table 70-1. Rather, it requires an
operator to take certain actions when a respirable dust sample meets or
exceeds the ECV in Table 70-1. The rationale for final paragraph (e) is
the same as that for final Sec. Sec. 70.207(d), 70.208(e), and
70.209(c) and is discussed elsewhere in this preamble under Sec.
70.208(e) of this preamble.
Final paragraph (e)(1), like proposed Sec. 70.207(g)(1) and
(i)(1), requires that the operator make approved respirators available
to affected miners in accordance with Sec. 72.700. Some commenters
expressed concern that it is inconsistent for MSHA to allow the use of
respiratory equipment after a violation of the standard, but not allow
respiratory equipment during other times to control miners' exposure.
Other commenters, who generally supported requiring operators to make
respiratory equipment available at the miner's request, stated that
respirators should not be allowed while the operator is attempting to
achieve compliance with the standard.
Final paragraph (e)(1) is derived from existing Sec. 70.300, which
requires an operator to make respirators available to all persons
whenever exposed to concentrations of respirable dust in excess of the
levels required to be maintained. The use of approved respiratory
equipment should be encouraged until the operator determines the cause
of the overexposure and takes corrective actions. Additional discussion
on the use of respirators to control exposure to respirable coal mine
dust is elsewhere in this preamble under Sec. 72.700.
Final paragraph (e)(2) is similar to proposed Sec. 70.207(g)(3)
and (i)(2). It requires that the operator immediately take corrective
action to lower the concentration of respirable coal mine dust to at or
below the standard. Paragraph (e)(2) is consistent with existing Sec.
70.201(d), which requires a mine operator to take corrective action to
lower the concentration of respirable dust. Paragraph (e)(2) clarifies
that corrective action must be taken immediately to protect miners from
overexposures.
Corrective actions include, for example, engineering or
environmental controls that control the level of respirable coal mine
dust by: (1) Reducing dust generation at the source with the dust
controls on the mining equipment; (2) suppressing the dust with water
sprays, wetting agents, foams or water infusion; (3) using ventilation
to dilute the dust; (4) capturing the dust with machine-mounted dust
collectors; and (5) diverting the dust being generated by the mining
process with shearer clearer or passive barriers. This provision will
protect miners' health because the operator will be required to review
the dust control parameters and determine what factors may have
contributed to the overexposure. To avoid confusion with the proposal's
timeframes as to when corrective action needs to be taken, final
paragraph (e)(2) requires that the action needs to be taken
immediately. MSHA will assess, on a case-by-case basis, the action that
must be taken immediately and the appropriate timeframe within which it
must occur. For example, under circumstances involving a relatively
minor correction, ``immediately'' would mean before the next shift.
Under circumstances involving the purchase of additional equipment or
parts, MSHA will accept a bona fide purchase order as immediate
corrective action. The purchase order must show the date of purchase
and expected delivery, and the equipment or part must be installed as
soon as it is delivered.
Final paragraph (e)(3) is similar to proposed Sec. 70.207(i)(3).
Final paragraph (e)(3) requires the mine operator to make a record of
the corrective actions taken. The record must be certified by the mine
foreman or equivalent mine official no later than the end of the mine
foreman's or equivalent mine official's next regularly scheduled
working shift. It also requires that the record be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
It further requires that the records be retained at a surface location
at the mine for at least 1 year and be made available for inspection by
authorized representatives of the Secretary and the representative of
miners.
One commenter supported proposed Sec. 70.207(i)(3) which would
have required the mine operator to make a record of the corrective
action taken in the same manner as required by existing Sec. 75.363.
Other commenters stated that the proposal was unnecessary and costly.
One commenter stated that entering the corrective actions in the book
of hazards sets up the operator for an unwarrantable failure order
because the operator would be required to document the circumstances as
a hazard and then could fail to correct the hazard if the corrective
actions did not reduce the dust levels to meet the standard. Other
commenters stated that examinations conducted under Sec. 75.363 are
for hazardous conditions found during the shift by the certified person
conducting the examination. They further stated that hazardous
conditions found during the Sec. 75.363 examination must be corrected
immediately, but any violation of the respirable dust standard cannot
be corrected immediately because the overexposure is not known until
after the shift is over and the District Manager must first approve the
corrective action.
As stated previously, ``MSHA would not consider excessive dust
concentrations or corrective actions to be hazardous conditions, since
the proposed requirement is not a section 75.363 required record.'' To
avoid confusion with the existing requirements at Sec. 75.363
regarding ``Hazardous conditions; posting, correcting and recording,''
final paragraph (e) does not contain any reference to Sec. 75.363 or
the term ``hazardous conditions.'' However, the certification and
record retention requirements of final paragraph (e)(3) are similar to
those required for records under existing Sec. 75.363. Under Sec.
75.363(c), the record must be made by the certified person or verified
by the certified person and must be countersigned by the mine foreman
or equivalent mine official. Paragraph (e)(3) is necessary because it
provides useful information to a mine operator, miners, and MSHA
regarding the corrective actions taken and whether the dust control
parameters in the approved ventilation plan are adequate. The record of
the corrective actions taken should be made by a responsible mine
official, such as the mine foreman or equivalent mine official. Records
and certification of corrective action taken
[[Page 24898]]
help identify excessive dust concentrations so they can be addressed
appropriately to better ensure miners' health. In addition, retaining
records at the mine for at least one year is consistent with many
existing MSHA record retention standards, particularly the proposal's
incorporation of existing Sec. 75.363(d). Record retention is
necessary to help the mine operator, MSHA, and the miners'
representative identify problems with dust controls and ensure that
excessive dust concentrations are corrected. The cost associated with
the record requirement is shown in Chapter IV of the Regulatory
Economic Analysis (REA).
Unlike proposed Sec. 70.207(g)(2), final paragraph (e) does not
require the submission of corrective actions to the District Manager
for approval. Comments on proposed Sec. 70.207(g)(2) are discussed
under final paragraph (h)(4).
For consistency between the sampling requirements of the final
rule, final paragraphs (e)(1)-(3) are identical to final Sec.
70.207(d)(1)-(3) regarding bimonthly sampling of designated areas,
Sec. 70.208(e)(1)-(3) regarding quarterly sampling of MMUs, Sec.
70.209(c)(1)-(3) regarding quarterly sampling of designated areas,
Sec. 71.206(h)(1)-(3) regarding quarterly sampling, and except for
conforming changes, to Sec. 90.207(c)(1)-(3) regarding quarterly
sampling.
Final paragraph (f) is redesignated and changed from proposed Sec.
70.207(e). Paragraph (f)(1) is similar to proposed Sec. 70.207(e)
regarding sampling of MMUs when using a CMDPSU and paragraph (f)(2) is
similar to proposed Sec. 70.208(e) regarding sampling of MMUs when
using a CPDM. Paragraph (f) states that noncompliance with the standard
is demonstrated during the sampling period when: (1) Two or more valid
representative samples meet or exceed the excessive concentration value
(ECV) in Table 70-1 that corresponds to the applicable standard and
particular sampling device used; or (2) The average for all valid
representative samples meets or exceeds the ECV in Table 70-2 that
corresponds to the applicable standard and particular sampling device
used.
In the March 8, 2011, request for comments (76 FR 12649), MSHA
stated that the Agency is interested in commenters' views on what
actions should be taken by MSHA and the mine operator when a single
shift respirable dust sample meets or exceeds the ECV. MSHA also
requested comments on alternative actions, other than those contained
in the proposal, for MSHA and the operator to take if operators use a
CPDM. MSHA further stated that it is particularly interested in
alternatives and how such alternatives would be protective of miners.
Many commenters expressed concern that compliance determinations
would be made on the basis of a single-shift measurement. Proposed
Sec. 70.207(e) would have required that when using a CMDPSU, no valid
single-shift sample equivalent concentration meet or exceed the ECV
that corresponds to the applicable standard in proposed Table 70-1.
In response to comments, final paragraph (f) provides two different
methods by which compliance determinations can be made. The rationale
for final paragraphs (f)(1) and (2) is the same as that for final
Sec. Sec. 70.207(e)(1) and (2), 70.208(f)(1) and (2), 70.209(d)(1) and
(2), 71.206(i)(1) and (2), and 90.207(d)(1) and (2), and is discussed
elsewhere in this preamble under Sec. 70.208(f)(1) and (2).
For consistency between the sampling requirements of the final
rule, final paragraphs (f)(1) and (2) are the same as final Sec. Sec.
70.207(e)(1) and (2), 70.208(f)(1) and (2), 70.209(d)(1) and (2), and,
except for conforming changes, final Sec. Sec. 71.206(i)(1) and (2),
and 90.207(d)(1) and (2).
Comments on the ECVs in proposed Table 70-1 are discussed elsewhere
in this preamble under Sec. 70.208(f). In addition, a detailed
discussion on the derivation of the ECVs in both final Tables 70-1 and
70-2 is included in Appendix A of the preamble. Comments that
questioned the accuracy of a single sample in making a compliance
determination are addressed elsewhere in this preamble under Sec.
72.800.
Final paragraph (g) is changed and redesignated from proposed Sec.
70.207(f). It requires that unless otherwise directed by the District
Manager, upon issuance of a citation for a violation of the standard
involving a DO in an MMU, paragraph (a) of this section will not apply
to that MMU until the violation is abated and the citation is
terminated in accordance with paragraphs (h) and (i) of this section.
Final paragraph (g) includes an exception to allow the District
Manager flexibility to address extenuating circumstances that would
affect sampling. An example of extenuating circumstances would occur
when an uncorrected violation would require abatement sampling that
continues into the next sampling period.
In addition, final paragraph (g) clarifies that a violation must be
abated and the citation must be terminated, in accordance with final
paragraphs (h) and (i), before resuming bimonthly sampling. Final
paragraphs (h) and (i) are discussed below. Final paragraph (g) is
similar to existing Sec. 70.207(c). MSHA did not receive comments on
the proposal.
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraph (g) is the same as
final Sec. Sec. 70.207(f), 70.208(g), Sec. 70.209(e), 71.206(j), and
90.207(e).
Final paragraph (h) is redesignated from and is similar to proposed
Sec. 70.207(g). It requires that upon issuance of a citation for
violation of the standard, the operator must take the following actions
sequentially: (1) Make approved respiratory equipment available; (2)
immediately take corrective action; (3) record the corrective actions;
and (4) conduct additional sampling. The actions required by paragraph
(h) are similar to those in proposed Sec. 70.207(g)(1)-(3) and (i)(3)
discussed under final paragraph (e). Paragraph (h) includes the term
``sequentially'' to ensure that corrective actions are taken in the
order they are listed.
Final paragraph (h)(1), like proposed Sec. 70.207(g)(1), requires
that the mine operator make approved respiratory equipment available to
affected miners in accordance with Sec. 72.700 of this chapter.
Comments on proposed Sec. 70.207(g)(1), together with the rationale
for final paragraph (h)(1), are discussed under final paragraph (e).
Final paragraph (h)(2) is similar to proposed Sec. 70.207(g)(3).
It requires that the operator immediately take corrective action to
lower the concentration of respirable coal mine dust to at or below the
standard. Paragraph (h)(2) is similar to proposed Sec. 70.207(g)(3)
which would have required a mine operator to implement the proposed
corrective actions. The types of corrective actions that could be taken
are discussed under paragraph (e)(2). The rationale for final paragraph
(h)(2) is the same as that for final paragraph (e)(2). As explained for
final paragraph (e)(2), in the event of extenuating circumstances in
which corrective actions cannot be taken immediately, i.e., the
corrective action involves the purchase of additional equipment or
parts, MSHA will accept a bona fide purchase order as immediate
corrective action. The purchase order must show the date of purchase
and expected delivery, and the equipment or part must be installed as
soon as it is delivered. Under those circumstances, MSHA will extend
the timeframe in which additional sampling is to begin in accordance
with paragraph (h)(4).
Final paragraph (h)(3) is similar to proposed Sec. 70.207(i)(3)
and is the same
[[Page 24899]]
as final paragraph (e)(3). It requires that the operator make a record
of the corrective actions taken. The record must be certified by the
mine foreman or equivalent mine official no later than the end of the
mine foreman's or equivalent mine official's next regularly scheduled
working shift. It also requires that the record must be made in a
secure book that is not susceptible to alteration or electronically in
a computer system so as to be secure and not susceptible to alteration.
It further requires that the records must be retained at a surface
location at the mine for at least 1 year and be made available for
inspection by authorized representatives of the Secretary and the
representative of miners. Comments on proposed Sec. 70.207(i)(3) and
the rationale for paragraph (h)(3) are discussed under paragraph
(e)(3).
Final paragraph (h)(4) is similar to proposed Sec. 70.207(g)(3).
It requires that the mine operator begin sampling, within 8 calendar
days after the date the citation is issued, the environment of the
affected occupation in the MMU on consecutive normal production shifts
until five valid representative samples are taken. Paragraph (h)(4) is
consistent with existing Sec. 70.201(d), which requires a mine
operator to sample each production shift until five valid respirable
dust samples are taken. In addition, it requires that the sampling must
begin within 8 calendar days after the issuance of the citation. The 8
calendar days allow sufficient time for the operator to receive the
citation and take corrective actions. Under proposed Sec. 70.207(g)(2)
and (3), sampling would have begun after submission to and approval by
the District Manager of the corrective actions taken.
One commenter stated that the proposal is unfair to mine operators
because MSHA Districts will not be able to process corrective action
submissions in a timely manner. The commenter also stated that the
requirement is too burdensome because it could result in many needless
revisions to the ventilation plan by mine operators and that the
approved corrective actions could be different from what is approved in
the mine ventilation plan.
In response to the comments, final paragraph (h) does not include
the proposed requirement that the operator submit corrective actions to
the District Manager for approval before corrective action can be
taken. In reevaluating the requirements of proposed Sec. 70.207(g),
MSHA determined that final paragraph (h) will allow for faster
abatement of a citation because immediate action must be taken to
correct the violation. The sampling conducted under paragraph (h)(4)
will ensure that the corrective actions taken by the mine operator are
effective in lowering the concentration of respirable dust to at or
below the standard. However, to ensure that the sampling begins
promptly after the operator implements the corrective actions,
paragraph (h)(4) clarifies that the sampling must begin within 8
calendar days after the date the citation is issued.
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraph (h) is the same as
final Sec. Sec. 70.207(g), 70.208(h), 70.209(f), 71.206(k), and
90.207(f).
Final paragraph (i) is redesignated from and is substantially
similar to proposed Sec. 70.207(h). Paragraph (i) contains
nonsubstantive and organizational changes from the proposal. It
provides that a citation for a violation of the standard will be
terminated by MSHA when: (1) Each of the five valid representative
samples is at or below the standard; and (2) the operator has submitted
to the District Manager revised dust control parameters as part of the
mine ventilation plan that applies to the MMU in the citation, and the
changes have been approved by the District Manager. It further provides
that the revised parameters must reflect the control measures used by
the operator to abate the violation.
Some commenters expressed concern with the proposed requirement
that all five of the operator's samples must be at or below the
standard for terminating a citation.
Requiring that each sample be at or below the standard provides
MSHA with a stronger indication that the corrective actions were
effective in continuously maintaining the average respirable dust
levels in the mine atmosphere during each shift to which each miner in
the active workings is exposed.
Several commenters stated coal mines should not be required to
commit to long-term ventilation plan approvals for short-term issues
particularly when those conditions are not representative of normal
mining conditions when considering the development of ventilation
plans.
The final rule, like the existing standards, requires that each
operator must continuously maintain the average concentration of
respirable dust in the mine atmosphere during each shift to which each
miner in the active workings is exposed at or below the respirable dust
standard. Like the existing standards, the revisions to the dust
control parameters that are required to be submitted to MSHA by the
operator under the final rule are parameters that the operator believes
will result in compliance with the dust standard. If the operator
encounters conditions where the existing dust control parameters are
not effective in controlling the dust levels to at or below the
respirable dust standard, the operator must adjust the dust control
parameters as necessary to control the dust concentrations to at or
below the standard.
Several commenters stated that submission of a change to the mine's
approved ventilation plan is unfair and burdensome to mine operators.
These commenters stated that the plan approval process places mine
operators at a disadvantage because MSHA can shut down the MMU if the
Agency does not get exactly what it wants and it is almost impossible
for a mine operator to get an expedited hearing. They also stated that
the proposal can result in considerable downtime for production because
MSHA does not have the personnel to review and process revisions to the
ventilation plans. They further stated that requiring different dust
control parameters for each MMU creates a paperwork burden for mine
operators and MSHA.
Mine ventilation plans are a long recognized means for addressing
safety and health issues that are mine-specific. Individually tailored
plans, with commonly accepted practices, are an effective method of
regulating such complex matters as dust control. Existing Sec. 75.370,
regarding the submission and approval of mine ventilation plans,
requires that each mine operator develop and follow a ventilation plan
that is approved by MSHA and that is designed to control methane and
respirable dust in the mine. Section 75.370 further requires that the
plan be suitable to the conditions and mining system at the mine. It
establishes the procedures for submittal, review, and approval of the
plan to ensure that the plan for each mine addresses the conditions in
that mine.
Requiring revisions to the dust control parameters as part of the
mine ventilation plan for the MMU in the citation provides the
necessary latitude to address the diversity of mining conditions found
in coal mines nationwide. Details must be shown in the plan and must be
specific to the conditions at each MMU. The paperwork burden associated
with final paragraph (i) is shown in Chapter VIII of the REA.
MSHA is committed to the timely processing of plan revisions. The
[[Page 24900]]
Agency believes that the plan approval system will not result in
considerable downtime for operators while MSHA reviews the plans.
Circumstances that require expedited action are handled by the District
Manager on a case-by-case basis. Generally, the District Manager is
guided by whether the condition, if uncorrected, could result in a
health or safety hazard or an imminent stoppage of production in the
mine or an area of the mine. In addition, a mine operator may take
action necessary to abate an imminent danger or hazardous condition, or
to safeguard persons and equipment. In order to take such action, the
operator would have to make a determination of the cause of the
problem.
For consistency with the sampling requirements of the final rule,
except for conforming changes, final paragraphs (i)(1) and (2) are the
same as final Sec. Sec. 70.207(h)(1) and (2), 70.208(i)(1) and (2),
and 70.209(g)(1) and (2).
10. Section 70.207 Bimonthly Sampling; Designated Areas
Final Sec. 70.207 is new, but is consistent with existing
standards. It requires bimonthly sampling of DAs until January 31,
2016, which is 18 months after the effective date of the final rule.
This section is included in the final rule to make the bimonthly
sampling period for Designated Areas (DAs) the same as the bimonthly
sampling period for MMUs under Sec. 70.206. It is similar to proposed
Sec. 70.207 regarding bimonthly sampling of MMUs when using a CMDPSU,
proposed Sec. 70.208 regarding quarterly sampling of MMUs when using a
CPDM, and proposed Sec. 70.209 regarding quarterly sampling of DAs
when using either a CMDPSU or CPDM. It is consistent with existing
Sec. 70.207 which requires bimonthly sampling of MMUs and existing
Sec. 70.208 which requires bimonthly sampling of DAs.
The proposal would have required that DAs be sampled quarterly and
MMUs be sampled bimonthly on the effective date of the rule. Under the
final rule, both MMUs under Sec. 70.206 and DAs under this Sec.
70.207 will continue the existing bimonthly sampling frequency and the
existing number of required samples for a period of 18 months following
the effective date of the rule. On February 1, 2016, quarterly sampling
under Sec. Sec. 70.208 for MMUs and 70.209 for DAs is required. This
preserves the status quo for the first 18 months in order to provide
operators time to concentrate on sampling changes related to full-shift
sampling and taking representative samples, as that term is defined in
final Sec. 70.2. It also allows them more time to establish procedures
for a new sampling frequency, and to upgrade existing controls, or to
take additional measures to meet the increase in samples required after
the 18-month period. Final Sec. 70.201(b) addresses the sampling
devices required for bimonthly sampling of DAs under this provision and
for quarterly sampling of DAs under final Sec. 70.209.
Final paragraph (a) is similar to proposed Sec. 70.207(a)
concerning bimonthly sampling of MMUs. It requires that each operator
take one valid representative sample from each designated area (DA) on
a production shift during each bimonthly period. Except for conforming
changes, the periods for bimonthly sampling of DAs in paragraph (a) are
the same as those in existing Sec. 70.208(a). The bimonthly periods
are: (1) February-March 31; (2) April 1-May 31; (3) June 1-July 31; (4)
August 1-September 30; (5) October 1-November 30; and, (6) December 1-
January 31.
Final paragraph (b) is similar to proposed Sec. Sec. 70.207(c),
70.208(c), and 70.209(b) concerning when the respirable dust standard
is changed when quartz is present. It requires that when the respirable
dust standard is changed in accordance with Sec. 70.101, the new
standard will become effective 7 calendar days after the date of the
notification of the change by MSHA. Paragraph (b) is essentially the
same as existing Sec. Sec. 70.207(b) and 70.208(b), but includes a
clarification on the effective date of the new standard when there is a
change in the applicable standard. The rationale for final paragraph
(b) is the same as that for final Sec. 70.208(c) and is discussed
elsewhere in this preamble under Sec. 70.208(c).
For consistency in the sampling requirements of the final rule,
paragraph (b) is identical to Sec. 70.206(c) regarding bimonthly
sampling of MMUs, Sec. 70.208(c) regarding quarterly sampling of MMUs,
Sec. 70.209(b) regarding quarterly sampling of DAs, Sec. 71.206(b)
regarding quarterly sampling, and Sec. 90.207(b) regarding quarterly
sampling.
Final paragraph (c) is essentially the same as existing Sec.
70.208(c). It requires that upon notification from MSHA that any valid
sample taken from a DA to meet the requirements of paragraph (a) of
this section exceeds the standard, the operator must take five valid
representative samples from that DA within 15 calendar days. It further
requires that the operator must begin sampling of the DA on the first
day on which there is a production shift following the day of receipt
of notification. As stated previously, final paragraph (c) preserves
the status quo for the first 18 months following the effective date of
the final rule.
Final paragraph (d) is similar to proposed Sec. Sec. 70.207(i)(1)-
(3) and (g)(1)-(3). Final paragraph (d) requires that when a valid
representative sample taken in accordance with this section meets or
exceeds the ECV in Table 70-1 that corresponds to the applicable
standard and particular sampling device used, the operator must: (1)
Make approved respiratory equipment available to affected miners in
accordance with Sec. 72.700 of this chapter; (2) Immediately take
corrective action to lower the concentration of respirable coal mine
dust to at or below the standard; and (3) Make a record of the
corrective actions taken. The record must be certified by the mine
foreman or equivalent mine official no later than the end of the mine
foreman's or equivalent mine official's next regularly scheduled
working shift. Paragraph (d)(3) further requires that the record must
be made in a secure book that is not susceptible to alteration or
electronically in a computer system so as to be secure and not
susceptible to alteration. It also requires that the records must be
retained at a surface location at the mine for at least 1 year and be
made available for inspection by authorized representatives of the
Secretary and the representative of miners.
The rationale for final paragraphs (d)(1)-(3) is the same as that
for final Sec. Sec. 70.206(e)(1)-(3), 70.208(e)(1)-(3), and
70.209(c)(1)-(3), and is discussed elsewhere in this preamble under
final Sec. 70.208(e)(1)-(3).
For consistency between the sampling requirements of the final
rule, final paragraphs (d)(1)-(3) are the same as final Sec.
70.206(e)(1)-(3) regarding bimonthly sampling of MMUs, Sec.
70.208(e)(1)-(3) regarding quarterly sampling of MMUs, Sec.
70.209(c)(1)-(3) regarding quarterly sampling of designated areas,
Sec. 71.206(h)(1)-(3) regarding quarterly sampling, and except for
conforming changes, Sec. 90.207(c)(1)-(3) regarding quarterly
sampling.
Final paragraph (e) provides two different methods by which
compliance determinations can be made. Paragraphs (e)(1) and (2)
provide that noncompliance with the standard is demonstrated during the
sampling period when: (1) Two or more valid representative samples meet
or exceed the ECV in final Table 70-1 that corresponds to the
applicable standard and the particular sampling device used; or (2) The
average for all valid
[[Page 24901]]
representative samples meets or exceeds the ECV in final Table 70-2
that corresponds to the applicable standard and the particular sampling
device used. Paragraph (e)(1) is similar to proposed Sec. Sec.
70.207(e), 70.208(d), and 70.209(c) regarding compliance based on a
single sample measurement. Paragraph (e)(2) is similar to proposed
Sec. 70.208(e) regarding weekly permissible accumulated exposure. The
rationale for final paragraphs (e)(1) and (2) is the same as that for
final Sec. Sec. 70.206(f)(1) and (2), 70.208(f)(1) and (2), and
70.209(d)(1) and (2), and is discussed elsewhere in this preamble under
Sec. 70.208(f)(1) and (2).
For consistency between the sampling requirements of the final
rule, final paragraphs (e)(1) and (2) are the same as final Sec. Sec.
70.206(f)(1) and (2), 70.208(f)(1) and (2), 70.209(d)(1) and (2), and,
except for conforming changes, 71.206(i)(1) and (2), and, 90.207(d)(1)
and (2).
Final paragraph (f) is derived and changed from proposed Sec.
70.209(d). It requires that unless otherwise directed by the District
Manager, upon issuance of a citation for a violation of the standard,
paragraph (a) of this section will not apply to that DA until the
violation is abated and the citation is terminated in accordance with
paragraphs (g) and (h) of this section. Final paragraphs (h) and (i)
are discussed below.
Final paragraph (f) includes an exception to allow the District
Manager flexibility to address extenuating circumstances that would
affect sampling. An example of extenuating circumstances would occur
when an uncorrected violation would require abatement sampling that
continues into the next sampling period.
Final paragraph (f) is similar to existing Sec. 70.208(d). MSHA
did not receive comments on the proposal.
In addition, for consistency between the sampling requirements of
the final rule, except for conforming changes, final paragraph (f) is
the same as final Sec. Sec. 70.206(g), 70.208(g), 70.209(e),
71.206(j), and 90.207(e).
Final paragraph (g) is similar to proposed Sec. Sec. 70.207(i)(3)
and 70.209(e). It requires that upon issuance of a citation for a
violation of the standard, the operator must take the following actions
sequentially: (1) Make approved respiratory equipment available to
affected miners in accordance with Sec. 72.700 of this chapter; (2)
immediately take corrective action to lower the concentration of
respirable coal mine dust to at or below the standard; (3) make a
record of the corrective actions taken. The record must be certified by
the mine foreman or equivalent mine official no later than the end of
the mine foreman's or equivalent mine official's next regularly
scheduled working shift. Paragraph (g)(3) further requires that the
record must be made in a secure book that is not susceptible to
alteration or electronically in a computer system so as to be secure
and not susceptible to alteration. It also requires that the records
must be retained at a surface location at the mine for at least 1 year
and be made available for inspection by authorized representatives of
the Secretary and the representative of miners.
Paragraph (g)(4) requires that the operator must begin sampling
within 8 calendar days after the date the citation is issued, the
environment of the affected DA on consecutive normal production shifts
until five valid representative samples are taken. In addition,
paragraph (g) includes the term ``sequentially'' to ensure that
corrective actions are taken in the order they are listed.
The rationale for final paragraphs (g)(1)-(4) is the same as that
for final Sec. Sec. 70.206(h)(1)-(4), 70.208(h)(1)-(4), and
70.209(f)(1)-(4), and is discussed elsewhere in this preamble under
Sec. 70.206(h)(1)-(4).
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraphs (g)(1)-(4) are
the same as final Sec. 70.206(h) regarding bimonthly sampling of MMUs,
Sec. 70.208(h) regarding quarterly sampling of MMUs, Sec. 70.209(f)
regarding quarterly sampling of designated areas, Sec. 71.206(k)
regarding quarterly sampling, and Sec. 90.207(f) regarding quarterly
sampling.
Final paragraph (h) is similar to proposed Sec. 70.209(f). It
provides that MSHA will terminate a citation for a violation of the
standard when the conditions listed in paragraphs (1) and (2) are met.
Paragraph (h)(1) requires that each of the five valid representative
samples taken must be at or below the standard. Paragraph (h)(2)
requires that the operator has submitted to the District Manager
revised dust control parameters as part of the mine ventilation plan
for the DA in the citation, and the changes have been approved by the
District Manager. It further requires that the revised parameters
reflect the control measures used by the operator to abate the
violation. The rationale for final paragraphs (h)(1) and (2) is
discussed elsewhere in this preamble under Sec. 70.206(i).
For consistency between the sampling requirements of the final
rule, final paragraphs (h)(1) and (2) are identical, except for
conforming changes, to final Sec. Sec. 70.206(i)(1) and (2),
70.208(i)(1) and (2), and 70.209(g)(1) and (2).
11. Section 70.208 Quarterly Sampling; Mechanized Mining Units
Final Sec. 70.208, like the proposal, addresses sampling of
mechanized mining units (MMUs). To be consistent with final Sec.
70.201(a), it includes a clarification that the sampling requirements
of this section start on February 1, 2016, which is 18 months after the
effective date of the final rule. The title of the section is changed
from the proposal by adding ``quarterly'' to distinguish the required
sampling periods for MMUs under this section from final Sec. 70.206,
which requires bimonthly sampling for MMUs. It also does not include
the term ``CPDM'' to avoid confusion with the sampling device required.
Specifically, in accordance with final Sec. 70.201(a), the operator is
required to take quarterly samples of the DO and ODO in each MMU with
an approved CPDM on February 1, 2016, unless directed by the Secretary
to use the CMDPSU to collect quarterly samples.
Final paragraphs (a)(1) and (2) are changed from the proposal.
Paragraph (a)(1) requires the mine operator to sample each calendar
quarter: The designated occupation (DO) in each MMU on consecutive
normal production shifts until 15 valid representative samples are
taken. It further provides that the DM may require additional groups of
15 valid representative samples when information indicates that the
operator has not followed the approved ventilation plan for any MMU.
Final paragraph (a)(2) requires that the operator sample each
calendar quarter: Each other designated occupation (ODO) specified in
paragraphs (b)(1) through (10) of this section in each MMU or specified
by the District Manager and identified in the approved mine ventilation
plan on consecutive normal production shifts until 15 valid
representative samples are taken. It also requires sampling of each ODO
type to begin after fulfilling the sampling requirements of paragraph
(a)(1) of this section. It further requires that when the operator is
required to sample more than one ODO type, each ODO type must be
sampled over separate time periods during the calendar quarter.
Final paragraph (a)(3) is redesignated from proposed Sec.
70.208(a)(2). It establishes the quarterly periods as: (1) January 1-
March 31; (2) April 1-June 30; (3) July 1-September 30; and (4) October
1-December 31.
[[Page 24902]]
On March 8, 2011, MSHA issued in the Federal Register a request for
comments (76 FR 12648). MSHA stated that the proposed rule addresses
the frequency of respirable dust sampling when using a CPDM, and MSHA
solicited comments on the proposed sampling frequencies and any
suggested alternatives. MSHA asked if sampling of DOs were less
frequent than proposed, what alternative sampling frequency would be
appropriate. MSHA also requested that commenters address a sampling
strategy in case of noncompliance with the respirable dust standard and
provide a rationale for the strategy. In addition, MSHA asked whether
CPDM sampling of ODOs should be more or less frequent than 14 calendar
days each quarter, and whether the proposed CPDM sampling of ODOs on
the MMU is sufficient to address different mining techniques, potential
overexposures, and ineffective use of approved dust controls. Some
commenters suggested that MSHA conduct the DO sampling on all shifts on
which coal is produced during a calendar week. Several commenters
opposed the proposed frequency of DO sampling, which would have
required mine operators who use CPDMs to sample the DO in each MMU
during each production shift, 7 days per week (Sunday through
Saturday), 52 weeks per year. These commenters stated that the proposal
was too expensive because it would require mine operators to purchase
an unreasonably large number of CPDMs due to the number of MMUs in each
mine. Some commenters stated that sampling every DO on every production
shift was excessive and was not needed to objectively determine miners'
exposure.
One commenter stated that proper control of respirable coal mine
dust to below the standard will not assure operators that they will not
be issued a violation for false overexposures due to the proposed
sampling strategy and use of 24/7 continuous sampling on all shifts.
Some commenters suggested that a miner should be allowed to request
additional sampling not already designated for sampling by MSHA if the
miner has reason to believe that miners are being exposed to excessive
respirable dust. Another commenter suggested that the sampling should
be a full-shift weekly dose not to exceed an average of 2.0 mg/m\3\ for
a 40-hour week.
One commenter stated that the proposed frequency of ODO sampling
was confusing. This commenter stated that the proposal, which would
have required sampling of ODOs in each MMU during each production shift
for 14 consecutive days during each quarterly period, could not be
accomplished because ODO personnel do not work 14 consecutive days.
Another commenter suggested that ODOs should be sampled the same as
DOs, 7 days a week, 52 weeks a year.
After considering all the comments, and based on MSHA's years' of
experience, MSHA concludes that sampling on consecutive normal
production shifts until 15 valid representative samples are taken is
sufficient to provide samples that are representative of normal mining
activities for DOs and ODOs during the production shifts. The proposal
would have required sampling of ODOs in each MMU during each production
shift for 14 consecutive days during each quarterly period. The 14-day
period was intended to indicate the completion of multiple mining
cycles. Subsequent to the proposal, MSHA surveyed its coal districts
and found that, under normal mining conditions, the majority of MMUs
should be able to complete at least two complete mining cycles while 15
representative samples are collected. A mining cycle consists of
cutting straight entries and crosscuts or multiple passes with a
longwall shearer in 15 shifts. If the mine produces coal on only one
shift a day, the sampling period for a DO or ODO could be 15
consecutive normal production days. The sampling period for a DO or ODO
could be as short as 8 consecutive normal production days, if the mine
produces coal on two shifts a day. Sampling in accordance with
paragraphs (a)(1) and (2) will provide representative measurements of
respirable dust concentrations in the DO and ODO's work environment and
allow both the operator and MSHA to evaluate the effectiveness of the
dust controls being used. Accordingly, MSHA determined that DO sampling
on every shift, every day, by each mine operator as proposed is not
necessary. Miners will be adequately protected by the sampling
requirements of paragraphs (a)(1) and (2) because the sampling results
will provide mine operators with information to evaluate the dust
controls specified in their approved ventilation plan and determine
whether the controls are being maintained. As long as dust controls are
properly maintained to ensure continuing compliance with the respirable
dust standard, miners will be protected from overexposures.
If information indicates that a mine operator has not followed the
approved mine ventilation plan for any MMU, (for example, mining when
the ventilation curtains are not properly maintained, or water sprays
are operated with inadequate pressure or some are inoperable),
paragraph (a)(1) provides that the District Manager may require
additional sampling of DOs by that operator. The additional sampling
under paragraph (a)(1) is intended to ensure that miners are provided
adequate protection from overexposure to respirable coal mine dust
without requiring all mine operators to sample DOs each production
shift, 7 days per week, 52 weeks per year as proposed.
Paragraph (a)(2) does not permit sampling of ODOs until after
sampling of DOs under paragraph (a)(1) is completed. However,
additional sampling of the DO, such as abatement sampling, will not
affect the ODO sampling required under this paragraph (a)(2). Paragraph
(a)(2) also does not permit simultaneous sampling of multiple ODO
types. In doing so, paragraphs (a)(1) and (2) establish monitoring that
protects miners through a longer period of sequential sampling.
Sequentially sampling the DOs and ODOs spreads the sampling over a
period that will ensure sufficient representative samples. Under
paragraph (a)(2), sampling of a specific ODO, such as a shuttle car
operator, will require all shuttle car operators on an MMU to be
sampled during the same time period until the 15 representative samples
are collected on each ODO. Sampling of the shuttle car operator cannot
begin until sampling of the DO under paragraph (a)(1) is completed. For
example: an MMU has a DO, and the following ODOs: One return air side
roof bolting machine operator and two shuttle car operators. The DO is
sampled until 15 representative samples are collected. Once the DO
sampling is completed, then the return air side roof bolting machine
operator is sampled until 15 representative samples are collected. When
sampling of the roof bolting machine operator is completed, the 2
shuttle car operators are both sampled until 15 representative samples
are collected on each. The shuttle car operators must be sampled at the
same time so both shuttle car operators are carrying sampling units
over the same time period.
The final rule's alternatives to the proposed sampling requirements
for DOs and ODOs described above significantly reduce the quantity of
CPDMs that operators will need to conduct MMU sampling. The proposal
would have required sampling of DOs every shift, every day, and
sampling of ODOs 14 consecutive days each quarter. Under the final
rule, DOs are sampled less frequently than under the proposed rule, and
under the final rule's
[[Page 24903]]
sequential sampling, DOs are sampled first, followed by sampling each
ODO type over separate time periods. This sequential sampling allows a
mine operator to use the same CPDM to conduct most MMU sampling.
Final paragraph (b) is similar to the proposal and requires that
unless otherwise directed by the District Manager, the approved
sampling device must be worn by the miner assigned to perform the
duties of the DO or ODO specified in paragraphs (b)(1) through (b)(10)
of this section or by the District Manager for each type of MMU.
Depending on mine or physical conditions (e.g., mining height, no
operating cab on the mining equipment to attach the sampling unit), the
District Manager may designate an alternate sampling location than
specified in paragraph (b). Paragraph (b) includes the term ``an
approved sampling device'' as a clarification. Under the final rule, an
operator is required to take quarterly samples of DOs in each MMU with
an approved CPDM, unless directed by the Secretary to use the CMDPSU.
Paragraphs (b)(1) through (10) are substantially similar to the
proposal. They identify the DOs that are required to be sampled under
paragraph (a)(1) and the ODOs that are required to be sampled under
paragraph (a)(2) for each specified MMU.
Paragraph (b)(1), like the proposal, requires that on a
conventional section using a cutting machine, the DO on the MMU is the
cutting machine operator.
Paragraph (b)(2), like the proposal, requires that on a
conventional section blasting off the solid, the DO on the MMU is the
loading machine operator.
Paragraph (b)(3) is changed from the proposal. It requires that on
a continuous mining section other than auger-type, the DO on the MMU is
the continuous mining machine operator or mobile bridge operator when
using continuous haulage. The ODOs for this type of MMU are revised as
follows: The roof bolting machine operator who works nearest the
working face on the return air side of the continuous mining machine;
the face haulage operators on MMUs using blowing face ventilation; the
face haulage operators on MMUs ventilated by split intake air
(``fishtail ventilation'') as part of a super-section; and the face
haulage equipment operators where two continuous mining machines are
operated on an MMU. The term ``shuttle car'' in the proposed rule is
replaced with ``face haulage'' in the final rule. This clarifies the
Agency's intent that any type of haulage on the MMU in this mining
situation is required to be monitored for respirable dust exposure in
the environment of the face haulage operator. The proposal used the
most common haulage vehicle--shuttle car--when the intent was to cover
all haulage operators including those on shuttle cars, ramcars, scoops,
etc. Moreover, the proposal provided that the District Manager had the
discretion to designate ODOs other than those specifically listed in
proposed Sec. 70.208(b). Face haulage operators are included in final
paragraph (b)(3) because they frequently experience exposure to high
dust levels. For example, some operators have two continuous mining
machines on a single MMU but do not operate them at the same time.
Starting operation of the second continuous mining machine after the
first continuous mining machine stops mining subjects the MMU face
haulage operators to respirable dust that has not cleared the entries
of the MMU. Historically, mine operators who use a common dumping point
for two MMUs will use face haulage equipment from either MMU as needed.
Creating ODOs on face haulage equipment operators for this type of
mining configuration will provide better protection from exposures to
respirable dust for face haulage equipment operators. Finally, face
haulage operators are included in final paragraph (b)(3) in response to
comments on proposed Sec. 75.332(a)(1), which would have required mine
operators to provide separate intake air to each MMU on each working
section. Comments on proposed Sec. 75.332(a)(1) regarding split intake
ventilation are discussed elsewhere in this preamble under Sec.
75.332.
Paragraph (b)(4), like the proposal, requires that on a continuous
mining section using auger-type machines, the DO on the MMU is the
jacksetter working nearest the working face on the return air side of
the continuous mining machine.
Paragraph (b)(5), like the proposal, requires that on a scoop
section using a cutting machine, the DO on the MMU is the cutting
machine operator.
Paragraph (b)(6), like the proposal, requires that on a scoop
section blasting off the solid, the DO on the MMU is the coal drill
operator.
Paragraph (b)(7), like the proposal, requires that on a longwall
section, the DO on the MMU is the longwall operator working on the
tailgate side of the longwall mining machine. The ODOs are the
jacksetter who works nearest to the return air side of the longwall
working face, and the mechanic.
Paragraph (b)(8), like the proposal, requires that on a hand
loading section with a cutting machine, the DO on the MMU will be the
cutting machine operator.
Paragraph (b)(9), like the proposal, requires that on a hand
loading section blasting off the solid, the DO on the MMU will be the
hand loader exposed to the greatest dust concentration.
Paragraph (b)(10), like the proposal, requires that on anthracite
mine sections, the DO on the MMU will be the hand loader exposed to the
greatest dust concentration.
In the March 8, 2011, request for comments (76 FR 12650), MSHA
stated that the proposed rule addresses: (1) Which occupations must be
sampled using CPDMs, and (2) which work positions and areas could be
sampled using either CPDMs or CMDPSUs. MSHA solicited comments on the
proposed sampling occupations and locations. For example, MSHA
requested comment on whether there are other positions or areas where
it may be appropriate to require the use of CPDMs. MSHA also asked
whether the proposed CPDM sampling of ODOs on the MMU is sufficient to
address different mining techniques, potential overexposures, and
ineffective use of approved dust controls.
Some commenters stated that individual occupations with the highest
potential for exposure should be sampled and MSHA should evaluate and
determine if additional occupations need to be sampled. The final rule
is based on historical sampling data on MMUs. The DOs and ODOs included
in paragraphs (b)(1) through (10) are those occupations with the
highest potential for exposure. Therefore, sampling these DOs and ODOs
is the most effective method for protecting all miners from excess
exposure to respirable coal mine dust.
One commenter expressed concern over giving the District Manager
too much discretion in determining the ODOs to sample because the rules
could change every time a determination was made by the District
Manager. In response, MSHA notes that allowing the District Manager to
identify ODOs is consistent with MSHA's existing policy concerning the
designation of sampling entities under the existing standards for DAs
and will continue to be based on MSHA's historical sampling data on
MMUs.
One commenter recommended that if a mine operator must sample
shuttle car operators on blowing type face ventilation, then shuttle
car operators on exhausting type face ventilation should be sampled
also. From MSHA's sampling experience, haulage operators working with
exhausting face
[[Page 24904]]
ventilation position themselves in intake air when coal is being loaded
by the continuous mining machine. By positioning themselves in this
manner, the haulage operators are in a more protected environment
during the time of greatest potential for exposure to respirable dust.
One commenter stated that other outby areas should be sampled such
as conveyor belt entries, belt heads, and dumping points. MSHA
recognizes that dust concentrations in the active workings of the mine
can vary from location to location, even within a small area near a
miner. MSHA will continue to require operator sampling of outby DAs.
The requirements for DA sampling are contained in final Sec. Sec.
70.207 and 70.209, which are discussed elsewhere in this preamble.
Limiting the dust concentration in outby areas ensures that no miner in
the active workings will be exposed to excessive respirable dust.
Final paragraph (c) is similar to proposed Sec. 70.208(c) and
clarifies the time frame for implementation when there is a change in
the applicable standard. It requires that when the respirable dust
standard is changed in accordance with Sec. 70.101 (Respirable dust
standard when quartz is present), the new standard will become
effective 7 calendar days after the date of the notification of the
change by MSHA. The ``date of notification'' is the date on the data
mailer that MSHA currently sends, via U.S mail, to operators informing
them of the quartz analyses that may result in a change in the
respirable dust standard. Under proposed Sec. 70.208(c), a new
standard would have gone into effect on the first production shift
following the operator's receipt of notification that the respirable
dust standard is changed in accordance with Sec. 70.101. However, MSHA
may not always know the date that the operator received the
notification. By allowing the new standard to become effective 7 days
after the date of the notification of the change, i.e., the date on the
data mailer, instead of requiring the standard to become effective on
the next production shift, MSHA will maintain the existing, historical
practice of providing 7 days for mailing before the new standard is
effective. It protects miners by ensuring the prompt implementation of
the reduced standard when high concentrations of quartz are present and
also allows for a uniform application of a new respirable dust standard
regardless of the physical location of a mine.
Final paragraph (d) is new. It is similar to proposed Sec.
70.207(d) and existing Sec. 70.207(d) regarding bimonthly sampling in
mechanized mining units. It requires that if a normal production shift
is not achieved, the DO or ODO sample for that shift may be voided by
MSHA. It further provides that any sample that, regardless of
production, exceeds the standard by at least 0.1 mg/m\3\ will be used
in the determination of the equivalent concentration for that
occupation.
Proposed Sec. 70.207(d), concerning sampling of MMUs with a
CMDPSU, provided that if a normal production shift is not achieved, the
DO sample for that shift may be voided by MSHA. It further provided
that any sample, regardless of production, that exceeds the standard by
at least 0.1 mg/m\3\ would be used to determine the equivalent
concentration for that MMU. As explained in the preamble for proposed
Sec. 70.207(d), voiding samples that indicate miners were exposed to a
concentration of respirable dust in excess of the standard does not
provide miners the intended health protection. For example, an MMU is
on a reduced standard of 0.5 mg/m\3\ due to the presence of quartz. A
sample taken on the MMU when a normal production shift was not achieved
shows the respirable dust concentration is 2.3 mg/m\3\. The existing
standard provides that any sample, regardless of production, with a
concentration greater than 2.5 mg/m\3\ will be used to determine the
average concentration. Under the existing standard, the 2.3 mg/m\3\
sample would not be used to determine the average concentration for the
MMU. However, MSHA believes that any sample that exceeds the standard
while production is less than normal should be used to determine the
respirable dust concentration of the MMU since operating at a higher
production would likely increase miners' respirable dust exposure (75
FR 64432, October 19, 2010).
The 2.5 mg/m\3\ value in the existing standard was based on: (1) An
earlier sampling and processing methodology that was less accurate than
the existing program; (2) a 2.0 mg/m\3\ standard; and (3) did not take
quartz into consideration. However, the accuracy of the CPDM and the
improvement in the accuracy of the CMDPSU has allowed MSHA to establish
the final 0.1 mg/m\3\ value, which also takes into consideration the
reduced standard due to quartz.
Under proposed Sec. 70.208 concerning sampling of MMUs with a
CPDM, the level of coal production would not have been a concern
because the proposal would have required sampling on each production
shift, 7 days per week, and 52 weeks per year, regardless of
production. Because compliance under the proposed rule would have been
based on 24/7 continuous sampling and single sample determinations,
there was no reason to have a provision to void a sample or to require
the use of a sample that exceeded the standard when production was low
for determining compliance based on averaging multiple samples.
However, under final paragraph (d), the sampling methodology is
modified from the proposal and, therefore, coal production levels and
representative sampling are as important for CPDM sampling as for
CMDPSU sampling. Under final Sec. 70.208, sampling is required on 15
consecutive shifts on a quarterly basis, which is necessary to ensure
that the operator collects samples that are representative of normal
mining activity. When a sample exceeds the standard while production is
less than normal, it should be used to determine the respirable dust
concentration of the MMU since operating at a higher production would
likely increase miners' respirable dust exposure. For these reasons,
final paragraph (d) includes the same criteria that apply to voiding DO
samples collected with a CPDM as that required by final Sec. 70.206(d)
when sampling with a CMDPSU.
Therefore, final paragraph (d) includes requirements that, with the
exception of conforming changes, are the same as proposed Sec.
70.207(d) and existing Sec. 70.207(d) regarding samples that may be
voided by MSHA based on production. The rationale for final paragraph
(d) is the same as that for final Sec. 70.206(d) and is discussed
elsewhere in this preamble under Sec. 70.206(d).
Final paragraph (e) is similar to proposed Sec. 70.208(f) and (g).
It requires that when a valid representative sample taken in accordance
with this section meets or exceeds the ECV in Table 70-1 that
corresponds to the applicable standard and particular sampling device
used, the operator must: (1) Make approved respiratory equipment
available; (2) Immediately take corrective action; and (3) Record the
corrective actions. The actions required by final paragraph (e) are
similar to those in proposed Sec. 70.208(g).
Proposed Sec. 70.208(f)(1)-(5) would have required that when a
valid end-of-shift measurement meets or exceeds the applicable ECV or a
weekly accumulated exposure exceeds the weekly permissible accumulated
exposure, the operator must take the following actions before
production begins on the next shift: (1) Make approved respiratory
equipment
[[Page 24905]]
available; (2) implement corrective actions; (3) submit to the District
Manager for approval the corrective actions implemented; (4) review the
adequacy of the approved CPDM Performance Plan; and (5) record the
corrective actions taken.
Proposed Sec. 70.208(g) would have required that when a valid end-
of-shift equivalent concentration exceeds the standard but is less than
the applicable ECV in Table 70-2, the operator would have to: (1) Make
approved respiratory equipment available to affected miners in
accordance with Sec. 72.700; (2) implement corrective actions to
ensure compliance with the standard on the next and subsequent
production shifts; (3) record the reported excessive dust condition as
part of and in the same manner as the records for hazardous conditions
required by Sec. 75.363; and (4) review the adequacy of the approved
CPDM Performance Plan and submit to the District Manager for approval
any plan revisions within 7 calendar days following posting of the end-
of-shift equivalent concentration on the mine bulletin board.
As noted previously in the discussion on final Sec. 70.206(e),
MSHA clarified, in the March 8, 2011, request for comments (76 FR
12648), that the proposal would require that operators record both
excessive dust concentrations and corrective actions in the same manner
as conditions are recorded under Sec. 75.363 and that ``MSHA would not
consider excessive dust concentrations or corrective actions to be
hazardous conditions, since the proposed requirement is not a section
75.363 required record'' (76 FR 12650).
Comments on proposed Sec. 70.208(g) were identical or similar to
those on proposed Sec. 70.207(i). The comments are consolidated and
discussed elsewhere in this preamble under Sec. 70.206(e).
In response to the comments, final paragraph (e) is changed from
the proposal. It does not require action if the dust sample exceeds the
standard but is less than the ECV in Table 70-1. Rather, it requires an
operator to take certain actions when a respirable dust sample meets or
exceeds the ECV in Table 70-1. Unlike the proposal, there would be no
violation if one operator full-shift sample meets or exceeds the ECV in
Table 70-1 that corresponds to the applicable standard and particular
sampling device used. Although the Secretary has determined that a
single full-shift measurement of respirable coal mine dust accurately
represents atmospheric conditions to which a miner is exposed during
each shift, MSHA has concluded that a noncompliance determination based
on a single full-shift sample will only be made on MSHA inspector
samples. With respect to operator samples, MSHA reevaluated its
enforcement strategy under the proposed rule. Under the final rule,
MSHA will not issue a citation when one operator sample meets or
exceeds the ECV but will require the operator to take corrective action
on a single overexposure to lower dust levels. This will protect miners
from subsequent overexposures.
In addition, final paragraph (e) results in a change to the
existing averaging method so that there is no longer an averaging
process where miners are exposed to high levels of respirable coal mine
dust and no action is taken to lower dust levels. Under the existing
standards, corrective action is required only after the average of five
operator samples exceeds the respirable coal mine dust standard and a
citation is issued. This permits specific instances of miners'
overexposures without requiring any corrective action by the operator
to reduce concentrations to meet the standard. For example, currently,
five dust samples of miners' exposures are averaged, with some samples
indicating that the miner is exposed to unhealthy dust levels above the
existing 2.0 mg/m\3\ standard. Five samples of: 2.3, 2.5, 2.5, 1.3, and
1.2 mg/m\3\ result in an average of 1.96 mg/m\3\, which meets the
existing 2.0 mg/m\3\ standard, but three of the five single samples
exceed the existing 2.0 mg/m\3\ standard. Under the existing standards,
there is no requirement for the operator to take any corrective action,
based on those high samples, to lower dust levels and to avoid further
overexposures. The final rule requires immediate corrective actions to
lower dust concentrations when a single, full-shift operator sample
meets or exceeds the ECV for the applicable dust standard. These
corrective actions will result in reduced respirable dust
concentrations in the mine atmosphere and, therefore, will provide
better protection of miners from further high exposures. The Secretary
has determined that a single full-shift measurement of respirable coal
mine dust accurately represents atmospheric conditions to which a miner
is exposed during such shift.
Under final paragraph (e), operators will protect miners from
overexposures by making respiratory equipment available and taking and
recording corrective actions.
If sampling with a CMDPSU, the actions must be taken upon
notification by MSHA that a respirable dust sample taken in accordance
with this section meets or exceeds the ECV for the applicable standard.
If sampling with a CPDM, the actions must be taken when the sampling
measurement shows that a dust sample taken in accordance with this
section meets or exceeds the ECV for the applicable standard.
Final paragraph (e)(1), like proposed Sec. 70.208(f)(1) and
(g)(1), requires that the operator make approved respiratory equipment
available to affected miners in accordance with final Sec. 72.700 of
this chapter. Comments on proposed Sec. 70.208(f)(1) and (g)(1) were
identical or similar to those on proposed Sec. 70.207(g)(1) and
(i)(1). The comments are consolidated and discussed elsewhere in this
preamble, together with the rationale for final paragraph (e)(1), under
Sec. 70.206(e)(1).
Final paragraph (e)(2) is similar to proposed Sec. 70.208(f)(2)
and (g)(2). It requires that the operator immediately take corrective
action to lower the concentration of respirable coal mine dust to at or
below the standard. Paragraph (e)(2) is consistent with existing Sec.
70.201(d), which requires a mine operator to take corrective action to
lower the concentration of respirable dust. The types of corrective
actions that could be taken are discussed elsewhere in this preamble
under Sec. 70.206(e)(2).
Proposed Sec. 70.208(f)(2) and (g)(2) would have required that
corrective action be taken on the next and subsequent production
shifts. Final paragraph (e)(2) requires that the corrective action must
be taken immediately to protect miners from subsequent overexposures.
The rationale for final paragraph (e)(2) is the same as that for final
Sec. 70.206(e)(2) and is discussed elsewhere in this preamble under
Sec. 70.206(e)(2).
Comments on proposed Sec. 70.208(g)(2) were identical or similar
to those on proposed Sec. 70.208(f)(2). One commenter stated that it
is not possible to implement corrective actions before production
begins on the next shift. Another commenter stated that the proposal
would eliminate ``hot-seating'', forcing mine operators to work only 8-
hour shifts because the weight of the sample is not known until the
production crew arrives on the surface and the data are downloaded.
Immediate corrective actions are necessary to ensure that miners
are not subject to subsequent overexposures and to provide improved
protection for miners. If sampling with a CMDPSU, the actions must be
taken upon notification by MSHA that a respirable dust sample taken in
accordance with this section meets or exceeds the ECV for the
applicable standard. MSHA has no information that operators will limit
shift lengths to 8 hours. Based on MSHA's experience, operators
establish
[[Page 24906]]
the length of work shifts primarily to accommodate production needs at
their mines.
Final paragraph (e)(3) is similar to proposed Sec. 70.208(f)(5)(v)
and (g)(3). Final paragraph (e)(3) requires that the mine operator make
a record of the corrective actions taken. The record must be certified
by the mine foreman or equivalent mine official no later than the end
of the mine foreman's or equivalent mine official's next regularly
scheduled working shift. It also requires that the record must be made
in a secure book that is not susceptible to alteration or
electronically in a computer system so as to be secure and not
susceptible to alteration. It further requires that the records must be
retained at a surface location at the mine for at least 1 year and must
be made available for inspection by authorized representatives of the
Secretary and the representative of miners. Comments on proposed Sec.
70.208(f)(5)(v) and (g)(3) were identical or similar to those on
proposed Sec. 70.207(i)(3). The comments are consolidated and
discussed, together with the rationale for final paragraph (e)(3),
elsewhere in this preamble under Sec. 70.206(e)(3).
Unlike proposed Sec. 70.208(f)(4) and (g)(4), final paragraph (e)
does not require the operator to review and revise a CPDM Performance
Plan. As discussed elsewhere in this preamble under Sec. 70.206, the
final rule does not include the proposed requirements for a CPDM
Performance Plan.
In addition, unlike proposed Sec. 70.208(f)(3), final paragraph
(e) does not require the submission of corrective actions to the
District Manager for approval. Comments on proposed Sec. 70.208(f)(3)
were the same as or similar to those on proposed Sec. 70.207(g)(2).
The comments are consolidated and discussed elsewhere in this preamble
under Sec. 70.206(h)(4).
For consistency between the sampling requirements of the final
rule, final paragraphs (e)(1)-(3) are identical to Sec. 70.206(e)(1)-
(3) regarding bimonthly sampling of MMUs, Sec. 70.207(d)(1)-(3)
regarding bimonthly sampling of designated areas, Sec. 70.209(c)(1)-
(3), regarding quarterly sampling of designated areas, Sec.
71.206(h)(1)-(3) regarding quarterly sampling, and except for
conforming changes, Sec. 90.207(c)(1)-(3) regarding quarterly
sampling.
Final paragraphs (f)(1) and (2) are redesignated and changed from
proposed Sec. 70.208(d) and (e). Paragraph (f) provides that
noncompliance with the standard is demonstrated during the sampling
period when: (1) Three or more valid representative samples meet or
exceed the excessive concentration value (ECV) in Table 70-1 that
corresponds to the applicable standard and particular sampling device
used; or (2) The average for all valid representative samples meets or
exceeds the ECV in Table 70-2 that corresponds to the applicable
standard and particular sampling device used.
In the March 8, 2011, request for comments (76 FR 12649), MSHA
stated that the Agency is interested in commenters' views on what
actions should be taken by MSHA and the mine operator when a single
shift respirable dust sample meets or exceeds the ECV. MSHA also
requested comments on alternative actions, other than those contained
in the proposal, for MSHA and the operator to take if operators use a
CPDM. MSHA further stated that it is particularly interested in
alternatives and how such alternatives would be protective of miners.
Several commenters stated that they supported the use of single,
full-shift samples for making noncompliance determinations. Other
commenters expressed concern about proposed Sec. 70.208(d), which
would have required that no valid end-of-shift equivalent concentration
measurement meet or exceed the ECV listed in Table 70-2 that
corresponds to the applicable standard.
In response to the comments, the final rule is changed from the
proposal. Final paragraph (f), like final Sec. Sec. 70.206(f),
70.207(e), and 70.209(d), provides that more than one operator sample
will be used to determine noncompliance with the standard during the
sampling period. Specifically under these final provisions, a violation
is established when either two or more valid representative samples
(bimonthly MMU and DA sampling, and quarterly DA sampling) or three or
more valid representative samples (quarterly MMU sampling) meet or
exceed the ECV in Table 70-1 that corresponds to the applicable
standard and particular sampling device used; or when the average for
all valid representative samples meets or exceeds the ECV in Table 70-2
that corresponds to the applicable standard and particular sampling
device used.
The final rule is changed from the proposal. Final paragraph (e),
like final Sec. Sec. 70.206(e), 70.207(d), and 70.209(c), provides
greater protection for miners. Under the final rule, when a single
full-shift operator sample meets or exceeds the ECV that corresponds to
the applicable standard and particular sampling device used, the
operator is made aware of a potential problem with the dust controls
being used. The final rule requires that an operator must make approved
respiratory equipment available; immediately take corrective action;
and record the corrective actions. Under the final rule, miners will be
afforded protection from overexposures during a single shift. In
addition, the final rule, will provide miners with the additional
protection afforded by MSHA's single sampling under Sec. 72.800.
Some commenters questioned the accuracy of a single sample used to
make compliance determinations. Some commenters were also concerned
that making compliance determinations on a single sample does not
represent a miner's long term exposures. The rationale for Sec. 72.800
and comments concerning the accuracy and validity of using a single
full-shift measurement are discussed elsewhere in this preamble under
Sec. 72.800.
Some commenters stated that issuing a citation based on a single
full-shift sample when the operator is required to submit multiple
samples did not allow for shift-to-shift variability.
There is no shift-to-shift variability that needs to be considered
if a violation is based on a single full-shift sample. However, because
the final rule provides that a violation of the respirable coal mine
dust standard is based on more than one operator single sample, MSHA
needed to adjust the number of samples on which a compliance
determination would be made. The probability of measurement error in at
least one shift increases when several multiple shifts are considered,
as under the final rule. Measurement error on multiple shift sampling
is due to shift-to-shift variability. Shift-to-shift variation could
include differences in sampling location, miners' wearing the sampling
device differently, or changes in air velocity. Therefore, MSHA needed
to modify the citation criteria in order to maintain 95 percent
confidence in every noncompliance determination.
Some commenters suggested that the exposure limit for a miner per
week should not be permitted to exceed the dose equivalent to that
received as if exposed to 10 mg/m\3\ for a scheduled forty-hour week
and that under no circumstances could the exposure limit for the week
be increased to a dose equivalent to above 2.0 mg/m\3\ for eight hours
if the work week is less than forty hours. These commenters stated that
measuring the dose over a week improves exposure accuracy and is
therefore an improvement over the single shift sample methodology.
The final rule does not include a weekly exposure limit.
In the final rule, MSHA changed the existing averaging method so
that there
[[Page 24907]]
is no longer an averaging process where miners can be exposed to high
levels of respirable coal mine dust and no action is taken to lower
dust levels. The existing averaging method may conceal high exposures
that could have an effect on risk. The accuracy and validity of using a
single full-shift measurement is discussed elsewhere in this preamble
under Sec. 72.800 and a detailed description of the issue involving
sampling bias due to averaging is provided in Appendix A of the 2000
single sample proposed rule (65 FR 42108), available at http://www.msha.gov/REGS/FEDREG/PROPOSED/2000PROP/00-14075.PDF].
Accordingly, the final rule is changed from the proposal. Final
paragraph (f)(1) provides that noncompliance with the standard is
demonstrated during the sampling period when three or more valid
representative samples meet or exceed the ECV in Table 70-1. Similarly,
final Sec. Sec. 70.206(f)(1), 70.207(e)(1), and 70.209(d)(1), all
provide that noncompliance is demonstrated when either two or more
valid representative samples meet or exceed the ECV in Table 70-1.
Additional information on the modified citation criteria for multiple
shift samples is provided in Appendix C of the July 7, 2000 proposed
rule. Appendix C is incorporated as part of this final rule, (http://www.msha.gov/REGS/FEDREG/PROPOSED/2000PROP/00-14075.PDF). Additional
discussion regarding variability and measurement error on single
samples, in response to comments, is in the Section-by-Section Analysis
related to final Sec. 72.800 of this preamble.
Final Table 70-1 is renumbered from proposed Table 70-2, which
included ECVs based on single-shift CPDM measurements. Table 70-1
includes ECVs based on single-shift measurements taken with either a
CMDPSU or a CPDM. Final Table 70-2 includes ECVs based on the average
of 5 or 15 full-shift measurements taken with a CMDPSU or a CPDM.
One commenter stated that the ECVs in proposed Table 70-1 were too
low. Another commenter stated that the sampling and analytical error
used in the calculations for the ECVs in proposed Table 70-2 was based
on unverified assumptions and would result in unjustified noncompliance
determinations.
The NIOSH Criteria Document recommended that MSHA make no upward
adjustment in exposure limits to account for measurement uncertainty
for single, full-shift samples used to determine noncompliance. The
Dust Advisory Committee made the same recommendation but it was not
unanimous.
The Secretary must show to a certain level of confidence that there
has been an overexposure before issuing a citation. The final rule is
consistent with generally accepted industrial hygiene principles for
health standards that include an error factor in determining
noncompliance to account for measurement uncertainty. The ECVs were
calculated to ensure that, if an ECV is met or exceeded, MSHA can
determine noncompliance with the applicable dust standard with at least
95 percent confidence.
Each ECV in final Table 70-1 was calculated to ensure that
citations would be issued only when a sample measurement from a single
shift demonstrates, with at least 95 percent confidence, that the
applicable dust standard has been exceeded. In Table 70-1, the ECV that
corresponds to the applicable standard differs depending on the
sampling device used. Final Table 70-1 revises two values in proposed
Table 70-2 due to rounding inconsistencies; the final ECV is changed
from proposed 1.59 mg/m\3\ to 1.58 mg/m\3\ when the applicable standard
is 1.4 mg/m\3\, and from proposed 0.80 mg/m\3\ to 0.79 mg/m\3\ when the
applicable standard is 0.7 mg/m\3\.
Final Table 70-2 includes ECVs corresponding to the average
concentration of either 5 or 15 samples that will provide the Secretary
with a 95 percent confidence level that the applicable respirable dust
standard has been exceeded. A more detailed discussion on the
derivation of the ECVs in both Tables 70-1 and 70-2 is included in
Appendix A of the preamble.
Many commenters supported proposed Sec. 70.208(e) that would have
required that no weekly accumulated exposure exceed the weekly
permissible accumulated exposure. Other commenters stated that this
provision would create problems when attempting to calculate the weekly
permissible accumulated exposure on a 40-hour week based on samples
collected on shifts greater than 8 hours. Commenters also stated that
this provision would not benefit miners and was unachievable on a day-
to-day basis.
Final paragraph (f)(2) is similar to proposed Sec. 70.208(e).
Proposed Sec. 70.208(e) would have provided for a compliance
determination based on whether a weekly accumulated exposure (WAE)
exceeded the weekly permissible accumulated exposure (WPAE). The WPAE
was defined as the maximum amount of accumulated exposure to respirable
coal mine dust, expressed in mg-hr per cubic meter of air (mg-hr/m\3\),
permitted for an occupation during a 40-hr work week (Sunday through
Saturday). The WAE was defined as the total exposure to respirable coal
mine dust, expressed in milligram-hour (mg-hr) per cubic meter of air
(mg-hr/m\3\), accumulated by an occupation during a work week (Sunday
thru Saturday). Determining the WPAE and the WAE would have required a
complex calculation that commenters found to be difficult to understand
and apply. Final paragraph (f) provides a simpler method than the
proposal for determining compliance.
In the March 8, 2011, request for comments (76 FR 12649), MSHA
stated that a commenter at a public hearing requested clarification on
whether there would be more than one violation of the respirable dust
standard if a single, full-shift sample exceeded the ECV during the
same week that the weekly permissible accumulated exposure (WPAE) limit
was exceeded. MSHA further stated that under the proposed rule, it
would be a violation for each occurrence that the ECV or WPAE is
exceeded. MSHA requested comments and alternatives to the proposed
rule.
A few commenters stated that it was unfair that a mine operator
could be cited for violating the single sample provision under proposed
Sec. 70.208(d) and the WAE provision under proposed Sec. 70.208(e).
As stated earlier, the final rule does not include the proposed WAE
provision. Under final paragraphs (f)(1) and (2), noncompliance is
based on 3 or more operator's samples or the average of the samples for
a particular DO or ODO.
For consistency between the sampling requirements of the final
rule, final paragraphs (f)(1) and (2) are the same as final Sec. Sec.
70.206(f)(1) and (2), 70.207(e)(1) and (2), 70.209(d)(1) and (2), and,
except for conforming changes, 71.206(i)(1) and (2), and 90.207(d)(1)
and (2).
Final paragraphs (g)(1) and (2) are new. They are similar to
proposed Sec. 70.207(f) and they are included in final Sec. 70.208
because proposed 24/7 sampling of DOs in each MMU is not included in
the final rule. Final paragraph (g)(1) requires that unless otherwise
directed by the District Manager, upon issuance of a citation for a
violation of the standard involving a DO in an MMU, paragraph (a)(1)
will not apply to the DO in that MMU until the violation is abated and
the citation is terminated in accordance with paragraphs (h) and (i) of
this section. Final paragraph (g)(2) requires that unless otherwise
directed by the District Manager, upon issuance of a citation for
[[Page 24908]]
a violation of the standard involving a type of ODO in an MMU,
paragraph (a)(2) will not apply to that ODO type in that MMU until the
violation is abated and the citation is terminated in accordance with
paragraphs (h) and (i) of this section.
Final paragraphs (g)(1) and (2) include an exception to allow the
District Manager flexibility to address extenuating circumstances that
would affect sampling. An example of extenuating circumstances would
occur when an uncorrected violation would require abatement sampling
that continues into the next sampling period.
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraphs (g)(1) and (2)
are the same as final Sec. Sec. 70.206(g), 70.207(f), 70.209(e),
71.206(j), and 90.207(e).
Final paragraph (h) is similar to proposed Sec. 70.208(f) and
(g)(3). It requires that upon issuance of a citation for violation of
the standard, the operator must take the following actions
sequentially: (1) Make approved respiratory equipment available; (2)
immediately take corrective action; (3) record the corrective actions;
and (4) conduct additional sampling. The actions required by paragraph
(h) are similar to those proposed in Sec. 70.208(f)(1)-(5) and (g)(3)
discussed under final paragraph (e). Paragraph (h) includes the term
``sequentially'' to ensure that corrective actions are taken in the
order they are listed.
Final paragraph (h)(1), like proposed Sec. 70.208(f)(1), requires
that the mine operator make approved respiratory equipment available to
affected miners in accordance with Sec. 72.700 of this chapter.
Comments on proposed Sec. 70.208(f)(1) are identical or similar to
those on proposed Sec. 70.207(g)(1) and (i)(1). The comments are
consolidated and discussed, together with the rationale for paragraph
(h)(1), elsewhere in this preamble under final Sec. 70.206(e)(1).
Final paragraph (h)(2) is substantially similar to proposed Sec.
70.208(f)(2). It requires that, if a citation is issued, the mine
operator must immediately take corrective action to lower the
concentration of respirable coal mine dust to at or below the standard.
Paragraph (h)(2) is consistent with existing Sec. 70.201(d), which
requires a mine operator to take corrective action to lower the
concentration of respirable dust. The types of corrective actions that
could be taken are discussed elsewhere in this preamble under Sec.
70.206(e)(2).
Proposed Sec. 70.208(f)(2) would have required that corrective
action be taken on the next and subsequent production shifts. Final
paragraph (h)(2) clarifies that the corrective action must be taken
immediately to protect miners from overexposures. Comments on proposed
Sec. 70.208(f)(2) were the same as or similar to comments on proposed
Sec. 70.208(g)(2). The comments are consolidated and discussed under
final paragraph (e)(2). In addition, the rationale for final paragraph
(h)(2) is the same as that for final Sec. 70.206(e)(2) and (h)(2) and
is discussed elsewhere in this preamble under Sec. 70.206(e)(2) and
(h)(2).
Paragraph (h)(3) is similar to proposed Sec. 70.208(f)(5)(v) and
(g)(3). It requires that the operator make a record of the corrective
actions taken. The record must be certified by the mine foreman or
equivalent mine official no later than the end of the mine foreman's or
equivalent mine official's next regularly scheduled working shift. It
also requires that the record must be made in a secure book that is not
susceptible to alteration or electronically in a computer system so as
to be secure and not susceptible to alteration. It further requires
that the records must be retained at a surface location at the mine for
at least 1 year and be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
Comments on proposed Sec. 70.208(f)(5)(v) are similar to those on
proposed Sec. 70.208(g)(3). The comments are consolidated and
discussed elsewhere in this preamble, together with the rationale for
final paragraph (h)(3), under Sec. 70.206(e)(3).
Final paragraph (h)(4) is similar to proposed Sec. 70.207(g)(3).
It requires that the mine operator, within 8 calendar days after the
date the citation is issued, begin sampling the environment of the
affected occupation in the MMU on consecutive normal production shifts
until five valid representative samples are taken. Under the proposed
rule, there was no reason to propose additional sampling to demonstrate
that subsequent respirable dust concentrations were in compliance with
the standard; the 24/7 continuous sampling results would have shown
whether the corrective actions were effective and compliance was
achieved. However, since the final rule does not include the proposed
24/7 sampling requirement, it is necessary to resample to confirm
compliance. The five additional representative samples required under
this section are less burdensome for operators than the proposed
sampling that would have been required every production shift, every
day. MSHA believes that the sampling requirements in the final rule are
sufficient to demonstrate compliance and protect miners from
overexposure. Final paragraph (h)(4) is consistent with existing Sec.
70.201(d), which requires the operator to sample each production shift,
after a citation is issued, until five valid respirable dust samples
are taken. In addition, paragraph (h)(4) requires that the sampling
must begin within 8 calendar days after the date the citation is
issued. The rationale for final paragraph (h)(4) is the same as that
for final Sec. 70.206(h)(4) and is discussed elsewhere in this
preamble under Sec. 70.206(h)(4).
Unlike proposed Sec. 70.208(f)(3), final paragraph (h) does not
require the submission of corrective actions to the District Manager
for approval. Comments on proposed Sec. 70.208(f)(3) were the same as
or similar to those on proposed Sec. 70.207(g)(2). The comments are
consolidated and discussed elsewhere in this preamble under Sec.
70.206(h)(4).
Unlike proposed Sec. 70.208(f)(4), final paragraph (h) does not
require the operator to review and revise a CPDM Performance Plan.
Several commenters stated that the CPDM Performance Plan would not be
necessary when sampling with the CPDM and additional plan requirements
were too burdensome on mine operators. As discussed elsewhere in this
preamble under Sec. 70.206, the final rule does not include the
proposed requirements for a CPDM Performance Plan.
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraph (h) is the same as
final Sec. 70.206(h) regarding bimonthly sampling of MMUs, Sec.
70.207(g) regarding bimonthly sampling of designated areas, Sec.
70.209(f) regarding quarterly sampling of designated areas, Sec.
71.206(k) regarding quarterly sampling, and Sec. 90.207(f) regarding
quarterly sampling.
Final paragraph (i) is similar to proposed Sec. Sec. 70.207(h) and
70.208(f)(3). It provides that a citation for a violation of the
standard will be terminated when: (1) Each of the five valid
representative samples is at or below the standard; and (2) the
operator has submitted to the District Manager revised dust control
parameters as a part of the mine ventilation plan for the MMU in the
citation and these changes have been approved by the District Manager.
It further requires that the revised parameters must reflect the
control measures used by the operator to abate the violation.
Under proposed Sec. 70.208(f)(3), a mine operator would have had
to submit corrective actions to the District Manager for approval in
the ventilation
[[Page 24909]]
plan, whenever a violation occurred. Unlike proposed Sec.
70.208(f)(3), final paragraph (i)(2) requires only the submission of
revised dust control parameters. Paragraph (i) is consistent with
MSHA's existing practice of including, in the body of a citation, a
requirement to submit revised dust control parameters as a condition
for terminating a citation.
Comments on proposed Sec. 70.207(h) and the rationale for
paragraphs (i)(1) and (2) are discussed elsewhere in this preamble
under Sec. 70.206(i).
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraphs (i)(1) and (2)
are the same as final Sec. Sec. 70.206(i)(1) and (2), 70.207(h)(1) and
(2), and, 70.209(g)(1) and (2).
Proposed Sec. 70.208(h) is not included in the final rule.
Proposed paragraph (h) would have provided that, during the 24 months
following the effective date of the final rule, if an operator is
unable to maintain compliance with the standard for an MMU and has
determined that all feasible engineering or environmental controls are
being used, the operator may use supplementary controls, including
worker rotation, to reduce exposure. These controls had to be used in
conjunction with CPDMS for a period of up to 6 months.
In the March 8, 2011, request for comments (76 FR 12650), MSHA
stated that the proposed sampling provisions address interim use of
supplementary controls when all feasible engineering or environmental
controls have been used but the mine operator is unable to maintain
compliance with the dust standard. MSHA further stated that with MSHA
approval, operators could use supplementary controls, such as rotation
of miners, or alteration of mining or of production schedules in
conjunction with CPDMs to monitor miners' exposures. MSHA solicited
comments on this proposed approach and any suggested alternatives, as
well as the types of supplementary controls that would be appropriate
to use on a short-term basis.
Many commenters stated that worker rotation was not the answer to
controlling respirable dust. They also stated that MSHA, not the
operator, should make the determination if all feasible engineering or
environmental controls have been exhausted. Other commenters stated
that miners should be able to rotate out of a DO and take the sampling
device with them, which would minimize respirable dust exposure to
individual miners. Some commenters were concerned whether proposed
paragraph (h) included the use of respirators such as powered air-
purifying respirators (PAPRS), or other suitable protective NIOSH-
approved respirators. In addition, these commenters stated that MSHA
should allow operators to use a ``hierarchy of controls'' to limit
miners' exposure to coal mine dust. This hierarchy of controls consists
of first using feasible engineering controls, then administrative
controls, and finally respirators including PAPRs.
As specified in Sections 201(b) and 202 of the Mine Act, operators
must continuously maintain the average concentration of respirable dust
in the mine atmosphere. The Mine Act provides further that respirators
must not be substituted for environmental controls.
Engineering controls, also known as environmental controls, are the
most protective means of controlling dust generation at the source.
MSHA requires engineering or environmental controls as the primary
means of controlling respirable dust in the mine environment. This
requirement is consistent with the Mine Act and generally accepted
industrial hygiene principles. Engineering controls reduce dust
generation at the source, or suppress, dilute, divert, or capture the
generated dust. Unlike administrative controls and respiratory
protection, well-designed engineering controls or environmental
controls provide consistent and reliable protection to all workers
because the controls are less dependent on individual human
performance, supervision, or intervention to function as intended. This
is an industrial hygiene principle that is widely supported in publicly
available literature.\59\ Comments on using a ``hierarchy of controls''
and the use of respirators including PAPRs, are further discussed in
the preamble under final Sec. 72.700.
---------------------------------------------------------------------------
\59\ For example, see: Alli, B.O., Fundamental Principles of
Occupational Health and Safety, the International Labour
Organization (2008), page 105, http://www.ilo.org/wcmsp5/groups/public/@dgreports/@dcomm/@publ/documents/publication/wcms_093550.pdf; Engineering Controls--NIOSH Workplace Safety and Health
Topic, http://www.cdc.gov/niosh/topics/engcontrols; Good Practice
Guidance on Occupational Health Risk Assessment, the International
Council on Mining & Metals, http://www.icmm.com/search-results?sortField=sort_rank&query=Good+practice+guidance+on+occupational+health+risk+assessment.
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MSHA has determined that proposed paragraph (h) is not necessary
and it is not included in the final rule. The proposal would have
allowed limited short-term use of measures to supplement engineering or
environmental controls to accommodate operators who may have had
difficulty meeting the standards by the compliance dates that would
have been established by the final rule. However, the final rule
includes changes from the proposal on the respirable dust standard in
Sec. 70.100, the implementation period for the final standard, and the
sampling program. These changes will allow mine operators sufficient
time to achieve compliance with the new standard using engineering or
environmental controls without the need to use supplementary controls.
12. Section 70.209 Quarterly Sampling; Designated Areas
Final Sec. 70.209, like the proposal, addresses quarterly sampling
of designated areas 18 months after the effective date of the final
rule.
Under final Sec. 70.201(b), until January 31, 2016, all DAs will
be sampled under final Sec. 70.207 regarding bimonthly sampling of
designated areas. On February 1, 2016: DAs associated with an MMU will
be redesignated as ODOs and will be subject to final Sec. 70.209
regarding quarterly sampling of MMUs; and DAs identified by the
operator under Sec. 75.371(t) (e.g., in outby areas) will be subject
to the quarterly sampling requirements under this final Sec. 70.209.
In addition, final Sec. 70.201(b) addresses the sampling devices
required for quarterly sampling of DAs under this final Sec. 70.209.
Final paragraph (a) makes clarifying non-substantive changes to
proposed Sec. 70.209(a). It requires that the operator must sample
quarterly each DA on consecutive production shifts until five valid
representative samples are taken. The quarterly periods are: (1)
January 1-March 31; (2) April 1-June 30; (3) July 1-September 30; and
(4) October 1-December 31.
On March 8, 2011, MSHA issued in the Federal Register a request for
comments (76 FR 12648). MSHA requested comments on all aspects of the
proposed rule including the areas that operators should sample, the
sampling frequency, and which areas could be sampled using CMDPSUs or
CPDMs.
One commenter stated that DA sampling should be discontinued
because it provides little indication of the miner's exposure.
Sampling DAs, such as belt transfer points, is necessary to
evaluate the dust generating sources that are not on an MMU and
provides protection from excessive respirable coal mine dust levels to
miners that work in outby areas of the mine. The final rule requires
mine operators to sample DAs. This provision is consistent with
existing Sec. 70.208 regarding sampling of DAs.
[[Page 24910]]
Some commenters stated that they should continue to use the
gravimetric sampling devices for DA sampling and not be required to use
the CPDM. Final Sec. 70.209(a), like proposed Sec. 70.209, allows the
operator to sample DA locations with either a CMDPSU or a CPDM.
One commenter suggested that additional DA sampling be included in
the final rule for major projects such as raise bore drilling of mine
shafts. MSHA has and will continue to evaluate situations that may
require additional DAs to be established for sampling.
Final paragraph (b) is similar to proposed Sec. 70.209(b) and
clarifies the time frame for implementation when there is a change in
the applicable standard. It requires that when the respirable dust
standard is changed in accordance with Sec. 70.101 (Respirable dust
standard when quartz is present), the new standard will become
effective 7 calendar days after the date of the notification of the
change by MSHA. Under proposed Sec. 70.209(b), a new standard would
have gone into effect on the first production shift following the
operator's receipt of notification after the respirable dust standard
is changed in accordance with Sec. 70.101. The rationale for final
paragraph (b) is discussed elsewhere in this preamble under Sec.
70.208(c). MSHA received no comments on the proposal.
Final paragraph (b) does not include the requirements in proposed
70.209(b)(1) and (b)(2). Proposed Sec. 70.209(b)(1) would have
required that if all samples from the most recent quarterly sampling
period do not exceed the new standard, respirable dust sampling of the
DA would begin the first production shift during the next quarterly
period following receipt of the change from MSHA. Proposed Sec.
70.209(b)(2) would have required that if any sample from the most
recent quarterly sampling period exceeded the new standard (reduced due
to the presence of quartz), the operator would have had to make
necessary adjustments to the dust control parameters in the mine
ventilation plan within three days and then collect samples from the
affected DA on consecutive shifts until five valid representative
samples are collected. It further provided that the samples collected
would be treated as normal quarterly samples. MSHA received one comment
on the proposal, which was similar to comments received on proposed
Sec. 70.207(c)(1) and (2). The comments are consolidated and
discussed, together with MSHA's rationale, elsewhere in this preamble
under Sec. 70.206(c)(1) and (2).
For consistency between the sampling requirements of the final
rule, final paragraph (b) is the same as final Sec. 70.206(c)
regarding bimonthly sampling of MMUs, Sec. 70.207(b) regarding
bimonthly sampling of designated areas, and Sec. 70.208(c) regarding
quarterly sampling of MMUs.
Final paragraph (c) is similar to proposed Sec. 70.209(e) and (g).
It requires that when a respirable dust sample taken in accordance with
this section meets or exceeds the ECV in Table 70-1 that corresponds to
the applicable standard and particular sampling device used, the
operator must: (1) Make approved respiratory equipment available; (2)
Immediately take corrective action; and (3) Record the corrective
actions. The actions required by paragraph (c) are similar to those in
proposed Sec. 70.209(e) and (g).
Proposed Sec. 70.209(e) would have required that, during the time
for abatement to be fixed in a citation, the operator: (1) Make
approved respiratory equipment available to affected miners in
accordance with Sec. 72.700; (2) submit to the District Manager for
approval proposed corrective actions to lower the concentration of
respirable dust to at or below the standard; and (3) upon approval by
the District Manager, implement the proposed corrective actions and
then sample the affected DA on each production shift until five valid
representative samples are taken.
Proposed Sec. 70.209(g) would have required that when using a CPDM
and a valid end-of-shift equivalent concentration exceeded the standard
but is less than the applicable ECV in Table 70-2, the operator would
have had to: (1) Make approved respiratory equipment available to
affected miners in accordance with Sec. 72.700; (2) implement
corrective actions to ensure compliance with the standard on the next
and subsequent production shifts; (3) record the reported excessive
dust condition as part of and in the same manner as the records for
hazardous conditions required by Sec. 75.363; and (4) review the
adequacy of the approved CPDM Performance Plan and submit to the
District Manager for approval any plan revisions within 7 calendar days
following posting of the end-of-shift equivalent concentration on the
mine bulletin board.
As noted previously in the discussion on final Sec. 70.206(e),
MSHA clarified, in the March 8, 2011 request for comments (76 FR
12648), that the proposal would require that operators record both
excessive dust concentrations and corrective actions in the same manner
as conditions are recorded under Sec. 75.363 and that ``MSHA would not
consider excessive dust concentrations or corrective actions to be
hazardous conditions, since the proposed requirement is not a section
75.363 required record'' (76 FR 12650).
Comments on proposed Sec. 70.209(g) were identical or similar to
those on proposed Sec. 70.207(i). The comments are consolidated and
discussed elsewhere in this preamble under Sec. 70.206(e). In response
to the comments, final paragraph (c) is changed from the proposal. It
does not require action if the dust sample exceeds the standard but is
less than the ECV in Table 70-1. Rather, it requires an operator to
take certain actions when a valid representative sample meets or
exceeds the ECV in Table 70-1. If sampling with a CMDPSU, actions must
be taken upon notification by MSHA that a respirable dust sample taken
in accordance with this section meets or exceeds the ECV for the
applicable standard. If sampling with a CPDM, the actions must be taken
when the sampling measurement shows that a dust sample taken in
accordance with this section meets or exceeds the ECV for the
applicable standard. The rationale for final paragraph (c) is the same
as that for Sec. Sec. 70.206(e), 70.207(d), and 70.208(e), and is
discussed elsewhere in this preamble under Sec. 70.208(e).
Final paragraph (c)(1), like proposed Sec. 70.209(e)(1) and
(g)(1), requires that the operator make approved respiratory equipment
available to affected miners in accordance with Sec. 72.700 of this
chapter. Comments on proposed Sec. 70.209(e)(1) and (g)(1) were
identical or similar to those on proposed Sec. Sec. 70.207(g)(1) and
(i)(1) and 70.208(f)(1) and (g)(1). The comments are consolidated and
discussed elsewhere in this preamble, together with the rationale for
paragraph (c)(1), under Sec. 70.206(e)(1).
Final paragraph (c)(2), is similar to proposed Sec. 70.209(e)(3)
and (g)(2). It requires that the operator immediately take corrective
action to lower the concentration of respirable coal mine dust to at or
below the standard. Paragraph (c)(2) clarifies that corrective action
needs to be taken immediately to protect miners from overexposures.
Comments on proposed Sec. 70.209(e)(3) and (g)(2) were identical or
similar to those on proposed 70.208(f)(2). The comments are
consolidated and discussed elsewhere in this preamble under Sec.
70.208(e)(2). The rationale for final paragraph (c)(2) is the same as
that for Sec. 70.206(e)(2) and is discussed under that section.
Final paragraph (c)(3) is similar to proposed Sec.
70.209(g)(3)(v). It requires that the mine operator make a record of
[[Page 24911]]
the corrective actions taken. The record must be certified by the mine
foreman or equivalent mine official no later than the end of the mine
foreman's or equivalent mine official's next regularly scheduled
working shift. It also requires that the record must be made in a
secure book that is not susceptible to alteration or electronically in
a computer system so as to be secure and not susceptible to alteration.
It further requires that the records must be retained at a surface
location at the mine for at least 1 year and be made available for
inspection by authorized representatives of the Secretary and the
representative of miners. Comments on proposed Sec. 70.209(g)(3) were
identical or similar to those on proposed Sec. Sec. 70.207(i)(3) and
70.208(g)(3). The comments are consolidated and discussed elsewhere in
this preamble, together with the rationale for paragraph (c)(3), under
Sec. 70.206(e)(3).
Unlike proposed Sec. 70.209(e)(2), final paragraph (c) does not
require the operator to submit corrective actions to the District
Manager for approval. Comments on proposed Sec. 70.209(e)(2) were the
same as or similar to those on proposed Sec. 70.207(g)(2). The
comments are consolidated and discussed elsewhere in this preamble
under Sec. 70.206(h)(4).
In addition, unlike proposed Sec. 70.209(g)(4), final paragraph
(c) does not require operators to review and revise a CPDM Performance
Plan. As discussed elsewhere in this preamble under Sec. 70.206, the
final rule does not include the proposed requirements for a CPDM
Performance Plan. Comments on proposed Sec. 70.209(g)(4) are similar
to those on proposed Sec. 70.208(f)(4). The comments are consolidated
and discussed elsewhere in this preamble under Sec. 70.208(h).
For consistency between the sampling requirements of the final
rule, final paragraphs (c)(1)-(3) are identical to final Sec.
70.206(e)(1)-(3) regarding bimonthly sampling of MMUs, Sec.
70.207(d)(1)-(3) regarding bimonthly sampling of designated areas,
Sec. 70.208(e)(1)-(3) regarding quarterly sampling of MMUs, Sec.
71.206(h)(1)-(3) regarding quarterly sampling, and except for
conforming changes, Sec. 90.207(c)(1)-(3) regarding quarterly
sampling.
Final paragraph (d) is redesignated and changed from proposed Sec.
70.209(c). Paragraph (d)(1) is similar to proposed Sec. 70.209(c)
regarding sampling of DAs, and paragraph (d)(2) is similar to proposed
Sec. 70.208(e) regarding sampling of MMUs. Paragraph (d) states that
noncompliance with the standard is demonstrated during the sampling
period when: (1) Two or more valid representative samples meet or
exceed the excessive concentration value (ECV) in Table 70-1 that
corresponds to the applicable standard and particular sampling device
used; or (2) The average for all valid representative samples meets or
exceeds the ECV in Table 70-2 that corresponds to the applicable
standard and particular sampling device used.
In the March 8, 2011, request for comments (76 FR 12649), MSHA
stated that the Agency is interested in commenters' views on what
actions should be taken by MSHA and the mine operator when a single
shift respirable dust sample meets or exceeds the ECV.
Proposed Sec. 70.209(c) would have required that, if using a
CMDPSU, no valid single-shift sample equivalent concentration meet or
exceed the ECV that corresponds to the applicable standard in proposed
Table 70-1; or if using a CPDM, no valid end-of-shift equivalent
concentration meet or exceed the applicable ECV in proposed Table 70-2.
Many commenters expressed concern that compliance determinations would
be made on the basis of a single-shift measurement.
In response to comments, final paragraph (d) provides two different
methods by which compliance determinations can be made. The rationale
for paragraphs (d)(1) and (2) is the same as that for Sec. Sec.
70.206(f)(1) and (2), 70.207(e)(1) and (2), and 70.208(f)(1) and (2),
and is discussed elsewhere in this preamble under Sec. 70.208(f)(1)
and (2).
For consistency between the sampling requirements of the final
rule, final paragraphs (d)(1) and (2) are the same as final Sec. Sec.
70.206(f)(1) and (2), 70.207(e)(1) and (2), 70.208(f)(1) and (2), and
except for conforming changes, Sec. 71.206(i)(1) and (2), and
90.207(d)(1) and (2).
Comments on the ECVs in proposed Table 70-1 are discussed elsewhere
in this preamble under Sec. 70.208(f). In addition, a detailed
discussion on the derivation of the ECVs in both final Tables 70-1 and
70-2 is included in Appendix A of the preamble. Comments that
questioned the accuracy of a single sample in making a compliance
determination are addressed elsewhere in this preamble under Sec.
72.800.
Final paragraph (e) is redesignated from proposed Sec. 70.209(d)
and makes clarifying and conforming changes. It requires that upon
issuance of a citation for a violation of the standard, paragraph (a)
of this section will not apply to that DA until the violation is abated
and the citation is terminated in accordance with paragraphs (f) and
(g) of this section. Paragraph (e) clarifies that a violation must be
abated and the citation must be terminated before resuming quarterly
sampling. Paragraphs (f) and (g) are discussed below.
Final paragraph (e) includes an exception to allow the District
Manager flexibility to address extenuating circumstances that would
affect sampling. An example of extenuating circumstances could occur
when an uncorrected violation would require abatement sampling that
continues into the next sampling period.
Final paragraph (e) is similar to existing Sec. 70.208(d). MSHA
did not receive comments on the proposal.
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraph (e) is the same as
final Sec. Sec. 70.206(g), 70.207(f), 70.208(g), 71.206(j), and
90.207(e).
Final paragraph (f) is similar to proposed Sec. 70.209(e) and (g).
It requires that upon issuance of a citation for violation of the
standard, the operator must take the following actions sequentially:
(1) Make approved respiratory equipment available; (2) immediately take
corrective action; (3) record the corrective actions; and (4) conduct
additional sampling. The actions required by paragraph (f) are similar
to those in proposed Sec. 70.209(e)(1)-(3) discussed in final
paragraph (c). In addition, paragraph (f) includes the term
``sequentially'' to ensure that corrective actions are taken in the
order they are listed.
Final paragraph (f)(1), like proposed Sec. 70.209(e)(1) and
(g)(1), requires that the mine operator make approved respiratory
equipment available to affected miners in accordance with Sec. 72.700
of this chapter. Paragraph (f)(1) is consistent with existing Sec.
70.300, which requires the operator to make respiratory equipment
available to all persons exposed to excessive concentrations of
respirable dust. Comments on proposed Sec. 70.209(e)(1) and (g)(1) are
identical or similar to those on proposed Sec. Sec. 70.207(g)(1) and
(i)(1) and 70.208(f)(1) and (g)(1). The comments are consolidated and
discussed elsewhere in this preamble, together with the rationale for
paragraph (f)(1), under Sec. 70.206(e)(1).
Final paragraph (f)(2) is similar to proposed Sec. 70.209(e)(3).
It requires that the operator immediately take corrective action to
lower the concentration of respirable coal mine dust to at or below the
standard. Paragraph (f)(2) is similar to proposed Sec. 70.209(e)(3)
which would have required a mine operator to implement the proposed
corrective actions. It is consistent with existing
[[Page 24912]]
Sec. 70.201(d), which requires a mine operator to take corrective
action to lower the concentration of respirable dust. Paragraph (f)(2)
clarifies that the corrective action must be taken immediately to
protect miners from overexposures. The types of corrective actions that
could be taken are discussed elsewhere in this preamble under Sec.
70.206(e)(2). Comments on proposed Sec. 70.209(e)(2) are the same as
or similar to those on proposed Sec. 70.208(f)(2) and are discussed
elsewhere in this preamble under Sec. 70.208(h)(2). The rationale for
final paragraph (f)(2) is discussed elsewhere in this preamble under
Sec. 70.206(e)(2) and (h)(2).
Final paragraph (f)(3) is similar to proposed Sec.
70.209(g)(3)(v). It requires that the operator make a record of the
corrective actions taken. The record must be certified by the mine
foreman or equivalent mine official no later than the end of the mine
foreman's or equivalent mine official's next regularly scheduled
working shift. It also requires that the record must be made in a
secure book that is not susceptible to alteration or electronically in
a computer system so as to be secure and not susceptible to alteration.
It further requires that the records must be retained at a surface
location at the mine for at least 1 year and be made available for
inspection by authorized representatives of the Secretary and the
representative of miners. Comments on proposed Sec. 70.209(g)(3)(v)
are similar to those on proposed Sec. Sec. 70.208(g)(3) and
70.207(i)(3). The comments are consolidated and discussed elsewhere in
this preamble, together with the rationale for final paragraph (f)(3),
under Sec. 70.206(e)(3).
Final paragraph (f)(4) is similar to proposed Sec. 70.209(e)(3).
It requires the mine operator, within 8 calendar days after the date
the citation is issued, to begin sampling the environment of the
affected DA on consecutive normal production shifts until five valid
representative samples are taken. Paragraph (f)(4) is consistent with
existing Sec. 70.201(d), which requires a mine operator to sample each
production shift until five valid respirable dust samples are taken. In
addition, it requires that the sampling must begin within 8 calendar
days after the date the citation is issued. The rationale for final
paragraph (f)(4) is the same as that for final Sec. 70.206(h)(4) and
is discussed elsewhere in this preamble under Sec. 70.206(h)(4).
Unlike proposed Sec. 70.209(e)(2), final paragraph (f) does not
require operators to submit corrective actions to the District Manager
for approval. Comments on proposed Sec. 70.209(e)(2) were the same as
or similar to those on proposed Sec. 70.207(g)(2). The comments are
consolidated and discussed elsewhere in this preamble under Sec.
70.206(h)(4).
For consistency between the sampling requirements of the final
rule, except for conforming changes, paragraph (f) is the same as Sec.
70.206(h) regarding bimonthly sampling of MMUs, Sec. 70.207(g)
regarding bimonthly sampling of designated areas, Sec. 70.208(h)
regarding quarterly sampling of MMUs, Sec. 71.206(k) regarding
quarterly sampling, and Sec. 90.207(f) regarding quarterly sampling.
Final paragraph (g) is similar to proposed Sec. 70.209(f) and
contains nonsubstantive and organizational changes from the proposal.
It provides that a citation for a violation of the standard will be
terminated when: (1) Each of the five valid representative samples is
at or below the standard; and (2) the operator has submitted to the
District Manager revised dust control parameters as a part of the mine
ventilation plan for the DA in the citation and the changes have been
approved by the District Manager. It further requires that the revised
parameters must reflect the control measures used by the operator to
abate the violation. Comments on proposed Sec. 70.209(f) are the same
or similar to those on proposed Sec. 70.207(h). The comments and the
rationale for final paragraphs (g)(1) and (2) are discussed elsewhere
in this preamble under Sec. 70.206(i).
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraphs (g)(1) and (2)
are the same as final Sec. Sec. 70.206(i)(1) and (2), 70.207(h)(1) and
(2), and 70.208(i)(1) and (2).
Proposed Sec. 70.209(h) would have provided that MSHA approval of
the operator's ventilation system and methane and dust control plan may
be revoked based on samples taken by MSHA or in accordance with this
part 70. Proposed Sec. 70.209(h) is moved to final Sec. 70.201(k)
because it applies to all underground sampling entities and not just
DAs. Comments on proposed Sec. 70.209(h) are discussed under final
Sec. 70.201(k) of this preamble.
13. Section 70.210 Respirable Dust Samples; Transmission by Operator
Final Sec. 70.210(a) is substantially similar to the proposal. It
requires the operator, if using a CMDPSU, to transmit within 24 hours
after the end of the sampling shift all samples collected, including
control filters, in containers provided by the manufacturer of the
filter cassette to MSHA's Pittsburgh Respirable Dust Processing
Laboratory, or to any other address designated by the District Manager.
Final paragraph (a) clarifies that operators must include the control
filters with the dust sample transmissions to the Respirable Dust
Processing Laboratory. As explained in the preamble to the proposed
rule, MSHA uses control filters to improve measurement accuracy by
eliminating the effect of differences in pre- and post-exposure
laboratory conditions, or changes introduced during storage and
handling of the filter cassettes. Including control filters with the
dust samples ensures that the appropriate control filter is associated
with the appropriate sample filter.
One commenter opposed the proposed 24-hour transmission time frame.
The commenter stated that the post office might not be open if the end
of the sampling shift is on a Saturday or the day before a federal
holiday.
The 24-hour transmission time frame is not a new requirement. It
has been required under existing Sec. 70.209(a) since 1980. MSHA
considers samples to be ``transmitted'' as long as they have been
deposited into a secure mail receptacle provided by the U.S. Postal
Service or other mail provider, such as FedEx. MSHA received no
comments indicating that operators have encountered problems with the
24-hour transmission time frame.
Final Sec. 70.210(b), like the proposal, is the same as existing
Sec. 70.209(b).
Final Sec. 70.210(c), is substantially similar to the proposal. It
requires that a person certified in sampling must properly complete the
dust data card that is provided by the manufacturer for each filter
cassette. It further requires that the dust data card must have an
identification number identical to that on the filter cassette used to
take the sample and be submitted to MSHA with the sample. It also
requires that each dust data card must be signed by the certified
person who actually performed the examinations during the sampling
shift and must include that person's MSHA Individual Identification
Number (MIIN).
As an example, the certified person who performs the required
examinations during the sampling shift is the individual responsible
for signing the dust data card and verifying the proper flowrate, or
noting on the back of the card that the proper flowrate was not
maintained. Since the certified person who conducted the examination is
most knowledgeable of the conditions surrounding the examination, final
paragraph (c) requires that certified
[[Page 24913]]
person sign the dust data card. In addition, the MIIN number
requirement is consistent with MSHA's existing policy. Since July 1,
2008, MSHA has required that the certified person section of the dust
data card include the MIIN, a unique identifier for the certified
person, instead of the person's social security number. To ensure
privacy and to comport with Federal requirements related to
safeguarding personally identifiable information, MSHA has eliminated
requirements to provide a social security number.
Finally, paragraph (c) provides that respirable dust samples with
data cards not properly completed may be voided by MSHA. This is a
change from the proposal. The proposal would have required that,
regardless of how small the error, an improperly completed dust data
card must be voided by MSHA. Final paragraph (c) allows MSHA
flexibility in voiding an improperly completed dust data card. MSHA
received no comments on this proposed provision.
Final Sec. 70.210(d) and (e) are the same as the proposal, and are
the same as existing Sec. 70.209(d) and (e).
Final Sec. 70.210(f) is changed from the proposal. It requires
that, if using a CPDM, the person certified in sampling must validate,
certify, and transmit electronically to MSHA within 24 hours after the
end of the sampling shift all sample data file information collected
and stored in the CPDM, including the sampling status conditions
encountered when sampling; and, not tamper with the CPDM or its
components in any way before, during, or after it is used to fulfill
the requirements of 30 CFR part 70, or alter any sample data files. It
further requires that all CPDM data files transmitted electronically to
MSHA must be maintained by the operator for a minimum of 12 months.
Final paragraph (f) includes the term ``person certified in
sampling'' rather than ``designated mine official.'' This change makes
paragraph (f) consistent with final paragraph (c). Final paragraph (f)
also includes a clarification that CPDM data files are
``electronically'' transmitted to MSHA, unlike the physical
transmission of samples collected with the CMDPSU.
MSHA received a number of comments on the data file transmission
time frame included in proposed paragraph (f), which would have
required the designated mine official to validate, certify and
electronically transmit to MSHA, within 12 hours after the end of the
last sampling shift of the work week, all daily sample and error data
file information collected during the previous calendar week (Sunday
through Saturday) and stored in the CPDM. Some commenters stated that
validating, certifying, and transmitting sampling data electronically
to MSHA, if using a CPDM, within 12 hours after the end of the last
shift of the work week was too short a time frame. Another commenter
was concerned that the 12-hour time limit after the end of the last
shift sampled would impose unnecessary additional work hours on persons
responsible for dust sampling activities since weekend work would be
required almost every week. This commenter also stated that the 12-hour
time frame was inconsistent with the 24-hour time frame allowed for the
transmission of samples taken with a CMDPSU and noted that sampling
data would still be timely and relevant if it were transmitted within
70 hours of collection.
MSHA evaluated the comments and concludes that a more appropriate
transmission time frame would be within 24 hours after the end of each
sampling shift. This 24-hour time frame is consistent with the existing
sample data transmission requirement in existing Sec. 70.209(a). It is
also consistent with the requirement in final Sec. 70.210(a) that
operators transmit CMDPSU sampling data within 24-hours of the end of
the sampling shift. Regardless of whether dust samples are collected
with a CMDPSU or a CPDM, the person certified in sampling must complete
the tasks associated with readying the collected samples for
transmission to MSHA within the 24-hour time frame after completion of
sampling. Transmitting the CPDM data in this time frame allows MSHA to
assess compliance with the standard in a timely manner. Additionally,
the commenter's suggestion for a 70-hour transmission time frame would
be too long because it could hinder timely corrective actions.
As a clarification to the proposal, final paragraph (f) does not
require error data file information to be transmitted to MSHA. Rather,
final paragraph (f) requires ``the sampling status conditions
encountered when sampling'' to be transmitted to MSHA. This terminology
clarifies that changes in conditions that may occur during the sampling
shift (e.g., flowrate, temperature, humidity, tilt indicator, etc.)
that are different from the CPDM's set parameters and that may affect
sampling results must be recorded and transmitted to MSHA.
The requirement in final paragraph (f) that the certified person
not tamper with the CPDM or alter any CPDM data files is new. It is
consistent with the requirements for CMDPSUs, under existing Sec.
70.209(b) and final Sec. 70.210(b), which provide that an operator not
open or tamper with the seal of any filter cassette, or alter the
weight of any filter cassette before or after it is used to fulfill the
requirements of 30 CFR part 70. It is also consistent with the
requirement in 30 CFR 74.7(m) that a CPDM be designed to be tamper-
resistant or equipped with an indicator that shows whether the
measuring or reporting functions of the device have been tampered with
or altered. This provision protects miners' health and ensures the
integrity of MSHA's dust sampling program. Therefore, a similar
requirement is included for samples taken with a CPDM.
14. Section 70.211 Respirable Dust Samples; Report to Operator; Posting
Final Sec. 70.211(a) is substantially similar to the proposal. It
states that MSHA must provide the operator, as soon as practicable, a
report with the data specified in paragraphs (a)(1)-(a)(6) on
respirable dust samples submitted or whose results were transmitted
electronically, if using a CPDM. Final paragraph (a) includes the term
as soon as practicable to clarify that, although MSHA intends to
provide an operator a timely report, there may be instances when
unexpected delays occur. Final paragraph (a) also includes language to
clarify that an MSHA report will be provided to an operator whose
sampling results were transmitted electronically to the Agency, if
using a CPDM. The proposal stated that MSHA would provide the operator
with a report on respirable dust samples submitted in accordance with
this part. Final paragraph (a) clarifies that samples submitted in
accordance with this part not only include samples collected by the
CMDPSU, but also include sampling results collected by the CPDM and
transmitted electronically to MSHA. MSHA received no comments on the
proposed provision.
Final paragraphs (a)(1), (2), (5) and (6) are the same as the
proposal: (a)(1) The mine identification number; (a)(2) the locations
within the mine from which the samples were taken; (a)(5) the
occupation code, where applicable; and (a)(6) the reason for voiding
any sample.
Final paragraphs (a)(3) and (4) include a clarifying change from
the proposal: (a)(3) The concentration of respirable dust expressed as
an equivalent concentration for each valid sample; and (a)(4) the
average equivalent concentration of respirable dust for all valid
samples. Paragraphs (a)(3) and (a)(4) clarify the proposal by not using
the term in milligrams per cubic meter of air (mg/m\3\). This
clarification conforms to the definition of equivalent
[[Page 24914]]
concentration, which is discussed elsewhere in the preamble under final
Sec. 70.2. MSHA received no comments on proposed paragraphs (a)(1)-
(a)(6).
Final Sec. 70.211(b), like the proposal, requires the operator,
upon receipt of the MSHA report, to post the data contained in the
report on the mine bulletin board for at least 31 days. Final paragraph
(b) is the same as existing Sec. 70.210(b). Under the existing
requirement, operators have historically posted the entire MSHA report.
MSHA anticipates that operators will continue this practice.
One commenter indicated that the 31-day posting requirement allows
interested parties sufficient opportunity to review the data. The
commenter suggested that data on the DOs that are sampled, as well as
the associated sampling results, should also be required to be posted.
The commenter stated that such information would reveal which DOs are
exposed to the most dust, and the mine's compliance record, and allow
interested parties to use the information for such purposes as bidding
on jobs.
Final paragraph (b) requires posting of the occupation code and the
dust concentration for each valid sample as suggested by the commenter
because these data are included in the report that MSHA provides to the
operator. Accordingly, final paragraph (b) is the same as the proposal.
Final paragraph (c) is similar to the proposal. It provides that if
using a CPDM, the person certified in sampling must, within 12 hours
after the end of each sampling shift, print, sign, and post on the mine
bulletin board a paper record (Dust Data Card) of the sample run. It
further requires that this hard-copy record must include the data
entered when the sample run was first programmed, and the following
information: (1) The mine identification number; (2) the locations
within the mine from which the samples were taken; (3) the
concentration of respirable dust, expressed as an equivalent
concentration reported and stored for each sample; (4) the sampling
status conditions encountered for each sample; and (5) the shift
length.
Final paragraph (c) does not include the term designated mine
official because the final rule does not include the proposed CPDM
Performance Plan section that would have required operators to
designate a mine official to perform CPDM-related activities. Instead,
the final rule requires that the CPDM-related duties under this section
be performed by persons certified in sampling. Persons certified in
sampling using a CPDM will be familiar with the operation of the CPDM
and thus, require the least amount of time to perform these tasks. The
certified person will need to perform the tasks for the mine's records
of sampling performed. This, in conjunction with the revised sampling
frequency contained in this final rule, makes it unnecessary to have a
mine official perform these activities. The certified person can ensure
the proper officials are aware of specific monitoring results that may
require attention.
Final paragraph (c) also does not include the proposed requirement
that would have required posting end-of-shift sampling results within 1
hour of the end of the shift. During the comment period, MSHA
specifically requested comment on the proposed requirement for posting
information on sampling results and miners' exposures on the mine
bulletin board. Several commenters expressed concern that it was
unrealistic to post end-of-shift sampling results within 1 hour of the
end of the shift. One commenter pointed out that up to two hours may
elapse between an oncoming crew's entrance into the mine and the ending
shift's exit from the mine if the operator hot-seats the shift change.
This commenter stated that this two-hour time span would require the
hiring of additional health technicians to be able to post the samples
within 1 hour. Another commenter stated it was too burdensome to
require posting within 1 hour. Another commenter saw no value in
requiring sampling results to be posted within an hour of the end of
the shift because the CPDM-wearer would have left the mine by the time
the results were posted, and therefore would not know the results until
the next scheduled shift; also miners on the oncoming shift would
already be in the mine before the data were posted.
After reviewing the comments, MSHA determined that posting within 1
hour of the end of the shift was not necessary and requiring an
operator to post the results from each sampling shift within 12 hours
after the end of the sampling shift adequately protects miners. Posting
the results from each sampling shift within 12 hours ensures that
miners and their representatives are informed of the results in a
timely manner. The 12-hour time frame is sufficient to have the results
from the monitored shifts available for review prior to the miners
returning to the same shift worked the next calendar day.
Final paragraph (c) clarifies that a paper record (Dust Data Card
that is programmed in the CPDM) of the sample run must be printed,
signed, and posted. The paper record provides information for miners to
review until the operator receives and posts the MSHA report referenced
in final paragraph (a).
Proposed Sec. 70.211(c) would have required certain sampling
information to be posted. However, it did not provide the means by
which the information was to be posted.
One commenter recommended that sampling results be offered
personally, including the option of having the results mailed to the
miner who wore the CPDM during the sampling shift. In response to this
comment, MSHA emphasizes that the final rule continues the Agency's
occupational and area sampling program. Because sampling under the
final rule is not personal, the data collected is intended to benefit
all miners who work in the area of the sample location, not just the
miner who wore the CPDM. Accordingly, the final rule does not adopt
this recommendation.
Final paragraph (c) does not include provisions that were in:
Proposed (c)(1)(iv), which would have required posting the total amount
of exposure accumulated by the sampled occupation during the shift;
proposed (c)(1)(v), which would have required posting the monitored
occupation code, where applicable; and proposed (c)(1)(vi), which would
have required posting the reasons for voiding any sample. These
proposed provisions are not included in the final rule because the
information will be included on the paper record (Dust Data Card) which
is posted for each sample run when samples are collected using a CPDM.
MSHA did not receive comments on proposed (c)(1)(i)-(c)(1)(vii).
Proposed paragraph (c)(1)(viii), which would have required posting
any other information required by the District Manager, is not included
in the final rule. One commenter did not support proposed (c)(1)(viii)
which would have allowed the District Manager to require posting of
additional information. MSHA determined that allowing the District
Manager to require posting of additional information is unnecessary
since all relevant information will be available on the paper record
(Dust Data Card).
Final paragraph (c)(3) uses the term equivalent concentration
instead of equivalent concentration in milligrams per cubic meter of
air. This clarification conforms to the definition in Sec. 70.2 and
its use in other sections of the final rule. Final paragraph (c)(3)
also includes a clarification that, when using a CPDM, the
concentration of respirable dust that must be documented in the record
is the concentration which is ``reported and
[[Page 24915]]
stored for'' each sample. The addition of the phrase ``reported and
stored for'' emphasizes that the dust concentration is reported by and
stored in the CPDM's memory, allowing the paper record (Dust Data Card)
which is part of the CPDM's internal programming, to be printed and
posted, as required.
Final paragraph (c)(4) is new and requires the paper record to
include the sampling status conditions encountered for each sample. The
proposal would have required the reason for voiding any sample to be
posted. The proposed posting requirement corresponded to the sampling
information that the operator would have been required to submit to
MSHA under proposed Sec. 70.210(f). Proposed Sec. 70.210(f) would
have required an operator to transmit error data file information to
MSHA. Error data file information referred to the information that was
provided by the CPDM as error codes. Essentially, the error codes were
an indication that the sampling conditions changed from the CPDM's set
parameters. For example, changes in the degree of tilt, heater
temperature, pump flowrate, mine temperature, or pump back pressure,
that were outside of the unit's set parameters, resulted in error
codes. While some of these error codes or changes in sampling
conditions could have resulted in a sample being voided by MSHA, it was
not necessarily an indication of a void sample. Technically, under the
proposal, an operator would not have been able to post the reason for
voiding any sample since only MSHA may void samples. However,
commenters had the misunderstanding that error codes always indicated a
void or unusable sample. Essentially, the commenters understood that
MSHA was referring to the error codes as the reason for voiding any
sample and noted as such in their comments that many CPDM samples would
be voided due to the presence of error codes.
During the rulemaking, the CPDM manufacturer, after discussion with
NIOSH, changed the reference in the approved CPDM product literature
from error codes to status conditions. The status conditions that occur
during sampling, like the error codes, are only indicated by the CPDM
when the sampling conditions changed from the CPDM's set parameters.
This terminology change by the CPDM manufacturer addressed mine
operators' misunderstanding that the error codes were always an
indication of a void or unusable sample. Consistent with this change by
the CPDM manufacturer, and as discussed previously under final Sec.
70.210(f), operators must transmit to MSHA the sampling status
conditions rather than the proposed error codes. In addition, to
correspond with the sampling status conditions that are transmitted in
accordance with final Sec. 70.210(f), final paragraph (c)(4) requires
an operator to post the sampling status conditions rather than post the
reason for voiding any sample. MSHA's evaluation of the sample record,
including the sampling status conditions, will determine which samples,
if any, may be voided. Final paragraph (c)(4) accurately reflects
MSHA's intent that posting of the sampling information was designed to
provide miners with timely sampling and exposure information. Providing
miners the sampling status conditions allows miners to determine if the
sample reported accurately represents the conditions under which that
particular sample was collected, thereby increasing their confidence in
the operators' monitoring program.
Proposed paragraph (c)(2) is not included in the final rule. It
would have required posting the weekly accumulated exposure (WAE) and
the weekly permissible accumulated exposure (WPAE) for each occupation
sampled in an MMU at the end of the last sampling shift of the work
week, within 2 hours. Posting the WAE and WPAE would have provided
miners with the total amount of coal mine dust accumulated during the
work week, as well as the maximum amount of accumulated exposure to
coal mine dust permitted to be received during a normal work week. One
commenter stated that posting within 2 hours is too restrictive and
recommended posting at least 1 hour before the start of the next
sampling shift. As noted elsewhere in this preamble under final Sec.
70.2, the final rule does not contain any requirements associated with
the WAE and WPAE.
Final Sec. 70.211(d) is redesignated and changed from proposed
Sec. 70.211(c)(3). It provides that the information required by
paragraph (c) of this section must remain posted until receipt of the
MSHA report covering the respirable dust samples. Under the proposal,
the information required by paragraph (c) would have been required to
be posted for at least 15 calendar days. The final rule's requirement
to post the information until the MSHA report is received ensures that
sampling information is available for the entire interim period between
the time the CPDM sampling results are electronically transmitted to
MSHA and the time that the operator receives the MSHA report, which
could exceed the proposed 15 calendar days. As discussed earlier, MSHA
anticipates that most reports will be received by the operator in a
timely manner, however, there may be occurrences where the MSHA report
is unexpectedly delayed. If there were a delay in providing the report
to the operator, the Agency wants to ensure that miners and their
representatives continue to have relevant, timely sampling data until
MSHA's consolidated report is available and posted. MSHA did not
receive any comments on this provision.
15. Section 70.212 Status Change Reports
Final Sec. 70.212 is derived from existing Sec. 70.220. Like
proposed Sec. 70.212, it addresses status change reports. One
commenter expressed general support for the proposal. Other commenters
stated that the proposal was unnecessary because operators are required
to notify MSHA of mine status changes under existing Sec. 41.12.
Sections 70.212 and 41.12 are not duplicative. Section 41.12
requires only that operators notify the Agency of changes to the legal
identity of the operator, but contains no requirement that operators
report changes that affect their respirable dust sampling obligations.
Section 70.212 serves a different purpose than Sec. 41.12 and is
included in the final rule.
Final Sec. 70.212, like the proposal, requires an operator to
report any change in operational status of the mine, mechanized mining
unit, or designated area that affects the respirable dust sampling
requirements of part 70 to the MSHA District Office or to any other
MSHA office designated by the District Manager. It further requires
that an operator must report the status changes in writing or
electronically within 3 working days after the status change has
occurred.
One commenter objected to the provision in proposed paragraph (a)
that permits the District Manager to designate an MSHA office other
than the District Office to which status change reports must be made.
The commenter stated that allowing District Managers to designate an
alternate office could lead to miscommunications that result in
reporting errors. In response, MSHA notes that proposed and final
paragraphs (a) are consistent with existing Sec. 70.220(a), which
contains an same requirement. MSHA received no information from
commenters that reporting errors have occurred and the Agency is
otherwise unaware of any reporting errors due to the provision. Also,
MSHA received no comment on the proposal to permit electronic
submissions of status change reports.
[[Page 24916]]
Final Sec. 70.212(b), like the proposal, defines each specific
operational status. MSHA received no comments on proposed paragraph (b)
and it is finalized as proposed.
Proposed Sec. 70.212(c) is not included in the final rule. It
would have required the designated mine official to report status
changes that affect the operational readiness of any CPDM within 24
hours after the status change had occurred. One commenter was concerned
with the recordkeeping burden associated with proposed Sec. 70.212(c).
Under the proposed rule, because operators were required to sample DOs
in each MMU during every production shift, it was particularly
important for MSHA to remain informed of circumstances affecting the
operational readiness or availability of an operator's CPDMs needed for
sampling. Examples of status changes affecting operational readiness of
a CPDM included a malfunction or breakdown of a CPDM or failure to have
a spare CPDM available for required sampling. However, the sampling
requirement for each DO in each MMU in final Sec. 70.208 requires
sampling each calendar quarter on consecutive normal production shifts
until 15 valid representative samples are taken, rather than the
proposed requirement to sample every shift. Given that the operator is
permitted to collect the required 15 consecutive samples at any time
during the calendar quarter, the rationale for the proposal, to inform
MSHA of circumstances that affect the operational readiness of the
CPDM, no longer applies. Under final Sec. 70.204, the certified person
will perform the necessary examination, testing and set-up procedures,
and external maintenance to ensure the operational readiness of the
CPDM before the sampling shift on which it will be used.
B. 30 CFR Part 71--Mandatory Health Standards--Surface Coal Mines and
Surface Work Areas of Underground Coal Mines
1. Section 71.1 Scope
Final Sec. 71.1, like the proposal, states that part 71 sets forth
mandatory health standards for each surface coal mine and for the
surface work areas of each underground coal mine subject to the Federal
Mine Safety and Health Act of 1977, as amended.
2. Section 71.2 Definitions
Act
The final rule, like the proposal, defines Act as the Federal Mine
Safety and Health Act of 1977, Public Law 91-173, as amended by Public
Law 95-164 and Public Law 109-236.
Active Workings
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of active workings.
Approved Sampling Device
The final rule, like the proposal, is the same as the final part 70
definition discussed elsewhere in the preamble related to final Sec.
70.2.
Certified Person
Final Sec. 71.2 makes nonsubstantive changes to the existing
definition of certified person. It does not include the parenthetical
text following the references to Sec. Sec. 71.202 and 71.203.
Coal Mine Dust Personal Sampler Unit (CMDPSU)
The final rule, like the proposal, is the same as the final part 70
definition discussed elsewhere in the preamble related to final Sec.
70.2.
Concentration
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of concentration.
Continuous Personal Dust Monitor (CPDM)
The final rule, like the proposal, is the same as the final part 70
definition discussed elsewhere in the preamble related to final Sec.
70.2.
Designated Work Position (DWP)
Final Sec. 71.2 is similar to the proposal. It defines designated
work position (DWP) as a work position in a surface coal mine or
surface work area of an underground mine designated for sampling to
measure respirable dust generation sources in the active workings. Each
DWP will be assigned a four-digit number assigned by MSHA identifying
the specific physical portion of the mine that is affected, followed by
a three-digit MSHA coal mining occupation code describing the location
to which a miner is assigned in the performance of his or her regular
duties.
The final definition includes nonsubstantive changes to the
proposed definition and adds language in the first sentence to clarify
the purpose of DWP sampling, i.e., to measure respirable dust
generation sources in the active workings. MSHA received no comments on
the proposed definition.
District Manager
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of District Manager.
Equivalent Concentration
The final rule is changed from the proposal. It is changed
consistent with changes made to the final part 70 definition as
discussed elsewhere in the preamble related to final Sec. 70.2.
MRE Instrument
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of MRE instrument.
MSHA
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of MSHA.
Normal Work Shift
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of normal work shift.
Quartz
The final rule is changed from the proposal. It is changed
consistent with changes made to the final part 70 definition as
discussed elsewhere in the preamble related to final Sec. 70.2.
Representative Sample
The final rule is substantially similar to the proposal. It defines
representative sample as a respirable dust sample, expressed as an
equivalent concentration, that reflects typical dust concentration
levels in the working environment of the DWP performing normal duties.
The final definition is identical to the proposed definition except
that the language, ``expressed as an equivalent concentration'' is
added. The added text clarifies that each respirable dust sample
measurement must be converted to an equivalent concentration as defined
under this final Sec. 71.2.
MSHA received one comment on the proposed definition. The commenter
stated that there was no need to define representative samples and that
MSHA should modify its sampling methodology such that personal samples,
rather than occupational samples, are taken.
With respect to the commenter's recommendation that MSHA replace
the occupational sampling methodology with personal sampling, MSHA
addresses this comment elsewhere in the preamble under final Sec.
70.201. In addition, a definition for representative sample ensures
that respirable dust samples accurately reflect the amount of dust to
which miners are exposed, i.e., the dust concentration levels in the
working environment of the DWP performing normal work duties. Without a
definition, operators could sample miners at times when they
[[Page 24917]]
perform work duties that under-represent, or bias, miners' dust
exposures. Thus, samples could under-represent, or bias, miners' dust
exposure. Therefore, under the final rule, respirable dust samples must
be taken while the DWP is engaged in normal work duties. The final
definition of representative samples will provide protection for
miners' health by allowing MSHA to objectively evaluate the functioning
of operators' dust controls and the adequacy of operators' approved
plans.
Respirable Dust
Final Sec. 71.2 makes nonsubstantive changes to the existing
definition of respirable dust. It is the same as the final part 70
definition discussed elsewhere in the preamble related to final Sec.
70.2.
Secretary
Final Sec. 71.2 makes nonsubstantive changes to the existing
definition of Secretary. It is the same as the final part 70 definition
discussed elsewhere in the preamble related to final Sec. 70.2.
Surface Area
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of surface area.
Surface Coal Mine
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of surface coal mine.
Surface Installation
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of surface installation.
Surface Work Area of an Underground Coal Mine
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of surface work area of an underground coal mine.
Surface Worksite
Final Sec. 71.2, like the proposal, makes no change to the
existing definition of surface worksite.
Valid Respirable Dust Sample
For clarification, the final rule revises the definition under
existing Sec. 71.2 for a valid respirable dust sample to mean a
respirable dust sample collected and submitted as required by this
part, including any sample for which the data were electronically
transmitted to MSHA, and not voided by MSHA.
The final definition adds language to clarify that for CPDM
samples, the data files are ``electronically'' transmitted to MSHA, and
not physically transmitted like samples collected with the CMDPSU. The
proposed rule did not include this clarification.
Work Position
Final Sec. 71.2, like the proposal, defines work position as an
occupation identified by an MSHA three-digit code describing a location
to which a miner is assigned in the performance of his or her normal
duties. The final definition ensures that MSHA can properly correlate
each dust sample with the work location, position, and shift from which
it was obtained. The definition is consistent with the Agency's
practice of identifying the specific position being sampled. MSHA did
not receive comments on the proposal.
3. Section 71.100 Respirable Dust Standard
Final Sec. 71.100(a) is changed from the proposal. It requires
that each operator continuously maintain the average concentration of
respirable dust in the mine atmosphere during each shift to which each
miner in the active workings of each mine is exposed, as measured with
an approved sampling device and expressed in terms of an equivalent
concentration, at or below: (1) 2.0 milligrams of respirable dust per
cubic meter of air (mg/m\3\) and (2) 1.5 mg/m\3\ as of August 1, 2016.
Final paragraph (a)(1) is the same as proposed paragraph (a)(1). It
retains the existing standard of 2.0 mg/m\3\ on the effective date of
this final rule. Final paragraph (a)(2) is renumbered from proposed
paragraph (a)(3) and changes the date on which the 1.5 mg/m\3\ standard
is effective from the proposed 12 months to 24 months after the
effective date of the final rule.
Unlike proposed paragraph (a)(2), the final rule does not the final
rule does not require that the standard be lowered to 1.7 mg/m\3\ 6
months after the effective date of the final rule, or to 1.0 mg/m\3\ 24
months after the effective date of the final rule.
MSHA received several comments on the proposed 1.0 mg/m\3\
standard. The comments were the same or similar to those on proposed
Sec. 70.100. Those comments, along with MSHA's rationale for final
paragraphs (a) and (b) are discussed elsewhere in this preamble under
Sec. 70.100.
4. Section 71.101 Respirable Dust Standard When Quartz Is Present
Final Sec. 71.101(a), like proposed Sec. 71.101(a), requires that
each operator must continuously maintain the average concentration of
respirable quartz dust in the mine atmosphere during each shift to
which each miner in the active working of each mine is exposed at or
below 0.1 mg/m\3\ (100 micrograms per cubic meter of air or [mu]g/m\3\)
as measured with an approved sampling device and expressed in terms of
an equivalent concentration.
Final Sec. 71.101(b), like proposed Sec. 71.101(b), requires that
when the equivalent concentration of respirable quartz dust exceeds 100
[mu]g/m\3\, the operator must continuously maintain the average
concentration of respirable dust in the mine atmosphere during each
shift to which each miner in the active workings is exposed as measured
with an approved sampling device and in terms of an equivalent
concentration at or below the applicable respirable dust standard. It
also states that the applicable dust standard is computed by dividing
the percent of quartz into the number 10. It further requires that the
application of this formula must not result in an applicable dust
standard that exceeds the standard established by Sec. 71.100(a).
Final paragraphs (a) and (b) are consistent with existing Sec.
71.101. The existing standard protects miners from exposure to
respirable quartz by requiring a reduced respirable dust standard when
the respirable dust in the mine atmosphere of the active workings
contains more than 5 percent quartz. The existing standard is based on
a formula that was prescribed by the Department of Health, Education
and Welfare (now DHHS). The formula, which applies when a respirable
coal mine dust sample contains more than 5.0 percent quartz, is
computed by dividing 10 by the concentration of quartz, expressed as a
percentage. The formula results in a continuous reduction in the
respirable dust standard as the quartz content of the respirable dust
increases over 5 percent (i.e., the higher the percentage of quartz,
the lower the reduced respirable dust standard). The standard in final
paragraph (a) is derived from the existing formula which was designed
to limit a miner's exposure to respirable quartz to 0.1 mg/m\3\ (100
[mu]g/m\3\-MRE), based on the existing 2.0 mg/m\3\ respirable dust
standard.
MSHA received several comments on the proposed Sec. 71.101. The
comments were the same or similar to those on proposed Sec. 70.101.
Those comments, along with MSHA's rationale for final paragraphs (a)
and (b) are discussed elsewhere in this preamble under Sec. 70.101.
The feasibility of Sec. 71.101 is discussed elsewhere in this preamble
under Section III.C.
[[Page 24918]]
5. Section 71.201 Sampling; General And Technical Requirements
Final Sec. 71.201, like the proposal, addresses general and
technical sampling requirements concerning operator sampling. One
commenter stated that operator sampling is not credible and that MSHA
should be responsible for all compliance sampling. This comment is
addressed elsewhere in this preamble under Sec. 70.201.
Final paragraph (a) is changed from the proposal. It requires that
each operator take representative samples of the concentration of
respirable dust in the active workings of the mine as required by this
part with an approved CMDPSU. On February 1, 2016, the operator may use
an approved CPDM if the operator notifies the District Manager in
writing that an approved CPDM will be used for all DWP sampling at the
mine. The notification must be received at least 90 days before the
beginning of the quarter in which CPDMs will be used to collect the DWP
samples. The term representative samples is defined in final Sec.
71.2. The proposal would have required that each operator take
representative samples of the concentration of respirable dust in the
active workings of the mine as required by this part.
The final rule clarifies that the operator may use one type of
approved sampling device while conducting DWP sampling. If operators
will be conducting DWP sampling using the CPDM rather than the CMDPSU,
the operators must notify MSHA of their intent to do so. This
clarification ensures that operators do not switch between sampling
devices on successive quarterly sampling periods, or use both sampling
devices during the same sampling period. The 90-day notification period
allows MSHA sufficient time to modify MSHA's health computer system to
accept CPDM electronic records for all DWPs located at the mine.
Some commenters stated that only the miner needs to be sampled to
get a miner's exposure. This comment is addressed elsewhere in this
preamble under Sec. 70.201(c).
Final paragraph (b), like the proposal, requires that sampling
devices be worn or carried directly to and from the DWP to be sampled.
Paragraph (b) also requires that sampling devices remain with the DWP
and be operational during the entire shift, which includes the total
time spent in the DWP and while traveling to and from the DWP being
sampled. It further requires that if the work shift to be sampled is
longer than 12 hours and the sampling device is a CMDPSU, the operator
must switch-out the unit's sampling pump prior to the 13th-hour of
operation; and, if the sampling device is a CPDM, the operator must
switch-out the CPDM with a fully charged device prior to the 13th-hour
of operation. Paragraph (b), which applies to DWPs, is consistent with
final Sec. 70.201(c), which applies to MMUs and DAs. The rationale for
paragraph (b) is the same as that for, and is discussed under, final
Sec. 70.201(c) of this preamble. Paragraph (b) is unchanged from the
proposal.
Final paragraph (c), like the proposal, requires that if using a
CMDPSU, one control filter must be used for each shift of sampling. It
further requires that each control filter must: (1) Have the same pre-
weight data (noted on the dust data card) as the filters used for
sampling; (2) remain plugged at all times; (3) be used for the same
amount of time, and exposed to the same temperature and handling
conditions as the filters used for sampling; and, (4) be kept with the
exposed samples after sampling and in the same mailing container when
transmitted to MSHA. MSHA received no comments on the proposal.
Final paragraph (c)(4) is changed from the proposal to clarify that
the control filter must be in the same mailing container as the exposed
samples when transmitted to MSHA. Paragraphs (c)(1)-(4) are identical
to final Sec. 70.201(d)(1)-(4). The rationale for paragraphs (c)(1)-
(4) is discussed under final Sec. 70.201(d)(1)-(4) of this preamble.
Final paragraph (d), like the proposal, requires that records
showing the length of each normal work shift for each DWP be made and
retained for at least six months and be made available for inspection
by authorized representatives of the Secretary and the representative
of miners and submitted to the District Manager when requested in
writing. Paragraph (d) is similar to final Sec. 70.201(e).
One commenter stated that production shift records are unnecessary
and excessively burdensome. This comment and the rationale for
paragraph (d) are discussed under final Sec. 70.201(e) of this
preamble. Paragraph (d) is unchanged from the proposal.
Final paragraph (e), like the proposal, requires that upon request
from the District Manager, the operator must submit the date and time
any respirable dust sampling required by this part will begin. It
further requires that this information must be submitted at least 48
hours prior to scheduled sampling. Paragraph (e) is identical to final
Sec. 70.201(f).
One commenter stated that the requirement creates an excessive
burden on MSHA. This comment and the rationale for paragraph (e) are
discussed under final Sec. 70.201(f) of this preamble. Paragraph (e)
is unchanged from the proposal.
Final paragraph (f), like the proposal, requires that upon written
request by the operator, the District Manager may waive the rain
restriction for a normal work shift as defined in Sec. 71.2 for a
period not to exceed two months, if the District Manager determines
that: (1) The operator will not have reasonable opportunity to complete
the respirable dust sampling required by this part without the waiver
because of the frequency of rain; and, (2) the operator did not have
reasonable opportunity to complete the respirable dust sampling
required by this part prior to requesting the waiver. Paragraph (f) is
identical to the existing requirements. MSHA received no comments on
the proposal. Paragraph (f) is unchanged from the proposal.
Final paragraph (g) is substantially the same as the proposal. It
requires that operators using CPDMs must provide training to all miners
expected to wear the CPDM. It makes a nonsubstantive change that the
training must be completed prior to a miner wearing the CPDM, as
opposed to prior to a miner ``being required to wear the CPDM,'' and
then every 12 months thereafter.
Final paragraphs (g)(1)-(4) are similar to proposed paragraphs
(g)(1)-(5). Proposed paragraph (g)(2) would have required miners to be
instructed on how to set up the CPDM for compliance sampling. One
commenter stated this was unnecessary and was concerned that it could
lead to persons who are not certified performing functions that require
certification to perform. In response, the final rule requires mine
operators to have certified persons set up the CPDM for compliance.
Therefore, training all miners on how to set up the CPDM for compliance
sampling is not necessary. Accordingly, the final rule does not include
this proposed provision.
Paragraph (g)(1) is similar to proposed (g)(5). Like the proposal,
it requires that the training include the importance of monitoring dust
concentrations and properly wearing the CPDM. Paragraph (g)(1) makes a
conforming change. The proposal would have required training on the
importance of ``continuously'' monitoring dust concentrations. Since
continuous monitoring is not required by the final rule, the term
``continuously'' is not included in paragraph (g)(1).
[[Page 24919]]
Final paragraph (g)(2) is the same as proposed (g)(1). It requires
that the training include explaining the basic features and
capabilities of the CPDM.
Final paragraph (g)(3), like the proposal, requires that the
training include discussing the various types of information displayed
by the CPDM and how to access that information.
Final paragraph (g)(4), like the proposal, requires that the
training include how to start and stop a short-term sample run during
compliance sampling.
The training requirements of paragraphs (g)(1)(4) are identical to
the training requirements of final Sec. 70.201(h)(1)(4). One commenter
stated that the training requirements create an excessive burden on
mine operators. This comment and the rationale for paragraphs (g)(1)-
(4) are discussed under final Sec. 70.201(h)(1)-(4) of this preamble.
Final paragraph (h), like the proposal, requires that an operator
keep a record of the CPDM training at the mine site for 24 months after
completion of the training. It also provides that an operator may keep
the record elsewhere if the record is immediately accessible from the
mine site by electronic transmission. It further requires that upon
request from an authorized representative of the Secretary, Secretary
of HHS, or representative of miners, the operator must promptly provide
access to any such training records. Final paragraphs (h)(1)-(3)
require the record to include the date of training, the names of miners
trained, and the subjects included in the training.
Paragraph (h) makes a non-substantive change by replacing the
proposed term ``2 years'' with ``24 months.''
Final paragraphs (h)(1)-(3) are new and clarify that the record
must contain sufficient information for an authorized representative of
the Secretary, Secretary of HHS, or miners' representative to determine
that the operator has provided CPDM training in accordance with
requirements in paragraph (g). Like final Sec. 70.201(i), this is the
type of information that is generally required for all training records
to establish that the training has occurred.
The record requirements of paragraph (h) are identical to final
Sec. 70.201(i). One commenter stated that the proposed recordkeeping
requirement is too burdensome. This comment and the rationale for
paragraph (h) are discussed elsewhere in this preamble under final
Sec. 70.201(i).
6. Sections 71.202 Certified Person; Sampling and 71.203 Certified
Person; Maintenance and Calibration
Final Sec. Sec. 71.202 and 71.203 are identical to final
Sec. Sec. 70.202 and 70.203. Comments on proposed Sec. Sec. 71.202
and 71.203 were the same as comments on proposed Sec. Sec. 70.202 and
70.203. The comments and MSHA's rationale are discussed elsewhere in
this preamble under Sec. Sec. 70.202 and 70.203.
7. Section 71.204 Approved Sampling Devices; Maintenance and
Calibration
Final Sec. 71.204 is identical to final Sec. 70.204. Comments on
proposed Sec. 71.204 were similar to comments on proposed Sec.
70.204. Comments on proposed Sec. 71.204 and MSHA's rationale are
discussed elsewhere in this preamble under final Sec. 70.204.
8. Section 71.205 Approved Sampling Devices; Maintenance and
Calibration
Final Sec. 71.205 is identical to final Sec. 70.205, except that
it does not exclude operators of certain anthracite mining operations
from performing the on-shift examination required by Sec.
71.205(b)(1). The rationale for not requiring the examination in
underground anthracite mines does not apply to surface coal mines and
surface work areas of underground coal mines subject to part 71
requirements. Comments on proposed Sec. 71.205 were similar to
comments on proposed Sec. 70.205. Comments and MSHA's rationale for
Sec. 71.205 are discussed elsewhere in this preamble under final Sec.
70.205.
9. Section 71.206 Quarterly Sampling
Final Sec. 71.206 is similar to proposed Sec. 71.207. The final
rule does not include requirements for a CPDM Performance Plan that
were proposed in Sec. 71.206. The proposed Plan was substantially
similar to the CPDM Performance Plan in proposed Sec. 70.206. Comments
on proposed Sec. 71.206 were the same or similar to those on proposed
Sec. 70.206. Comments and MSHA's rationale for not including the
proposal in the final rule are discussed elsewhere in this preamble
under Sec. 70.206.
Final Sec. 71.206 revises the existing requirements on bimonthly
sampling of designated work positions (DWP) under existing Sec.
71.208. The title of Sec. 71.206, ``Quarterly sampling,'' is changed
from the proposal's title, ``Sampling of designated work positions,''
to be consistent with the required quarterly sampling frequency.
Final paragraph (a) is like proposed Sec. 71.207(a) but contains
conforming changes. It requires that each operator must take one valid
representative sample from the DWP during each quarterly period. The
term ``valid representative sample'' is discussed elsewhere in this
preamble under Sec. 70.206. Paragraph (a) further provides that the
quarterly periods are: January 1-March 31; April 1-June 30; July 1-
September 30; and October 1-December 31.
One commenter stated that because strip mining is very dusty, the
proposal should not reduce sampling from bimonthly to quarterly.
Rather, oversight and sampling should increase.
The final rule, like the proposal, reduces the existing DWP
sampling frequency from bimonthly to quarterly. As discussed below in
final paragraph (c), the final rule requires operators to sample an
increased number of specific work positions as DWPs, which have
historically been associated with higher dust concentrations, at a
frequency to ensure that all miners in those positions are protected.
Final paragraph (b) is redesignated from and is similar to proposed
Sec. 71.207(h). Paragraph (b) clarifies the time frame for
implementation when there is a change in the standard. It requires that
when the respirable dust standard is changed in accordance with Sec.
71.101, the new standard will become effective 7 calendar days after
the date of the notification of the change by MSHA. Under proposed
Sec. 71.207(h), a new standard would have gone into effect on the
first normal work shift following the operator's receipt of
notification after the respirable dust standard is changed in
accordance with Sec. 71.101. MSHA received no comments on the
proposal.
Paragraph (b) is substantially similar to Sec. Sec. 70.206(c),
70.207(b), 70.208(c), 70.209(b), and 90.207(b), except for conforming
changes. The rationale for paragraph (b) is discussed elsewhere in this
preamble under Sec. 70.208(c). Final paragraph (b) does not include
the requirements in proposed Sec. 71.207(h)(1) and (2). Proposed Sec.
71.207(h)(1) would have required that if all samples for the DWP from
the most recent quarterly sampling period do not exceed the new
standard (reduced due to the presence of quartz), the operator would
begin sampling of the DWP on the first normal work shift during the
next quarterly period following notification from MSHA of the change in
the standard. Proposed Sec. 71.207(h)(2) would have required that if
any sample from the most recent quarterly sampling period exceeds the
new standard (reduced due to the presence of quartz), the operator must
make necessary adjustments to the dust control parameters within three
days, and then collect a sample from the affected DWP on a normal work
shift. It
[[Page 24920]]
further provided that the sample would be treated as a normal quarterly
sample. MSHA did not receive comments on the proposal.
Proposed Sec. 71.207(h)(1) and (2) is similar to proposed
Sec. Sec. 70.207(c)(1) and (2), and 70.209(b)(1) and (2). The
rationale for not including proposed Sec. 71.207(h)(1) and (2) in the
final rule is discussed elsewhere in this preamble under Sec.
70.206(c)(1) and (2).
Final paragraph (c) is redesignated from and is substantially
similar to proposed Sec. 71.207(b). Paragraph (c) requires that DWP
samples must be collected at locations to measure respirable dust
generation sources in the active workings. In addition, paragraph (c)
clarifies that the ``specific'' work positions at each mine where DWP
samples must be collected include: (1) Each highwall drill operator
(MSHA occupation code 384); (2) bulldozer operators (MSHA occupation
code 368); and (3) other work positions designated by the District
Manager for sampling in accordance with Sec. 71.206(m). Like the
proposal, the final rule requires each highwall drill operator to be
sampled since historical sampling data and MSHA experience indicate
that these positions have the greatest potential of being overexposed
to respirable quartz and respirable coal mine dust. Bulldozer operators
are DWPs since they have similar risks and need additional protection.
Under circumstances specified in final paragraph (d) concerning
multiple work positions, discussed below, some bulldozer operators
could be exempt from sampling requirements. Also, the District Manager
could designate other work positions for sampling in accordance with
final paragraph (c)(3), which is discussed below. Final paragraph (c)
will provide improved health protection for miners in work positions
that have increased risks of overexposure to respirable dust and
quartz.
MSHA received several comments on the proposal. One commenter
stated that the front end loader operator should be included as a DWP.
Another commenter stated that the proposal was too aggressive because
designating all high wall drill operators and bulldozer operators as
DWPs attempts to correct an overexposure problem that does not exist.
According to MSHA's historical sampling data and experience, high
wall drill operators and bulldozer operators, but not the front end
loader operator, are the work positions with the greatest potential for
overexposure to respirable dust and respirable dust when quartz is
present. However, the District Manager may designate the front end
loader operator for sampling in accordance with paragraph (m) of this
section discussed later in this section.
Final paragraph (d) is redesignated from and is the same as
proposed Sec. 71.207(c) except for conforming changes. It requires
that operators with multiple work positions specified in paragraphs
(c)(2) (bulldozer operators) and (c)(3) (other work positions) of this
section must sample the DWP exposed to the greatest respirable dust
concentration in each work position performing the same activity or
task at the same location at the mine and exposed to the same dust
generation source. It also requires each operator to provide the
District Manager with a list identifying the specific work positions
where DWP samples will be collected for: (1) Active mines--by October
1, 2014; (2) new mines--within 30 calendar days of mine opening; (3)
DWPs with a change in operational status that increases or reduces the
number of active DWPs--within 7 calendar days of the change in status.
The final rule takes into consideration the fact that some
bulldozer operator positions, or other work positions designated by the
District Manager, may have variable respirable dust exposure. Under
those circumstances, assuming the positions perform similar work, the
mine operator must sample only the DWP exposed to the greatest
respirable dust concentration. For example, if two bulldozer operators
push overburden at the same location, the operator must sample the
bulldozer operator exposed to the greatest concentration of respirable
dust to ensure that other miners performing similar tasks at the same
location are protected from excessive dust exposure. However, as
another example, if some bulldozer operators push overburden and others
perform reclamation work, the mine operator must sample one bulldozer
operator exposed to the greatest concentration of respirable dust
pushing overburden and one bulldozer operator exposed to the greatest
concentration of respirable dust performing reclamation work. A
respirable dust sample for the designated bulldozer operator performing
reclamation work does not constitute a representative sample of the
working environment for the bulldozer operators pushing overburden.
One commenter stated that the miner assigned to the DWP needed to
be sampled, not just the work position, to get the miner's dust
exposure. The final rule maintains the historical practice of sampling
the occupation of the DWP. This comment is addressed further elsewhere
in this preamble under Sec. 70.201(c).
Some commenters stated that requiring an operator to submit a list
identifying the specific work locations to the District Manager is too
burdensome.
Paragraph (d) ensures that the appropriate DWPs are identified for
sampling. In addition, the time given to operators to identify and
submit the list should reduce or eliminate any perceived burden. With
the addition of new DWP designations in this final rule, the quarterly
sampling requirements of DWPs provide significantly more sampling than
is required under the existing standards.
Final paragraph (e) is redesignated from and is substantially
similar to proposed Sec. 71.207(d). It states that each DWP sample
must be taken on a normal work shift. Final paragraph (e) requires that
if a normal work shift is not achieved, the respirable dust sample must
be transmitted to MSHA with a notation by the person certified in
sampling on the back of the dust data card stating that the sample was
not taken on a normal work shift. The term ``person certified in
sampling'' replaces the term ``certified person'' in the proposal.
Paragraph (e) further provides that when a normal work shift is not
achieved, the sample for that shift may be voided by MSHA. It also
specifies that MSHA will use any sample, regardless of whether a normal
work shift was achieved, that exceeds the standard by at least 0.1 mg/
m\3\, to determine the equivalent concentration for that occupation.
The text ``in the determination of the equivalent concentration for
that occupation'' replaces the term ``to determine compliance with this
part'' in the proposal.
Comments on proposed Sec. 71.207(d) are the same as comments on
proposed Sec. 70.207(d). The comments and MSHA's rationale are
discussed elsewhere in this preamble under Sec. 70.206(d).
Final paragraph (f) is redesignated from and is the same as
proposed Sec. 71.207(e). It requires that unless otherwise directed by
the District Manager, DWP samples must be taken by placing the sampling
device as follows: (1) Regarding an equipment operator, on the
equipment operator or on the equipment within 36 inches of the
operator's normal working position; (2) regarding a non-equipment
operator, on the miner assigned to the DWP or at a location that
represents the maximum concentration of dust to which the miner is
exposed.
Final paragraph (f) is the same as the existing standard except for
a
[[Page 24921]]
nonsubstantive change to replace ``designated work position'' with
``DWP.'' MSHA did not receive any comments on the proposal.
Final paragraph (g) is similar to proposed Sec. 71.207(m) and (n).
Like the proposal, it requires that upon notification from MSHA that
any valid representative sample taken from a DWP to meet the
requirements of paragraph (a) of this section exceeds the standard, the
operator must, within 15 calendar days of notification, sample that DWP
each normal work shift until five valid representative samples are
collected. It further requires that the operator must begin sampling on
the first normal work shift following receipt of notification.
Proposed Sec. 71.207(m) would have required five valid samples if
any sample taken with a CMDPSU exceeded the standard but was below the
applicable ECV in proposed Table 71-1. Proposed Sec. 71.207(n) would
have required five valid samples if any sample taken with a CPDM
exceeded the standard but was below the applicable ECV in proposed
Table 71-2. It would also have required the operator to review the
adequacy of the approved CPDM Performance Plan and submit any plan
revisions to the District Manager for approval within 7 calendar days
following posting of the end-of-shift equivalent concentration on the
mine bulletin board.
One commenter stated that any plan revisions should be provided to
the miners' representative.
Respirable dust control plans for DWPs that are submitted by the
operator for approval are required to include the corrective actions
taken to reduce the respirable dust concentrations to at or below the
standard. The requirements for the operator to submit these respirable
dust control plans is contained in Sec. 71.300. Section 71.300 also
includes a requirement that an operator must notify a representative of
the miners at least 5 days prior to submitting the plan for approval.
Final paragraph (g) is essentially the same as existing Sec.
71.208(d) except for nonsubstantive changes. The existing standard
requires that upon notification from MSHA that any respirable dust
sample taken from a DWP exceeds the dust standard, the operator must
take five samples from that DWP within 15 calendar days beginning on
the first normal work shift following notification.
Final paragraph (g), unlike proposed Sec. 71.207(m) and (n), does
not include a specific reference to either the CMDPSU or CPDM. Rather,
final paragraph (g) includes requirements for samples taken with any
approved sampling device. It also does not include the unnecessary
references in proposed (m) and (n) regarding a sample being below the
applicable ECV in proposed Tables 71-1 or 71-2. In addition, it does
not include the requirements in proposed Sec. 71.207(n) to review and
revise the CPDM Performance Plan. As discussed in this section and
elsewhere in this preamble under Sec. 70.206, the CPDM Performance
Plan is not included in the final rule.
Final paragraph (h) is similar to proposed Sec. 71.207(k). It
requires that when a valid representative sample taken in accordance
with this section meets or exceeds the ECV in Table 71-1 that
corresponds to the applicable standard and particular sampling device
used, the operator must take the actions listed in paragraphs (h)(1)
through (3). Unlike proposed Sec. 71.207(i), there is no violation
under final paragraph (i) if one operator full-shift sample exceeds the
ECV in Tables 71-1 or 71-2 that corresponds to the applicable standard
and particular sampling device used. Although the Secretary has
determined that a single full-shift measurement of respirable coal mine
dust accurately represents atmospheric conditions to which a miner is
exposed during such shift, MSHA has concluded that a noncompliance
determination based on a single full-shift sample will only be made on
MSHA inspector samples. With respect to operator samples, MSHA
reevaluated its enforcement strategy under the proposed rule. MSHA
determined that the proposal would have resulted in little time for an
operator to correct noncompliance determinations based on an operator's
single sample. The final rule ensures that an operator takes corrective
actions on a single sample overexposure. This will protect miners from
subsequent overexposures.
Proposed Sec. 71.207(k) would have required that during the time
for abatement fixed in a citation for violation of the standard, the
operator would have to: (1) Make approved respiratory equipment
available to affected miners in accordance with Sec. 72.700 of this
chapter; (2) submit to the District Manager for approval proposed
corrective actions to lower the concentration of respirable dust to at
or below the standard; (3) upon approval by the District Manager,
implement the proposed corrective actions and then sample the affected
DWP on each normal work shift until five valid representative samples
are taken; and (4) if using a CPDM to meet the requirements of
paragraph (a) of this section, review the adequacy of the approved CPDM
Performance Plan and submit any plan revisions to the District Manager
for approval within 7 calendar days following posting of the end-of-
shift equivalent concentration on the mine bulletin board.
Final paragraph (h)(1), like proposed Sec. 71.207(k)(1), requires
that the mine operator make approved respiratory equipment available to
affected miners in accordance with Sec. 72.700 of this chapter.
Comments on proposed Sec. 71.207(k)(1) were identical or similar to
those on proposed Sec. 70.207(g)(1) and (i)(1). The comments are
consolidated and discussed elsewhere in this preamble, together with
the rationale for final paragraph (h)(1), under Sec. 70.206(e)(1) and
(h)(1).
Paragraph (h)(2) is substantially similar to proposed Sec.
71.207(k)(3). It requires that the mine operator immediately take
corrective action to lower the concentration of respirable coal mine
dust to at or below the standard. Paragraph (h)(2) is consistent with
existing Sec. 71.201(d), which requires a mine operator to take
corrective action to lower the concentration of respirable dust.
Paragraph (h)(2) clarifies that corrective action needs to be taken
immediately to protect miners from overexposures. Comments on proposed
Sec. 71.207(k)(3) were similar to those on proposed Sec. 70.207(g)(3)
and (i)(2). The comments are consolidated and discussed elsewhere in
this preamble, together with the rationale for final paragraph (h)(2),
under Sec. 70.206(e)(2).
Paragraph (h)(3) is new and is similar to proposed Sec.
70.207(i)(3). Final paragraph (h)(3) requires that the mine operator
make a record of the corrective actions taken. The record must be
certified by the mine foreman or equivalent mine official no later than
the end of the mine foreman's or equivalent mine official's next
regularly scheduled working shift. It also requires that the record
must be made in a secure book that is not susceptible to alteration or
electronically in a computer system so as to be secure and not
susceptible to alteration. It further requires that the records must be
retained at a surface location at the mine for at least 1 year and be
made available for inspection by authorized representatives of the
Secretary and the representative of miners.
Final paragraph (h)(3) significantly simplifies the proposal. For
example, final paragraph (h)(3) only requires a record of the
corrective action taken. Proposed Sec. 71.206(k)(2) and (3) would have
required more corrective action submissions to the District Manager,
and dust control plan submissions and plan revisions to the District
Manager
[[Page 24922]]
regarding the DWP identified in the citation. Under proposed Sec.
71.207(k)(2) and (3), each time a citation would have been issued, the
operator would have been required to submit proposed corrective actions
to the District Manager and obtain approval before corrective actions
could be implemented. As one of the conditions to terminate the
citation under proposed Sec. 71.207(l), the operator would have had to
submit, for District Manager approval, a proposed dust control plan or
changes to an approved plan for that DWP. Under final paragraph (h),
operators are only required to take immediate corrective action and
make a record of the action taken. Like the existing rule, a respirable
dust control plan for the DWP is required under Sec. 71.300 only after
a citation is issued and terminated.
The rationale for final paragraph (h)(3) is the same as that for
final Sec. 70.206(e)(3). The requirement to make and retain a record
of corrective actions ensures that miners are not subject to subsequent
overexposures and that the corrective actions taken are effective. When
a dust control plan or changes to an approved plan are submitted to the
District Manager for approval, the operators and MSHA are able to check
the required records to ensure that the control measures used to abate
the violation are entered in the dust control plan for the DWP
identified in the citation.
In addition, final paragraph (h)(3) provides useful information to
a mine operator, miners, and MSHA regarding the corrective actions
taken and whether the dust control parameters in the approved
ventilation plan are adequate. The record of the corrective actions
taken should be made by a responsible mine official, such as the mine
foreman or equivalent mine official. Records and certification of
corrective action taken help identify excessive dust concentrations so
they can be addressed appropriately to better ensure miners' health. In
addition, retaining records at the mine for at least one year is
consistent with many existing MSHA record retention standards,
particularly the proposal's incorporation of existing Sec. 75.363(d).
Record retention is necessary to help MSHA, the mine operator, and the
miners' representative identify problems with dust controls and ensure
that excessive dust concentrations are corrected. The cost associated
with the record requirement is shown in Chapter IV of the Regulatory
Economic Analysis (REA).
Unlike proposed Sec. 71.207(k)(2), final paragraph (h) does not
include operators to submit corrective actions to the District Manager
for approval. Comments on proposed Sec. 71.207(k)(2) were the same as
or similar to those on proposed Sec. 70.207(g)(2). The comments are
consolidated and discussed elsewhere in this preamble under Sec.
70.206(h)(4).
In addition, unlike proposed Sec. 71.207(k)(4), final paragraph
(h) does not require operators to review and revise a CPDM Performance
Plan. As discussed in this section and elsewhere in this preamble under
Sec. 70.206, the final rule does not include the proposed requirements
for a CPDM Performance Plan.
For consistency between the sampling requirements of the final
rule, final paragraphs (h)(1)-(3) are identical to final Sec.
70.206(e)(1)-(3) regarding bimonthly sampling of MMUs, Sec.
70.207(d)(1)-(3) regarding bimonthly sampling of designated areas,
Sec. 70.208(e)(1)-(3) regarding quarterly sampling of MMUs, Sec.
70.209(c)(1)-(3), regarding quarterly sampling of designated areas, and
except for conforming changes, Sec. 90.207(c)(1)-(3) regarding
quarterly sampling.
Final paragraph (i) is changed from proposed Sec. 71.207(i). It
states that noncompliance with the standard is demonstrated during the
sampling period when: (1) Two or more valid representative samples meet
or exceed the ECV in Table 71-1 (Excessive Concentration Values (ECV)
Based on Single, Full-Shift CMDPSU/CPDM Concentration Measurements)
that corresponds to the applicable standard and the particular sampling
device used; or (2) The average for all valid representative samples
meets or exceeds the ECV in Table 71-2 (Excessive Concentration Values
(ECV) Based on the Average of Five Full-Shift CMDPSU/CPDM Concentration
Measurements) that corresponds to the applicable standard and the
particular sampling device used.
In the March 8, 2011, request for comments (76 FR 12649), MSHA
stated that the Agency was interested in commenters' views on what
actions should be taken by MSHA and the mine operator when a single
shift respirable dust sample meets or exceeds the ECV.
Commenters expressed concern that compliance determinations would
be made on the basis of a single-shift measurement. Proposed Sec.
71.207(i) would have required that if using a CMDPSU, no valid single-
shift sample equivalent concentration meet or exceed the ECV that
corresponds to the standard in proposed Table 71-1; or, if using a
CPDM, no valid end-of-shift equivalent concentration meet or exceed the
applicable ECV in proposed Table 71-2.
In response to comments, final paragraph (i) provides two different
methods by which compliance determinations can be made. The rationale
for final paragraphs (i)(1) and (2) is the same as that for final
Sec. Sec. 70.206(f)(1) and (2), 70.207(e)(1) and (2), 70.208(f)(1) and
(2), 70.209(d)(1) and (2), and 90.207(d)(1) and (2), and is discussed
elsewhere in this preamble under Sec. 70.208(f)(1) and (2).
For consistency between the sampling requirements of the final
rule, final paragraphs (i)(1) and (2) are the same as, except for
conforming changes, final Sec. Sec. 70.206(f)(1) and (2), 70.207(e)(1)
and (2), 70.208(f)(1) and (2), 70.209(d)(1) and (2), and 90.207(d)(1)
and (2).
Comments on the ECVs in proposed Table 71-1 are discussed elsewhere
in this preamble under Sec. 70.208(f). In addition, a detailed
discussion on the derivation of the ECVs in both final Tables 71-1 and
71-2 is included in Appendix A of the preamble. Comments that
questioned the accuracy of a single sample in making a compliance
determination are addressed elsewhere in this preamble under Sec.
72.800.
Final paragraph (j) is redesignated from proposed Sec. 71.207(j)
and makes clarifying and conforming changes. It provides that upon
issuance of a citation for a violation of the standard, paragraph (a)
of this section will not apply to that DWP until the violation is
abated and the citation is terminated in accordance with final
paragraphs (k) and (l) of this section. Paragraph (j) clarifies that a
violation must be abated and the citation must be terminated before
resuming quarterly sampling. Final paragraphs (k) and (l) are discussed
below.
Final paragraph (j) includes an exception to allow the District
Manager flexibility to address extenuating circumstances that would
affect sampling. An example of extenuating circumstances would occur
when an uncorrected violation would require abatement sampling that
continues into the next sampling period.
Final paragraph (j) is similar to existing Sec. 71.208(d). MSHA
did not receive comments on the proposal.
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraph (j) is the same as
final Sec. Sec. 70.206(g), 70.207(f), 70.208(g), 70.209(e), and
90.207(e).
Final paragraph (k) is similar to proposed Sec. 71.207(k). It
requires that upon issuance of a citation for violation of the
standard, the operator must take the following actions sequentially:
(1) Make approved respiratory equipment available; (2) immediately take
[[Page 24923]]
corrective action; (3) record the corrective actions; and (4) conduct
additional sampling. The actions required by paragraph (k) are similar
to those in proposed Sec. 71.207(k)(1)-(4) discussed under paragraph
(h). In addition, paragraph (k) includes the term ``sequentially'' to
ensure that corrective actions are taken in the order they are listed.
Final paragraph (k)(1), like proposed Sec. 71.207(k)(1), requires
that the mine operator make approved respiratory equipment available to
affected miners in accordance with Sec. 72.700 of this chapter.
Comments on proposed Sec. 71.207(k)(1) were identical or similar to
those on proposed Sec. 70.207(g)(1) and (i)(1). The comments are
consolidated and discussed elsewhere in this preamble, together with
the rationale for final paragraph (h)(1), under Sec. 70.206(e)(1) and
(h)(1).
Paragraph (k)(2) is substantially similar to proposed Sec.
71.207(k)(3). It requires that the mine operator immediately take
corrective action to lower the concentration of respirable coal mine
dust to at or below the standard. Paragraph (k)(2) clarifies that
corrective action needs to be taken immediately to protect miners from
overexposures. Comments on proposed Sec. 71.207(k)(3) were similar to
those on proposed Sec. 70.207(g)(3) and (i)(2). The comments are
consolidated and discussed elsewhere in this preamble, together with
the rationale for final paragraph (k)(2), under Sec. 70.206(e)(2) and
(h)(2).
Paragraph (k)(3) is new. It requires that the mine operator make a
record of the corrective actions taken. The record must be certified by
the mine foreman or equivalent mine official no later than the end of
the mine foreman's or equivalent mine official's next regularly
scheduled working shift. It also requires that the record must be made
in a secure book that is not susceptible to alteration or
electronically in a computer system so as to be secure and not
susceptible to alteration. It further requires that the records must be
retained at a surface location at the mine for at least 1 year and be
made available for inspection by authorized representatives of the
Secretary and the representative of miners. Like final paragraph
(h)(3), final paragraph (k)(3) significantly simplifies the proposal.
Proposed Sec. 71.206(k)(2) and (3) would have required more corrective
action submissions to the District Manager, and dust control plan
submissions and plan revisions to the District Manager regarding the
DWP identified in the citation. Under proposed Sec. 71.207(k)(2) and
(3), each time a citation would have been issued, the operator would
have been required to submit proposed corrective actions to the
District Manager and obtain approval before corrective actions could be
implemented. As one of the conditions to terminate the citation under
proposed Sec. 71.207(l), the operator would have had to submit, for
District Manager approval, a proposed dust control plan or changes to
an approved plan for that DWP. Under final paragraph (k), operators are
only required to take immediate corrective action and make a record of
the action taken. Like the existing rule, a respirable dust control
plan for the DWP is required under Sec. 71.300 only after a citation
is issued and terminated.
The rationale for final paragraph (k)(3) is the same as that for
final Sec. 70.206(h)(3). The requirement to make and retain a record
of corrective actions ensures that miners are not subject to subsequent
overexposures and that the corrective actions taken are effective. When
a dust control plan or changes to an approved plan are submitted to the
District Manager for approval, the operators and MSHA are able to check
the required records to ensure that the control measures used to abate
the violation are entered in the dust control plan for the DWP
identified in the citation.
It provides useful information to a mine operator, miners, and MSHA
regarding the corrective actions taken and whether the dust control
parameters in the approved ventilation plan are adequate. The record of
the corrective actions taken should be made by a responsible mine
official, such as the mine foreman or equivalent mine official. Records
and certification of corrective action taken help identify excessive
dust concentrations so they can be addressed appropriately to better
ensure miners' health. In addition, retaining records at the mine for
at least one year is consistent with many existing MSHA record
retention standards, particularly the proposal's incorporation of
existing Sec. 75.363(d). Record retention is necessary to help MSHA,
the mine operator, and the miners' representative identify problems
with dust controls and ensure that excessive dust concentrations are
corrected. The cost associated with the record requirement is shown in
Chapter IV of the Regulatory Economic Analysis (REA).
The rationale for final paragraph (k)(3) is the same as that
discussed in final paragraph (h) and in final Sec. 70.206(e)(3).
Final paragraph (k)(4) is similar to proposed Sec. 71.207(k)(3).
It requires that the mine operator begin sampling, within 8 calendar
days after the date the citation is issued, the environment of the
affected DWP on consecutive normal production shifts until five valid
representative samples are taken. Paragraph (k)(4) is consistent with
existing Sec. 71.201(d), which requires a mine operator to sample each
normal work shift until five valid respirable dust samples are taken.
In addition, it requires that the sampling must begin within 8 calendar
days after the date the citation is issued. Under proposed Sec.
71.207(k)(2) and (3), sampling would have begun after submission to and
approval by the District Manager of the corrective actions taken. The
rationale for final paragraph (k)(4) is the same as that for final
Sec. 70.206(h)(4) and is discussed elsewhere in this preamble under
Sec. 70.206(h)(4).
Unlike proposed Sec. 71.207(k)(4), final paragraph (k) does not
require operators to review and revise a CPDM Performance Plan. As
discussed in this section and elsewhere in this preamble under Sec.
70.206, the final rule does not include the proposed requirements for a
CPDM Performance Plan.
In addition, unlike proposed Sec. 71.207(k)(2), final paragraph
(k) does not require operators to submit corrective actions to the
District Manager for approval. Comments on proposed Sec. 71.207(k)(2)
were the same as or similar to those on proposed Sec. 70.207(g)(2).
The comments are consolidated and discussed elsewhere in this preamble
under Sec. 70.206(h)(4).
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraph (k) is the same as
final Sec. Sec. 70.206(h), 70.207(g), 70.208(h), 70.209(f), and
90.207(f).
Final paragraph (l) is changed from proposed Sec. 71.207(l). It
provides that a citation for a violation of the standard will be
terminated by MSHA when the equivalent concentration of each of the
five valid representative samples is at or below the standard. It does
not include the proposed requirement that within 15 calendar days after
receipt of the sampling results from MSHA, the operator must submit to
the District Manager for approval a proposed dust control plan for the
DWP in the citation or notice or proposed changes to the approved dust
control plan as prescribed in Sec. 71.300. It also does not include
the requirement that the proposed plan parameters or proposed changes
reflect the control measures used to abate the violation. The proposed
requirement to submit a dust control plan for the DWP with proposed
plan parameters or revisions is included in final Sec. 71.300, which
also requires a description of the specific control
[[Page 24924]]
measures used to abate the dust violation. Therefore, the same
requirements did not need to be included in final paragraph (l). MSHA
did not receive any comments on the proposal.
Final paragraph (m) is similar to proposed Sec. 71.207(f). It
allows the District Manager to designate for sampling under this
section additional work positions at a surface coal mine and at a
surface work area of an underground coal mine where a concentration of
respirable dust exceeding 50 percent of the standard in effect at the
time the sample is taken, or a concentration of respirable dust
exceeding 50 percent of the standard established in accordance with
Sec. 71.101 has been measured by one or more MSHA valid representative
samples.
One commenter stated that other work positions designated by the
District Manager should include any work sites where miners are exposed
to dust, such as preparation plants, load out facilities, stockpiles,
barges, and other areas at surface coal mines and surface areas of
underground coal mines.
According to MSHA's historical sampling data and experience,
highwall drill operators and bulldozer operators are the work positions
with the greatest potential of overexposure to respirable dust and
respirable dust when quartz is present. However, under the final rule,
the District Manager may designate additional work positions for DWP
sampling provided that either criteria in paragraph (m) are met.
One commenter expressed concern that the proposal permits the
District Manager to greatly expand the sampling requirements. The final
rule, like the proposal, is derived from existing Sec. 71.208(e).
Under the existing standard, the District Manager has the discretion to
designate the work positions at each surface coal mine and surface work
area of an underground coal mine for respirable dust sampling. That
discretion continues under the final rule. Final paragraph (m) is
consistent with the existing standard and does not expand the existing
District Manager's authority.
Final paragraph (n) is redesignated from and is essentially the
same as proposed Sec. 71.207(g) except for nonsubstantive and
conforming changes. It provides that the District Manager may withdraw
from sampling any DWP designated for sampling under paragraph (m) of
this section upon finding that the operator is able to maintain
continuing compliance with the standard. It further provides that this
finding will be based on the results of MSHA and operator valid
representative samples taken during at least a 12-month period. MSHA
did not receive comments on the proposal.
10. Section 71.207 Respirable Dust Samples; Transmission by Operator
Final Sec. 71.207 is similar to proposed Sec. 71.208. Like the
proposal, final Sec. 71.207 revises existing Sec. 71.208(a) and (c),
and adds a new paragraph (f). It also redesignates, without change,
existing Sec. 71.208(b), (d) and (e).
Final Sec. 71.207(a) is substantially similar to the proposal. It
requires the operator, if using a CMDPSU, to transmit within 24 hours
after the end of the sampling shift all samples collected, including
control filters, in containers provided by the manufacturer of the
filter cassette to MSHA's Pittsburgh Respirable Dust Processing
Laboratory, or to any other address designated by the District Manager.
Final paragraph (a) clarifies that operators must include the control
filters with the dust sample transmissions to the Respirable Dust
Processing Laboratory. As explained in the preamble to the proposed
rule, MSHA uses control filters to improve measurement accuracy by
eliminating the effect of differences in pre- and post-exposure
laboratory conditions, or changes introduced during storage and
handling of the filter cassettes. Including control filters with the
dust samples ensures that the appropriate control filter is associated
with the appropriate sample filter.
Final Sec. 71.207(b), like proposed Sec. 71.208(b), is the same
as existing Sec. 71.209(b).
Final Sec. 71.207(c) is substantially the same as proposed Sec.
71.208(c). It requires that a person certified in sampling must
properly complete the dust data card that is provided by the
manufacturer for each filter cassette. It further requires that the
dust data card must have an identification number identical to that on
the filter cassette used to take the sample and be submitted to MSHA
with the sample. It also requires that each dust data card must be
signed by the certified person who actually performed the examinations
during the sampling shift and must include that person's MSHA
Individual Identification Number (MIIN).
As an example, the certified person who performs the required
examinations during the sampling shift is the individual responsible
for signing the dust data card and verifying the proper flowrate, or
noting on the back of the card that the proper flowrate was not
maintained. Since the certified person who conducted the examination is
most knowledgeable of the conditions surrounding the examination, final
paragraph (c) requires that certified person sign the dust data card.
In addition, the MIIN number requirement is consistent with MSHA's
existing policy. Since July 1, 2008, MSHA has required that the
certified person section of the dust data card include the MIIN, a
unique identifier for the certified person, instead of the person's
social security number. To ensure privacy and to comport with Federal
requirements related to safeguarding personally identifiable
information, MSHA has eliminated requirements to provide a social
security number.
Finally, paragraph (c) provides that respirable dust samples with
data cards not properly completed may be voided by MSHA. This is a
change from the proposal. The proposal would have required that,
regardless of how small the error, an improperly completed dust data
card must be voided by MSHA. Final paragraph (c) allows MSHA
flexibility in voiding an improperly completed dust data card. MSHA
received no comments on this proposed provision.
Final Sec. 71.207(d) and (e) are the same as proposed Sec.
71.208(d) and (e) and are the same as existing Sec. 71.209(d) and (e).
Final Sec. 71.207(f) is changed from the proposal. It requires
that, if using a CPDM, the person certified in sampling must validate,
certify, and transmit electronically to MSHA within 24 hours after the
end of the sampling shift all sample data file information collected
and stored in the CPDM, including the sampling status conditions
encountered when sampling each DWP; and, not tamper with the CPDM or
its components in any way before, during, or after it is used to
fulfill the requirements of 30 CFR part 71, or alter any sample data
files. It further requires that all CPDM data files transmitted
electronically to MSHA must be maintained by the operator for a minimum
of 12 months.
Final paragraph (f) includes the term ``person certified in
sampling'' rather than ``designated mine official.'' This change makes
paragraph (f) consistent with final paragraph (c). Final paragraph (f)
also includes a clarification that CPDM data files are
``electronically'' transmitted to MSHA, unlike the physical
transmission of samples collected with the CMDPSU. As a clarification
to the proposal, final paragraph (f) does not require ``error data file
information'' to be transmitted to MSHA. Rather, final paragraph (f)
requires ``the sampling status conditions encountered when sampling''
to be transmitted to MSHA. This terminology is consistent with that
used in the
[[Page 24925]]
approved CPDM manufacturer's literature. The clarification ensures that
conditions that may occur during the sampling shift (e.g., flowrate,
temperature, humidity, tilt indicator, etc.) and that may affect
sampling results are recorded and transmitted to MSHA.
The requirement in final paragraph (f) that the certified person
not tamper with the CPDM or alter any CPDM data files is new. It is
consistent with the requirements for CMDPSUs, under existing Sec.
71.209(b) and final Sec. 71.207(b), which provide that an operator not
open or tamper with the seal of any filter cassette or alter the weight
of any filter cassette before or after it is used to fulfill the
requirements of 30 CFR part 71. It is also consistent with the
requirement in 30 CFR 74.7(m) that a CPDM be designed to be tamper-
resistant or equipped with an indicator that shows whether the
measuring or reporting functions of the device have been tampered with
or altered. MSHA has a long history of taking action against persons
who have tampered with CMDPSUs or altered the sampling results obtained
from such devices in order to protect miners' health and ensure the
integrity of MSHA's dust program. Therefore, a similar requirement is
included for samples taken with a CPDM.
Final Sec. 71.207 and its rationale are identical to final Sec.
70.210, discussed elsewhere in this preamble under Sec. 70.210. One
commenter expressed general support for the proposal.
11. Section 71.208 Respirable Dust Samples; Report to Operator; Posting
Final Sec. 71.208 is similar to proposed Sec. 71.209. It is
substantially the same as final Sec. 70.211, and the rationale is
discussed elsewhere in this preamble related to final Sec. 70.211.
Additional rationale, as appropriate, is discussed below.
Final paragraph (a)(4) is new and provides that the MSHA report
will include the average equivalent concentration of respirable dust
for all valid samples. This provision is included to ensure that
operators, as well as miners and their representatives, are informed as
to the average concentration of respirable dust for all valid samples.
Final Sec. 71.208(b) is changed from proposed Sec. 71.209(b). It
requires that, upon receipt, the operator must post on the mine
bulletin board the data contained in the MSHA report for at least 31
days.
The proposal would have required posting for 46 days. As explained
in the preamble to the proposed rule, existing standards under parts 70
and 71 require operators to post sampling data for 50 percent of the
specified sampling period (e.g., 31 days is 50 percent of the bimonthly
sampling period specified in existing Sec. 71.208(a)). Since proposed
Sec. 71.207 would have required operators to take DWP samples every
calendar quarter, posting the sampling data for 46 days, which is
approximately 50 percent of a quarterly sampling period, would have
been consistent with existing posting requirements.
One commenter stated that the purpose and benefit of posting
sampling data for 46 days was not apparent. In response to this
comment, MSHA concludes that posting for the existing 31 days is
adequate time for interested parties to review the data. The 31-day
time period is consistent with the posting requirement under final
Sec. 70.211(b). Another commenter expressed general support for the
proposed posting, stating that the specified data should be available
to all interested parties at any time. In response, MSHA agrees that
the data required to be posted under final paragraph (b) provides
valuable sampling data. However, the final rule does not include the
commenter's suggestion that the data should be permanently available to
interested parties. The Agency believes that the 31-day posting period
provides adequate opportunity for interested persons to review the
information.
Final Sec. 71.208(c)(1), (c)(2), (c)(3), and (c)(5) are
redesignated from proposed Sec. 71.209(c)(1)(i), (c)(1)(ii),
(c)(1)(iii), and (c)(1)(v), respectively. Final paragraph (c) does not
include provisions that were in proposed Sec. 71.209(c)(1)(iv) and
(c)(1)(vi) for the same reasons that identical provisions in proposed
Sec. 70.211(c)(1)(vi) and (c)(1)(viii) are not included in final Sec.
70.211(c), i.e., the information that would have been required will
already be included on the paper record (Dust Data Card) for each
sample run when samples are collected using a CPDM.
Final paragraph (c)(2), like the proposal and existing Sec.
71.210(a)(2), requires that the paper record include the DWP at the
mine from which the samples were taken. MSHA received no comment on the
proposed provision.
Final paragraph (c)(3) is the same as final Sec. 70.211(c)(3) and
its rationale is the same as that stated in the preamble discussion for
final Sec. 70.211(c)(3).
Final paragraph (c)(4) is new and requires that the paper record
include the ``sampling status conditions encountered for each sample.''
The rationale for this provision is the same as that stated in the
preamble discussion for final Sec. 70.211(c)(4).
Final Sec. 71.208(d) is changed from proposed Sec. 71.209(c)(2).
It requires the information required by paragraph (c) to remain posted
until receipt of the MSHA report covering the respirable dust samples
collected using a CPDM. Proposed Sec. 71.209(c)(2) would have required
the information under proposed Sec. 71.209(c)(1)(i)-(c)(1)(vi) to be
posted for at least 46 calendar days. The rationale for paragraph (d)
is the same as that stated in the preamble discussion of final Sec.
70.211(d). MSHA received no comments on this provision.
12. Section 71.209 Status Change Reports
Final Sec. 71.209 is similar to proposed Sec. 71.210 and existing
Sec. 71.220. One commenter expressed general support for the proposal.
Final Sec. 71.209(a), like the proposal, provides an operator the
option of reporting changes electronically, as an alternative to
reporting the changes in writing. MSHA received no comment on this
provision. Final paragraph (a) is similar to final Sec. 70.212(a). The
rationale for paragraph (a) is discussed elsewhere in this preamble
under final Sec. 70.212(a).
Final Sec. 71.209(b) is the same as the proposal and existing
Sec. 71.220(b). MSHA received no comment on this provision and it is
finalized as proposed.
Unlike proposed Sec. 71.210(c), final Sec. 71.209 does not
require the designated mine official to report status changes affecting
the operational readiness of any CPDM within 24 hours after the status
change occurred. One commenter was concerned with the recordkeeping
burden associated with proposed Sec. 71.210(c). After reviewing the
commenter's concern, MSHA has determined that proposed requirement is
not necessary and, therefore, it is not included in the final rule.
13. Section 71.300 Respirable Dust Control Plan; Filing Requirements
Final Sec. 71.300 contains requirements for operators who must
file a dust control plan when they receive a citation for a DWP sample.
It requires that, within 15 calendar days after the termination date of
a citation for a violation of the standard, the operator must submit to
the District Manager for approval a written respirable dust control
plan for the DWP identified in the citation. It further requires that
the respirable dust control plan and any revisions must be suitable to
the conditions and the mining system of the coal mine and be adequate
to
[[Page 24926]]
continuously maintain respirable dust to at or below the standard at
the DWP identified in the citation.
Final Sec. 71.300(a) is changed from proposed Sec. 71.300(a).
Under the proposal, in order to terminate a citation for a violation of
the respirable dust standard, the operator would have had to first
submit, to the District Manager for approval, a dust control plan or
revisions to the dust control plan after abatement sampling results
showed compliance. MSHA has reevaluated the requirements of proposed
Sec. 71.300(a). MSHA has concluded that final paragraph (a) will allow
for faster abatement of a citation because, under final Sec.
71.207(g)(2), immediate action must be taken to correct the violation
and the citation may be terminated before submitting a plan or
revisions to the District Manager for approval. Final paragraph (a) is
consistent with existing Sec. 71.300(a) which does not require a plan
submission as a requirement to terminate a citation.
Also, final paragraph (a) replaces the reference to Sec. 71.207(l)
with ``Within 15 calendar days after the termination date of a citation
for violation of the applicable standard.'' This is consistent with
similar wording in existing Sec. 71.300. It simplifies the wording to
specify the time frame and circumstance that initiate the requirement
for the operator to submit the plan for District Manager approval,
rather than reference to another regulatory section. Final paragraph
(a), like the proposal, provides that the plan requirements are
specific to the DWP identified in the citation. In addition, the 15-day
requirement to submit the plan for MSHA approval is the same as the
proposed and existing rules.
One commenter expressed concern that proposed Sec. 71.300 was
requiring another plan.
MSHA is not requiring a new plan. The requirement to submit a
respirable dust control plan after termination of a citation for
violation of the dust standard has been in existence since 1980. No
other comment was received on proposed paragraph (a) and the final rule
includes only the above nonsubstantive revisions.
Final paragraph (a)(1), like the proposal, requires that the mine
operator notify the representative of miners at least 5 days prior to
submitting a proposed respirable dust control plan, or proposed
revisions to an existing plan, to the District Manager for approval. It
also requires that, if requested, the operator must provide a copy to
the representative of miners at the time of the 5-day notification.
Final paragraph (a)(2), like the proposal, requires the operator to
make available for inspection by the miners' representative a copy of
the proposed respirable dust control plan and any proposed revisions
that have been submitted for District Manager approval. Final paragraph
(a)(3), like the proposal, requires a copy of the proposed respirable
dust control plan, and any proposed revision, to be posted on the mine
bulletin board at the time of submittal to the District Manager for
approval. It further requires that the proposed plan or revision remain
posted on the bulletin board until approved, withdrawn, or denied.
Final paragraph (a)(4), like the proposal, allows the miners'
representative, following receipt of a proposed dust control plan or
proposed revision, to submit timely written comments to the District
Manager for consideration during the plan review process. Final
paragraph (a)(4), like the proposal, also requires the District Manager
to provide operators with a copy of the miners' representatives'
comments when requested to do so.
One commenter stated that, to allow for sufficient review and
comment, the operator should be required to provide a copy of the
respirable dust control plan to the miners' representative, without the
representative having to request it, at least 10 days before the
operator's submission to the District Manager.
MSHA agrees from experience that input from miners on proposed dust
control measures in plans is important. However, providing a copy of
the proposed plan, or revisions, to the miners' representative within
the 5-day notification period, upon request, allows sufficient time and
opportunity for the miners' representative to become familiar with the
proposed plan or revisions and to discuss and resolve any issues prior
to its submission to the District Manager for approval. In addition,
the requirement is consistent with procedures for submitting plans in
other MSHA standards. Final paragraphs (a)(1)-(4) ensure that miners'
representatives have access to copies of proposed plan documents for
their review, that miners are made aware of the contents of the
proposed plan, and that all parties to the dust control plan process
are aware of each other's positions on potential issues.
Final Sec. 71.300(b), like the proposal, requires that each
respirable dust control plan include at least the following: (1) The
mine identification number and DWP number assigned by MSHA, the
operator's name, mine name, mine address, and mine telephone number and
the name, address, and telephone number of the principal officer in
charge of health and safety at the mine; (2) the specific DWP at the
mine to which the plan applies; (3) a detailed description of the
specific respirable dust control measures used to abate the violation
of the respirable dust standard; and (4) a detailed description of how
each of the respirable dust control measures described in response to
paragraph (b)(3) of this section will continue to be used by the
operator, including at least the specific time, place, and manner the
control measures will be used. Except for nonsubstantive changes, the
requirements of final paragraph (b)(1)-(4) are the same as existing
Sec. 71.300(b)(1)-(4). MSHA did not receive comments on these
provisions and they are finalized as proposed.
14. Section 71.301 Respirable Dust Control Plan; Approval by District
Manager and Posting
Final Sec. 71.301(a), like the proposal, provides that the
District Manager will approve respirable dust control plans on a mine-
by-mine basis. It further provides that when approving respirable dust
control plans, the District Manager must consider whether: (1) The
respirable dust control measures would be likely to maintain
concentrations of respirable coal mine dust at or below the standard;
and (2) the operator's compliance with all provisions of the respirable
dust control plan could be objectively ascertained by MSHA.
One commenter questioned why the criteria are not an MSHA internal
document or published guideline, instead of a regulation.
Final paragraph (a)(1) is derived from existing Sec. 71.301(a)(1).
Under existing Sec. 71.301(a)(1), the District Manager considers
whether the dust control measures would likely maintain ``compliance
with the respirable dust standard.'' Like the proposal, final paragraph
(a)(1) clarifies that the District Manager's review will ensure that
control measures in the plan would likely maintain respirable dust
concentrations at or below the standard at the DWP identified in the
citation so that concentrations do reach ECV levels. This clarification
will improve protection for miners.
Final paragraph (a)(2), like the proposal, is the same as existing
Sec. 71.301(a)(2).
Final Sec. 71.301(b), like the proposal, provides that MSHA may
take respirable dust samples to determine whether control measures in
the operator's plan effectively maintain concentrations of respirable
coal mine dust at or below the standard. Final paragraph (b), like
[[Page 24927]]
the proposal, is derived from existing Sec. 71.301(b). Paragraph (b)
clarifies that MSHA sampling will ensure that control measures in the
plan are effective at maintaining respirable dust concentrations at or
below the standard. This clarification will improve protection for
miners. MSHA did not receive comments on proposed paragraph (b) and it
is finalized as proposed.
Final Sec. 71.301(c), like the proposal, is the same as existing
Sec. 71.301(c).
Final Sec. 71.301(d)(1), (2) and (3), like the proposal, requires
that the approved respirable dust control plan and any revisions must
be: Provided upon request to the representative of miners; made
available for inspection by the representative of miners; posted on the
mine bulletin board within 1 working day following notification of
approval; and remain posted for the period that the plan is in effect.
Miners and their representatives play an important role in the plan
approval process and need to be kept aware of the contents of the
approved plan. Consistent with procedures for plan approval in other
MSHA standards, final paragraphs (d)(1), (2), and (3) ensure that
miners and their representatives have timely access to the approved
plan or plan revisions following notification of approval. These
provisions also ensure that miners and their representatives are
informed of the respirable dust controls in the approved plan that
should be in use at the mine. Posting on the mine bulletin board within
1 working day following notification of approval is a reasonable time
and provides improved protection for miners.
MSHA did not receive comments on proposed paragraphs (d)(1)-(3) and
they are finalized as proposed.
C. 30 CFR Part 72--Health Standards for Coal Mines
1. Section 72.100 Periodic Examinations
Final Sec. 72.100(a), like the proposal, requires each operator of
a coal mine to provide to each miner periodic examinations including
chest x-rays, spirometry, symptom assessment, and occupational history
at a frequency specified in this section and at no cost to the miner.
The examinations are important for the early detection and prevention
of disease.
Final paragraph (a)(1), like the proposal, requires each operator
to use NIOSH-approved facilities to provide the examinations specified
in final paragraph (a).
Final paragraph (a)(2) is new. It requires that the results of
examinations or tests made pursuant to this section be furnished only
to the Secretary of Labor, the Secretary of HHS, or, at the request of
the miner, to the miner's designated physician.
Final paragraph (b), like the proposal, pertains to voluntary
examinations. It requires that each operator provide the opportunity to
have the examinations specified in paragraph (a) at least every 5 years
to all miners employed at a coal mine. It also requires that the
examinations be made available during a 6-month period that begins no
less than 3.5 years and not more than 4.5 years from the end of the
last 6-month period. Final paragraph (b) allows some flexibility for
mine operators and approved facilities in scheduling examinations and
is consistent with the time frames established in NIOSH's existing
program. For example: If an operator provided examinations to miners
during a 6-month period of July 1, 2009 to December 31, 2009, the
operator would be notified by NIOSH by April 1, 2013, 3 months prior to
July 1, 2013, to schedule the next 6-month period within which to offer
miners the examinations.
Final paragraph (c) pertains to mandatory examinations and is the
same as the proposed rule. It requires that for each miner who begins
work at a coal mine for the first time, the operator must provide an
examination specified in final paragraph (a). Final paragraph (c)(1)
requires that the operator provide the initial examination no later
than 30 days after beginning employment. Final paragraph (c)(2)
requires the operator to provide a follow-up examination no later than
3 years after the initial examination in paragraph (c)(1). Final
paragraph (c)(3) requires the operator to provide a follow-up
examination no later than 2 years after the examination in paragraph
(c)(2), if the chest x-ray shows evidence of pneumoconiosis or if the
spirometry examination indicates evidence of decreased lung function.
Paragraph (c)(3) also specifies that for this purpose, evidential
criteria will be defined by NIOSH.
On March 8, 2011, MSHA issued in the Federal Register a request for
comments (76 FR 12648). MSHA solicited comments on the periodic medical
surveillance provisions in the proposed rule. The proposal would have
required operators to provide an initial examination to each miner who
begins work at a coal mine for the first time and then at least one
follow-up examination after the initial examination.
Commenters generally supported periodic medical surveillance
examinations for all coal miners including underground and surface coal
miners. Most commenters also supported spirometry, occupational
history, and symptom assessment examinations in addition to the X-ray
examinations that are required by NIOSH's existing regulations at 42
CFR part 37 pertaining to Specifications for Medical Examinations of
Underground Coal Miners. One commenter did not support adding more
medical tests, including spirometry. Another commenter suggested that
more frequent mandatory chest x-rays would be more beneficial than
spirometry testing.
Final Sec. 72.100 is consistent with the existing ``Coal Workers'
X-Ray Surveillance Program'' administered by NIOSH. The Program was
established under the Federal Coal Mine Health and Safety Act of 1969,
as amended by Section 203(a) of the Mine Act (30 U.S.C. 843(a)). The
existing NIOSH regulations, 30 CFR part 37, consist of specifications
for giving, interpreting, classifying, and submitting chest X-rays for
underground coal miners. According to 30 CFR 37.3, mandatory chest X-
rays include an initial chest X-ray within 6 months of beginning
employment, another chest X-ray 3 years later, and a third chest X-ray
2 years after the second if the miner is still engaged in underground
coal mining and if the second chest X-ray showed evidence of category 1
or higher pneumoconiosis. In addition to these mandatory chest X-rays,
mine operators are required to offer an opportunity for periodic,
voluntary chest X-rays every 5 years.
Final Sec. 72.100 is also consistent with the 1996 Dust Advisory
Committee Report and 1995 NIOSH Criteria Document. The Advisory
Committee Report unanimously recommended that, in addition to the chest
X-rays at the time of employment and then at the specified intervals
thereafter, spirometry and questionnaire data should be collected
periodically during a miner's employment. The Advisory Committee also
unanimously recommended that medical testing of underground coal miners
should be extended to surface miners.
The NIOSH Criteria Document recommended that spirometric
examinations be included in the medical screening and surveillance
program for coal miners. NIOSH also recommended the inclusion of
surface coal miners in medical screening and surveillance program.
Requiring operators to provide spirometry, symptom assessment, and
occupational history, in addition to X-
[[Page 24928]]
rays, and include surface coal miners in the periodic examination
requirement will provide increased protection of health for every coal
miner. A spirometry examination complements a chest x-ray by detecting
effects, other than pneumoconiosis, of dust on the lung, such as
Chronic Obstructive Pulmonary Disease (COPD). COPD cannot be detected
by a chest x-ray. A spirometry examination is the most practical
screening tool to detect reduced lung function in miners, which is
common evidence of COPD. Periodic chest x-rays and spirometry will
enable early detection of pneumoconiosis and COPD, respectively, both
of which are irreversible and, for miners who are subject to continued
overexposure to respirable dust, progressive. Spirometry examination
results would provide miners with the knowledge of an abnormal decline
in lung function, which would enable them to be proactive in their
approach to their health. In the absence of medical monitoring and
early intervention, a miner may continue to be overexposed, allowing
disease to progress so that the miner may suffer material impairment of
health or functional capacity.
Surface coal miners are included in final Sec. 72.100 because they
too are at risk of developing pneumoconiosis and COPD as a result of
exposure to respirable coal mine dust. MSHA data indicate that some
occupations at surface mines (e.g., drill operators, bulldozer
operators, and truck drivers) experience high exposure to respirable
coal mine dust, including silica, and there are many former underground
miners among surface miners with chest x-rays that show CWP. Surface
miners, like underground miners, would benefit from the availability of
periodic medical monitoring. It would provide them with information on
the status of their health and enable them to take actions to prevent
disease progression. For example, for miners at surface mines who are
not provided any periodic examinations under existing regulations, a
chest x-ray that shows evidence of pneumoconiosis under the final rule
would allow them to exercise their rights to work in a less dusty job
of the mine under 30 CFR part 90.
Some commenters stated that the proposal will cause confusion with
the existing NIOSH X-ray surveillance program. These commenters stated
that the NIOSH Program only covers chest X-rays for underground coal
miners and that MSHA and NIOSH must coordinate the medical surveillance
program to ensure a seamless program.
MSHA intends to work with NIOSH to coordinate each agency's
regulatory requirements, where appropriate, and to implement a smooth
transition to ensure medical examinations are provided to all coal
miners under the CWHSP. Including these requirements in the final rule
will allow MSHA to use its inspection and enforcement authority to
protect miners' health and ensure that operators comply with the
examination requirements.
One commenter stated that the proposal is not clear about who
should review chest radiographs and suggested that they be reviewed by
B-readers to ensure accuracy and consistency.
The final rule only requires that operators use NIOSH-approved
facilities to provide the periodic examinations, but does not address
who should review the chest x-rays. NIOSH regulations under 42 CFR part
37 provide specifications for giving, interpreting, classifying, and
submitting chest x-rays. A discussion of NIOSH's B-reader program is
included in Section III.A., Health Effects, of the preamble.
Some commenters stated that miners do not participate in NIOSH's
surveillance program due to concerns that their private medical
information will not be kept confidential. They also expressed concern
with how the medical information will be used. One commenter referred
to OSHA's asbestos rule that requires that the results of medical
examinations be given to employers, and a NIOSH Criteria Document that
recommends that medical findings for refractory ceramic fibers workers
be provided to employers.
Final paragraph (a)(2) is responsive to commenters' concerns on
confidentiality. It limits the persons who can be provided miners'
examination and test results. Although MSHA will not routinely get
results of a miner's examination or tests, there will be shared
information when necessary. For example, MSHA will be informed when a
miner's chest x-ray from a mandatory follow-up examination under final
paragraph (c)(2) shows evidence of pneumoconiosis. This information is
crucial so that MSHA can ensure that the operator provides the affected
miner with a subsequent follow-up examination under final paragraph
(c)(3) of this section. In addition, final paragraph (a)(2) is
consistent with Federal privacy laws, such as HIPAA, the Privacy Act,
and FOIA, which protect personal medical data from disclosure.
Many commenters supported mandatory medical monitoring, but for all
coal miners. Some of these commenters stated that voluntary
examinations exclude some miners and that such exclusion violates
Section 101(a)(6)(A) of the Mine Act, which requires MSHA to set
standards which most adequately assure that no miner will suffer
material impairment of health or functional capacity. Other commenters
stated that voluntary miner participation has not succeeded in
improving disease prevention. Some commenters stated that mandatory
participation by all miners would provide early diagnosis of disease
and is the best tool to implement intervention measures and prevent
disease progression. One commenter added that mandatory miner
participation would provide a true measure of health under the existing
2.0 mg/m\3\ standard and the opportunity to be proactive in stopping
disease progression.
Some commenters supported voluntary examinations for miners and
expressed concern that medical information may be used in a retaliatory
manner against miners. One commenter objected to being subjected to
radiation and medical testing as a result of any regulation.
MSHA does not believe that requiring mandatory medical examinations
for all miners is appropriate. MSHA acknowledges the concerns of the
commenters who believe that the voluntary program has not worked and
deprives miners of examinations that could detect respiratory disease
and information to address potential disease. However, as noted in
Section III.A., Health Effects, of the preamble, although the numbers
vary over time, the percentage of actively employed underground miners
who volunteered for medical surveillance in NIOSH's Coal Workers'
Health Surveillance Program (CWHSP) has increased from a low of
approximately 20% in the 1990-1994 time period to approximately 43% in
the 2005-2009 time period (see Table III-2).
MSHA also recognizes that periodic examinations, such as those
required under final paragraph (b), are necessary for early detection
of respiratory disease and early intervention to prevent its
progression. However, MSHA is reluctant to require all miners to submit
to medical examinations that they do not wish to undergo. MSHA is also
reluctant to require miners to submit to the examinations when the
miners may have concerns about the privacy and confidentiality of
medical test records and follow-up evaluations. These concerns include
medical test results that could be used to fire a miner, challenge
claims for black lung benefits, or could be obtained as part of a
Freedom of Information Act request.
[[Page 24929]]
One commenter stated that follow-up spirometry examinations should
be repeated at least every 3 years. This commenter added that
spirometry testing every 3 years would provide an opportunity for early
identification of miners who have accelerated loss of lung function
greater than that expected from aging alone, and would allow for
interventional and preventive health strategies. In addition, this
commenter stated that surveillance chest x-rays should be coordinated
with the spirometry surveillance schedule, with the additional chest x-
rays being obtained at 9 to 12 years' duration of coal mine employment
and every 6 years thereafter.
Mandatory examinations provided in close proximity to when miners
are first hired and first exposed to respirable coal mine dust are
necessary in order to establish an accurate baseline of each miner's
health. Miners may not recognize early symptoms of pneumoconiosis or
COPD and, therefore, they might not be likely to seek medical
assistance. A chronic respiratory symptom complex develops after
prolonged exposure to respirable dust and includes chronic cough,
phlegm development, and shortness of breath. However, several
researchers have noted that the decline in lung function due to dust is
non-linear, sometimes with much of the decline coming early in the
miner's career, often in less than 3 years (Attfield and Hodous, 1992;
Seixas et al., 1993). There are some individuals who respond adversely
to respirable coal mine dust exposure relatively quickly, and it is
important to identify those individuals early. A 3-year interval at the
start of a miner's career will provide necessary information for
evaluating the results of subsequent spirometry tests and final
paragraph (c)(1) requires a mandatory follow-up examination be given 3
years after the miner's initial examination.
Final Sec. 72.100 does not include the suggestion that additional
chest radiographs be provided after 9 to 12 years of coal mine
employment and every 6 years thereafter. The final rule is consistent
with NIOSH regulations under 42 CFR 37.3(b)(2) and (b)(3). Both
pneumoconiosis and COPD develop slowly. It is unusual, for example, for
a miner to have a positive chest x-ray less than 10 years from first
exposure to respirable coal mine dust. However, if a miner has a
positive chest x-ray, it is important to intervene as promptly as
possible for maximum health protection. An interval of 5 years or less
between each miner's periodic spirometry examinations provides a
reasonable opportunity to ensure detection of important declines in a
miner's lung function due to dust exposure.
Final paragraph (d) is redesignated from proposed paragraph (d) and
includes a clarification. It requires each mine operator to develop and
submit for approval to NIOSH a plan in accordance with 42 CFR part 37
for providing miners with the examinations specified in paragraph (a)
and a roster specifying the name and current address of each miner
covered by the plan. The text ``in accordance with 42 CFR part 37'' was
added to final paragraph (d) to provide a reference to corresponding
NIOSH's requirements. The plan is essential to ensure that mine
operators provide the examinations within the time frames established
under this section and under 42 CFR part 37 and at an approved
facility. The final requirement for medical examinations will allow for
early detection and treatment and, to be effective, must be part of a
comprehensive program designed to prevent further progression of early
respiratory disease. The requirement for submitted plans to include a
roster specifying the name and current address of each miner covered by
the plan will provide NIOSH with the ability to ensure adequate
notification of the availability of medical examinations to covered
coal miners. NIOSH has found through its existing CWHSP that directly
contacting coal miners who are due for a chest examination results in a
higher participation rate. According to NIOSH, coal miners have
indicated that they would prefer to receive a letter from CWHSP at
their residence, rather than being notified by their employer, because
they feel that direct contact with the program provides them greater
confidentiality. NIOSH has requested that such rosters be provided
since the early 1990s and almost all operators have complied; so this
requirement would not create an additional burden for mine operators.
Some commenters stated that the content of the plan should be
clarified. NIOSH originally published the requirements for such plans
in 1978 (43 FR 33715) under 42 CFR 37.4, Plans for chest
roentgenographic examinations. Most recent amendments to Sec. 37.4
included changing the title of this section to Plans for chest
radiographic examinations (77 FR 56718, September 13, 1978). This is
the plan that is referenced in final paragraph (d).
Final paragraph (e), like the proposal, requires each mine operator
to post the approved plan for providing periodic examinations specified
in paragraph (a) on the mine bulletin board and to keep it posted at
all times. Posting the approved plan on the mine bulletin board can
help to improve miners' awareness of the plan, along with its purpose
and provisions. This is the same requirement that exists in 42 CFR
37.4(e). MSHA received no comments on this provision, and this
provision is finalized as proposed.
One commenter suggested that the proposal regarding the medical
surveillance should be addressed in a separate rulemaking.
Rather than address medical monitoring separately, MSHA is
including periodic examination requirements in this final rule as part
of its comprehensive initiative to ``End Black Lung--Act Now!'' The
Agency believes it is important to incorporate these requirements at
this time to identify, prevent, and reduce the incidence of adverse and
life-threatening respiratory diseases, including CWP, PMF, COPD, and
emphysema, which result from occupational exposure to respirable coal
mine dust.
2. Section 72.700 Respiratory Equipment; Respirable Dust
Final Sec. 72.700 establishes requirements for operators to make
available NIOSH-approved respiratory equipment, provide respirator
training, and to keep training records. Final Sec. 72.700 is the same
as the proposal except for revisions to clarify final paragraph (c).
Final Sec. 72.700, like the proposal, is derived from existing Sec.
70.300. It expands the scope of existing Sec. 70.300 to include all
coal mines, whether surface or underground, and includes coverage of
part 90 miners.
Two commenters stated that final Sec. 72.700 should require
operators to establish and implement a comprehensive respiratory
protection program similar to OSHA's program, which includes
requirements for medical examinations and fit testing, as well as
respirator maintenance, care, and storage.
In response, MSHA clarifies that the intent of the proposal was
only to extend respiratory protection equipment coverage to persons at
surface mines, persons at surface areas of underground mines, and part
90 miners and to provide equivalent health protection to all coal
miners regardless of the type of mine at which they work. Extending
coverage to part 90 miners is particularly important given the fact
that they have medical evidence of the development of pneumoconiosis.
Another commenter suggested that the final rule should revise and
update existing Sec. 72.710, which incorporates by reference the
American National
[[Page 24930]]
Standards Institute's (ANSI's) ``Practices for Respiratory Protection
ANSI Z88.2-1969'' standard. The commenter stated that the 1969 ANSI
standard is grossly outdated.
MSHA did not propose to modify the substance of Sec. 72.710. The
1969 ANSI standard still provides sufficient guidance to mine operators
for respiratory protection for coal miners in the limited situations
specified in MSHA regulations. Additionally, MSHA's emphasis in the
dust program is consistent with the Mine Act which does not permit the
substitution of respirators in lieu of environmental and engineering
controls.
Final Sec. 72.700(a), like the proposal, requires respiratory
protection equipment approved by NIOSH under 42 CFR part 84 (Approval
of Respiratory Protective Devices) to be made available to all persons
as required under parts 70, 71, and 90. In addition, it provides that
the use of respirators must not be substituted for environmental
control measures in the active workings. It also requires that each
operator must maintain an adequate supply of respirators.
MSHA received a number of comments on this provision. One commenter
supported the requirement that operators make respirators available to
persons when their respirable dust exposure exceeds the standard. The
commenter, however, stated the rule should clarify that operators are
prohibited from offering respirators that are not NIOSH-approved. In
response, final paragraph (a) is explicit in requiring that operators
must make available respiratory equipment approved by NIOSH in
accordance with 42 CFR part 84. Respirators that have not been approved
by NIOSH under 42 CFR part 84 have not met the construction,
performance, and respiratory protection thresholds established by
NIOSH.
Many commenters offered a number of reasons why respirators,
including powered air-purifying respirators (PAPRs), should be required
as a primary or supplemental means of controlling a miner's exposure to
respirable coal mine dust. Some commenters stated that respirators
provide the most protective and cost-effective way to protect miners
from respirable dust, especially in certain applications, such as on
longwalls and at mines on a reduced standard due to the presence of
quartz. Other commenters said that engineering and environmental
controls alone cannot protect miners' health. Some commenters stated
that respirators provide an added layer of health protection and ensure
that miners take a proactive role in protecting their own health.
In addition, several commenters stated that MSHA should allow mine
operators to use a hierarchy of controls to limit miners' exposure to
coal mine dust. This hierarchy of controls consists of using
engineering controls first, followed by administrative controls, and
finally suitable respirators, including NIOSH-approved PAPRs. These
commenters noted that MSHA permits the use of a hierarchy of controls
in metal and nonmetal mines to control miners' exposure to diesel
particulate matter. They also stated a rulemaking under section 101 of
the Mine Act could be used to establish a hierarchy of controls and
supersede the interim standard established by section 202(h) of the
Mine Act which prohibits the use of respirators as a substitute for
environmental controls in the active workings of the mine.
Some of these commenters stated that MSHA's failure to allow the
use of respirators, such as PAPRs, as a temporary supplemental control
is inconsistent with MSHA's 2000 and 2003 Plan Verification proposed
rules previously issued under two different Administrations. These
commenters noted that the previous proposed rules would have allowed
the use of PAPRs in limited circumstances as a supplementary control.
They further added that, even though MSHA had never considered PAPRs or
any other respirator to be an engineering control, MSHA included a
provision for PAPRs as a supplementary control in the previously
proposed rules, in part, as a response by MSHA to a Petition for
Rulemaking filed by the Energy West Mining Company. These commenters
stated that MSHA failed to provide any explanation for rejecting the
use of PAPRs as supplementary controls in the proposed rule and that
MSHA's failure to do so is a violation of Section 555(e) of the
Administrative Procedure Act. Finally, these commenters stated that
PAPRs should be treated as environmental controls similar to
environmentally controlled cabs that are allowed to be used on
bulldozers or shuttle cars.
Other commenters stated that using respirators as a means of
complying with the dust standard is contrary to the Mine Act and would
provide miners with a false sense of protection. Some commenters cited
the difficulty of wearing respirators in hot and sweaty jobs, and
dusty, dirty conditions, including in low coal. One commenter stated
that carrying a respirator adds an additional load to miners, who are
already overburdened with other equipment that they must carry into the
mine. The commenter further stated that allowing a mine operator to
control a miner's exposure to respirable dust by the use of a
respirator rather than engineering controls could result in dangerous
concentrations of dust suspended in the atmosphere, increasing the risk
of a coal dust explosion.
In the preambles to the 2000 and 2003 Plan Verification proposed
rules, MSHA stated that the Agency was addressing the Energy West
petition for rulemaking to allow the use of PAPRs as a supplemental
means of compliance. In the preamble to the 2000 proposed rule, MSHA
stated that the Agency would ``permit, under certain circumstances, the
limited use of either approved loose-fitting PAPRs or verifiable
administrative controls for compliance purposes'' (65 FR 42135). In the
preamble to the 2003 proposed rule, MSHA stated that the Agency was
proposing to ``permit the limited use of either approved PAPRs,
administrative controls, or a combination of both, for compliance
purposes, in those circumstances where further reduction of dust levels
cannot be reasonably achieved using all feasible engineering controls''
(68 FR 10800). In so doing, MSHA emphasized that the Mine Act
specifically prohibits using respirators as a substitute for
environmental controls in the active workings of the mine because
environmental or engineering controls are reliable, provide consistent
levels of protection to a large number of miners, allow for predictable
performance levels, can be monitored continually and inexpensively, and
can remove harmful levels of respirable coal mine dust from the
workplace (68 FR 10799). MSHA further stated that the proposed rule,
which would expand the use of supplementary controls under limited
circumstances to protect individual miners, ``is not a departure from
the Agency's long-standing practice of relying on engineering controls
to achieve compliance, since these measures would not be used as a
substitute or replacement for engineering control measures in the
active workings'' (68 FR 10800).
In the preamble to the 2010 proposed rule, MSHA noted that it had
received comments on the 2000 and 2003 Plan Verification proposed rules
that operators should be allowed to use respiratory equipment in lieu
of environmental and engineering controls to achieve compliance with
the proposed dust standards (75 FR 64446). In response, MSHA stated:
[[Page 24931]]
. . . proposed Sec. 72.700(a) would retain the existing requirement
that environmental controls be used as the primary means of
complying with applicable dust standards. MSHA experience indicates
that even when respirators are made available, miners may not use
them because they can be uncomfortable and impractical to wear while
performing work duties. In some cases, a miner may not be able to
use a respirator due to health issues. General industrial hygiene
principles recognize that engineering and environmental controls
provide more consistent and reliable protection.
The final rule does not contain provisions to allow operators to
use the hierarchy of controls or to use respirators, including PAPRs,
as supplementary controls to achieve compliance with the respirable
dust standards. As specified in Sections 201(b) and 202(h) of the Mine
Act and since passage of the 1969 Coal Act, MSHA has enforced an
environmental standard at coal mines; that is, the Agency samples the
concentration of respirable dust in the mine atmosphere rather than the
personal exposure of any individual. This is discussed elsewhere in the
preamble under final Sec. 70.201(c).
Engineering controls, also known as environmental controls, are the
most protective means of controlling dust generation at the source.
Used in the mining environment, engineering controls work to reduce
dust generation or suppress, dilute, divert, or capture the generated
dust. Well-designed engineering controls, such as environmentally
controlled cabs, provide consistent and reliable protection to all
workers because the controls are, relative to administrative controls
and respirators, less dependent upon individual human performance,
supervision, or intervention to function as intended.
The use of engineering controls as the primary means to control
respirable dust in the mine atmosphere is consistent with Sections
201(b) and 202(h) of the Mine Act. Section 201(b) of the Mine Act
states that the purpose of the dust standards is ``to provide, to the
greatest extent possible, that the working conditions in each
underground coal mine are sufficiently free of respirable dust
concentrations in the mine atmosphere . . .'' (30 U.S.C. 841(b)). In
addition, Section 202(h) of the Mine Act, and MSHA's existing
respiratory equipment standard under 30 CFR 70.300, both explicitly
state that ``[u]se of respirators shall not be substituted for
environmental control measures in the active workings'' (30 U.S.C.
842(h)).
Final paragraph (a) is also consistent with the Dust Advisory
Committees' unanimous recommendation that respiratory equipment should
not be permitted to replace environmental control measures, but should
continue to be provided to miners until environmental controls are
implemented that are capable of maintaining respirable dust levels in
compliance with the standard.
The final rule requires an operator to make respirators available
to all persons whenever exposed to concentrations of respirable dust in
excess of the levels required to be maintained. The use of approved
respiratory equipment should be encouraged until the operator
determines the cause of the overexposure and takes corrective actions.
NIOSH also recognized the importance of controlling miners'
exposure to respirable coal mine dust by using environmental controls.
NIOSH's 1995 Criteria Document recommends that engineering controls
continue to be relied on as the primary means of protecting coal miners
from respirable dust.
Under the final rule, operators must continue to engineer such dust
out of the mine atmosphere in order to maintain ambient dust levels in
the active workings at or below the standard. In the preambles to the
2000 and 2003 Plan Verification proposed rules, MSHA explained that its
experience at that time was that there were limited situations where
exposures could not be consistently controlled by available
technologies (65 FR 42134; 68 FR 10798-10799, 10818). MSHA has
determined that it is technologically feasible for mine operators to
achieve compliance with the dust standards in this final rule using
existing and available engineering controls and work practices.
Engineering controls, unlike respirators or administrative controls,
have the advantage of curbing atmospheric dust concentrations, which
reasonably ensures that all miners in the area are adequately protected
from overexposures. Based on MSHA's experience, respirators are not as
effective as engineering controls in reducing miners' exposures to
respirable coal mine dust. MSHA is aware that miners are likely to
remove their respirators when the miners are performing arduous tasks,
chewing tobacco, sick, hot or sweaty, or when the respirator is
uncomfortable, thereby subjecting the miner to ambient dust
concentrations that may not meet the standard.
Similarly, the effectiveness of administrative controls requires
oversight to ensure that miners adhere to the controls, such as
restrictions of time in an area or switching duties. Using
administrative controls also requires that there must be a sufficient
number of qualified miners available to perform the specific duties.
Moreover, as pointed out by some commenters, using engineering
controls to regulate dust concentrations provides a critical collateral
safety benefit because such control mechanisms, by reducing dust, also
reduce the risk of coal dust-fueled explosions or fires. Rotating
miners in and out of dusty atmospheres or requiring them to use
respirators in dusty conditions does not ensure that coal mine dust, an
explosive fuel, is suppressed in the first instance.
For these reasons, the final rule, like existing Sec. 70.300,
requires mine operators to rely on engineering or environmental dust
controls to ensure that respirable dust concentrations in the
atmosphere do not exceed the respirable dust standard.
Final Sec. 72.700(b), like the proposal, provides that when
required to make respirators available, the operator must provide
training prior to the miner's next scheduled work shift, unless the
miner received training within the previous 12 months on the types of
respirators made available. It further requires that the training must
include the care, fit, use, and limitations of each type of respirator.
The final training requirements are consistent with the
recommendations made in the 1995 NIOSH Criteria Document. As explained
in the proposal, the training requirement ensures that miners are
informed about the respiratory protection options available to them.
The value of all personal protective equipment, including respirators,
is partially contingent on the correct use, fit, and care of the device
by the wearer. Meaningful instruction to miners in how to use, care,
and fit the available respirators, as well as their technical and
functional limitations, encourages miners to actively participate in
maximizing the potential benefits of using a respirator, especially
during periods when the respirable dust levels are reported as
exceeding the allowable level. In addition, retraining on the
respiratory equipment is necessary when the miner has not been trained
within the previous 12 months on the specific types of respirators that
are made available. Retraining should reiterate the information
presented during the initial training session to refresh miners'
knowledge.
One commenter stated that the training should include a requirement
that operators explain why respirators are necessary. This commenter
stated that an explanation of the need for
[[Page 24932]]
respirators would motivate miners to use them. Final paragraph (b) is
intended to provide a basic framework for minimum areas of instruction.
Because the training required by final paragraph (b) is performance-
oriented, operators can adapt the training to best meet the needs of
their miners. As clarified in the proposal, operators can develop a
training module that includes course content beyond the subject-matter
requirements set forth in final paragraph (b), or they can choose to
allot a different amount of training time to each subject matter, based
on the particular skills and knowledge of the miners. Although final
paragraph (b) does not explicitly provide that operators must explain
why respirators may be needed, MSHA anticipates that such a basic topic
will be addressed in any well-designed training curriculum.
Final paragraph (b) neither specifies a minimum required duration
for the training, nor requires MSHA approval of the operator's training
curriculum. Mine operators should customize training programs, and
adjust them as needed, so as to best accommodate the individual
circumstances at each mine.
During the public comment period, MSHA requested comment on whether
the time required for respirator training should be separate from part
48 training. One commenter responded. This commenter recommended that
training time should be specifically devoted for that purpose, rather
than allow such training to be subsumed by part 48 training.
Like the proposal, final paragraph (b) requires that the training
provided under this section be in addition to the training given to
fulfill part 48 requirements. Separating the training on how to use,
care, and fit the available respirators, as well as their technical and
functional limitations, from the part 48 training requirements will
give each of the specified areas the focused treatment that is needed
for effective training.
Final Sec. 72.700(c) includes a nonsubstantive change from the
proposal. It requires that an operator keep the training record at the
mine site for 24 months after completion of the training. The proposal
would have required a ``2 year'' retention period. The term ``24
months'' included in final paragraph (c) is consistent with other
provisions in the final rule. Final paragraph (c) further provides that
an operator may keep the training record elsewhere if the record is
immediately accessible from the mine site by electronic transmission.
In addition, it requires that upon request from an authorized
representative of the Secretary, Secretary of HHS, or representative of
miners, the operator must promptly provide access to any training
records. Final paragraphs (c)(1)-(3) require the record to include the
date of training, the names of miners trained, and the subjects
included in the training.
Final paragraphs (c)(1)-(i)(3) are new; the paragraphs were added
to ensure that authorized representatives of the Secretary or Secretary
of HHS, or the miners' representative can determine whether and when
the training required by Sec. 72.700(b) has been provided to miners
who may use respiratory protection equipment.
During the public comment period, MSHA solicited comment on the
proposed requirement that operators retain the training record for 2
years. MSHA received a few comments supporting the proposal. As with
MSHA's other training record requirements, the 24-month retention
requirement allows MSHA sufficient time within which to verify that the
required training has been provided. In addition, because a 12-month
interval can elapse before retraining becomes applicable, the 24-month
record retention period is reasonable.
MSHA recognizes that it may be more efficient for some mine
operators to store records at a centralized location. Given that
electronic recordkeeping has become commonplace in the mining industry,
final paragraph (c) allows mine operators to store the training record
at locations that are remote or at a distance from the mine site, so
long as they are immediately accessible by electronic transmission
(e.g., fax or computer). In addition, final paragraph (c) is consistent
with MSHA's other recordkeeping provisions, as well as with the
Agency's statutory right to access records under Section 103(h) of the
Mine Act.
3. Section 72.701 Respiratory Equipment; Gas, Dusts, Fumes or Mists
Final Sec. 72.701 is the same as the proposal. Final Sec. 72.701,
like the proposal, is derived from existing Sec. 70.305. It expands
the scope of existing Sec. 70.305 to include all coal mines, whether
surface or underground, and includes coverage of part 90 miners. It
requires that respiratory equipment approved by NIOSH under 42 CFR part
84 must be provided to persons exposed for short periods to inhalation
hazards from gas, dusts, fumes, or mists. It further requires that when
exposure is for prolonged periods, the operator must take other
measures to protect such persons or to reduce the hazard.
Because inhalation hazards from gases, dusts, fumes, and mists can
be found at surface operations too, the final rule expands the scope of
coverage to include miners at both surface and underground operations.
MSHA's longstanding interpretation of the term ``short periods'' means,
for example, the time required to drill three or four holes for trolley
hangers, to drill holes to take down a piece of loose roof, to drill
shot holes in a roof fall, to make small spray applications of paint or
sealing compound. MSHA considers prolonged periods to be any duration
of time that does not fit the interpretation of ``short periods.''
One commenter stated that MSHA standards for respiratory protection
are outdated. The commenter pointed out that, in 1998, NIOSH revised
its requirements to require a cartridge change schedule to be
established for air purifying respirators that are used to reduce the
inhalation hazards from gas. The commenter also added that OSHA's
standards address the cartridge change schedule.
In response, MSHA clarifies that the intent of the proposal was
only to extend the respiratory equipment coverage to persons at surface
mines, persons at surface areas of underground mines, and part 90
miners. The proposal did not intend to modify the existing technical
standards concerning respiratory equipment to control miners' exposure
to gas, dusts, fumes, or mists. Any revisions of that nature would be
undertaken in a separate rulemaking.
4. Section 72.800 Single, Full-Shift Measurement of Respirable Coal
Mine Dust
Final Sec. 72.800 is clarified from the proposal. It provides that
the Secretary will use a single, full-shift measurement of respirable
coal mine dust to determine the average concentration on a shift, since
that measurement accurately represents atmospheric conditions to which
a miner is exposed during such shift.
Proposed Sec. 72.800 provided that the Secretary may use a single
full-shift sample to determine compliance with the dust standard if a
single sample is an accurate measurement of miners' exposure to
respirable coal mine dust. The Secretary has found, in accordance with
sections 101 (30 U.S.C. 811) and 202(f)(2) (30 U.S.C. 842(f)(2)) of the
Mine Act, that the average concentration of respirable dust to which
each miner in the active workings of a coal mine is exposed can be
accurately measured over a single shift. Accordingly, the
[[Page 24933]]
1972 Joint Finding,\60\ by the Secretary of the Interior and the
Secretary of Health, Education, and Welfare, on the validity of single-
shift sampling is rescinded. Final Sec. 72.800 clarifies that MSHA
will make a compliance determination based on a single full-shift MSHA
inspector sample.
---------------------------------------------------------------------------
\60\ See footnote 2 of this preamble.
---------------------------------------------------------------------------
In addition, final Sec. 72.800 clarifies that noncompliance with
the respirable dust standard or the applicable respirable dust standard
when quartz is present, in accordance with subchapter O, is
demonstrated when a single, full-shift measurement taken by MSHA meets
or exceeds the applicable ECV in Table 70-1, 71-1, or 90-1, that
corresponds to the applicable standard and the particular sampling
device used. Final Sec. 72.800 is consistent with proposed Sec. Sec.
70.207(e); 70.208(d); 70.209(c); 71.207(i); 90.208(c); and 90.209(c).
Those proposed provisions provided that no single full-shift sample
meet or exceed the ECV that corresponds to the applicable dust standard
in Tables 70-1, 71-1, and 90-1, and would have applied to both operator
and MSHA inspector samples. However, as explained elsewhere in this
preamble under final Sec. 70.208(e), under the final rule, a
noncompliance determination based on a single full-shift sample only
applies to MSHA inspector samples and not operator samples.
Accordingly, the single full-shift sampling provision is included in
final Sec. 72.800 and not in parts 70, 71, and 90.
Likewise, final Sec. 72.800 clarifies that upon issuance of a
citation for a violation of the standard, and for MSHA to terminate the
citation, the operator must take the specified actions in subchapter O,
as applicable. Final Sec. 72.800 is consistent with the actions
specified in proposed Sec. Sec. 70.207(g) and (h); 70.208(f);
70.209(e) and (f); 71.207(k) and (l); and 90.209(e). Those proposed
provisions would have applied to both operator and MSHA inspector
single full-shift samples. Under final Sec. 72.800, a noncompliance
determination on a single full-shift sample is only based on an MSHA
inspector's single full-shift sample and not an operator's single full-
shift sample. Noncompliance based on an operator's samples consists of
either 2 or 3 operator samples (depending on where the sample is taken)
or the average of all operator samples, but not both. Accordingly, the
specified actions are included in final Sec. 72.800. These actions are
consistent with final Sec. Sec. 70.206(h) and (i); 70.207(g) and (h);
70.208(h) and (i); 70.209(f) and (g); 71.206(k) and (l); and 90.207(f),
which apply when a citation is issued based on an operator's samples.
Several commenters stated that, in accordance with Sec. 202(f) of
the Mine Act, MSHA is required to conduct congressionally-mandated
joint rulemaking with NIOSH to support a finding that single full-shift
samples provide accurate results and that MSHA cannot unilaterally
rescind the 1972 Joint Finding. Nothing in Section 202(f) of the Mine
Act requires a joint rulemaking with NIOSH either to rescind the 1972
Joint Finding by MSHA and HHS or to promulgate the single sample
provision. Section 202(f) of the Mine Act states verbatim from Sec.
202(f) of the Coal Act. It states that the term ``average
concentration'' means a determination that accurately represents the
atmospheric conditions regarding the respirable coal mine dust to which
each miner in the active workings is exposed as measured over a single
shift only, unless the Secretary and the Secretary of Health and Human
Services find, in accordance with section 101 of the Mine Act, that
such single shift measurement will not accurately represent such
atmospheric conditions during such shift.
On July 17, 1971, MSHA's predecessor, the Department of the
Interior, Mining Enforcement and Safety Administration, together with
the Secretary of Health, Education, and Welfare, issued a proposed
``Notice of Finding That Single Shift Measurements of Respirable Dust
Will Not Accurately Represent Atmospheric Conditions During Such
Shift'' (36 FR 13286). The proposed notice stated that pursuant to
Section 101 of the Federal Coal Mine Health and Safety Act of 1969, the
Secretaries were planning to jointly issue a finding ``that single
shift measurement of respirable dust will not, after applying valid
statistical techniques to such measurement, accurately represent the
atmospheric conditions to which the miner is continuously exposed.'' On
February 23, 1972, the Agencies issued the Notice of Finding That a
Single Shift Measurement of Respirable Dust Will Not Accurately
Represent Atmospheric Conditions During Such Shift (37 FR 3833) (1972
Joint Finding).
The 1972 Joint Finding is based on Section 202(f) of the Mine Act.
Section 201(a) of the Mine Act states that sections 202 through 206 are
interim standards. Therefore, the 1972 Joint Finding is an interim
mandatory health standard. See National Mining Association v. Secretary
of Labor, 153 F.3d 1264, 1267-68 (11th Cir. 1998).
Section 201(a) of the Mine Act gives the Secretary the authority to
supersede interim mandatory health standards of the Mine Act with
``improved mandatory health and safety standards.'' In doing so,
Section 201(a) states that the Secretary must enact the new standards
according to the provisions of Section 101 of the Mine Act. Id. at
1268. Section 101(a)(6) authorizes the Secretary, alone, to promulgate
mandatory health standards. The use of a single, full-shift measurement
of respirable coal mine dust to determine average concentration on a
shift is an improved mandatory health standard promulgated by MSHA
under section 101 of the Mine Act. One commenter acknowledged that, in
accordance with Section 201(a) of the Mine Act, an ``interim mandatory
health standard under the Mine Act can be revised under the rulemaking
provisions of the Mine Act Sec. 101.'' In accordance with Sec.
201(a), the 1972 Joint Finding is superseded by final Sec. 72.800--an
improved mandatory health standard.
In addition, final Sec. 72.800 is consistent with the 1998 Final
Joint Finding, issued by both MSHA and NIOSH, which concluded that the
1972 Joint Finding was incorrect and that the average respirable dust
concentration to which a miner is exposed can be accurately measured
over a single shift (63 FR 5664). Final Sec. 72.800 is also consistent
with the 1995 Criteria Document which recommends the use of single,
full-shift samples to compare miners' exposures to the recommended
exposure limit (REL).
Several commenters stated that they supported the use of single,
full-shift samples to make noncompliance determinations. Others
questioned the accuracy of single, full-shift samples, stating a
preference for MSHA's existing five-sample average approach.
Final Sec. 72.800 allows MSHA to base determinations of
noncompliance on the results of single, full-shift samples collected by
the Agency. It is based on MSHA's experience, review of section 202(f)
of the Mine Act, significant improvements in sampling technology,
updated data, and comments and testimony on previous notices and
proposals addressing the accuracy of single, full-shift measurements
meeting the NIOSH Accuracy Criterion. In addition, this finding is
consistent with recommendations contained in both the 1995 NIOSH
Criteria Document and the 1996 Dust Advisory Committee Report. In the
Criteria Document, NIOSH recommended the use of single, full-shift
samples to compare worker exposures with its REL and concluded that
this action is consistent with
[[Page 24934]]
Section 202(f) of the Act. The Dust Advisory Committee recommended that
MSHA change its compliance sampling program to allow the use of single
full-shift samples for determining compliance; seven of nine Committee
members affirmed this recommendation.
Section 202(f) of the Mine Act does not define the term
``accurately represent.'' Therefore, MSHA applied the accuracy
criterion developed and adopted by NIOSH (Kennedy et al., 1995) in
judging whether a single, full-shift measurement will accurately
represent the full-shift atmospheric dust concentration on the
particular shift sampled. For a single, full-shift concentration to be
considered an accurate measurement, the NIOSH Accuracy Criterion
requires that such measurement come within 25 percent of the
corresponding true dust concentration at least 95 percent of the time
(Kennedy et al., 1995). It covers both precision and uncorrectable
bias. Because a single, full-shift sample measures the average
respirable coal mine dust on a specific shift at the sampling location,
environmental variability beyond what occurs at the sampling location
on the specific shift sampled is not relevant to assessing measurement
accuracy.
Since first published in 1977 (Taylor et al., 1977), the NIOSH
Accuracy Criterion has been used by NIOSH and others in the
occupational health professions to validate sampling and analytical
methods. It was devised as a goal for the development and acceptance of
sampling and analytical methods capable of generating reliable exposure
data for contaminants at or near the OSHA permissible exposure limits.
MSHA recognizes that all measurements of atmospheric conditions are
susceptible to some degree of measurement error. Although the Mine Act
requires that each measurement ``accurately represent'' the
concentration of respirable dust, the Act neither defines ``accurately
represent'' nor provides limits on the degree of potential error to be
tolerated. The NIOSH Accuracy Criterion is relevant and widely
recognized and accepted in the occupational health professions as
providing acceptable limits for industrial hygiene measurements. MSHA
considers a single, full-shift measurement of respirable coal mine dust
to ``accurately represent'' atmospheric conditions at the sampling
location, if the sampling and analytical method used meet the NIOSH
Accuracy Criterion.
Although the NIOSH Accuracy Criterion does not require field
testing to determine method accuracy, it recognizes that field testing
does provide a further test of the method. However, in order to avoid
confusing real differences in dust concentration with measurement
errors when testing is done in the field, precautions may have to be
taken to ensure that all samplers are exposed to the same
concentrations (Kennedy et al., 1995). To determine, so far as
possible, the accuracy of its sampling and analytical method under
mining conditions, MSHA conducted 22 field tests in an underground coal
mine. To provide a valid basis for assessing accuracy, 16 CMDPSUs were
exposed to the same dust concentration during each field test using a
specially designed portable chamber. The data from these field
experiments were used by NIOSH in its direct approach to determining
whether MSHA's method meets the long-established NIOSH Accuracy
Criterion (Kogut et al., 1997).
The criterion requires that, with high confidence, measurements
must consistently fall within a specified percentage of the true
concentration being measured. Measurements that were repeatable but
significantly biased, so that they systematically missed the mark by a
wide margin, would not meet the Accuracy Criterion. Therefore,
fulfilling the NIOSH Accuracy Criterion depends not only on measurement
precision, but also on measurement bias if any such bias exists.
Precision refers to consistency or repeatability of results, while bias
refers to a systematic error that is present in every measurement.
Since the amount of dust present on a filter capsule in a CMDPSU
used by an MSHA inspector is measured by subtracting the pre-exposure
weight from the post-exposure weight, any bias present in both weight
measurements is mathematically canceled out by subtraction.
Furthermore, as will be discussed later, a control (i.e., unexposed)
filter capsule has been and will continue to be pre- and post-weighed
along with the exposed filter capsule. The weight gain of the exposed
capsule will be adjusted by the weight gain or loss of the control
filter capsule. Therefore, any bias that may be associated with
differences in pre- and post-exposure laboratory conditions or with
changes introduced during storage and handling of the filter capsules
used with the CMDPSU will also be mathematically canceled out. The use
of control filters is unnecessary when sampling with the approved CPDM
due to the unit's design. Unlike the CMDPSU, which is a dust sampling
pump capable of only collecting respirable dust particles from the mine
air that must be weighed later in the laboratory, the CPDM is a
complete sampling system that does the sample collection and pre- and
post-weighing of the collection filter on the same day. As a result,
there is no need to address the potential bias that may be associated
with day-to-day changes in laboratory conditions or introduced during
storage and handling of the collection filter. Therefore, MSHA
concludes that the improved sampling and analytical method is
statistically unbiased. This means that such measurements contain no
systematic error. In addition, if any systematic error existed, it
would be present in all measurements, and so, measurement bias would
not be reduced by making multiple measurements.
For unbiased sampling and analytical methods, a standard
statistic--called the Coefficient of Variation (CV)--is used to
determine if the method meets the NIOSH Accuracy Criterion. The CV,
which is expressed as either a fraction (e.g., 0.05) or a percentage
(e.g., 5 percent), quantifies measurement accuracy for an unbiased
method. An unbiased method meets the NIOSH Accuracy Criterion if the
true CV is no more than 0.128 (12.8 percent). However, since it is not
possible to determine the true CV with 100-percent confidence, the
NIOSH Accuracy Criterion contains the additional requirement that there
be 95-percent confidence that measurements will come within 25 percent
of the true concentration 95 percent of the time. Stated in
mathematically equivalent terms, an unbiased method meets the NIOSH
Accuracy Criterion if there is 95-percent confidence that the true CV
is less than or equal to 0.128 (12.8 percent).
OSHA has frequently employed a version of the NIOSH Accuracy
Criterion when issuing new or revised single substance standards. For
example, OSHA's benzene standard provides: ``[m]onitoring shall be
accurate, to a confidence level of 95 percent, to within plus or minus
25 percent for airborne concentrations of benzene'' (29 CFR 1910.1028).
Similar wording can be found in the OSHA standards for vinyl chloride
(29 CFR 1910.1017); arsenic (29 CFR 1910.1018); lead (29 CFR
1910.1025); 1, 2-dibromo-3-chloropropane (29 CFR 1910.1044);
acrylonitrile (29 CFR 1910.1045); ethylene oxide (29 CFR 1910.1047);
and formaldehyde (29 CFR 1910.1048). For vinyl chloride and
acrylonitrile, the margin of error permitted for the method is 35 percent at 95 percent confidence at the permissible exposure
limit.
[[Page 24935]]
When measuring exposures for enforcement purposes, OSHA uses, when
possible, methods that meet the NIOSH Accuracy Criterion. However,
measurement techniques meeting the NIOSH Accuracy Criterion are not
available for some substances. In either case, the CV determined for
the method is used in a test procedure to determine noncompliance, with
at least 95-percent confidence. The noncompliance test procedure was
described in the 1977 NIOSH Occupational Exposure Sampling Strategies
Manual. The OSHA inspector should use the sampling and analytical
method CV to determine compliance on a single shift (Leidel et al.,
U.S. Department of Health, Education, and Welfare, NIOSH Publication
No. 77-173, 1977). The procedure NIOSH described is mathematically
identical to that used, both then and now, by OSHA compliance officers.
Some commenters stated that averaging should continue to be used
because coal mine dust exposure is related to chronic health effects
that occur over a lifetime and not as a result of single shift's
overexposure. Other commenters stated that a single, full-shift
measurement cannot accurately estimate a miner's exposure on a normal
workday because a single sample with high or low weight gains may be an
aberration due to dust suspended in the atmosphere or changing
conditions in the mine such as the height and slope of the seam.
Section 202(b) of the Mine Act (30 U.S.C. 842(b)), explicitly
requires that the average dust concentration be continuously maintained
at or below the applicable standard on each shift. Overexposures above
the standard may occur even when the average is below the standard. In
the context of MSHA's single sample finding, the ``atmospheric
conditions'' means the fluctuating concentration of respirable coal
mine dust during a single shift. These are the atmospheric conditions
to which a miner at the sampling location may be exposed. Therefore,
MSHA's single-sample determination pertains only to the accuracy in
representing the average of the fluctuating dust concentration over a
single shift.
Some commenters stated that the average dust concentration over a
full shift is not identical at every point within a miner's work area
due to humidity, weather outside, or occasional geological phenomenon.
Section 202(a) of the Mine Act gives the Secretary the discretion to
determine the area to be represented by respirable dust sampling
collected over a single shift. Although dust concentrations in the mine
environment can vary from location to location, even within a small
area near a miner, the Mine Act does not specify the area that the
measurement is supposed to represent, and the sampler unit may
therefore be placed in any location, reasonably calculated to determine
excessive exposure to respirable dust. Because the Secretary intends to
prevent excessive exposures by limiting dust concentrations in the
active workings as intended by the Mine Act, it is sufficient that each
measurement accurately represent the respirable dust concentration at
the corresponding sampling location only. Limiting the dust
concentration ensures that no miner in the active workings will be
exposed to excessive concentrations of respirable coal mine dust.
Moreover, MSHA does not intend to use a single, full-shift measurement
to estimate any miner's exposure (personal) because no sampling device
can exactly duplicate the particle inhalation and deposition
characteristics of a miner at any work rate (these characteristics
change with work rate), let alone at the various work rates occurring
over the course of a shift. Limiting the respirable dust concentration
to which each miner is exposed in the active workings (area sampling)
ensures that the respirable dust concentration inhaled by any miner is
limited.
Some commenters supported the use of single, full-shift samples
because it eliminates an important source of sampling bias due to
averaging.
Final Sec. 72.800 provides for single, full-shift sampling by MSHA
because the single, full-shift samples may be above the standard even
when multiple shift averages are below the standard. For example, five
samples of: 3.4, 2.7, 2.6, 0.7, and 0.5 would result in an average of
1.98 mg/m\3\, which meets the 2.0 mg/m\3\ standard, although 3 single
samples exceed the standard.
Moreover, averaging multiple samples is not likely to produce
results that are more accurate than the results of a single sample.
MSHA intends to apply a single sample measurement taken during a shift,
and is not extrapolating those results to other past shifts. A detailed
description of the issue involving sampling bias due to averaging is
provided in Appendix A of the 2000 single sample proposed rule (65 FR
42108). Available at http://www.msha.gov/REGS/FEDREG/PROPOSED/2000PROP/00-14075.PDF].
Although averaging is one of the two methods of determining
noncompliance with the respirable coal dust standard pertaining to
operator sampling, in the final rule, MSHA changed the existing
averaging method so that there is no longer an averaging process where
miners are exposed to high levels of respirable coal mine dust and no
action is taken to lower dust levels. Under the existing standards,
corrective action is required only after the average of five operator
samples exceeds the respirable coal mine dust standard and a citation
is issued. This permits specific instances of miners' overexposures
without requiring any corrective action by the operator to reduce
concentrations to meet the standard. The final rule requires immediate
corrective actions to lower dust concentrations when a single, full-
shift operator sample meets or exceeds the excessive concentration
value for the applicable dust standard. These corrective actions will
result in reduced respirable dust concentrations in the mine atmosphere
and, therefore, will provide better protection of miners from further
high exposures.
Of the commenters who questioned the accuracy of single full-shift
sampling, some stated that dust sample results from the existing and
proposed sampler are only estimates of actual dust exposures and those
estimates of exposures are dependent on the performance of the sampler,
the impact of the conditions under which the sample is collected, and
the accuracy of the analysis and weighing of the collected sample.
Therefore, they stated that averaging produces a more accurate
representation of the dust to which a miner is exposed, and that making
health risk and protection decisions on less accurate data provides
less protection than making decisions on more accurate data.
Due to advances in sampling technology, MSHA has safeguards in
place to ensure that a single sample taken with an approved CMDPSU will
accurately measure coal mine dust concentrations during a shift. To
eliminate the potential for any bias that may be associated with day-
to-day changes in laboratory conditions or introduced during storage
and handling of filter capsules, MSHA is using new stainless steel
backed filter cassettes which demonstrate better weighing stability to
minimize pre-and post-weighing variability. In addition, both MSHA and
the manufacturer of the filter cassette are using semi-micro balances
with improved weighing procedures. Finally, the new generation of
sampling pumps currently in use, which incorporates the latest
technology in pump design to provide more constant flow throughout the
sampling period, increases the accuracy of MSHA-collected dust samples.
The validity of the sampling and analytical process is
[[Page 24936]]
an important aspect of obtaining accurate measurements. Since passage
of the Coal Act, there has been an ongoing effort by MSHA and NIOSH to
improve the accuracy and reliability of the entire sampling process. In
1980, MSHA issued regulations revising sampling, maintenance and
calibration procedures in 30 CFR parts 70, 71, and 90. These revisions
were designed to minimize human and mechanical errors and ensure that
samples collected with the approved CMDPSU accurately represent the
full-shift, average atmospheric dust concentration at the location of
the sampler unit. These provisions require: (1) Certification of the
competence of all individuals involved in the sampling process and in
maintaining the sampling equipment; (2) calibration of each sampler
unit at least every 200 hours; (3) examination, testing, and
maintenance of units before each sampling shift to ensure that the
units are in proper working order; and (4) checking of sampler units
during and at the end of sampling to ensure that they are operating
properly and at the proper flow rate. In addition, significant changes,
including robotic weighing and the use of electronic balances, were
made in 1984, 1994, and 1995. These changes improved the reliability of
sample weighings at MSHA's Respirable Dust Processing Laboratory and
are discussed below.
In addition, in 2010, MSHA published revised requirements that it
and NIOSH use to approve sampling devices that monitor miner exposure
to respirable coal mine dust (75 FR 17512, April 6, 2010). The final
rule updated approval requirements for the existing CMDPSU to reflect
improvements in this sampler over the past 15 years. The final rule
also established criteria for approval of the new CPDM.
All of these efforts have improved the accuracy and reliability of
the sampling process since the time of the 1971 proposed and the 1972
final Joint Findings. A discussion follows on each of the three phases
of the sampling process involving the use of the approved CMDPSU:
sampler unit performance, collection procedures, and sample processing.
In addition, the accuracy of measurements taken with an approved CPDM
is discussed in Section III.C., Feasibility in this preamble, and in
greater detail by Volkwein, et al., in two NIOSH Reports of
Investigations (RI 9663, 2004; and RI 9669, 2006).
In accordance with the provisions of section 202(e) of the Mine Act
(30 U.S.C. 842(e)), both MSHA and NIOSH administer a comprehensive
certification process under 30 CFR part 74 to approve dust sampler
units for use in coal mines. To be approved for use, a sampler unit
must be intrinsically safe, which is determined by MSHA. A sampler unit
must also meet stringent technical and performance requirements
established by NIOSH that govern the quantity of respirable dust
collected and flow rate consistency over the full shift or up to 12
hours when operated at the prescribed flow rate. As necessary, NIOSH
also conducts performance audits of approved sampler units purchased on
the open market to determine if the units are being manufactured in
accordance with the specifications upon which the approval was issued.
The system of technical and quality assurance checks currently in place
is designed to prevent a defective sampler unit from being manufactured
and made commercially available to the mining industry or to MSHA. In
the event that these checks identify a potential problem with the
manufacturing process, established procedures require immediate action
to correct the problem.
In 1992, NIOSH approved the use of new tamper-resistant filter
cassettes with features that enhanced the integrity of the sample
collected when using the CMDPSU. A backflush valve was incorporated
into the outlet of the cassette, preventing reverse airflow through the
filter cassette, and an internal flow diverter was added to the filter
capsule, reducing the possibility of dust dislodged from the filter
surface from falling out of the capsule inlet.
In 1999, based on MSHA studies (Kogut et al., 1999) involving the
weighing stability of the CMDPSU filter design, and in an effort to
standardize the manufacturing process, the filter cassette manufacturer
submitted for NIOSH approval a modification to the design. The
modification involved replacing the Tyvek[supreg] support pad with a
stainless steel wheel, similar to the one located on the inlet side of
the collection filter. On October 18, 2000, NIOSH approved the filter
cassettes with stainless steel backup pads to be used to collect
respirable coal mine dust exposure measurements. OSHA also began using
filter cassettes with stainless steel backup pads to determine
exposures for various particulates.
In 1995, MSHA replaced all pumps in use by inspectors with new
constant-flow pumps that incorporated the latest technology in pump
design. These pumps provide more consistent flow throughout the
sampling period. Nevertheless, MSHA recognizes that as these pumps age,
deterioration of the performance of older pumps could become a concern.
However, there is no evidence that the age of the equipment affects its
operational performance if the equipment is maintained as prescribed by
30 CFR parts 70, 71, and 90. Therefore, in addition to using these
pumps, inspection procedures require MSHA inspectors to make a minimum
of two flow rate checks during a sampling shift to ensure that the
sampler unit is operating properly.
A sample is voided if the proper flow rate was not maintained
during the final check at the conclusion of the sampling shift. In
fiscal year 2011, only 118 samples, or approximately 0.2 percent, of
the 54,809 inspector samples processed were voided because the sampling
pump either failed to operate throughout the entire sampling period or
failed to maintain the proper flow rate during the final check. Units
found not meeting the requirements of part 74 are immediately repaired,
adjusted, or removed from service.
The potential effect of vibration on the accuracy of a respirable
dust measurement was recognized by NIOSH in 1981. An investigation,
supported by NIOSH, was conducted by the Los Alamos National Laboratory
which found that vibration has an insignificant effect on sampler
performance (Gray and Tillery, 1981).
MSHA regulations at 30 CFR parts 70, 71, and 90 prescribe the
manner in which mine operators are to take respirable dust samples. The
collection procedures are designed to ensure that the samples
accurately represent the amount of respirable dust in the mine
atmosphere to which miners are exposed on the shift sampled. MSHA
considers samples taken with an approved sampler in accordance with
these procedures to be valid.
Some commenters stated that a single, full-shift measurement cannot
accurately estimate a miner's exposure on a normal workday due to a
miner's behavior such as dropping the sampling unit on a machine or the
mine floor, brushing off dust from work clothes, or briefly taking the
unit off. These commenters stated that averaging multiple samples would
provide leeway by reducing the impact of an aberrant sample.
In response to commenters' concerns, the Agency notes that MSHA
inspectors are normally in the general vicinity of the sampling
location, and therefore have knowledge of the specific conditions under
which samples are taken. In addition, MSHA inspectors are instructed to
ask miners wearing the sampler units whether anything that could have
affected the validity of the sample occurred during the shift. If so,
the inspector will note this on the data
[[Page 24937]]
card and request that the sample be examined to determine its validity.
In addition, when sampling with the CMDPSU, MSHA inspectors use
unexposed control filters to eliminate any bias that may be associated
with changes in laboratory conditions or changes introduced during
storage and handling of the filter capsules. A control filter is an
unexposed filter that was pre-weighed on the same day and in the same
laboratory as the filter used for sampling. This control filter is used
to adjust the weight gain obtained on each exposed filter. Any change
in weight of the control filter capsule is subtracted from the change
in weight of each exposed filter capsule. MSHA began using control
filters on May 7, 1998, and has continued this practice. The control
filter cassette, which is carried by the inspector in a shirt or
coverall pocket during the sampling inspection, is plugged to prevent
exposure to the mine environment.
Processing samples collected with the CMDPSU consists of weighing
the exposed and control (unexposed) filter capsules, recording the
weight changes, and examining certain samples in order to verify their
validity. Sample processing also includes electronic transmission of
the results to the MSHA Standardized Information System (MSIS) center
where dust concentrations are computed. The results are then
transmitted to MSHA enforcement personnel and to mine operators.
The procedures and analytical equipment, as well as the facility
used by MSHA to process respirable coal mine dust samples have been
continuously improved since 1970 to maintain a state-of-the-art
laboratory. From 1970 to 1984, samples were manually weighed using
semi-microbalances. MSHA automated this process in 1984 with the
installation of a state-of-the-art robotic system and electronic
balances, which increased the precision of sample-weight
determinations. MSHA improved the weighing precision in 1994, when both
the robotic system and balances were upgraded. Also, beginning in early
1998, all respirable coal mine dust samples were processed in a new,
specially designed clean room facility that maintains the temperature
and humidity of the environment. Currently, the temperature and
humidity are maintained at 21.0 [deg]C 2.0 [deg]C and 50%
10%, respectively. Using a modified HEPA filtration
system, the environment is maintained at a clean room classification of
1000 (near optimum for clean room cleanliness).
In mid-1995, MSHA implemented two modifications to its procedures
for processing inspector samples. One involved pre- and post-weighing
filter capsules to the nearest microgram ([mu]g) (0.001 mg) within
MSHA's laboratory. Prior to mid-1995, capsules had been weighed in the
manufacturer's laboratory before sampling, and then in MSHA's
laboratory after sampling. To maintain the integrity of the weighing
process, 8% of all filter capsules are systematically weighed a second
time. If a significant deviation is found, the balance is recalibrated
and all capsules with questionable weights are reweighed.
The other modification was to discontinue the practice of
truncating (to 0.1 mg) the recorded weights used in calculating dust
concentrations. MSHA now uses all significant digits associated with
the weighing capability of the balance (0.001 mg) when processing
samples. Both modifications improved the overall accuracy of the
measurement process.
To eliminate the potential for any bias that may be associated with
day-to-day changes in laboratory conditions or introduced during
storage and handling of the filters, MSHA is using control filters in
its enforcement program. Any change in the weight of the control filter
is subtracted from the measured change in weight of the exposed
filter.\61\
---------------------------------------------------------------------------
\61\ If a control filter either shows a weight gain greater than
60 micrograms or a weight loss greater than 30 micrograms, the
control filter is invalid and the associated concentration
measurements are not used for enforcement purposes.
---------------------------------------------------------------------------
Since MSHA began pre- and post-weighing filter capsules to the
nearest [mu]g, coal mine operators have asked to use filter capsules
pre-weighed to a [mu]g to collect optional samples that they submit to
MSHA for quartz analysis. The use of these pre-weighed filter capsules
may eliminate the need to sample multiple shifts in order to obtain
sufficient dust mass on the collection filter for quartz analysis.
Currently, filter capsules used by coal mine operators to sample in
accordance with 30 CFR parts 70, 71, and 90 are pre-weighed by the
manufacturer to the nearest [mu]g. However, for samples taken with
filters pre-weighed to the nearest [mu]g, only those with a net weight
gain of at least 450 [mu]g, contain sufficient dust mass to permit the
percentage of quartz to be determined. In 1996, the manufacturer
upgraded its equipment used to pre-weigh filter capsules and now uses
the same type of balance as MSHA's Respirable Dust Processing
Laboratory. This permits weight gain measurements to be made to the
nearest [mu]g.
The procedure requiring inspector samples to be pre- and post-
weighed in the same laboratory was developed prior to adopting control
filters and was based on the assumption that no control filters were
being used. Since use of the control filters adjusts for differences
that may exist in laboratory conditions on the days of pre- and post-
weighing, it is no longer necessary to pre- and post-weigh the filters
in the same laboratory. Currently, all filter cassettes being
manufactured for use with the approved CMDPSU are pre-weighed by the
manufacturer and post-weighed by MSHA.
To determine the viability of using exposed filters pre-weighed by
the manufacturer and post-weighed by MSHA in establishing the
percentage of quartz, MSHA conducted a study to quantify weighing
variability between the manufacturer and MSHA laboratories (Parobeck et
al., 1997). Based on this study, the overall imprecision of an
interlaboratory weight-gain measurement was estimated to be 11.5 [mu]g
for capsules with a stainless steel filter support pad. This estimate
closely matches the 11.6 [mu]g result reported for capsules with
stainless steel support pads in another study (Kogut et al., 1999). In
the latter study, unexposed capsules were pre-weighed by MSHA,
assembled into cassettes by the manufacturer, sent out to the field and
carried during an inspection, and then post-weighed by MSHA.
Using the higher estimate from the two studies, NIOSH reevaluated
the accuracy of MSHA's improved sampling and analytical method using
the CMDPSU, which incorporates a control filter adjustment and the
redesigned filter capsule. NIOSH concluded that the control filter
adjustment will correct for any potential biases due to differences in
laboratory conditions, so that it is no longer necessary to pre- and
post-weigh filter capsules in the same laboratory (Grayson, 1999a,
1999b). Therefore, in accordance with NIOSH, MSHA revised the
processing procedures for inspector samples from pre- and post-weighing
samples (filter capsules) in the same laboratory (with adjustment by a
control filter) to pre- and post-weighing of samples to the nearest
[mu]g in different laboratories (with continued adjustment by a control
filter).
To ensure the precision and accuracy of the pre-weight of filters
used by inspectors, MSHA instituted a quality assurance program to
monitor the daily production of filters weighed to the nearest [mu]g by
the manufacturer. This program conformed to MIL-STD-105D,
[[Page 24938]]
which was replaced by ANSI/ASQ Z1.4. The most recent version is ANSI/
ASQ Z1.4-2008, which defines the criteria currently used to monitor the
quality of pre-weighed filters used in MSHA's operator sampling
program.
One commenter stated that a new CPDM filter is used to collect
respirable coal mine dust without current lab procedures that analyze
blank filters to prevent known filter contamination and variability
from creating false weight readings. As was discussed earlier, because
of the CPDM's unique built-in weighing system, there is no need for a
blank or control filter. The CPDM, unlike the CMDPSU which is primarily
a sampling pump, incorporates a complete sampling and sophisticated
weighing system that is designed to pre-weigh the collection filter,
collect a dust sample, and then post-weigh the filter to determine the
weight of respirable dust collected on the filter on the same day. This
eliminates the need to address the potential bias that may be
associated with day-to-day changes in laboratory conditions or
introduced during storage and handling of the collection filter. More
importantly, the CPDM is designed to self-zero itself at the end of the
warm-up period so that any mass that may have been deposited on the
filter prior to sampling is not recorded.
All respirable dust samples collected using a CMDPSU and submitted
are considered valid unless the dust deposition pattern on the
collection filter appears to be abnormal or other special circumstances
are noted that would cause MSHA to examine the sample further. Standard
laboratory procedures, involving visual and microscopic examination as
necessary, are used to verify the validity of samples. Samples with a
weight gain of 1.4 milligrams (mg) or more are examined visually for
abnormalities such as the presence of large dust particles (which can
occur from agglomeration of smaller particles), abnormal discoloration,
abnormal dust deposition pattern on the filter, or any apparent
contamination by materials other than respirable coal mine dust. Also,
samples weighing 0.1 mg or less are examined for insufficient dust
particle count. Similar checks are also performed in direct response to
specific inspector or operator concerns noted on the dust data card to
which each sample is attached.
Regarding the presence of large dust particles, some greater than
10 microns ([mu]m) can be inhaled and reach the alveoli of the lungs
(Lippman and Albert, 1969). According to the British National Coal
Board, particles as large as 20 [mu]m diameter may be deposited on the
lungs although most lie in the range below 10 [mu]m diameter (Goddard
et al., 1973). Furthermore, due to the irregular shapes of dust
particles, the respirable dust collected by the MRE instrument (the
dust sampler used by the British Medical Research Establishment in the
epidemiological studies on which the U.S. respirable coal mine dust
standard was based) may include some dust particles as large as 20
[mu]m (Goddard et al., 1973). Moreover, MSHA studies have shown that
nearly all samples taken with approved CMDPSUs contain some oversized
particles (Tomb, 1981).
There are occasions, however, when oversized particles may be
considered a contaminant. For example, an excessive number of such
particles could enter the filter capsule if the sampling head assembly
is accidentally or deliberately ``dumped'' (turned upside down)
possibly causing some of the contents of the cyclone grit pot to be
deposited on the collection filter. When MSHA has reason to believe
that contamination has occurred, the suspect sample is examined to
verify its validity.
In addition, MSHA's laboratory procedures require any sample
exhibiting an excessive weight gain (over 6 mg) or showing evidence of
being ``dumped'' to be examined microscopically for the presence of an
excessive number of oversized particles (U.S. Department of Labor, MSHA
Method P-19, 2012). Samples identified by an inspector or mine operator
as possibly contaminated are also examined. If this examination
indicates that the sample contains an excessive number of oversized
particles according to MSHA's established criteria, then that sample is
considered to be invalid, and is voided and not used. In fiscal year
2011, only 26 of the 54,809 inspector and 42 of the 46,846 operator
samples processed were found to contain an excessive number of oversize
particles and thus were voided.
While rough handling of the CMDPSU or an accidental mishap could
conceivably cause a sample with a weight gain less than 6 mg to become
contaminated, short-term accidental inclinations of the cyclone will
not affect respirable mass measurements made with CMDPSU (Treaftis and
Tomb, 1974). CMDPSUs are built to withstand the rigors of the mine
environment, and are therefore less susceptible to contamination than
suggested by some commenters. In any event, the validity checks
discussed above that are currently in place will detect contaminated
samples.
With regard to the CPDM collecting respirable dust and not
oversized, non-respirable dust particles, NIOSH found, through
microscopic examination of previously exposed CPDM filters, no oversize
particle contamination resulting from the use and cleaning of the
device after 200 hours of operation (Volkwein JC, 2008).
One commenter who questioned the accuracy of a single sample in
assessing miners' long term exposure stated that mine dust
concentrations show great variability and that the greater the
variability, the smaller the probability that a single day's sample
will accurately describe the average exposure of a miner.
In response to the commenter, MSHA notes that overall variability
in measurements collected on different shifts and sampling locations
comes from two sources: (1) Environmental variability in the true dust
concentration and (2) errors in measuring the dust concentration in a
specific environment. Variability in the dust concentration is under
the control of the mine operator and does not depend on the degree to
which the dust concentration can be accurately measured. Measurement
uncertainty, on the other hand, stems from the differing measurement
results that could arise, at a given sampling location on a given
shift, because of potential sampling and analytical errors. Therefore,
unlike variability in dust concentration, measurement uncertainty
depends directly on the accuracy of the measurement system. Measurement
errors generally contribute only a small portion of the overall
variability observed in datasets consisting of dust concentration
measurements.
Because the measurement objective is to accurately represent the
average dust concentration at the sampling location over a single
shift, dust concentration variability between shifts or locations does
not contribute to measurement uncertainty. Therefore, sources of dust
concentration variability are not considered in determining whether a
measurement is accurate. The only sources of variability relevant to
establishing accuracy of a single, full-shift measurement are those
related to sampling and analytical error.
As discussed above, filter capsules are weighed prior to sampling.
After a single, full-shift sample is collected, the filter capsule is
weighed a second time, and the weight gain (g) is obtained by
subtracting the pre-exposure weight from the post-exposure weight,
which will then be adjusted for the weight gain or loss observed in the
control filter capsule. A measurement (x) of the atmo-spheric condition
sampled is then calculated by Equation 1:
[[Page 24939]]
[GRAPHIC] [TIFF OMITTED] TR01MY14.006
Where:
x is the single, full-shift dust concentration measurement (mg/
m\3\);
1.38 is a constant MRE-equivalent conversion factor;
g is the observed weight gain (mg) after adjustment for the control
filter capsule; and
v is the estimated total volume of air pumped through the filter
during a typical full shift.
Random variability, inherent in any measurement process, may cause
x to deviate either above or below the true dust concentration. The
difference between x and the true dust concentration is the measurement
error, which may be either positive or negative. Measurement
uncertainty arises from a combination of potential errors in the
process of collecting a sample and potential errors in the process of
analyzing the sample. These potential errors introduce a degree of
uncertainty when x is used to represent the true dust concentration.
The statistical measure used to quantify uncertainty in a single,
full-shift measurement is the total sampling and analytical coefficient
of variation, or CVtotal. The CVtotal quantifies
the magnitude of probable sampling and analytical errors and is
expressed as either a fraction (e.g., 0.05) or as a percent (e.g., 5
percent) of the true concentration. For example, if a single, full-
shift measurement (x) is collected in a mine atmosphere with true dust
concentration equal to 1.5 mg/m\3\, and the standard deviation of
potential sampling and analytical errors associated with x is equal to
0.075 mg/m\3\, the uncertainty associated with x would be expressed by
the ratio of the standard deviation to the true dust concentration:
CVtotal = 0.075/1.5 = 0.05, or 5 percent.
There are three sources of uncertainty in a single, full-shift
measurement, which together make up CVtotal: (1) Variability
attributed to weighing errors or handling associated with exposed and
control filters capsules, CVweight; (2) variability in the
total volume of air pumped through the filter capsule,
CVpump; and (3) variability in the fraction of dust trapped
on the filter, CVsampler.
CVweight covers any variability in the process of
weighing the exposed or control filter capsules prior to sampling (pre-
weighing), assembling the exposed and control filter cassettes,
transporting the filter cassettes to and from the mine, and weighing
the exposed and control filter capsules after sampling (post-weighing).
CVpump covers variability associated with calibration of
the pump rotameter,\62\ variability in adjustment of the flow rate at
the beginning of the shift, and variation in the flow rate during
sampling. It should be noted that variation in flow rate during
sampling was identified as a separate component of variability in
MSHA's February 18, 1994, notice (59 FR 8356). Here, it is included in
CVpump.
---------------------------------------------------------------------------
\62\ The rotameter consists of a weight or ``float'' that is
free to move up and down within a vertical tapered tube which is
larger at the top than the bottom. Air being drawn through the
filter cassette passes through the rotameter, suspending the
``float'' within the tube. The pump is ``calibrated'' by drawing air
through a calibration device (usually what is known as a bubble
meter) at the desired flow rate and marking the position of the
float on the tube. The processes of marking the position on the tube
(laboratory calibration) and adjusting the pump speed in the field
so that the float is positioned at the mark are both subject to
error.
---------------------------------------------------------------------------
CVsampler, the variability in the fraction of dust
trapped on the filter, is attributable to physical differences among
cyclones.
These three components of measurement uncertainty can be combined
to form an indirect estimate of CVtotal by means of the
standard propagation of errors formula:
[GRAPHIC] [TIFF OMITTED] TR01MY14.007
These three components are discussed in greater detail, along with
responses to specific previous comments, in Appendix B to the July 7,
2000 proposed rule, http://www.msha.gov/REGS/FEDREG/PROPOSED/2000PROP/00-14075.PDF
Exposure variability due to job, location, shift, production level,
effectiveness of engineering controls, and work practices will be
different from mine to mine. This type of variability is unrelated to
measurement accuracy and depends on factors under the control of the
mine operator. The sampler unit is not intended to account for these
factors.
In addition, CVtotal does not account for spatial
variability, or the differences in concentration related to location.
Dust concentrations vary between locations in a coal mine, even within
a relatively small area. However, real variations in concentration
between locations, while sometimes substantial, do not contribute to
measurement error. The measurement objective is to accurately measure
average atmospheric conditions, or concentration of respirable dust, at
a sampling location over a single shift. What is being measured is the
average respirable coal mine dust concentration on a specific shift at
the sampling location. For example, there may be variation in
measurements collected simultaneously on opposite shoulders of miners
due to a combination of measurement imprecision and real, differences
in the average concentration over the full shift. But these shoulder-
to-shoulder differences in average full-shift concentration result from
how miners orient themselves in the confines of the mining environment,
with respect to the sources of dust and the direction of the air
stream. These differences have no bearing on the accuracy of the
average, full-shift concentration as measured on a particular shoulder.
Regarding the differences or variations in dust concentrations that
occur shift to shift, the measurement objective is to measure average
atmospheric conditions on the specific shift sampled. This is
consistent with the Mine Act, which requires that concentrations of
respirable mine dust be maintained at or below the standard during each
shift.
One commenter questioned the value MSHA is using to represent
variability in initially setting the pump flow rate. MSHA conducted a
study to verify the magnitude of this variability component. This study
simulated flow rate adjustment under realistic operating conditions by
including a number of persons checking and adjusting initial flow rate
under various working situations (Tomb, September 1, 1994). Results
showed the coefficient of
[[Page 24940]]
variation associated with the initial flow rate adjustment to be 3
0.5 percent, which is less than the 5-percent value used
by MSHA in the February 18, 1994 notice (59 FR 8356). In addition,
based on a review of published results, MSHA has concluded that the
component of uncertainty associated with the combined effects of
variability in flow rate during sampling and potential errors in
calibration is actually less than 3 percent. As explained in Appendix C
of the July 7, 2000 proposed rule (http://www.msha.gov/REGS/FEDREG/PROPOSED/2000PROP/00-14075.PDF), these two sources of uncertainty can
be combined to estimate uncertainty in the total volume of air pumped
through the filter, as expressed by CVpump. After reviewing
the available data and the comments submitted, MSHA concludes that the
best available estimate of CVpump is 4.2 percent.
Some commenters stated that MSHA improperly calculated the MRE
equivalency of the CPDM which adversely impacts the accuracy of single
shift samples for representing miner exposure. The CPDM performance was
compared to the defined and accepted reference standard within the U.S.
mining industry, which uses the gravimetric method, and was described
in detail in a NIOSH paper by Page et al. (2008). In its evaluation of
CPDM performance, NIOSH collected and analyzed samples that were
statistically representative of the underground bituminous coal mining
industry. The samples were collected at approximately 20 percent of the
active mechanized mining units. Statistically representative samples
are critical for correct estimation of the bias of the CPDM relative to
the existing approved gravimetric method being used to collect
respirable coal mine dust samples in coal mines, in that the bias will
not necessarily be properly estimated from studies conducted in a
limited number of mines and regions, regardless of the number of
samples obtained at these locations. The methodology used by NIOSH was
reviewed and approved by various members of the mining sector prior to
data collection and prior to publishing the final results. In terms of
bias, the results presented by one of the commenters supported those
published by NIOSH, demonstrating that the average concentration
measured by the approved CMDPSU (0.83 mg/m\3\) was virtually identical
to the CPDM average value of 0.82 mg/m\3\. MSHA believes that NIOSH has
conducted sufficient experiments with the CPDM that demonstrate that
the precision of the CPDM is equivalent to that of the CMDPSU.
Additional discussion on the accuracy of the CPDM is contained
elsewhere in this preamble under Section III.C. concerning Feasibility.
Some commenters stated that MSHA did not properly evaluate the
inaccuracy of single full-shift sampling because MSHA must analyze
single full-shift results, not averages, which smooth inaccuracies and
reduce the variability of single full-shift results. These commenters
stated that this accuracy analysis was not conducted for both the
CMDPSU and CPDM sampling methods for the proposed 1.0 mg/m\3\ limit,
the extended shift lower limits (e.g., 0.8 mg/m\3\ for 10-hour shifts
and 0.67 mg/m\3\ for 12-hour shifts), and silica content reduced
limits.
One commenter submitted sampling results and stated that the
results demonstrate the inaccuracy of MSHA's single shift sampling
results. According to the commenter: (1) MSHA ignored the accepted
scientific concept of calculating the impact of compounding errors
because MSHA did not analyze or consider the significant errors
associated with silica analysis on its accuracy finding, even though
MSHA reduces its coal mine dust standard for silica content,
significantly impacting coal mine dust sampling accuracy; (2) MSHA did
not evaluate increased errors and inaccuracy at the proposed lower
exposure levels, mandated by the proposed adjustment for shift lengths,
nor the proposed silica content exposure level reduction adjustment;
and (3) MSHA did not analyze its accuracy finding at the lower levels
of coal mine dust reported by current MSHA sampling data, acknowledged
by the scientific literature to create greater levels of measurement
inaccuracy than higher levels.
In response to the commenter's concerns, MSHA points out that the
accuracy of a respirable dust concentration measurement is different
from the concerns expressed by the commenters. To establish the
accuracy of a single full-shift sample, MSHA need not address lower
respirable dust levels, shift length, or silica content.
MSHA has a separate program in which silica analysis is used to set
the applicable respirable coal mine dust standard, in accordance with
section 205 of the Mine Act (30 U.S.C. 845), when the respirable dust
in the mine atmosphere of the active workings contains more than 5
percent quartz. As shown by Equation 1 above, no silica analysis is
used in a single, full-shift measurement of the respirable dust
concentration. There is a critical difference between the process of
setting a reduced standard and the use of single shift samples for
compliance purposes. MSHA's measurements of quartz content are used to
set standards that apply to multiple shifts, while MSHA's measurements
of dust concentration relate to compliance on individual shifts. Any
standard, whether or not reduced, remains in effect until it is revised
based on a subsequent determination of quartz content. Therefore, the
objective of a quartz content determination is to derive a standard
that will continue to protect miners over multiple shifts.
Compliance with the applicable standard, on the other hand, must be
maintained on each shift, in accordance with Section 202(b)(2) of the
Mine Act. Therefore, as described earlier in this preamble, the
measurement objective in determining compliance relates entirely to the
specific shift on which the sample is taken. Because of this crucial
difference in measurement objectives, averaging measurements of quartz
content for purposes of setting a reduced standard has no bearing on
the question of whether it is appropriate to average dust concentration
measurements for purposes of a compliance determination. It is
appropriate to average measurements of quartz content from several
shifts to determine a standard that will apply to multiple shifts. But,
since MSHA's objective is to regulate compliance on every shift, MSHA
is discontinuing the existing practice of averaging respirable dust
concentration measurements from multiple occupations on the same shift,
based on MSHA-collected samples.
NIOSH's first independent analysis of MSHA's sampling and
analytical method involved MSHA's 1995 field study data using CMDPSUs
(Kogut et al., 1997). These data incorporated certain improvements that
NIOSH had proposed for MSHA's sampling and analytical method. These
improvements were later adopted for all MSHA inspector samples. From
these data, NIOSH determined, with 95-percent confidence, that the true
CVtotal for MSHA's proposed sampling and analytical method
was less than the target maximum value of 12.8 percent for dust
concentrations of 0.2 mg/m\3\ or greater (Wagner, 1995). This
demonstrated that MSHA's sampling and analytical method for collecting
and processing single full-shift samples would meet the NIOSH Accuracy
Criterion whenever the true dust concentration was at least 0.2 mg/
m\3\.
In the same analysis, NIOSH also applied an indirect approach for
assessing the accuracy of MSHA's sampling and analytical method. The
[[Page 24941]]
indirect approach involved combining separate estimates of weighing
imprecision, pump-related variability, and variability associated with
physical differences between individual sampler units. This indirect
approach also indicated that MSHA's sampling and analytical method
would meet the NIOSH Accuracy Criterion at concentrations greater than
or equal to 0.2 mg/m\3\, thereby corroborating the analysis of MSHA's
field data.
MSHA later obtained data suggesting that filter capsules containing
Tyvek[supreg] backup pads sometimes exhibit spurious changes in weight.
Although the changes observed were relatively small compared to weight
gains required for MSHA's noncompliance determinations, these changes
led MSHA to begin using unexposed control filters in its enforcement
program. The use of a control filter adjustment eliminates systematic
errors due to such effects, but also affects the precision of a single,
full-shift measurement. Consequently, NIOSH reevaluated the accuracy of
MSHA's sampling and analytical method, taking into account the effects
of using a control filter capsule (Wagner, 1997). After accounting for
the effects of control filter capsules on both bias and precision,
NIOSH concluded, based on both its direct and indirect approaches, that
a single, full-shift measurement will meet the NIOSH Accuracy Criterion
at true dust concentrations greater than or equal to 0.3 mg/m\3\.
MSHA compiled data showing that weight stability of the filter
capsule would be improved, minimizing pre-and post-weighing
variability, by substituting stainless steel support grids for the
Tyvek[supreg] support pads that were in use (Kogut et al., 1999).
Consequently, NIOSH again reevaluated the accuracy of MSHA's method,
this time taking into account the proposal to switch to stainless steel
support grids (Grayson, 1999a; 1999b). After accounting for the effects
of switching to stainless steel support grids, and of using unexposed
control filters to adjust for any potential systematic errors that
might remain, NIOSH once again concluded that a single, full-shift
measurement met the NIOSH Accuracy Criterion at true dust
concentrations greater than or equal to 0.3 mg/m\3\.
The purpose of any measurement process is to produce an estimate of
an unknown quantity. MSHA has concluded that its sampling and
analytical method for inspectors meets the NIOSH Accuracy Criterion for
true concentrations at or above 0.3 mg/m\3\, but it is also possible to
calculate the range of measurements for which the Accuracy Criterion is
fulfilled. Since CVtotal increases at the lower
concentrations, all that is necessary is to determine the lowest
measurement at which the NIOSH Accuracy Criterion is met. This is done
as follows: if the true concentration exactly equaled the lowest
concentration at which MSHA's sampling and analytical method meets the
Accuracy Criterion (i.e., 0.3 mg/m\3\), then no more than 5% of single,
full-shift measurements are expected to exceed 0.36 mg/m\3\ (Wagner,
May 28, 1997). Conversely, if a measurement equals or exceeds 0.36 mg/
m\3\, it can be inferred, with at least 95% confidence, that the true
dust concentration equals or exceeds 0.3 mg/m\3\ (Wagner, 1997).
Consequently, MSHA's improved sampling and analytical method satisfies
the NIOSH Accuracy Criterion whenever a single, full-shift measurement
is at or above 0.36 mg/m\3\.
Future technological improvements in MSHA's CMDPSU sampling and
analytical method may reduce CVtotal below its current
value. Also, as additional data are accumulated, updated estimates of
CVtotal may become available. However, so long as the method
remains unbiased and CVtotal remains at or below 12.8
percent, at a 95-percent confidence level, the sampling and analytical
method will continue to meet the NIOSH Accuracy Criterion, and the
present finding will continue to be valid.
NIOSH's studies of the equivalency of the CPDM with the CMDPSU are
more representative and more appropriate for evaluating the suitability
of the CPDM as a compliance instrument (Volkwein et al., NIOSH, RI
9663, 2004, and NIOSH RI 9669, 2006; Page et al., 2008) than sampling
results submitted by the commenter. In terms of bias, the results
presented by the commenter support those published by NIOSH
demonstrating that the average concentration measured by the CMDPSU
(0.83 mg/m\3\) was virtually identical to the CPDM average value of
0.82 mg/m\3\. The conclusion that should be drawn from both the
commenter and NIOSH data sets is that there is no statistically
significant difference and that the bias between the CPDM and the
approved CMDPSU is zero.
MSHA has concluded that: Sufficient data exist for determining the
uncertainty associated with a single, full-shift measurement; rigorous
requirements are in place, as specified by 30 CFR parts 70, 71, and 90,
to ensure the validity of a respirable coal mine dust sample; and valid
statistical techniques were used to determine that MSHA's improved dust
sampling and analytical method meets the NIOSH Accuracy Criterion. For
these reasons, the Secretary of Labor finds that a single, full-shift
CMDPSU concentration measurement at or above 0.36 mg/m\3\ will
accurately represent atmospheric conditions to which a miner is exposed
during such shift. The Secretary also finds that a single, full-shift
CPDM concentration measurement at or above 0.2 mg/m\3\ will accurately
represent atmospheric conditions to which a miner is exposed during
such shift, based on Section III.C., Feasibility, of this preamble, two
NIOSH Reports of Investigations (Volkwein et al., NIOSH RI 9663, 2004,
and NIOSH RI 9669, 2006), and requirements in 30 CFR 74.8. Therefore,
pursuant to section 202(f) (30 U.S.C. 842(f)) and in accordance with
section 101 (30 U.S.C. 811) of the Mine Act, the 1972 Joint Notice of
Finding is rescinded.
Both approved CMDPSU and CPDM sampling devices are capable of
accurately measuring levels of respirable coal mine dust at low levels
of exposure. The minimum detection limits of the commercial CPDM and
the CMDPSU are 0.2 mg/m\3\ and 0.11 mg/m\3\, respectively (Page et al.,
2008). Therefore, the concern expressed by some commenters that the
CPDM is not as accurate as the CMDPSU is not an issue.
Some commenters stated that the single full-shift provision
violates section 101(a)(6) of the Mine Act because MSHA has neither
grounded its 2010 proposed single shift finding on any evaluation or
declaration of increased risk of material impairment of health
resulting from the 1972 Joint Finding, nor any health benefits
resulting from the implementation of the 2010 proposed finding.
Section 101(a)(6) of the Mine Act provides that, in promulgating
mandatory health standards, the Secretary shall set standards which
most adequately assure on the basis of the best available evidence that
no miner will suffer material impairment of health from exposure to
toxic materials or harmful physical agents over his working life. (30
U.S.C. 811(a)(6)(A)).
MSHA complied with section 101(a)(6) of the Mine Act by addressing,
in the QRA to the proposed rule, the following three questions
regarding the proposed single shift sampling provision: (1) Whether
potential health effects associated with existing exposure conditions
constitute material impairments to a miner's health or functional
capacity; (2) whether existing exposure conditions place miners at a
significant risk of incurring any of these material impairments; and
(3) whether
[[Page 24942]]
the proposed rule has the potential to substantially reduce those
risks.
MSHA's QRA for the proposed rule included an observation of single-
shift dust concentrations by occupation and estimated the reduction in
health risks under the proposed respirable dust standard and single
shift sampling provisions. The QRA for the proposal showed that these
two proposed provisions should reduce the risks of CWP, severe
emphysema, and death from non-malignant respiratory disease (NMRD).
The QRA for the final rule is changed from the QRA for the proposed
rule because the final rule includes respirable dust standards of 1.5
mg/m\3\ for most miners and 0.5 mg/m\3\ for intake air and part 90
miners, rather than the proposed standards of 1.0 mg/m\3\ for most
miners and 0.5 mg/m\3\ for intake air and part 90 miners. The QRA to
the final rule establishes that exposures at existing levels are
associated with CWP, COPD including severe emphysema, and death due to
NMRD. All of these outcomes constitute material impairments to a
miner's health or functional capacity. In addition, the QRA to the
final rule establishes that, in every exposure category, including
clusters of occupational environments showing the lowest average dust
concentrations, existing exposure conditions place miners at a
significant risk of incurring each of the material impairments
considered. Lastly, the QRA to the final rule establishes that the
final rule is expected to reduce the risks of CWP, severe emphysema,
and NMRD mortality attributable to respirable coal mine dust exposures.
Additional discussion is in the QRA to the final rule, which is
summarized in Section III.B, Quantitative Risk Assessment, of this
preamble.
In addition, MSHA projects that there would be additional
reductions in cases of CWP, PMF, severe emphysema, and NMRD resulting
from the definition of normal production shift in the final rule. If
the normal production shift definition had been in effect in 2009, the
amount of dust on the samples would have been higher because of the
higher levels of production during sampling. Lowering exposures from
these higher levels to the levels in the final rule will result in
additional benefits beyond those associated with the recorded sampling
results. MSHA used additional data from the feasibility assessment to
extrapolate the further impact of the normal production shift
provision. Additional discussion of the benefits of the final rule is
provided in Section V.B., Benefits, of this preamble.
Some commenters stated that MSHA must consider whether single-shift
sampling provides any benefit to miner health, or reduces protections,
or whether it simply makes compliance more difficult and costly without
corresponding benefits. These commenters analyzed the 71,959 sample
results in the MSHA sampling database for 2010 and concluded that,
under the proposed single-shift sample provision, there would be a
dramatic increase in both the number of required operator DO and ODO
samples and the number of violations for exceeding the permissible
level.
MSHA estimates that the number of noncompliance determinations
under the final rule will be less than those in the proposal because of
changes made in the final rule. The final rule does not require an
operator to sample 24 hours a day, 7 days per week. It also does not
include the proposed 1.0 mg/m\3\ standard and the proposed provision
that a noncompliance determination could be made on a single full-shift
operator sample. Instead, the final rule provides that a noncompliance
determination for operator sampling is based on either two or three
valid representative operator samples depending on where the sample is
taken, or the average of all operator samples collected during the
sampling period. In addition, the feasible dust standards in the final
rule are 1.5 mg/m\3\ for underground and surface mines and 0.5 mg/m\3\
for intake air at underground mines and part 90 miners. Additional
discussion on the feasibility of the dust standards in the final rule
is provided in Section III.C., Feasibility, of this preamble.
Additional discussion on the estimate of the number of required
corrective actions and determinations of noncompliance in the final
rule are provided in Appendix A of the REA to this final rule.
Noncompliance determinations based on single full-shift MSHA
sampling will improve working conditions for miners because mine
operators will be compelled either to implement and maintain more
effective dust controls or to take corrective actions to lower those
dust concentrations that are shown to be in excess of the standard. To
the extent that the use of single full-shift samples reduces a miner's
cumulative exposure to respirable coal mine dust, compared to the
current method of dust sampling, single full-shift samples will reduce
a miner's risk of developing occupational respiratory disease. The
health benefit that each miner receives from this rule will vary
depending on each miner's cumulative exposure over the years worked and
other associated factors, such as the percentage of quartz and rank of
the coal. Yet, all miners, irrespective of their cumulative exposure to
respirable coal mine dust, will benefit by having fewer shifts with
overexposures to respirable coal mine dust over the course of each
miner's working life, thus reducing their occupational hazard--the risk
of developing simple CWP or PMF.
Some commenters stated that the single full-shift sampling
provision fails to comply with the Mine Act and the Administrative
Procedure Act (APA) because it is not based on the best or latest data
and science, and that the use of dormant rulemaking and stale data is
arbitrary and capricious. These commenters stated that much of the
information relied upon by MSHA to support the proposed accuracy
finding, risk assessment, and rule provisions is contained in the 1995
NIOSH Criteria Document and the 1996 Dust Advisory Committee Report.
The commenters added that even though MSHA stated in the proposed rule
that new science changed the basis of the 2000 proposal, there is no
evidence that MSHA re-examined the Criteria Document or Dust Advisory
Committee Report, or the updated information it used for this
rulemaking, in light of the latest scientific research, such as: (a)
2006-2010 NIOSH prevalence and MSHA exposure data; (b) technological
advances like the deployment of the new sampler; and (c) published
studies targeting silica as the cause of the geographically limited new
CWP cases.
As discussed in Section III.A., Health Effects, of this preamble,
MSHA evaluated over 150 peer-reviewed papers as part of the Agency's
health effects assessment (75 FR 64460, October 19, 2010), in addition
to the data from MSHA's proposed rule on Plan Verification (68 FR
10784, March 6, 2003). The literature review focused on studies of
morbidity and mortality among coal miners in many countries, including
the United States, South Africa, Europe, Britain, China, Australia,
Turkey, and Japan. This research evaluated the relationship between
respirable coal mine dust exposure and the respiratory diseases it
causes. The research reported on the etiology of these adverse
respiratory diseases, including coal workers pneumoconiosis (CWP), the
more advanced form of CWP--progressive massive fibrosis (PMF), and
nonmalignant respiratory diseases (NMRD), such as chronic obstructive
pulmonary disease (COPD) and emphysema. The fact that similar results
have been found in decades of research, covering a wide variety of
populations
[[Page 24943]]
at various respirable coal mine dust exposure levels and working
conditions, supports the determination that exposure to coal mine dust
is a significant causal factor in the development of respiratory
disease in coal miners. The conclusion of MSHA's review of this
research is that chronic coal mine dust exposure causes respiratory
health effects including CWP, PMF, COPD, and emphysema.
In addition, some commenters stated the latest report of scientific
research on coal mine dust related disease published by NIOSH (2011)
should have been included in the proposed rule. As stated previously in
this preamble, MSHA did not use the 2011 NIOSH document in the proposed
rule's health effects assessment because it was unavailable when the
proposed rule was published in October 2010, otherwise it would have
been included as a secondary literature source. The conclusions of the
NIOSH (2011) review of literature since 1995 concur with MSHA's
conclusions based on the same literature.
Some commenters stated that prevalence of coal workers'
pneumoconiosis was overstated in the proposed rule and, if it does
occur, is due to silica exposure. MSHA addressed prevalence issues and
associated comments in Section III.A. Health Effects of the preamble of
this final rule.
Commenters also suggested that silica exposure, not coal dust
exposure, is behind the increased incidence of CWP. According to the
research, exposure to quartz does not change the risk of CWP due to
exposure to respirable coal mine dust. MSHA has concluded that evidence
the Agency reviewed and presented indicates that respirable coal mine
dust exposure is an independent causative factor in the development of
CWP and NMRD, including COPD and emphysema. Additional detailed
discussion on this topic is located in Section III.A. Health Effects
and section III.B. Quantitative Risk Assessment of this preamble. In
addition, some commenters stated that MSHA used old data to estimate
risk. The QRA used exposure data from 2004 through 2008 and estimated
risks based on those data.
Some commenters stated that, in relying on NIOSH Reports RI 9663
(USDHHS, CDC, NIOSH, 2004) and RI 9669 (USDHHS, CDC, NIOSH, 2006) to
declare the accuracy and precision of the CPDM, the accuracy, precision
and bias calculations relied upon by MSHA are false, based on how they
were determined. These commenters further stated that the accuracy and
precision of the new sampler are proven false by the side-by-side
analysis submitted by a commenter that sets forth actual accuracy and
precision data. These issues are discussed in Section III.C. of this
preamble (Feasibility).
The variability reported by one of the commenters was primarily due
to large sample variability (due to uncontrolled variables) known to
exist in field samples, even when two identical samplers are placed
side-by-side. Because the experimental design did not control for the
variability resulting from the samplers themselves, the commenter's
analysis was not an appropriate estimate of the CPDM's precision.
Instead, the data introduced by the commenter included variability
potentially caused by significant dust gradients known to exist,
sampler inlet location differences, and the nature of mine ventilation.
MSHA recognizes that ventilation currents found in mines can produce
widely varying results or seemingly poor precision between two
identical side-by-side instruments, even though their inlets may be
separated by only a few inches. To correctly estimate the precision of
the CPDM, the experimental design must minimize the uncontrolled
variables in the sampling.
MSHA concurs with NIOSH's assessment, included in its comments to
the rulemaking record, that the data and analysis introduced by the
commenter are based upon flawed experimental design and analysis
methods. NIOSH has conducted the necessary scientific studies, whose
results were published in a peer-reviewed document, which adequately
demonstrated the CPDM to be an accurate instrument by meeting the long-
standing NIOSH Accuracy Criterion. The 2011 NIOSH approval of the
commercial instrument as meeting the CPDM requirements of 30 CFR part
74 is further evidence of the CPDM's readiness as a compliance sampling
device for use in coal mines, in that it is approved as meeting the
required accuracy.
Some of the commenters stated that MSHA failed to analyze
alternatives to the proposed single sample provision such as whether
specific occupations or specific regions or specific conditions should
be addressed, rather than imposing new industry-wide mandates.
As discussed in Section III.A., Health Effects, of the preamble,
occupational lung disease continues to occur at in coal mines
throughout the country, not just in specific occupations, regions, or
under specific conditions.
In any event, MSHA considered alternatives to the proposed single
sample provision. Section 202(f) of the Mine Act expresses a preference
for measurements ``over a single shift only.'' Eighteen months after
the enactment of Mine Act, the ``average concentration'' of respirable
dust in coal mines was to be measured over a single shift only. The
Senate's Report of its bill provides a clear interpretation of section
202(f) when read with the statutory language. The Senate Committee
stated:
The committee * * * intends that the dust level not exceed the
specified standard during any shift. It is the committee's intention
that the average dust level at any job, for any miner in any active
working place during each and every shift, shall be no greater than
the standard.
One of the alternatives that MSHA specifically considered, and
requested comments on, was whether taking single shift samples to
determine noncompliance with the proposed respirable dust standard
should apply only to MSHA inspector samples, or to both operator and
MSHA samples (75 FR 64415). In response, commenters only recommended as
an alternative MSHA's existing sampling method consisting of averaging
five samples, which applies to both MSHA inspector sampling and mine
operator sampling.
During development of the final rule, MSHA evaluated alternatives
to determining compliance. With respect to determining noncompliance
based on operator samples, MSHA reevaluated its enforcement strategy.
MSHA determined that the proposal would have resulted in little time
for an operator to correct noncompliance determinations based on an
operator's single sample. The final rule ensures that an operator will
take corrective action on a single overexposure and, therefore,
provides protection similar to the protection that would have been
provided under the proposal. Under the final rule, when a single full-
shift operator sample meets or exceeds the ECV that corresponds to the
applicable standard and particular sampling device used, the operator
is made aware of a potential problem with the dust controls being used.
Therefore, the final rule requires that an operator must make approved
respiratory equipment available; immediately take corrective action;
and record the corrective actions. These protections are similar to
those that would have been required by the proposal in the event that
an operator's single full-shift sample exceeded the ECV for the
standard. Therefore, miners will be afforded protection from
overexposures during a single shift. In addition, the final rule, like
the proposal, will provide miners' with the additional protection
afforded by MSHA's single sampling under Sec. 72.800. Under the final
rule, only MSHA inspector samples will be used
[[Page 24944]]
to make compliance determinations based on a single full-shift
measurement.
D. 30 CFR Part 75--Mandatory Safety Standards--Underground Coal Mines
1. Section 75.325 Air Quantity
Final Sec. 75.325(a)(2), like the proposal, requires that the
quantity of air reaching the working face be determined at or near the
face end of the line curtain, ventilation tubing, or other ventilation
control device. It also requires that if the curtain, tubing, or device
extends beyond the last row of permanent roof supports, the quantity of
air reaching the working face be determined behind the line curtain or
in the ventilation tubing at or near the last row of permanent
supports. It further requires that when machine-mounted dust collectors
are used in conjunction with blowing face ventilation systems, the
quantity of air reaching the working face be determined with the dust
collector turned off.
Several commenters supported the proposal stating that determining
air measurement reaching the working face with the dust collector
(scrubber) turned off will ensure that the minimum amount of air will
ventilate the face. Other commenters stated that the dust collector
(scrubber) should not be turned off because the scrubbers are a useful
means of controlling dust and mitigating exposure. Some of these
commenters stated that the proposal appeared to discourage the use of
scrubbers or limit the effectiveness of scrubber technology.
A dust collector, or scrubber, is a supplemental dust control
device that is used primarily to assist in filtering dust from the air.
After filtering, the scrubber exhausts clean air out the back of the
dust collector system. Although a scrubber is a useful means of
controlling dust and mitigating exposure to dust, the required quantity
of air in the working face areas must be maintained to ensure that the
dust collector operates efficiently. More importantly, the required
quantity of air is essential to protecting miners' health.
Underground coal mines need adequate quantities of air to ventilate
the working face to dilute, render harmless, and carry away flammable,
explosive, noxious and harmful gases, dusts, smoke, and fumes. Before
mining begins in a working face, an operator must measure the amount of
air coming into that area. To ensure that the working face is
ventilated with the amount of air required by the approved ventilation
plan, final paragraph (a)(2), like existing Sec. 75.325(a)(2), states
where the air quantity measurement at the face must be taken: At or
near the face end of the line curtain, ventilation tubing, or other
ventilation control device. However, if the curtain, tubing, or device
extends beyond the last row of permanent roof supports, the quantity of
air reaching the working face must be determined behind the line
curtain or in the ventilation tubing at or near the last row of
permanent supports.
The requirement in the final paragraph (a)(2) that the quantity of
air reaching the working face must be determined with the dust
collector turned off does not discourage the use of scrubbers or limit
the effectiveness of scrubber technology. Rather, the requirement
ensures that the required quantity of air reaches the working face.
Some mine operators that are using blowing ventilation in the working
face are measuring the air quantity in that area after the continuous
mining machine is moved into the area and the dust collector system on
the machine is turned on. This practice does not provide an accurate
measurement of the air coming into the working face. When the dust
collector system is on, it acts as a vacuum. It pulls air from behind
the line curtain and recirculates air from the scrubber exhaust, which
results in a higher air quantity measurement in the working face than
the actual quantity of air reaching the area. Therefore, the final
paragraph (a)(2) requires mine operators who use a dust collector
system in conjunction with blowing face ventilation systems to
determine the air quantity with the dust collector turned off. This
provision ensures that the mine operator gets a more accurate air
quantity reading thereby providing better protection for the miners.
2. Section 75.332 Working Sections and Working Places
Final Sec. 75.332(a)(1) is unchanged from existing Sec.
75.332(a)(1). Proposed Sec. 75.332(a)(1) would have revised existing
Sec. 75.332(a)(1) to require that each ``MMU'' on each working section
and each area where mechanized mining equipment is being installed or
removed, be ventilated by a separate split of intake air directed by
overcasts, undercasts or other permanent ventilation controls. During
the public comment period, MSHA solicited comment on the impact, if
any, of proposed paragraph (a)(1) on current mining operations, any
suggested alternatives, and how the alternatives would be protective of
miners. Many commenters expressed economic and feasibility concerns
with requiring that each MMU be ventilated by a separate split of
intake air directed by overcasts, undercasts or other permanent
ventilation controls. The majority of commenters did not support the
proposal because it would prohibit an operator from using a single
intake airway to provide intake air to two mechanized mining units.
Many stated, for example, that operators would no longer be able to
split intake air inby the section loading point to provide intake air
to two MMUs. This practice, referred to as ``fish-tail'' ventilation,
is used by numerous operators. Several commenters stated that proposed
Sec. 75.332(a)(1) would also eliminate the practice of two MMUs
sharing a common section loading point.
Some commenters supported the proposed Sec. 75.332(a)(1)
requirement that a separate split of intake air be provided to each
MMU. These commenters stated proposed Sec. 75.332(a)(1) would better
protect the health and safety of the miners working on the MMU by
ensuring that fresh, uncontaminated air is provided to each MMU.
MSHA evaluated all the comments and determined not to include the
proposed requirement in the final rule. MSHA does not intend to
potentially restrict the use of a single intake airway to provide
intake air to two mechanized mining units or eliminate the practice of
two MMUs sharing a common section loading point. Therefore, existing
Sec. 75.332(a)(2) remains unchanged. However, in an effort to ensure
miners are protected from exposures to excessive concentrations of
respirable coal mine dust, the final rule establishes as ODOs, as
defined in final Sec. 70.2, all face haulage equipment operators who
are on sections that use split ventilation (fish-tail ventilation) to
provide intake air to two MMUs. Additional discussion on ODOs is
located elsewhere in this preamble under Sec. Sec. 70.201 and 70.208.
2. Section 75.350 Belt Air Course Ventilation
Final Sec. 75.350(b)(3)(i)(A), like the proposal, includes the
same requirement in existing Sec. 75.350(b)(3)(i) that the average
concentration of respirable dust in the belt air course, when used as a
section intake air course, be maintained at or below 1.0 mg/m\3\.
Final Sec. 75.350(b)(3)(i)(B) is changed from the proposal. It
requires that as of August 1, 2016, the average concentration of
respirable dust in the belt air course, when used as a section intake
air course, be maintained at or below 0.5 mg/m\3\.
The proposal would have required the 0.5 mg/m\3\ respirable dust
standard be implemented 6 months after the effective date of the final
rule. The
[[Page 24945]]
August 1, 2016 compliance date in final paragraph (b)(3)(i)(B) is 24
months after the effective date of the final rule and allows a mine
operator adequate time to comply with the dust standard. It is also
consistent with the 24-month period for other respirable dust standards
in the final rule. MSHA did not receive any comments on the proposed 6-
month period.
Several commenters supported the proposed 0.5 mg/m\3\ standard
because of the large amount of dust generated and directed onto the
working face. One commenter suggested reducing the standard to below
0.5 mg/m\3\, but did not recommend a specific level.
MSHA has historically required that a lower dust standard be
maintained in the belt entry when belt air is used as a source of
intake air. Maintaining the dust concentration in the belt entry at or
below 0.5 mg/m\3\ when belt air is used as a source of intake air
ensures that relatively clean air is used to ventilate the face where
major dust generating sources are located. This will improve health
protection for miners. Also, maintaining the lower dust level in the
belt entry by using available engineering controls makes it more likely
that an operator can maintain compliance with respirable dust standards
in the MMU. The relatively clean air will supplement the intake air to
the face which will further dilute the respirable dust levels generated
in the face areas.
Final Sec. 75.350(b)(3)(ii), like the proposal, makes a conforming
change to existing Sec. 75.350(b)(3)(ii). It requires that where
miners on the working section are on a reduced standard below that
specified in Sec. 75.350(b)(3)(i), the average concentration of
respirable dust in the belt entry must be at or below the lowest
applicable standard on that section. Final paragraph (b)(3)(ii)
replaces ``1.0 mg/m\3\'' in the existing standard with ``that specified
in Sec. 75.350(b)(3)(i)'' because the standard changes from 1.0 mg/
m\3\ to 0.5 mg/m\3\ after 24 months. MSHA did not receive any comments
on the proposal.
3. Section 75.362 On-Shift Examinations
Final Sec. 75.362(a)(2) is similar to the proposal. Like the
proposal, Sec. 75.362(a)(2) requires that a person designated by the
operator conduct an examination and record the results and the
corrective actions taken to assure compliance with the respirable dust
control parameters specified in the approved mine ventilation plan.
However, Sec. 75.362(a)(2) clarifies that in those instances when a
shift change is accomplished without an interruption in production on a
section, the examination must be made anytime within 1 hour after the
shift change. The proposal would have required that the examination be
made anytime within 1 hour of the shift change. Final paragraph (a)(2)
clarifies that, when ``hot-seating,'' an on-shift examination must be
done after the shift change so that the miners who are working after
the shift change know that the dust controls are in place and working
properly.
Final paragraph (a)(2), like the proposal, further requires that in
those instances when there is an interruption in production during the
shift change, the examination be made before production begins on a
section. It also requires that deficiencies in dust controls be
corrected before production begins or resumes.
Final paragraph (a)(2), like the proposal, requires that the
examination include: Air quantities and velocities; water pressures and
flow rates; excessive leakage in the water delivery system; water spray
numbers and orientations; section ventilation and control device
placement; roof bolting machine dust collector vacuum levels; scrubber
air flow rate; work practices required by the ventilation plan; and any
other dust suppression measures. In the final rule, MSHA reorganized
the paragraph to clarify that the examination requires that all listed
parameters must be measured or observed and the results recorded.
Lastly, paragraph (a)(2) in the final rule states that measurements
of the air velocity and quantity, water pressure and flow rates are not
required if continuous monitoring of these controls is used and
indicates that the dust controls are functioning properly.
Final Sec. 75.362(g)(2)(i) and (ii), like the proposal, requires
that the certified person directing the on-shift examination to assure
compliance with the respirable dust control parameters specified in the
approved mine ventilation plan must certify by initials, date, and time
on a board maintained at the section load-out or similar location
showing that the examination was made prior to resuming production; and
verify, by initials and date, the record of the results of the on-shift
examination required under paragraph (a)(2) to assure compliance with
the respirable dust control parameters specified in the mine
ventilation plan. It further requires that the verification must be
made no later than the end of the shift for which the examination was
made.
Final Sec. 75.362(g)(3), like the proposal, requires that the mine
foreman or equivalent mine official countersign each examination record
required under paragraph (a)(2) after it is verified by the certified
person under paragraph (g)(2)(ii), and no later than the end of the
mine foreman's or equivalent mine official's next regularly scheduled
working shift. It further requires that the record must be made in a
secure book that is not susceptible to alteration or electronically in
a computer system so as to be secure and not susceptible to alteration.
Final Sec. 75.362(g)(4), like the proposal, requires that records
must be retained at a surface location at the mine for at least 1 year
and must be made available for inspection by authorized representatives
of the Secretary and the representative of miners.
One commenter stated that requiring mine management officials to
countersign examination records would hold them accountable and
emphasize the seriousness of these critical health protections. Another
commenter stated that it was unnecessary to require every on-shift
respirable dust control examination to be entered in a record book,
signed and countersigned each shift by a certified person and the mine
official. The commenter added that the rationale for requiring the
records is no longer valid, since the CPDM records dust concentration
data on the device.
In response to commenters' concerns, MSHA notes that an on-shift
record of the results and corrective actions taken to assure compliance
with the respirable dust control parameters specified in the approved
mine ventilation plan is vital to protecting miners' health. The record
assists a mine operator and MSHA in evaluating whether dust control
parameters approved in the mine ventilation plan continue to be
effective in controlling miners' respirable dust exposure. This is
particularly important since the final rule does not require 24/7
continuous sampling of the MMU. The record provides a mine operator
with an early warning of deteriorating dust controls. This will enable
the mine operator to take corrective action before dust controls fail.
Paragraph (a)(2) in the final rule is consistent with the Dust
Advisory Committee's unanimous recommendations that a mine operator
should record the results of on-shift examinations and that MSHA should
examine all recorded operational data and information on miner exposure
and dust control measures as part of MSHA's ongoing and six-month
review of the ventilation plan.
Similarly, final rule paragraphs (g)(2)(i) and (ii) ensure that the
on-shift examinations are being conducted and that the certified person
and other mine officials are aware of the examination
[[Page 24946]]
results and corrective action taken. The requirement to post a
certification on a board maintained at the section load-out or similar
location, under paragraph (g)(2)(i), allows miners on the section to
confirm easily that the required examination was made in a timely
manner.
In addition, verification by the certified person of the record of
the examination results and subsequent countersigning of that record by
a mine foreman or equivalent mine official, under paragraphs (g)(2)(ii)
and (g)(3), emphasize accountability and ensure that a person with
authority is informed and can implement any necessary changes to dust
control parameters to maintain compliance with respirable dust
standards. Verification helps ensure that an operator is complying with
the provisions of the dust control parameters of the approved
ventilation plan on all production shifts, not just when respirable
dust samples are collected. This provides miners with some assurance
that if the plan parameters control respirable dust when samples are
being collected, then they will control respirable dust when samples
are not being collected.
The requirement in final paragraph (g)(3) that the examination and
corrective action record be kept in a secure book that is not
susceptible to alteration or recorded electronically in a secure
computer system will provide a history of the conditions documented at
the mine. It will alert miners and mine management to recurring
problems or conditions that need to be corrected, and corrective
actions taken. The final rule allows records to be kept in the
traditional manner in a secure book, or to be kept electronically in a
secure manner. To ensure their integrity, the records must be
maintained so that they are not susceptible to alteration. To satisfy
the requirements of final paragraph (g)(3), electronically stored
records are permitted provided that they are able to capture the
information and signatures required, and are accessible to the
representative of miners and MSHA. Electronic records meeting these
criteria are as practical and as reliable as traditional records. Once
records are properly completed and reviewed, mine management can use
them to evaluate whether dust control parameters are adequate or need
appropriate adjustments; whether the same conditions or problems, if
any, are recurring; and whether corrective measures are effective.
Finally, final paragraph (g)(3) is consistent with the Dust
Advisory Committee's unanimous recommendation that mine operators
should conduct periodic reviews of the adequacy of the dust control
parameters stipulated in the mine ventilation plan and make
modifications necessary to achieve and maintain compliance with the
dust standard.
Final paragraph (g)(4) is consistent with recordkeeping provisions
in other MSHA standards. The one-year retention period is sufficient to
allow for MSHA's evaluation during several inspections and inspection
by miners' representatives. In addition, it is consistent with the Dust
Advisory Committee's unanimous recommendation that recordkeeping be
required as a part of on-shift examinations under Sec. 75.362. The
Committee explained that the results of the on-shift examinations were
informative and should be recorded and shared with workers who have
been properly trained concerning their interpretation and importance.
Furthermore, the Committee unanimously recommended that MSHA
inspections should include: A review of recorded parameter data; dust
control measures observed in operation; and input from miners regarding
whether the dust controls and coal production are representative of
usual operations.
4. Section 75.371 Mine Ventilation Plan; Contents
Final Sec. 75.371(f), like the proposal, requires the operator to
specify in the mine ventilation plan for each MMU, the section and face
ventilation systems used and the minimum quantity of air that will be
delivered to the working section for each MMU, including drawings
illustrating how each system is used, and a description of each dust
suppression system used on equipment, identified by make and model, on
each working section, including: (1) The number, types, location,
orientation, operating pressure, and flow rate of operating sprays; (2)
the maximum distance that ventilation control devices will be installed
from each working face when mining or installing roof bolts in entries
and crosscuts; (3) procedures for maintaining the roof bolting machine
dust collection system in approved condition; and (4) recommended best
work practices for equipment operators to minimize dust exposures. A
nonsubstantive change was made in final paragraph (f)(3) to replace
``roof bolter'' with ``roof bolting machine.''
Final Sec. 75.371(j) is unchanged from the proposal. It requires
the operator to include in the mine ventilation plan the operating
volume of machine mounted dust collectors or diffuser fans, if used
(see Sec. 75.325(a)(3)), including the type and size of dust collector
screen used, and a description of the procedures to maintain dust
collectors used on equipment.
Final Sec. 75.371(t) is the same as the proposal, except for a
conforming change. It requires that the operator specify locations
where samples for ``designated areas'' will be collected, including the
specific location of each sampling device, and the respirable dust
control measures used at the dust generating sources for these
locations (see Sec. Sec. 70.207 and 70.209 of this chapter). Final
paragraph (t) includes a reference to Sec. 70.207 as a conforming
change from the proposal. Except for the conforming change, final
paragraph (t) is the same as existing Sec. 75.371(t).
Some commenters generally supported the additional information
required to be included in the approved mine ventilation plan. One
commenter suggested that the operator should determine the best dust
control methods rather than have MSHA impose unrealistic requirements
that do not take into account different conditions at the mine.
In response to commenters, MSHA notes that it is each mine
operator's responsibility to determine the best measures to control
respirable dust at his mine. The final rule does not limit the
operator's flexibility to make that determination or appropriate
adjustments to mine ventilation and dust suppression systems for MMUs
based on the conditions at the mine. The additional information
required under the final rule will eliminate ambiguities in the mine
ventilation plan requirements, assist miners in determining the types
of dust controls being used, assist on-shift mine examiners in
conducting adequate on-shift examinations of the dust controls, and
allow operators, miners, and MSHA to observe and measure specific dust
control parameters to better evaluate the effectiveness of dust control
systems. In addition, if a respirable dust standard were exceeded, the
operator and MSHA would be in a more advantageous position to determine
what areas of dust control should be evaluated and adjusted to provide
miners with protection from exposures to hazardous dust levels on each
shift.
Final Sec. 75.371(f), (j), and (t) are consistent with the
recommendations of the 1992 Report of the Coal Mine Respirable Dust
Task Group which identified insufficient detail and specificity as a
major factor that can adversely affect the quality of dust control
plans. In addition, final paragraphs (f)(1) through (3) are consistent
with the recommendations of an enforcement initiative conducted by
[[Page 24947]]
MSHA's Respirable Dust Emphasis Teams, which focused on miners'
exposures to respirable coal mine dust at selected underground coal
mines as part of the Agency's Comprehensive Black Lung Initiative to
End Black Lung--Act Now! MSHA determined that due to ambiguities in
ventilation plans, miners had trouble determining the types of dust
controls to use and how to evaluate their effectiveness. After
reviewing results from this initiative, MSHA concluded that mine
operators needed to include in mine ventilation plans: The type of
water sprays and water volume at the minimum pressure to be used;
orifice size; spray pattern; location where each type of spray will be
used; and minimum number of sprays that will be maintained. MSHA also
recommended that the ventilation plans include the location of curtains
where roof bolting is being performed, since the distance from the face
is important in the effectiveness of ventilation, and guidance was
provided to mine operators on the proper maintenance of roof bolting
machine dust collectors.
E. 30 CFR Part 90--Mandatory Health Standards--Coal Miners Who Have
Evidence of the Development of Pneumoconiosis
1. Section 90.1 Scope
Final Sec. 90.1, like the proposal, states that this part 90
establishes the option of miners who are employed at coal mines and who
have evidence of the development of pneumoconiosis to work in an area
of a mine where the average concentration of respirable dust in the
mine atmosphere during each shift is continuously maintained at or
below the standard as specified in Sec. 90.100. It also states that
the rule sets forth procedures for miners to exercise this option, and
establishes the right of miners to retain their regular rate of pay and
receive wage increases and that the rule also sets forth the operator's
obligations, including respirable dust sampling for part 90 miners.
Additionally, it states that this part 90 is promulgated pursuant to
section 101 of the Act and supersedes section 203(b) of the Federal
Mine Safety and Health Act of 1977, as amended.
Final Sec. 90.1 revises existing Sec. 90.1 by including surface
coal miners. It extends to miners at all coal mines who have evidence
of the development of pneumoconiosis the option to work in an area of a
mine where the average concentration of respirable dust in the mine
atmosphere during each shift is continuously maintained at or below the
standard as specified in Sec. 90.100. Miners at surface coal mines, as
well as miners at underground mines, are at risk of developing chronic
lung disease as a result of exposure to respirable coal mine dust. In
the absence of medical monitoring and intervention, a miner may
continue to be exposed, allowing the disease to progress so that the
miner may suffer material impairment of health or functional capacity.
Commenters supported extending the scope of part 90 to surface coal
miners.
2. Section 90.2 Definitions
The final rule does not include the proposed definitions for Weekly
Accumulated Exposure and Weekly Permissible Accumulated Exposure that
would have applied when operators use a CPDM to collect respirable dust
samples under proposed part 90. These two definitions are not needed
since the related proposed sampling requirements are not included in
the final rule. In addition, final part 90 does not include the
existing definitions for ``surface work area of an underground coal
mine'' and ``underground coal mine'' as those terms are no longer used.
Act
The final rule, like the proposal, defines Act as the Federal Mine
Safety and Health Act of 1977, Public Law 91-173, as amended by Public
Law 95-164 and Public Law 109-236.
Active Workings
Final Sec. 90.2, like the proposal, makes no change to the
existing definition of active workings.
Approved Sampling Device
The final Sec. 90.2 definition, like the proposal, is the same as
the final part 70 definition discussed elsewhere in the preamble
related to final Sec. 70.2.
Certified Person
Final Sec. 90.2 makes nonsubstantive changes to clarify the
existing definition of certified person. It does not include the
parenthetical text following the references to Sec. Sec. 90.202 and
90.203.
Coal Mine Dust Personal Sampler Unit (CMDPSU)
The final Sec. 90.2 definition, like the proposal, is the same as
the final part 70 definition discussed elsewhere in the preamble
related to final Sec. 70.2.
Concentration
Final Sec. 90.2, like the proposal, makes no change to the
existing definition of concentration.
Continuous Personal Dust Monitor (CPDM)
The final Sec. 90.2 definition, like the proposal, is the same as
the final part 70 definition discussed elsewhere in the preamble
related to final Sec. 70.2.
District Manager
Final Sec. 90.2, like the proposal, makes no change to the
existing definition of District Manager.
Equivalent Concentration
The final Sec. 90.2 definition is changed from the proposal. It is
the same as the final part 70 definition discussed elsewhere in the
preamble related to final Sec. 70.2.
Mechanized Mining Unit (MMU)
The final definition of MMU is clarified from the proposal. It is
the same as the final part 70 definition discussed elsewhere in the
preamble related to final Sec. 70.2.
MRE Instrument
Final Sec. 90.2, like the proposal, makes no change to the
existing definition of MRE instrument.
MSHA
Final Sec. 90.2, like the proposal, makes no change to the
existing definition of MSHA.
Normal Work Duties
Final Sec. 90.2, like the proposal, makes no change to the
existing definition of normal work duties.
Part 90 Miner
The final definition of part 90 miner is substantially the same as
the proposal. Like the proposal, the definition applies to a miner
employed at a coal mine and replaces the 1.0 mg/m\3\ standard in the
existing definition with ``the applicable standard.'' This change
reflects that, under final Sec. 90.100, the respirable dust standard
changes from 1.0 mg/m\3\ to 0.5 mg/m\3\ 24 months after the effective
date of the rule.
Quartz
The final definition of quartz is changed from the proposal. It is
the same as the final part 70 definition discussed elsewhere in the
preamble related to final Sec. 70.2.
Representative Sample
The final rule defines a representative sample as a respirable dust
sample, expressed as an equivalent concentration, that reflects typical
dust concentration levels in the working environment of the part 90
miner when
[[Page 24948]]
the miner is performing normal work duties.
The final definition is identical to the proposed definition except
that the language, ``expressed as an equivalent concentration'' is
added. The added text clarifies that each respirable dust sample
measurement must be converted to a concentration that is equivalent to
one measured by the MRE instrument. MSHA did not receive comment on the
proposed definition.
Under the final rule, MSHA would consider ``typical dust
concentration levels'' to exist during sampling if they approximate and
are characteristic of the part 90 miner's dust concentration levels
during periods of non-sampling. Samples would be required to be taken
while the part 90 miner performs ``normal work duties,'' as that term
is defined in Sec. 90.2. A sample that is taken when the part 90 miner
is engaged in an atypical task, or some other activity that does not
mirror the duties that the miner performs on a routine, day-to-day
basis in the part 90 miner's job classification at the mine, would not
be considered a representative sample of the part 90 miner. The final
definition ensures that operators conduct respirable dust sampling when
working conditions and work duties accurately represent part 90 miners'
dust exposures. Ensuring that dust samples for part 90 miners are
representative of their exposures is important for these miners, as
they already have medical evidence of the development of
pneumoconiosis. The final definition of representative samples will
provide protection for miners' health by allowing MSHA to objectively
evaluate the functioning of operators' dust controls and the adequacy
of operators' approved plans.
Respirable Dust
Final Sec. 90.2 makes nonsubstantive changes to the existing
definition of respirable dust. It is the same as the final part 70
definition discussed elsewhere in the preamble related to final Sec.
70.2.
Secretary
Final Sec. 90.2 makes nonsubstantive changes to the existing
definition of Secretary. It is the same as the final part 70 definition
discussed elsewhere in the preamble related to final Sec. 70.2.
Secretary of Health and Human Services
Final Sec. 90.2, like the proposal, makes no change to the
existing definition of Secretary of Health and Human Services.
Transfer
Final Sec. 90.2 makes a nonsubstantive change to the existing
definition of transfer. It uses the abbreviation MMU for mechanized
mining unit.
Valid Respirable Dust Sample
For clarification, the final rule revises the definition under
existing Sec. 90.2 for a valid respirable dust sample to mean a
respirable dust sample collected and submitted as required by this
part, including any sample for which the data were electronically
transmitted to MSHA, and not voided by MSHA.
The final definition adds language to clarify that for CPDM
samples, the data files are ``electronically'' transmitted to MSHA, and
not physically transmitted like samples collected with the CMDPSU. The
proposed rule did not include this clarification.
3. Section 90.3 Part 90 Option; Notice of Eligibility; Exercise of
Option
Final Sec. 90.3(a), like the proposal, requires that any miner
employed at a coal mine who, in the judgment of the Secretary of HHS,
has evidence of the development of pneumoconiosis based on a chest X-
ray, read and classified in the manner prescribed by the Secretary of
HHS, or based on other medical examinations must be afforded the option
to work in an area of a mine where the average concentration of
respirable dust in the mine atmosphere during each shift to which that
miner is exposed is continuously maintained at or below the standard.
It further requires that each of these miners be notified in writing of
eligibility to exercise the option.
Final paragraph (a) revises existing Sec. 90.3(a) by extending to
surface coal miners the option to work in an area of a mine where the
average concentration of respirable dust in the mine atmosphere during
each shift is continuously maintained at or below the standard. As
explained in the preamble discussion of Sec. 90.1, miners at surface
coal mines, as well as miners at underground coal mines, are at risk of
developing chronic lung disease as a result of exposure to respirable
coal mine dust. In addition, it replaces the ``1.0 milligrams per cubic
meter of air'' standard with ``the applicable standard.'' This change
reflects that, under final Sec. 90.100, the respirable dust standard
changes from 1.0 mg/m\3\ to 0.5 mg/m\3\ 24 months after the effective
date of the rule.
Final Sec. 90.3(b) is the same as existing Sec. 90.3(b). It
requires that any miner who is a section 203(b) miner on January 31,
1981, will be a part 90 miner on February 1, 1981, entitled to full
rights under this part to retention of pay rate, future actual wage
increases, and future work assignment, shift, and respirable dust
protection. The proposal did not include any changes to existing Sec.
90.3(b).
Final Sec. 90.3(c) is the same as existing Sec. 90.3(c). It
requires that any part 90 miner who is transferred to a position at the
same or another coal mine will remain a part 90 miner entitled to full
rights under this part at the new work assignment. The proposal did not
include any changes to existing Sec. 90.3(c).
Final Sec. 90.3(d), like the proposal, requires that the option to
work in a low dust area of the mine may be exercised for the first time
by any miner employed at a coal mine who was eligible for the option
under the old section 203(b) program (36 FR 20601, October 27, 1971,
precursor to the current part 90 program), or is eligible for the
option under this part by signing and dating the Exercise of Option
Form and mailing the form to the Chief, Division of Health, Coal Mine
Safety and Health, MSHA, 1100 Wilson Boulevard, Arlington, Virginia
22209. Final paragraph (d) includes a conforming change to existing
Sec. 90.3(d) to extend the part 90 transfer option to surface coal
miners. It also makes a nonsubstantive change from the proposal by
including ``(36 FR 20601, October 27, 1971),'' which is the citation to
the section 203(b) program that is stated in the existing definition.
Final Sec. 90.3(e), like the proposal, requires that the option to
work in a low dust area of the mine may be re-exercised by any miner
employed at a coal mine who exercised the option under the old section
203(b) program (36 FR 20601, October 27, 1971), or exercised the option
under this part by sending a written request to the Chief, Division of
Health, Coal Mine Safety and Health, MSHA, 1100 Wilson Boulevard,
Arlington, Virginia 22209. It further requires that the request should
include the name and address of the mine and operator where the miner
is employed. Final paragraph (e) includes a conforming change to
existing Sec. 90.3(e) to extend the part 90 transfer option to surface
coal miners. It also makes a nonsubstantive change from the proposal by
including ``(36 FR 20601, October 27, 1971),'' which is the citation to
the section 203(b) program that is stated in the existing definition.
Final Sec. 90.3(f) is substantially the same as existing Sec.
90.3(f). It states that no operator shall require from a miner a copy
of the medical information received from the Secretary or Secretary
[[Page 24949]]
of HHS. The proposal did not include any changes to existing Sec.
90.3(f). Final paragraph (f) includes a nonsubstantive change. It uses
the abbreviation HHS.
A few commenters recommended that mandatory transfers to less dusty
areas of the mine be required for all part 90 miners. Some commenters
supported mandatory part 90 transfers for miners diagnosed with more
severe CWP (e.g., Category 2). However, MSHA recognizes that a
mandatory transfer program would violate the confidentiality of the
medical monitoring program. It would reveal information about a miner's
medical condition and would have a chilling effect on a miners'
participation in the medical monitoring program. Consequently, the
final rule does not include a mandatory transfer provision.
Some commenters recommended that miners who have developed
occupational chronic obstructive pulmonary disease (COPD) due to coal
mine dust exposure be included as part 90 miners with the transfer
option since it would reduce the risk of worsening their lung disease.
While the final rule includes a new requirement for spirometry, it
continues to afford the part 90 transfer option only to coal miners who
have been diagnosed with pneumoconiosis based on x-ray evidence.
Administration of chest x-rays and the criteria used in diagnosing
pneumoconiosis are governed by HHS regulations under 42 CFR part 37.
The addition of spirometry examinations will provide miners with
supplementary information concerning the health of their lungs on which
to base future potential occupational exposures. With this information,
for example, miners may choose to bid on less dusty jobs or modify
their work practices to minimize coal mine dust exposures.
4. Section 90.100 Respirable Dust Standard
Final Sec. 90.100, is almost identical to proposed Sec. 90.100.
It requires that after the 20th calendar day following receipt of
notification from MSHA that a part 90 miner is employed at the mine,
the operator must continuously maintain the average concentration of
respirable dust in the mine atmosphere during each shift to which the
part 90 miner in the active workings of the mine is exposed, as
measured with an approved sampling device and expressed in terms of an
equivalent concentration, at or below: (a) 1.0 milligrams of respirable
dust per cubic meter of air (mg/m\3\), and (b) 0.5 mg/m\3\ as of August
1, 2016.
Final Sec. 90.100 makes a nonsubstantive change from proposed
Sec. 90.100. The term ``expressed,'' which was inadvertently omitted
from the proposal, is added.
Final paragraph (b) replaces the proposed 6-month phase-in period
with an implementation date that is 24 months after the effective date
of the final rule. This is consistent with the time periods in final
Sec. Sec. 70.100(b) and 71.100(b).
The 0.5 mg/m\3\ standard provides protection for part 90 miners
when coupled with the final rule's requirements that the sampling
devices remain operational during the part 90 miner's entire shift,
including time spent performing normal work duties and traveling to and
from the assigned work location, and that the required samples are
representative of the miner's exposure while performing normal work
duties. The final 0.5 mg/m\3\ standard will ensure that part 90 miners,
who are already suffering from decreased lung function, are adequately
protected. In addition, most operators are already in compliance with
the final standard and MSHA has concluded that the final standard is
feasible. The feasibility of the 0.5 mg/m\3\ standard is discussed in
more detail elsewhere in this preamble under Section III. C.,
concerning the Technological Feasibility of Achieving the Required Dust
Standards. Commenters supported the proposed standard.
5. Section 90.101 Respirable Dust Standard When Quartz Is Present
Final Sec. 90.101(a), like proposed Sec. 90.101(a), requires that
each operator continuously maintain the average concentration of
respirable quartz in the mine atmosphere during each shift to which a
part 90 miner in the active workings of each mine is exposed at or
below 0.1 mg/m\3\ (100 micrograms per cubic meter or [micro]g/m\3\) as
measured with an approved sampling device and expressed in terms of an
equivalent concentration.
Final paragraph (b), like the proposed rule, requires that when the
mine atmosphere of the active workings where the part 90 miner performs
his or her normal work duties exceeds 100 [mu]g/m\3\ of respirable
quartz dust, the operator must continuously maintain the average
concentration of respirable dust in the mine atmosphere during each
shift to which a part 90 miner is exposed as measured with an approved
sampling device and expressed in terms of an equivalent concentration
at or below the applicable standard. It also states that the applicable
standard is computed by dividing the percent of quartz into the number
10 and that application of this formula must not result in an
applicable standard that exceeds the standard specified in Sec.
90.100.
Final paragraphs (a) and (b) include a nonsubstantive change and
add the term ``expressed'' which was inadvertently omitted from the
proposal, but is contained in existing Sec. 90.101.
Final Sec. 90.101, like proposed Sec. 90.101, includes an example
of how a reduced standard is calculated, based on the equivalent
concentration of 0.5 mg/m\3\ dust standard. The example states that:
Suppose a valid respirable dust sample with an equivalent concentration
of 0.50 mg/m\3\ contains 25.6% of quartz dust, which corresponds to a
quartz concentration of 128 [mu]g/m\3\. The average concentration of
respirable dust in the mine atmosphere associated with that part 90
miner must be maintained on each shift at or below 0.4 mg/m\3\ (10/
25.6% = 0.4 mg/m\3\).
Commenters supported the proposed standard.
6. Section 90.102 Transfer; Notice
Final Sec. 90.102(a), like the proposal, requires that whenever a
part 90 miner is transferred in order to meet the standard (Sec.
90.100, the respirable dust standard or Sec. 90.101, the respirable
dust standard when quartz is present), the operator must transfer the
miner to an existing position at the same coal mine on the same shift
or shift rotation on which the miner was employed immediately before
the transfer. It further provides that the operator may transfer a part
90 miner to a different coal mine, a newly-created position or a
position on a different shift or shift rotation if the miner agrees in
writing to the transfer. It states that the requirements of this
paragraph do not apply when the respirable dust concentration in a part
90 miner's work position complies with the standard but circumstances,
such as reductions in workforce or changes in operational status,
require a change in the miner's job or shift assignment.
Final paragraph (a) revises existing Sec. 90.102(a) by
establishing an exception to the transfer requirement. The exception is
consistent with existing Agency policy, which is to accommodate an
operator's good faith need to reassign a part 90 miner when unforeseen
circumstances and unexpected mine or market conditions arise. The
exception provides a mine operator with flexibility with respect to the
assignment of a part 90 miner without compromising the objectives of
the part 90 program.
The Agency received one comment on proposed Sec. 90.102 in which
the commenter expressed general support for the standard.
[[Page 24950]]
Final Sec. 90.102(b) is unchanged from the proposal and
substantially the same as existing Sec. 90.102(b). It requires that on
or before the 20th calendar day following receipt of notification from
MSHA that a part 90 miner is employed at the mine, the operator must
give the District Manager written notice of the occupation and, if
applicable, the MMU unit to which the part 90 miner will be assigned on
the 21st calendar day following receipt of the notification from MSHA.
The proposal did not include any substantive change to existing Sec.
90.102(b). Like the proposal, final paragraph (b) makes nonsubstantive
changes to existing Sec. 90.102(b).
Final Sec. 90.102(c) is unchanged from the proposal and
substantially the same as existing Sec. 90.102(c). It requires that
after the 20th calendar day following receipt of notification from MSHA
that a part 90 miner is employed at the mine, the operator must give
the District Manager written notice before any transfer of a part 90
miner. It further requires that this notice include the scheduled date
of the transfer. The proposal did not include any substantive change to
existing Sec. 90.102(c). Final paragraph (c) includes a nonsubstantive
change to existing Sec. 90.102(c).
7. Section 90.103 Compensation
Final Sec. 90.103(a) is unchanged from the proposal and
substantially the same as existing Sec. 90.103(a). It requires that
the operator compensate each part 90 miner at not less than the regular
rate of pay received by that miner immediately before exercising the
option under Sec. 90.3. The proposal did not include any substantive
change to existing Sec. 90.103(a). Final paragraph (a) makes a
nonsubstantive change to existing Sec. 90.103(a). It does not include
the parenthetical text following the reference to Sec. 90.3.
Final Sec. 90.103(b) is unchanged from the proposal. It requires
that, whenever a part 90 miner is transferred, the operator must
compensate the miner at not less than the regular rate of pay received
by that miner immediately before the transfer. The proposal did not
include any changes to existing Sec. 90.103(b).
Final Sec. 90.103(c), like the proposal, requires that once a
miner has been placed in a position in compliance with the provisions
of part 90, paragraphs (a) and (b) of this section do not apply when
the part 90 miner initiates and accepts a change in work assignment for
reasons of job preference.
One commenter generally expressed support for the proposal.
Final paragraph (c) is consistent with MSHA's longstanding policy
of not applying the part 90 miner compensation provisions under the
circumstances where, once a miner has been placed in a position that
complies with the provisions in part 90, the part 90 miner on his own
initiative applies for and accepts another job in a work area with an
average respirable dust concentration at or below the part 90
respirable dust standard. As an example: A miner exercised the part 90
option when the miner's job paid $20 per hour. If the operator keeps
the part 90 miner in the same work position because compliance with the
part 90 respirable dust standard is maintained, or if the operator
transfers the miner to a new work position to achieve compliance with
part 90, the miner cannot be paid less than $20 per hour--the amount
paid immediately before exercising the option. However, once the
operator has placed the miner in a position that complies with the
provisions of part 90, if the miner prefers a different job and
initiates and accepts a job change that only pays $17 per hour, the
miner would receive $17 per hour in the new position. Under final
paragraph (c), a miner-initiated job change to a position that is at or
below the part 90 respirable dust standard would not constitute a
waiver of other part 90 rights. In the new job, the miner would retain
part 90 status and all other requirements of part 90 continue in
effect, including the operator's obligations to continuously maintain
the part 90 respirable dust standard and to give MSHA notice whenever
the miner's work assignment changes or lasts longer than one shift.
Final Sec. 90.103(d) is unchanged from the proposal. It is
redesignated from and is the same as existing Sec. 90.103(c). It
requires that the operator compensate each miner who is a section
203(b) miner on January 31, 1981, at not less than the regular rate of
pay that the miner is required to receive under section 203(b) of the
Act immediately before the effective date of this part. The proposal
did not include any changes to existing Sec. 90.103(c).
Final Sec. 90.103(e) is unchanged from the proposal. It is
redesignated from and is substantially the same as existing Sec.
90.103(d). It requires that, in addition to the compensation required
to be paid under paragraphs (a), (b), and (d) of this section, the
operator must pay each part 90 miner the actual wage increases that
accrue to the classification to which the miner is assigned. Final
paragraph (e), like the proposal, includes a conforming change
referring to paragraphs (a), (b), and (d) of this section.
Final Sec. 90.103(f), like the proposal, is redesignated from and
is substantially similar to existing Sec. 90.103(e). It requires that
if a miner is temporarily employed in an occupation other than his or
her regular work classification for two months or more before
exercising the option under Sec. 90.3, the miner's regular rate of pay
for purposes of paragraphs (a) and (b) of this section is the higher of
the temporary or regular rates of pay. If the temporary assignment is
for less than two months, the operator may pay the part 90 miner at his
or her regular work classification rate regardless of the temporary
wage rate. The proposal did not include any changes to existing Sec.
90.103(e). Final paragraph (e) includes two nonsubstantive changes. It
deletes the parenthetical text following the reference to Sec. 90.3
and changes the word ``paragraph'' in the proposal to ``paragraphs''.
Final Sec. 90.103(g)(1) and (2) is substantially the same as the
proposal and is redesignated from existing Sec. 90.103(f)(1) and (2).
It requires that if a part 90 miner is transferred, and the Secretary
subsequently notifies the miner that notice of the miner's eligibility
to exercise the part 90 option was incorrect, the operator must retain
the affected miner in the current position to which the miner is
assigned and continue to pay the affected miner the rate of pay
provided in paragraphs (a), (b), (d), and (e) of this section, until:
(1) The affected miner and operator agree in writing to a position
with pay at not less than the regular rate of pay for that occupation;
or
(2) A position is available at the same coal mine in both the same
occupation and on the same shift on which the miner was employed
immediately before exercising the option under Sec. 90.3 or under the
old section 203(b) program (36 FR 20601, October 27, 1971).
(i) When such a position is available, the operator shall offer the
available position in writing to the affected miner with pay at not
less than the regular rate of pay for that occupation.
(ii) If the affected miner accepts the available position in
writing, the operator shall implement the miner's reassignment upon
notice of the miner's acceptance. If the miner does not accept the
available position in writing, the miner may be reassigned and
protections under part 90 shall not apply. Failure by the miner to act
on the written offer of the available position within 15 days after
notice of the offer is received from the operator shall operate as an
election not to accept the available position.
[[Page 24951]]
The proposal did not include any substantive changes to existing
Sec. 90.103(f)(1) and (2). Final paragraph (g)(2) makes a
nonsubstantive change from the proposal by including ``(36 FR 20601,
October 27, 1971),'' which is the citation to the section 203(b)
program that is stated in the existing definition.
8. Section 90.104 Waiver of Rights; Re-Exercise of Option
Final Sec. 90.104 is unchanged from the proposal. It provides that
a part 90 miner may waive his or her rights and be removed from MSHA's
active list of miners who have rights under part 90 by: (1) Giving
written notification to the Chief, Division of Health, Coal Mine Safety
and Health, MSHA, that the miner waives all rights under this part; (2)
applying for and accepting a position in an area of a mine which the
miner knows has an average respirable dust concentration exceeding the
standard; or (3) refusing to accept another position offered by the
operator at the same coal mine that meets the requirements of
Sec. Sec. 90.100, 90.101 and 90.102(a) after dust sampling shows that
the present position exceeds the standard.
Final paragraph (a)(1) is the same as existing Sec. 90.104(a)(1).
Final paragraphs (a)(2) and (3) change existing Sec. 90.104(a)(2) and
(3) by including the term ``applicable standard'' rather than ``1.0
milligrams per cubic meter of air or the respirable dust standard
established by Sec. 90.101 (Respirable dust standard when quartz is
present.'' These are conforming changes consistent with other
provisions of the final rule.
Final Sec. 90.104(b), like the proposal, provides that if rights
under part 90 are waived, the miner gives up all rights under part 90
until the miner re-exercises the option in accordance with Sec.
90.3(e) (Part 90 option; notice of eligibility; exercise of option).
Final paragraph (b) is the same as existing Sec. 90.104(b).
Final Sec. 90.104(c), like the proposal, provides that if rights
under part 90 are waived, the miner may re-exercise the option under
this part in accordance with Sec. 90.3(e) (Part 90 option; notice of
eligibility; exercise of option) at any time. Final paragraph (c) is
the same as existing Sec. 90.104(c).
MSHA received one comment expressing general support for this
section and it is finalized as proposed.
9. Section 90.201 Sampling; General and Technical Requirements
Final Sec. 90.201 addresses general and technical requirements
concerning operator sampling. One commenter expressed support for the
proposal.
Final paragraph (a) is substantially similar to the proposal. It
requires that an approved coal mine dust personal sampler unit (CMDPSU)
must be used to take samples of the concentration of respirable coal
mine dust in the working environment of each part 90 miner as required
by this part for the first 18 months after the effective date of the
rule. Paragraph (a) changes the implementation date for using the
approved CPDM from the proposed 12 months to 18 months after the
effective date of the rule. On February 1, 2016, part 90 miners must be
sampled only with a CPDM as required by this part, and an approved
CMDPSU must not be used unless notified by the Secretary to continue to
use an approved CMDPSU to conduct quarterly sampling. The rationale for
paragraph (a) is the same as that for final Sec. 70.201(a), which is
discussed elsewhere in this preamble. MSHA received no comments on the
proposal.
Final paragraph (b) is like the proposal with nonsubstantive
changes. It requires that if using a CMDPSU, the sampling device must
be worn or carried to and from each part 90 miner, and if using a CPDM,
the sampling device must be worn by the part 90 miner at all times. It
also requires that approved sampling devices be operated portal-to-
portal and remain operational during the part 90 miner's entire shift,
which includes the time spent performing normal work duties and while
traveling to and from the assigned work location. It further requires
that if the work shift to be sampled is longer than 12 hours and the
sampling device is a CMDPSU, the operator must switch-out the unit's
sampling pump prior to the 13th-hour of operation; and, if the sampling
device is a CPDM, the operator must switch-out the CPDM with a fully
charged device prior to the 13th-hour of operation.
Paragraph (b) is similar to final Sec. 70.201(b). The rationale
for paragraph (b) is the same as that for final Sec. 70.201(b), which
is discussed elsewhere in this preamble. MSHA received no comments on
the proposal.
Final paragraph (c) is unchanged from the proposal and is identical
to existing requirements. It requires that unless otherwise directed by
the District Manager, the respirable dust samples required under this
part using a CMDPSU be taken by placing the sampling device as follows:
(1) On the part 90 miner; (2) on the piece of equipment which the part
90 miner operates within 36 inches of the normal working position; or,
(3) at a location that represents the maximum concentration of dust to
which the part 90 miner is exposed. MSHA received no comments on the
proposal.
Final paragraph (d), like the proposal, requires that if using a
CMDPSU, one control filter must be used for each shift of sampling. It
further requires that each control filter must: (1) Have the same pre-
weight date (noted on the dust data card) as the filter used for
sampling; (2) remain plugged at all times; (3) be used for the same
amount of time, and exposed to the same temperature and handling
conditions as the filter used for sampling; and (4) be kept with the
exposed samples after sampling and in the same mailing container when
transmitted to MSHA. Final paragraph (d)(4) clarifies that the control
filter must be in the same mailing container as the exposed samples
when transmitted to MSHA. MSHA received no comments on the proposal.
In addition, paragraphs (d)(1)-(4) are identical to final Sec.
70.201(d)(1)--(4). The rationale for paragraphs (d)(1)-(4) is discussed
under final Sec. 70.201(d)(1)-(4) of this preamble.
Final paragraph (e), like the proposal, requires that the
respirable dust samples required by this part and taken with a CMDPSU
must be collected while the part 90 miner is performing normal work
duties. Paragraph (e) is substantially the same as the existing
requirement. MSHA received no comments on the proposal. Paragraph (e)
is unchanged from the proposal.
Final paragraph (f), like the proposal, requires that records
showing the length of each shift for each part 90 miner be made and
retained for at least six months, and be made available for inspection
by authorized representatives of the Secretary and submitted to the
District Manager when requested in writing. Paragraph (f) is similar to
final Sec. 70.201(e). The rationale for paragraph (f) is discussed
elsewhere in this preamble under Sec. 70.201(e). Paragraph (f) is
unchanged from the proposal.
Final paragraph (g), like the proposal, requires that upon request
from the District Manager, the operator must submit the date and time
any respirable dust sampling required by this part will begin. It
further requires that this information be submitted at least 48 hours
prior to scheduled sampling. Paragraph (g) is identical to final Sec.
70.201(f). The rationale for paragraph (g) is discussed under final
Sec. 70.201(f). Paragraph (g) is unchanged from the proposal.
Final paragraph (h) is substantially the same as the proposal. It
requires that operators using CPDMs provide training to all part 90
miners. It makes nonsubstantive changes to require that the training
must be completed prior to
[[Page 24952]]
a part 90 miner wearing a CPDM and then every 12 months thereafter.
Final paragraphs (h)(1)-(4) are similar to proposed paragraphs
(h)(1)-(5). Proposed paragraph (h)(2) would have required miners to be
instructed on how to set up the CPDM for compliance sampling. The final
rule requires mine operators to have certified persons set up the CPDM
for compliance. Therefore, the final rule does not include this
proposed provision.
Paragraph (h)(1) is similar to proposed (h)(5). Like the proposal,
it requires that the training include the importance of monitoring dust
concentrations and properly wearing the CPDM. Paragraph (h)(1) makes a
conforming change. The proposal would have required training on the
importance of ``continuously'' monitoring dust concentrations. Since
continuous monitoring is not required by the final rule, the term
``continuously'' is not included in paragraph (h)(1).
Final paragraph (h)(2) is the same as proposed (h)(1). It requires
that the training include explaining the basic features and
capabilities of the CPDM.
Final paragraph (h)(3), like the proposal, requires that the
training include discussing the various types of information displayed
by the CPDM and how to access that information.
Final paragraph (h)(4), like the proposal, requires that the
training include how to start and stop a short-term sample run during
compliance sampling.
The training requirements of paragraphs (h)(1)-(4) are identical to
the training requirements of final Sec. 70.201(h)(1)-(4). The
rationale for paragraph (h)(1)-(4) is discussed under final Sec.
70.201(h)(1)-(4) of this preamble.
Final paragraph (i), like the proposal, requires that an operator
keep a record of the CPDM training at the mine site for 24 months after
completion of the training. It also provides that an operator may keep
the record elsewhere if the record is immediately accessible from the
mine site by electronic transmission. It further requires that upon
request from an authorized representative of the Secretary or Secretary
of HHS, the operator must promptly provide access to any such training
records. Final paragraphs (i)(1)-(3) require the record to include the
date of training, the names of miners trained, and the subjects
included in the training.
Paragraph (i) includes a non-substantive change by replacing the
proposed term ``2 years'' with ``24 months.''
Final paragraphs (i)(1)-(3) are new and were added to clarify that
the record must contain sufficient information for an authorized
representative of the Secretary or Secretary of HHS to determine that
the operator has provided CPDM training in accordance with requirements
in paragraph (h). Like final Sec. 70.201(i), this is the type of
information that is generally required for all training records to
establish that the training has occurred.
The requirements of paragraph (i) are identical to final Sec.
70.201(i). The rationale for paragraph (i) is discussed elsewhere in
this preamble under final Sec. 70.201(i).
Final paragraph (j) is new. It provides that an anthracite mine
using the full box, open breast, or slant breast mining method may use
either a CPDM or a CMDPSU to conduct the required sampling. It requires
that the mine operator notify the District Manager in writing of its
decision to not use a CPDM.
Paragraph (j) is identical to final Sec. 70.201(j). The rationale
for paragraph (j) is discussed elsewhere in this preamble under final
Sec. 70.201(j).
10. Sections 90.202 Certified Person; Sampling and 90.203 Certified
Person; Maintenance and Calibration
Final Sec. Sec. 90.202 and 90.203 are identical to final
Sec. Sec. 70.202 and 70.203. Comments on proposed Sec. Sec. 90.202
and 90.203 were the same as comments on proposed Sec. Sec. 70.202 and
70.203. The comments and MSHA's rationale are discussed elsewhere in
this preamble under Sec. Sec. 70.202 and 70.203.
11. Section 90.204 Approved Sampling Devices; Maintenance and
Calibration
Final Sec. 90.204 and its rationale are identical to final Sec.
70.204, discussed elsewhere in this preamble under final Sec. 70.204.
One commenter generally supported proposed Sec. 90.204.
12. Section 90.205 Approved Sampling Devices; Maintenance and
Calibration
Final Sec. 90.205 and its rationale are identical to final Sec.
70.205, discussed elsewhere in this preamble under final Sec. 70.205.
One commenter generally supported proposed Sec. 90.205.
13. Section 90.206 Exercise of Option or Transfer Sampling
Final Sec. 90.206 is derived from existing Sec. 90.207 pertaining
to ``Compliance sampling.'' Final Sec. 90.206 changes the existing
section heading to distinguish sampling that occurs when a part 90
miner opts to exercise his option to work in a low dust area of a mine
or when a transfer in the part 90 miner's work assignment occurs from
the quarterly compliance sampling required under final Sec. 90.207.
Final Sec. 90.206(a)(1) and (2) require that the operator take
five valid representative dust samples for each part 90 miner within 15
calendar days after: (1) The 20-day period specified for each part 90
miner in Sec. 90.100; and (2) implementing any transfer after the 20th
calendar day following receipt of notification from MSHA that a part 90
miner is employed at the mine. Final paragraph (a)(1) is the same as
proposed Sec. 90.207(a)(1). Final paragraph (a)(2) is the same as
proposed Sec. 90.207(a)(3). Proposed Sec. 90.207(a)(2), which was the
same as existing Sec. 90.207(a)(2), would have specified the action
that an operator would take when the operator received notification
from MSHA that compliance samples taken under part 90 exceeded the
standard. Proposed Sec. 90.207(a)(2) is not included in the final rule
because final Sec. 90.207(c) specifies the actions that a mine
operator must take when part 90 miner sample results show respirable
dust overexposures.
Final Sec. 90.206(b), like the proposal, provides that
noncompliance with the standard be determined in accordance with final
Sec. 90.207(d). Under the proposal, noncompliance determinations would
have been determined in accordance with proposed Sec. 90.207(d)
pertaining to a part 90 miner's single-shift exposure, as well as the
miner's weekly accumulated exposure. However, for reasons discussed
elsewhere in this preamble, the proposed single-shift sampling and
weekly accumulated exposure provisions for operators' sampling are not
included in the final rule. Rather, final Sec. 90.207(d) lists the two
means by which noncompliance with the standard will be determined and
is discussed elsewhere in this preamble under Sec. 90.207(d). Final
paragraph (b) ensures that operators are aware how compliance
determinations will be made for exercise of option and transfer samples
taken under final paragraphs (a)(1) and (a)(2).
Final Sec. 90.206(c), like the proposal, provides that upon
issuance of a citation for a violation of the standard, the operator
must comply with Sec. 90.207(f). Final paragraph (c) is derived from
existing Sec. 90.201(d), which requires corrective action and an
additional five samples from the part 90 miner after a citation is
issued. Final paragraph (c) ensures that a mine operator is aware of
the abatement termination procedures that apply when a citation is
issued for respirable dust overexposure on
[[Page 24953]]
samples taken after a miner exercises the part 90 option to work in a
low dust area of the mine or when a part 90 miner is transferred.
The Agency received one comment on proposed Sec. 90.207 in which
the commenter expressed general support for the proposal.
14. Section 90.207 Quarterly Sampling
Final Sec. 90.207 is redesignated proposed Sec. 90.208 regarding
procedures for sampling with CMDPSUs and Sec. 90.209 regarding
procedures for sampling with CPDMs. It revises the sampling
requirements of existing Sec. Sec. 90.207 and 90.208. The section
heading is changed from the proposal by adding ``quarterly'' to
distinguish the required sampling period under Sec. 90.207 from that
specified for exercise of option or transfer sampling under final Sec.
90.206. It does not include the specific sampling device because the
device is specified under final Sec. 90.201.
According to final Sec. 90.201(a), part 90 miners must be sampled
with a CMDPSU on the effective date of the final rule. On February 1,
2016, part 90 miners must be sampled only with an approved continuous
personal dust monitor (CPDM) as required by this part and an approved
CMDPSU must not be used, unless notified by the Secretary to continue
to use an approved CMDPSU to conduct quarterly sampling.
Final Sec. 90.207(a) is substantially similar to proposed Sec.
90.208(a). It requires that each operator must take five valid
representative samples every calendar quarter from the environment of
``each'' part 90 miner while performing normal work duties. Final
paragraph (a) further requires that part 90 miner samples must be
collected on consecutive work days. The quarterly periods are: (1)
January 1-March 31; (2) April 1-June 30; (3) July 1-September 30; (4)
October 1-December 31.
Final paragraph (a) does not include the 24/7 continuous sampling
frequency in proposed Sec. 90.209(a) while using a CPDM. Proposed
Sec. 90.209(a) would have required that, when using the CPDM, each
operator sample the working environment of the part 90 miner during
each shift, 7 days per week, if applicable, 52 weeks per year.
One part 90 commenter stated that the CPDM would affect miners'
performance, back, hips, legs and knees.
In response to the comment, MSHA has concluded that 24/7 continuous
sampling of a part 90 miner using a CPDM may be too burdensome on a
part 90 miner who is already suffering from decreased lung function.
Therefore, final paragraph (a) includes the sampling frequency in
proposed Sec. 90.208(a) which would have required the operator to take
five samples each calendar quarter when using the CMDPSU.
Because the proposed sampling frequency while using a CPDM could
have affected a part 90 miner's performance, and back, hips, legs and/
or knees, final paragraph (a) replaces the existing bimonthly sampling
period with a quarterly sampling period and increases sampling from one
to five samples collected on consecutive work days during a quarterly
period. This is the same sampling frequency in proposed Sec. 90.208(a)
which would have required the operator to take five samples each
calendar quarter when using the CMDPSU. Sampling part 90 miners during
five consecutive work days on a quarterly basis provides a better
representation of typical dust conditions to which a part 90 miner is
exposed as compared to the existing bimonthly sampling period.
Therefore, final paragraph (a) provides greater protection for miners
than the existing standard. In addition, final paragraph (a) protects
part 90 miners because the sampling results obtained during the
quarterly sampling periods will provide mine operators with information
to evaluate the dust controls specified in their approved ventilation
plan and the maintenance of those controls. As long as dust controls
are properly maintained to ensure continuing compliance with the
respirable dust standard, part 90 miners will be protected from
overexposures. This is particularly so because MSHA certifies that the
part 90 miner is in an occupation that meets the respirable dust
standard and cannot be moved to a different occupation unless certified
by MSHA.
Final paragraph (b) is redesignated from and is similar to proposed
Sec. Sec. 90.208(b) and 90.209(b). Paragraph (b) clarifies the time
frame for implementation when there is a change in the applicable
standard. Paragraph (b) requires that when the respirable dust standard
is changed in accordance with Sec. 90.101, the new standard becomes
effective 7 calendar days after the date of the notification of the
change by MSHA. Under the proposal, a new standard would have gone into
effect on the first shift after receipt of notification. MSHA did not
receive comments on proposed Sec. Sec. 90.208(b) or 90.209(b).
Final paragraph (b) is substantially similar to final Sec. Sec.
70.206(c), 70.207(b), 70.208(c), 70.209(b) and 71.206(b), except for
conforming changes. The rationale for paragraph (b) is discussed
elsewhere in this preamble under final Sec. 70.208(c).
Final paragraph (b) does not include the requirements in proposed
Sec. 90.208(b)(1) and (b)(2). Proposed Sec. 90.208(b)(1) would have
required that if all samples for the part 90 miner from the most recent
quarterly sampling period do not exceed the new standard (reduced due
to the presence of quartz), respirable dust sampling of the part 90
miner would begin on the first shift on which that miner is performing
normal work duties during the next quarterly period following
notification of the change. Proposed Sec. 90.208(b)(2) would have
required that if any sample from the most recent quarterly sampling
period exceeds the new standard (reduced due to the presence of
quartz), the operator must make necessary adjustments to the dust
control parameters within three days and then collect samples from the
affected part 90 miner on consecutive work days until five valid
representative samples are collected. It further provided that the
samples collected will be treated as normal quarterly samples under
this part. MSHA did not receive any comments on the proposal.
MSHA's rationale for not including Sec. 90.208(b)(1) and (b)(2) is
discussed elsewhere in this preamble under final Sec. 70.206(c)(1) and
(2).
Final paragraph (c) is changed from the proposal. It requires that
when a valid representative sample taken in accordance with this
section meets or exceeds the ECV in Table 90-1 that corresponds to the
applicable standard and particular sampling device used, the operator
must: (1) Make approved respiratory equipment available; (2)
Immediately take corrective action; and (3) Record the corrective
actions. Paragraph (c) is similar to proposed Sec. 90.208(e) and (g),
regarding compliance sampling procedures for sampling with CMDPSUs, and
Sec. 90.209(e) and (f), regarding compliance sampling procedures for
sampling with CPDMs. The actions required by final paragraph (c) are
similar to those proposed.
Proposed Sec. 90.208(e) would have applied to sampling with a
CMDPSU and would have required that during the time for abatement fixed
in a citation, the operator would have to: (1) Make approved
respiratory equipment available, (2) submit proposed corrective actions
to the District Manager, and either (i) implement the corrective
actions after District Manager approval and conduct additional
sampling, or (ii) transfer the part 90 miner to a work position meeting
the standard and conduct additional sampling.
[[Page 24954]]
Proposed Sec. 90.208(g) would have applied to sampling with a
CMDPSU and would have required that when a valid sample exceeds the
standard but is less than the applicable ECV in proposed Table 90-1,
the operator would have to: (1) Make approved respiratory equipment
available, (2) take corrective action, and (3) record the corrective
action taken in the same manner as the records for hazardous conditions
required by Sec. 75.363.
Proposed Sec. 90.209(e) would have applied to sampling with a CPDM
and would have required that when a valid end-of-shift equivalent
concentration meets or exceeds the applicable ECV, or a weekly
accumulated exposure exceeds the weekly permissible accumulated
exposure, the operator would have to: (1) Make approved respiratory
equipment available, (2) implement corrective actions, (3) submit dust
control measures to the District Manager for approval, (4) review and
revise the CPDM Performance Plan, (5) record the excessive dust
condition as part of and in the same manner as the records for
hazardous conditions required by Sec. 75.363, and (6) sample any
transferred part 90 miner.
Proposed Sec. 90.209(f) would have applied to sampling with a CPDM
and would have required that when a valid end-of-shift equivalent
concentration exceeds the standard but is less than the applicable ECV,
the operator would have to: (1) Make approved respiratory equipment
available, (2) implement corrective actions, (3) record the excessive
dust condition as part of and in the same manner as the records for
hazardous conditions required by Sec. 75.363, and the corrective
actions taken, and (4) review and revise the CPDM Performance Plan.
As noted previously in the discussion on final Sec. 70.206(e),
MSHA clarified, in the March 8, 2011, request for comments (76 FR
12650), that the proposal would require that operators record both
excessive dust concentrations and corrective actions in the same manner
as conditions are recorded under Sec. 75.363 and that ``MSHA would not
consider excessive dust concentrations to be hazardous conditions,
since the proposed requirement is not a section 75.363 required
record'' (76 FR 12650). MSHA did not receive any comments on the
proposal.
Final paragraph (c) is changed from the proposal. It does not
require action if the dust sample exceeds the standard but is less than
the ECV in Table 90-1. Rather, it requires an operator to take certain
actions when a respirable dust sample meets or exceeds the ECV in Table
90-1. Although the Secretary has determined that a single full-shift
measurement of respirable coal mine dust accurately represents
atmospheric conditions to which a miner is exposed during such shift,
MSHA has concluded that a noncompliance determination based on a single
full-shift sample will only be made on MSHA inspector samples. With
respect to operator samples, MSHA reevaluated its enforcement strategy
under the proposed rule. MSHA determined that the proposal would have
resulted in little time for an operator to correct noncompliance
determinations based on an operator's single sample. The final rule
ensures that an operator takes corrective actions on a single
overexposure. If sampling with a CMDPSU, the actions must be taken upon
notification by MSHA that a respirable dust sample taken in accordance
with this section meets or exceeds the ECV for the applicable standard.
If sampling with a CPDM, the actions must be taken when the sampling
measurement shows that a dust sample taken in accordance with this
section meets or exceeds the ECV for the applicable standard.
Final paragraph (c)(1) is similar to proposed Sec. Sec.
90.208(e)(1) and (g)(1) and 90.209(e)(1) and (f)(1). It requires that
the operator make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter. Some commenters
stated that a part 90 miner should not be required to wear a respirator
and should be removed from the environment when any sample exceeds the
respirable dust standard.
The combination of specific actions that an operator is required to
take under the final rule, which includes making approved respiratory
equipment available, immediately taking corrective action, and
recording the corrective actions, provides immediate health protection
to a part 90 miner. Additional discussion on the rationale for final
paragraph (c)(1) can be found elsewhere in this preamble under final
Sec. 70.206(e)(1).
Final paragraph (c)(2) is similar to proposed Sec. Sec.
90.208(e)(2)(i) and (g)(2) and 90.209(e)(2) and (f)(2). It requires
that the operator immediately take corrective action to lower the
concentration of respirable coal mine dust to at or below the standard.
Paragraph (c)(2) is consistent with existing Sec. 90.201(d), which
requires a mine operator to take corrective action to lower the
concentration of respirable dust. Paragraph (c)(2) clarifies that
corrective action needs to be taken immediately to protect miners from
overexposures. MSHA did not receive any comments on the proposal. The
rationale for final paragraph (c)(2) is the same as that for final
Sec. 70.206(e)(2) and is discussed in that section.
Final paragraph (c)(3) is similar to proposed Sec. Sec.
90.208(g)(3) and 90.209(f)(3)(v). Final paragraph (c)(3) requires that
the mine operator make a record of the corrective actions taken. The
record must be certified by the mine foreman or equivalent mine
official no later than the end of the mine foreman's or equivalent mine
official's next regularly scheduled working shift. It also requires
that the record must be made in a secure book that is not susceptible
to alteration or electronically in a computer system so as to be secure
and not susceptible to alteration. Final paragraph (c)(3) further
requires that the records must be retained at a surface location at the
mine for at least 1 year and be made available for inspection by
authorized representatives of the Secretary and the part 90 miner. MSHA
did not receive any comments on the proposal. The rationale for
paragraph (c)(3) is the same as that for final Sec. 70.206(e)(3) and
is discussed in that section.
Final paragraph (c) does not include the provisions in proposed
Sec. Sec. 90.208(e)(2) and 90.209(e)(3) regarding the submission of
corrective actions to the District Manager for approval. MSHA did not
receive comments on the proposal. MSHA's rationale is discussed
elsewhere in this preamble under final Sec. 70.206(h)(4).
In addition, unlike proposed Sec. 90.209(e)(4) and (f)(4), final
paragraph (c) does not require operators to review and revise a CPDM
Performance Plan. MSHA did not receive any comments on the proposal. As
discussed elsewhere in this preamble under Sec. 70.206, the final rule
does not include the proposed requirements for a CPDM Performance Plan.
For consistency between the sampling requirements of the final
rule, final paragraphs (c)(1)-(3) are identical to final Sec.
70.206(e)(1)-(3) regarding bimonthly sampling of MMUs, Sec.
70.207(d)(1)-(3) regarding bimonthly sampling of designated areas,
Sec. 70.208(e)(1)-(3) regarding quarterly sampling of MMUs, Sec.
70.209(c)(1)-(3) regarding quarterly sampling of designated areas, and
Sec. 71.206(h)(1)-(3) regarding quarterly sampling, except for
conforming changes. Under final paragraph (c)(3), the operator must
make the corrective action record available for inspection to the part
90 miner and not to the representative of the miners, due to privacy
considerations.
[[Page 24955]]
Final paragraph (d) is redesignated and changed from proposed
Sec. Sec. 90.208(c) and 90.209(c) and (d). It states that
noncompliance with the standard is demonstrated during the sampling
shift when: (1) Two or more valid representative samples meet or exceed
the excessive concentration value (ECV) in Table 90-1 that corresponds
to the applicable standard and the particular sampling device used; or
(2) The average for all valid representative samples meets or exceeds
the ECV in Table 90-2 that corresponds to the applicable standard and
the particular sampling device used.
In the March 8, 2011, request for comments (76 FR 12649), MSHA
stated that the Agency was interested in commenters' views on what
actions should be taken by MSHA and the mine operator when a single
shift respirable dust sample meets or exceeds the ECV. The Agency also
requested comments on alternative actions, other than those contained
in the proposal, for MSHA and the operator to take if operators use a
CPDM. MSHA further stated that it was particularly interested in
alternatives to those in the proposal and how such alternatives would
be protective of miners.
Proposed Sec. Sec. 90.208(c) and 90.209(c) would have required
that no valid end-of-shift equivalent concentration meet or exceed the
ECV that corresponds to the applicable standard in the respective Table
90-1 or 90-2. Proposed Sec. 90.209(d) would have required that no
weekly accumulated exposure exceed the weekly permissible accumulated
exposure.
MSHA did not receive any comments on proposed Sec. Sec. 90.208(c)
or 90.209(c) and (d). The rationale for paragraphs (d)(1) and (2) is
the same as that for final Sec. Sec. 70.206(f)(1) and (2),
70.207(e)(1) and (2), 70.208(f)(1) and (2), 70.209(d)(1) and (2), and
71.206(i)(1) and (2), and is discussed elsewhere in this preamble under
final Sec. 70.208(f)(1) and (2).
For consistency between the sampling requirements of the final
rule, final paragraphs (d)(1) and (2) are the same as, except for
conforming changes, final Sec. Sec. 70.206(f)(1) and (2), 70.207(e)(1)
and (2), 70.208(f)(1) and (2), 70.209(d)(1) and (2), and 71.206(i)(1)
and (2).
Comments on the ECVs in proposed Tables 90-1 and 90-2 are discussed
elsewhere in this preamble under Sec. 70.208(f). In addition, a
detailed discussion on the derivation of the ECVs in both Tables 90-1
and 90-2 is included in Appendix A of the preamble. Final Table 90-1
revises one ECV when the CPDM is used from proposed Table 70-2 due to
rounding inconsistencies; the final ECV is changed from proposed 0.80
mg/m\3\ to 0.79 mg/m\3\ when the applicable standard is 0.7 mg/m\3\.
This is consistent with the change to the ECV in final Table 70-1.
Final paragraph (e) is redesignated from proposed Sec. 90.208(d)
and makes clarifying and conforming changes. It provides that upon
issuance of a citation for a violation of the standard, paragraph (a)
of this section will not apply to that part 90 miner until the
violation is abated and the citation is terminated in accordance with
paragraphs (f) and (g) of this section. Paragraph (e) clarifies that a
violation must be abated and the citation must be terminated before
resuming quarterly sampling. Final paragraphs (f) and (g) are discussed
below.
Final paragraph (e) includes an exception to allow the District
Manager flexibility to address extenuating circumstances that would
affect sampling. An example of extenuating circumstances would occur
when an uncorrected violation would require abatement sampling that
continues into the next sampling period.
Final paragraph (e) is similar to existing Sec. 90.208(c). MSHA
did not receive comments on the proposal.
For consistency between the sampling requirements of the final
rule, except for conforming changes, final paragraph (e) is the same as
final Sec. Sec. 70.206(g), 70.207(f), 70.208(g), 70.209(e), and
71.206(j).
Final paragraph (f) is redesignated from proposed Sec. Sec.
90.208(e) and 90.209(e). It requires that upon issuance of a citation
for a violation of the standard, the operator must take the following
actions sequentially: (1) Make approved respiratory equipment
available, (2) immediately take corrective action, and (3) record the
corrective action. The actions required by paragraph (f) are similar to
those in proposed Sec. Sec. 90.208(e)(1)-(2) and 90.209(e)(1)-(6)
which are discussed in this preamble under final paragraph (c). In
addition, paragraph (f) includes the term ``sequentially'' to ensure
that corrective actions are taken in the order they are listed.
Final paragraph (f)(1), like proposed Sec. Sec. 90.208(e)(1) and
90.209(e)(1), requires that the mine operator make approved respiratory
equipment available to affected miners in accordance with Sec. 72.700
of this chapter. Comments on proposed Sec. Sec. 90.208(e)(1) and
90.209(e)(1) are discussed under final paragraph (c). The rationale for
final paragraph (f)(1) is the same as that for final Sec.
70.206(e)(1), which is discussed elsewhere in this preamble.
Final paragraph (f)(2) is similar to proposed Sec. Sec.
90.208(e)(2)(i) and (ii) and 90.209(e)(2) and (6). It requires that the
operator immediately take corrective action to lower the concentration
of respirable coal mine dust to at or below the standard.
Paragraph (f)(2) is consistent with existing Sec. 90.201(d), which
requires a mine operator to take corrective action to lower the
concentration of respirable dust. Paragraph (f)(2) clarifies that the
corrective action must be taken immediately to protect miners from
overexposures. The types of corrective actions that could be taken to
reduce the respirable dust levels in the work position of the part 90
miner are discussed elsewhere in this preamble under Sec. 70.206(e)(2)
and could also include modifications to the part 90 miner's normal work
duties. Final paragraph (f)(2)(i) makes a minor change to proposed
paragraph (e)(2)(i). It replaces ``environment'' with ``position'' to
clarify that respirable dust levels in the part 90 miner's specific
work position must be reduced to meet the standard. Under final
paragraph (f)(2)(ii), corrective action could also include transferring
the part 90 miner to another work position. MSHA received no comments
on the proposal. The rationale for final paragraph (f)(2) is the same
as that for final Sec. 70.206(e)(2) and (h)(2), which are discussed
elsewhere in this preamble under Sec. 70.206(e)(2) and (h)(2).
Final paragraph (f)(2) further provides that if the corrective
action involves reducing the respirable dust levels in the work
position of the part 90 miner identified in the citation, the operator
must implement the proposed corrective actions and begin sampling the
affected miner within 8 calendar days after the date the citation is
issued until five valid representative samples are taken. If the
corrective action involves transferring the part 90 miner to another
work position at the mine to meet the standard, the operator must
comply with Sec. 90.102 and then sample the affected miner in
accordance with Sec. 90.206(a).
Final paragraph (f)(2)(i) clarifies that the operator must sample
within 8 calendar days after the date the citation is issued. Proposed
Sec. 90.208(e)(2)(i) would have required sampling after corrective
actions were approved by the District Manager and implemented. The
final rule does not require the submission of corrective actions to the
District Manager for approval. Final paragraph (f)(2)(ii) is the same
as proposed Sec. Sec. 90.208(e)(2)(ii) and 90.209(e)(6), except for
conforming
[[Page 24956]]
changes. MSHA received no comments on the proposal.
Final paragraph (f)(3) is similar to proposed Sec.
90.209(e)(5)(v). Final paragraph (f)(3) requires that the operator make
a record of the corrective actions taken. The record must be certified
by the mine foreman or equivalent mine official no later than the end
of the mine foreman's or equivalent mine official's next regularly
scheduled working shift. It also requires that the record must be made
in a secure book that is not susceptible to alteration or
electronically in a computer system so as to be secure and not
susceptible to alteration. Final paragraph (f)(3) further requires that
the records must be retained at a surface location at the mine for at
least 1 year and be made available for inspection by authorized
representatives of the Secretary and the representative of miners. MSHA
did not receive any comments on the proposal. The rationale for final
paragraph (f)(3) is the same as that for final Sec. 70.206(e)(3) and
is discussed elsewhere in this preamble under final Sec. 70.206(e)(3).
Final paragraph (f) does not include the provisions in proposed
Sec. 90.208(e)(2) regarding the submission of corrective actions to
the District Manager for approval. MSHA received no comments on the
proposal. MSHA's rationale for omitting this provision is discussed in
this preamble under final Sec. 70.206(h)(4).
In addition, unlike proposed Sec. 90.209(e)(3), final paragraph
(f) does not require operators to submit corrective actions to the
District Manager pertaining to the part 90 dust control plan because
the requirements are contained in final Sec. 90.300 (Respirable dust
control plan; filing requirements). MSHA received no comments on the
proposal.
Unlike proposed Sec. 90.209(e)(4), final paragraph (f) also does
not require operators to review and revise a CPDM Performance Plan.
MSHA did not receive any comments on the proposal. As discussed
elsewhere in this preamble under Sec. 70.206, the final rule does not
include the proposed requirements for a CPDM Performance Plan.
For consistency between the sampling requirements of the final
rule, except for conforming changes, paragraph (f) is the same as final
Sec. 70.206(h) regarding bimonthly sampling of MMUs, Sec. 70.207(g)
regarding bimonthly sampling of designated areas, Sec. 70.208(h)
regarding quarterly sampling of MMUs, Sec. 70.209(f) regarding
quarterly sampling of designated areas, and Sec. 71.206(k) regarding
quarterly sampling. Under final paragraph (f)(3), the operator must
make available for inspection the corrective action record to the part
90 miner under Sec. 90.207(c)(3), and not to the representative of the
miners, due to privacy considerations.
Final paragraph (g) is similar to proposed Sec. 90.208(f). It
provides that a citation for a violation of the standard will be
terminated by MSHA when the equivalent concentration of each of the
five valid representative samples is at or below the standard. The
final rule does not include the proposed requirement that within 15
calendar days after receipt of the sampling results from MSHA
indicating the concentration has been reduced to at or below the
standard, the operator must submit to the District Manager for approval
a proposed dust control plan for that part 90 miner or proposed changes
to the approved dust control plan as prescribed in Sec. 90.300. It
also does not include the proposed requirement that the revised
parameters reflect the control measures used to maintain the
concentration of respirable dust to at or below the standard. The
proposed requirements to submit a dust control plan with revised dust
control measures for a part 90 miner are included in final Sec.
90.300, which also requires a description of the specific control
measures used to continuously maintain respirable dust concentration to
at or below the standard. Therefore, these requirements are not
included in final paragraph (f). MSHA did not receive any comments on
the proposal.
15. Section 90.208 Respirable Dust Samples; Transmission by Operator
Final Sec. 90.208 is similar to proposed Sec. 90.210. Final Sec.
90.208, like the proposal, revises existing Sec. 90.209(a) and (c),
and adds a new paragraph (f). It also redesignates, without change,
existing Sec. 90.209(b), (d) and (e) to paragraphs (b), (d), and (e),
respectively, of this section.
Final Sec. 90.208(a) is changed from the proposal. It requires the
operator, if using a CMDPSU, to transmit within 24 hours after the end
of the sampling shift all samples collected, including control filters,
in containers provided by the manufacturer of the filter cassette to
MSHA's Pittsburgh Respirable Dust Processing Laboratory, or to any
other address designated by the District Manager. Final paragraph (a)
clarifies that operators must include the control filters with the dust
sample transmissions to the Respirable Dust Processing Laboratory. As
explained in the preamble to the proposed rule, MSHA uses control
filters to improve measurement accuracy by eliminating the effect of
differences in pre- and post-exposure laboratory conditions, or changes
introduced during storage and handling of the filter cassettes.
Including control filters with the dust samples ensures that the
appropriate control filter is associated with the appropriate sample
filter.
Final Sec. 90.208(b) is the same as proposed Sec. 71.208(b).
Final Sec. 90.208(c) is substantially the same as proposed Sec.
90.208(c). It requires that a person certified in sampling must
properly complete the dust data card that is provided by the
manufacturer for each filter cassette. It further requires that the
dust data card must have an identification number identical to that on
the filter cassette used to take the sample and be submitted to MSHA
with the sample. It also requires that each dust data card must be
signed by the certified person who actually performed the examinations
during the sampling shift and must include that person's MSHA
Individual Identification Number (MIIN).
As an example, the certified person who performs the required
examinations during the sampling shift is the individual responsible
for signing the dust data card and verifying the proper flowrate, or
noting on the back of the card that the proper flowrate was not
maintained. Since the certified person who conducted the examination is
most knowledgeable of the conditions surrounding the examination, final
paragraph (c) requires that certified person sign the dust data card.
In addition, the MIIN number requirement is consistent with MSHA's
existing policy. Since July 1, 2008, MSHA has required that the
certified person section of the dust data card include the MIIN, a
unique identifier for the certified person, instead of the person's
social security number. To ensure privacy and to comport with Federal
requirements related to safeguarding personally identifiable
information, MSHA has eliminated requirements to provide a social
security number.
Finally, paragraph (c) provides that respirable dust samples with
data cards not properly completed may be voided by MSHA. This is a
change from the proposal. The proposal would have required that,
regardless of how small the error, an improperly completed dust data
card must be voided by MSHA. Final paragraph (c) allows MSHA
flexibility in voiding an improperly completed dust data card. MSHA
received no comments on this proposed provision.
Final Sec. 90.208(d) and (e) are the same as proposed Sec.
90.208(d) and (e) and are the same as existing Sec. 90.209(d) and (e).
[[Page 24957]]
Final Sec. 90.208(f) is changed from the proposal. It requires
that, if using a CPDM, the person certified in sampling must validate,
certify, and transmit electronically to MSHA within 24 hours after the
end of the sampling shift all sample data file information collected
and stored in the CPDM, including the sampling status conditions
encountered when sampling each part 90 miner; and, not tamper with the
CPDM or its components in any way before, during, or after it is used
to fulfill the requirements of 30 CFR part 90, or alter any sample data
files. It further requires that all CPDM data files transmitted
electronically to MSHA must be maintained by the operator for a minimum
of 12 months.
Final paragraph (f) includes the term ``person certified in
sampling'' rather than ``designated mine official.'' This change makes
paragraph (f) consistent with final paragraph (c). Final paragraph (f)
also includes a clarification that CPDM data files are
``electronically'' transmitted to MSHA, unlike the physical
transmission of samples collected with the CMDPSU. As a clarification
to the proposal, final paragraph (f) does not require ``error data file
information'' to be transmitted to MSHA. Rather, final paragraph (f)
requires ``the sampling status conditions encountered when sampling''
to be transmitted to MSHA. The clarification ensures that conditions
that may occur during the sampling shift (e.g., flowrate, temperature,
humidity, tilt indicator, etc.) and that may affect sampling results
are recorded and transmitted to MSHA. This change is also consistent
with final Sec. 70.210(f).
The requirement in final paragraph (f) that the certified person
not tamper with the CPDM or alter any CPDM data files is new. It is
consistent with the requirements for CMDPSUs, under existing Sec.
90.209(b) and final Sec. 90.208(b), which provide that an operator not
open or tamper with the seal of any filter cassette, or alter the
weight of any filter cassette before or after it is used to fulfill the
requirements of 30 CFR part 90. It is also consistent with the
requirement in 30 CFR 74.7(m) that a CPDM be designed to be tamper-
resistant or equipped with an indicator that shows whether the
measuring or reporting functions of the device have been tampered with
or altered. MSHA has a long history of taking action against persons
who have tampered with CMDPSUs or altered the sampling results obtained
from such devices in order to protect miners' health and ensure the
integrity of MSHA's dust program. Therefore, a similar requirement is
included for samples taken with a CPDM.
MSHA received one comment on proposed Sec. 90.210. The commenter
expressed general support for the proposal and suggested that each
operator be required to maintain CPDM data files for a minimum of 24
months, rather than for 12 months, as proposed. Further, the commenter
suggested that the rule include a requirement that all CPDM data files
be made available to all parties.
MSHA believes that a 12-month retention period is reasonable in
light of other requirements in the final rule. Specifically, under
final Sec. 90.209(b), the part 90 miner will receive a copy of the
MSHA report to the mine operator that provides a variety of data on the
respirable dust samples that were collected from the affected miner.
Also, under final Sec. 90.209(c), when a CPDM is used to sample, the
part 90 miner will receive a paper record of the sample run within 12
hours of the end of each sampling shift. Because these provisions of
the final rule ensure that the affected part 90 miner has ongoing
access to sampling data, there is no need to require a mine operator to
retain CPDM data files for more than 12 months. Moreover, the final
rule does not include the commenter's suggestion that CPDM data files
be made available to all parties. Special consideration must be given
to part 90 miners' sampling data due to personal privacy implications
associated with sampling such miners. Making the sampling data of part
90 miners available to all parties would be inappropriate and would
jeopardize part 90 miners' privacy rights.
Final Sec. 90.208 and its rationale are identical to final Sec.
70.210, discussed elsewhere in this preamble under Sec. 70.210.
16. Section 90.209 Respirable Dust Samples; Report to Operator
Final Sec. 90.209 is similar to proposed Sec. 90.211. One
commenter expressed general support for the proposal.
Paragraph (c) of final Sec. 90.209 is essentially the same as the
proposed rule except for conforming changes. Final Sec. 90.209(a)(1)-
(a)(6), and (c)(1)-(c)(5) are identical to final Sec. 70.211(a)(1)-
(a)(6), and (c)(1)-(c)(5), and the rationale is the same as that
discussed elsewhere in this preamble related to final Sec. 70.211.
Final paragraph (c) requires that if using a CPDM, the person
certified in sampling must print, sign, and provide to each part 90
miner, a paper record (Dust Data Card) of the sample run within one
hour after the start of the part 90 miner's next work shift.
Three provisions of final Sec. 90.209 are unique to part 90 and
are not included in final Sec. 70.211. First, final paragraph (a)(7),
like the proposal, provides that MSHA's report will contain the part 90
miner's MSHA Individual Identification Number (MIIN) instead of a
social security number. To ensure privacy and to comport with Federal
requirements related to safeguarding personally-identifiable
information, MSHA has eliminated the use of social security numbers on
its document.
Second, final Sec. 90.209(b), like the proposed rule, requires
that upon receipt of the MSHA report provided to the operator under
final Sec. 90.209(a), the operator must provide a copy of this report
to the part 90 miner. It also prohibits the operator from posting on
the mine bulletin board the original or a copy of the MSHA report.
Final paragraph (b) is identical to existing Sec. 90.210(b).
Third, final Sec. 90.209(d), like the proposal, does not allow the
operator to post data on respirable dust samples for part 90 miners on
the mine bulletin board. No specific comments were received on these
three provisions and they are finalized as proposed.
17. Section 90.210 Status Change Reports
Final Sec. 90.210 is similar to proposed Sec. 90.212 and existing
Sec. 90.220. One commenter expressed general support for the proposal.
Final Sec. 90.210, like proposed Sec. 90.212(a), provides an
operator the option of reporting to MSHA changes in the status of a
part 90 miner electronically instead of in writing. MSHA received no
comment on this provision and it is finalized as proposed.
Unlike proposed Sec. 90.212(b), final Sec. 90.210 does not
require the designated mine official to report status changes affecting
the operational readiness of any CPDM within 24 hours after the status
change occurred. MSHA received no comment on this provision. The
rationale for not including proposed Sec. 90.212(b) in the final rule
is the same as the rationale for not including proposed Sec. 70.212(c)
in the final rule, which is discussed in the preamble related to final
Sec. 70.212.
18. Section 90.300 Respirable Dust Control Plan; Filing Requirements
Final Sec. 90.300 is derived from existing Sec. 90.300 and
addresses requirements for operators to file a respirable dust control
plan for a part 90 miner.
Final Sec. 90.300(a) requires that if an operator abates a
violation of the standard by reducing the respirable dust
[[Page 24958]]
level in the work position of the part 90 miner, the operator must
submit to the District Manager for approval a written respirable dust
control plan for the part 90 miner in the work position identified in
the citation within 15 calendar days after the citation is terminated.
It further requires that the respirable dust control plan and any
revisions must be suitable to the conditions and the mining system of
the coal mine and be adequate to continuously maintain respirable dust
to at or below the standard for that part 90 miner.
Final paragraph (a) does not include the proposal's references to
Sec. Sec. 90.208(f) and 90.209(e)(3) because they were confusing and
duplicative of final Sec. 90.300 requirements. Instead, final
paragraph (a) is consistent with existing Sec. 90.300(a) regarding
when a respirable dust control plan is required. It also establishes
the same 15 calendar-day time period requirement for plan submission
for operators using a CMDPSU or a CPDM.
One commenter, who generally supported the proposal, suggested that
the plan be made available to the miners' representative.
To prevent the disclosure of the part 90 miner's identity and
ensure the miner's privacy, the final rule does not include the
commenter's suggestion.
Final Sec. 90.300(b), like the proposal, specifies the required
content of each part 90 miner respirable dust control plan. Final
paragraph (b)(1) requires that the plan include the mine identification
number assigned by MSHA, the operator's name, mine name, mine address,
and mine telephone number, and the name, address, and telephone number
of the principal officer in charge of health and safety at the mine.
Final paragraph (b)(2) requires that the plan include the name and MSHA
Individual Identification Number of the part 90 miner and the position
at the mine to which the plan applies. Final paragraph (b)(3) requires
that the plan contain a detailed description of the specific respirable
dust control measures used to continuously maintain concentrations of
respirable coal mine dust at or below the standard. Final paragraph
(b)(4) requires that the plan include a detailed description of how
each of the respirable dust control measures described in final
paragraph (b)(3) will continue to be used by the operator, including at
least the specific time, place, and manner the control measures will be
used. Except for minor changes, final paragraphs (b)(1)-(4) are
substantially the same as existing Sec. 90.300(b)(1)-(4). MSHA did not
receive comments on proposed paragraphs (b)(1)-(b)(4) and they are
finalized as proposed.
19. Section 90.301 Respirable Dust Control Plan; Approval by District
Manager; Copy to Part 90 Miner
Final Sec. 90.301, like the proposal, addresses the criteria that
MSHA will use to approve the respirable dust control plan for each part
90 miner, and requires operators' compliance with all provisions of the
approved plan. Final Sec. 90.301(a) through (c) and (e) are identical
to final Sec. 71.301(a) through (c) and (e), discussed elsewhere in
this preamble.
Final Sec. 90.301(d), like the proposal, requires the operator to
provide a copy of the current respirable dust control plan to the
affected part 90 miner and prohibits the operator from posting the
original or a copy of the plan on the mine bulletin board.
One commenter, who generally supported the proposal, suggested that
the plan be made available to the miners' representative. Final Sec.
90.301 does not include the commenter's suggestion for the same reason
it is not included in final Sec. 90.300, which is discussed elsewhere
in this preamble under final Sec. 90.300(a). MSHA did not receive
other comments on Sec. 90.301 and it is finalized as proposed.
V. Executive Order 12866: Regulatory Planning and Review; and Executive
Order 13563: Improving Regulation and Regulatory Review
Executive Orders (E.O.) 12866 and 13563 direct regulatory agencies
to assess all costs and benefits of regulations and, if regulation is
necessary, to select regulatory approaches that maximize net benefits
(including potential economic, environmental, public health and safety
effects, distributive impacts, and equity). Executive Order 13563
emphasizes the importance of quantifying both costs and benefits,
reducing costs, harmonizing rules, and promoting flexibility. To comply
with the provisions of E.O. 12866 and 13563, MSHA has prepared a
Regulatory Economic Analysis (REA) for this final rule. The REA
contains supporting data and explanations for the summary presented in
this preamble section, including the types of mines covered by the
final rule, the costs and benefits of the final rule, the economic
feasibility of the final rule, the impact of the final rule on small
businesses, and the paperwork burden of the final rule on the affected
sectors of the mining industry. The REA can be accessed electronically
at http://www.msha.gov/rea.htm or http://www.regulations.gov. A copy of
the REA can be obtained from MSHA by request to Sheila McConnell at
[email protected], by phone request to 202-693-9440, or by
facsimile to 202-693-9441.
Under E.O. 12866, MSHA must determine whether a regulatory action
is ``significant'' and subject to review by the Office of Management
and Budget (OMB). Section 3(f) of E.O. 12866 defines a ``significant
regulatory action'' as an action that is likely to result in a rule:
(1) Having an annual effect on the economy of $100 million or more, or
adversely and materially affecting a sector of the economy,
productivity, competition, jobs, the environment, public health or
safety or state local or tribal governments or communities (also
referred to as ``economically significant''); (2) creating serious
inconsistency or otherwise interfering with an action taken or planned
by another agency; (3) materially altering the budgetary impacts of
entitlements, grants, user fees, or loan programs or the rights and
obligations of recipients thereof; or (4) raising novel legal or policy
issues arising out of legal mandates, the President's priorities, or
the principles set forth in this Executive Order.
MSHA has determined that the final rule may have an effect of $100
million or more on the economy in at least one year, and is therefore
an ``economically significant'' regulatory action in accordance with
Sec. 3(f) of E.O. 12866 and is subject to OMB review.
A. Population at Risk
The final rule applies to all underground coal mines, surface coal
mines, and surface areas of underground coal mines in the United
States. For the 12 months ending January 2010, there were an average of
424 active underground coal mines employing approximately 47,000 miners
and contractors (excluding office workers) and 1,123 active surface
coal mines employing approximately 56,000 miners and contractors
(excluding office workers).
B. Benefits
The final rule significantly improves health protections for coal
miners by reducing their occupational exposure to respirable coal mine
dust and lowering the risk that they will suffer material impairment of
health or functional capacity over their working lives. The primary
benefit of the final rule is the reduction of ``black lung'' disease
among coal miners by improving MSHA's existing standards for respirable
coal mine dust, thereby reducing miners' exposure to respirable
[[Page 24959]]
coal mine dust. Chronic exposure to respirable coal mine dust causes
lung diseases including coal workers' pneumoconiosis (CWP), emphysema,
silicosis, and chronic bronchitis, known collectively as ``black
lung.'' These diseases are debilitating and can result in disability
and premature death.
The REA benefits chapter provides a detailed description of how
MSHA used the estimated risk reduction in the QRA for the final rule to
calculate benefits. For the proposed rule, MSHA based its estimate of
the benefits on the QRA for the proposed rule, which focused on the
effects of the proposed lowering of the standard to 1.0 mg/m\3\ for
most miners (0.5 mg/m\3\ for part 90 miners) and the proposed use of
single shift samples to determine noncompliance.
The final rule lowers the existing 2.0 mg/m\3\ standard to 1.5 mg/
m\3\, rather than to the 1.0 mg/m\3\ standard in the proposed rule. The
QRA for the final rule uses the same methodology that was used in the
QRA for the proposed rule but with the final standard.
As in the QRA for the proposed rule, MSHA's QRA for the final rule
compares the risks for two hypothetical cohorts of miners with the same
occupation/coal rank. One cohort, designed to characterize risks to the
current workforce, was assigned 45-year lifetime exposures based on
current sampling data. The comparison cohort was assigned 45-year
lifetime exposures designed to represent risks associated with two
provisions of the final rule (i.e., lowering the existing standard from
2.0 mg/m\3\ to 1.5 mg/m\3\, and basing noncompliance determinations on
a single MSHA inspector sample rather than the average of 5 samples
under the existing dust standard). Since the two cohorts compared are
independent, there are two caveats: (1) No benefits were projected for
delaying or stopping the progression of disease among the population
that has experienced respirable coal mine dust exposures during their
working lifetime; and (2) due to the latency between exposure and
disease, especially for severe emphysema, a large portion of the
benefits estimated by this analysis are not expected to accrue for many
years.
Using this analysis, MSHA estimates that the two provisions of the
final rule considered in the QRA (i.e., lowering the standard from 2.0
mg/m\3\ to 1.5 mg/m\3\, and basing determinations of noncompliance on
single inspector samples rather than the average of 5 samples) will
result in the prevention of the adverse health effects shown in Table
V-1.
Table V-1--Estimated Number of Adverse Health Effects Prevented, as of Age 73, 45-Year Working Lifetime, Two Provisions of the Final Rule
[Lowering the standard from 2.0 mg/m\3\ to 1.5 mg/m\3\ and basing determinations of noncompliance on single inspector samples]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Severe Deaths from
CWP 1+ CWP 2+ PMF emphysema NMRD
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of Cases Prevented Over a 45-Year Work Life................. 593 473 319 248 26
--------------------------------------------------------------------------------------------------------------------------------------------------------
For the proposed rule, MSHA assumed additional reductions in
adverse health effects from converting respirable coal mine dust
samples to an equivalent 8-hour concentration for work shifts longer
than eight hours, and from the final definition of normal production
shift. After considering comments and relevant data, MSHA is no longer
requiring adjustments for shifts longer than 8 hours in the final rule;
therefore, the reductions in adverse health effects associated with
this provision are no longer assumed.
MSHA continues to assume additional reductions in cases of CWP,
PMF, severe emphysema, and NMRD from the revised definition of normal
production shift. If the requirement for the revised definition of
normal production shift had been in effect in 2009, the amount of dust
on the samples would have been higher due the higher levels of
production during sampling. Lowering respirable coal mine dust
exposures from these higher levels to the levels in the final rule will
result in additional benefits beyond those associated with the recorded
sampling results. MSHA used additional data from the feasibility
assessment to extrapolate the further impact of this provision.
Table V-2--Estimated Number of Adverse Health Effects Prevented, as of Age 73, 45-Year Working Lifetime, Three Provisions of the Final Rule
[Lowering the standard from 2.0 mg/m\3\ to 1.5 mg/m\3\, basing noncompliance on a single inspector sample and the revised definition of normal
production shift]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Severe Deaths from
CWP 1+ CWP 2+ PMF emphysema NMRD
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of Cases Prevented Over a 45-Year Work Life................. 869 655 433 374 65
--------------------------------------------------------------------------------------------------------------------------------------------------------
MSHA also projects that the final rule will result in additional
reductions in cases of other adverse health effects beyond those being
quantified even after making the adjustment for the revised definition
of normal production. While MSHA did not quantify the benefits
associated with full-shift sampling as well as several other provisions
of the final rule, MSHA believes that these provisions will
significantly reduce coal mine dust exposures and reduce the incidences
of disease.
To estimate the monetary values of the reductions in cases of CWP
1+, CWP 2+, PMF, severe emphysema, and deaths from non-malignant
respiratory disease (NMRD) for the proposed rule, MSHA analyzed the
imputed value of illnesses and fatalities avoided based on a
willingness-to-pay approach. In the final rule, MSHA continues to use
the willingness-to-pay approach to estimate the Agency's preferred
dollar values of disease and death. However, in the final rule, MSHA
estimated benefits using a range of disease values. These values and
the resulting benefit estimates are discussed more fully in Chapter V
of the REA.
The total undiscounted benefits are between $2.9 billion and $4.1
billion. However, using the Agency's preferred dollar values for
disease, total undiscounted benefits are $3.4 billion
[[Page 24960]]
over a 65-year period. The total net benefit at 65 years, with a 3
percent discount rate, is $344.0 million, and the annualized net
benefit is $12.1 million. At a 7 percent discount rate, the total net
benefit is -$114.7 million and the annualized net benefit is -$8.1
million.
For the proposed rule, MSHA monetized the reduction in the number
of deaths from NMRD using a study by Viscusi and Aldy (2003). MSHA
retained this approach for the final rule. Viscusi and Aldy (2003)
conducted an analysis of studies that use a willingness-to-pay approach
to estimate the imputed value of life-saving programs (i.e., meta-
analysis) and found that each fatality avoided was valued at
approximately $7 million. Using the GDP Deflator (U.S. Bureau of
Economic Analysis, 2010), the inflation-adjusted estimates are $8.7
million for each fatality avoided in 2010 dollars. This value of a
statistical life (VSL) estimate is within the range of the majority of
estimates in the literature ($1 million to $10 million per statistical
life), as discussed in OMB Circular A-4 (OMB, 2003).
MSHA emphasizes that, although VSL is a useful statistical concept
for monetizing benefits, it does not represent the value of a life.
Rather, it represents a measurement related to risk reduction so that
various options can be compared.
Coal Workers' Pneumoconiosis (CWP) is an occupational lung disease
typically not incurred by the general population. When coal dust
particles enter the lungs, they irritate the delicate lung tissue and
eventually form massive impenetrable fibrous tissue that significantly
restricts the lung's functions and causes scarring, which can lead to
lung failure and death. Once CWP develops, it cannot be reversed and,
in many cases, the condition will get progressively worse even after
exposure of the harmful coal dust has stopped. In this way, or through
continued exposure, CWP can progress to total disability in the form of
PMF and severe emphysema and can cause premature death.
Valuation of Avoided Cases of CWP 1+ and CWP 2+
Research has shown that lung-function decreases and the degree of
impairment increases with the transition from CWP 1+ to CWP 2+. NIOSH
defines impairment of lung function as a forced expiratory volume
(FEV1) less than 80 percent of predicted normal values.
Miners with simple pneumoconiosis (CWP 1+ and CWP 2+) or chronic
bronchitis exhibit an FEV1 of 80 percent or less of
predicted normal values. For the proposed rule, MSHA monetized the
reduction in cases of CWP 1+ and CWP 2+ using the study by Viscusi and
Aldy (2003) that valued each lost work-day injury at approximately
$50,000 in 2000 dollars. Using the GDP deflator, the inflation-adjusted
estimate was $62,000 for each injury avoided in 2010 dollars.
In the final rule, MSHA's preferred dollar value for avoiding a
case of CWP 1+ continues to be based on the Viscusi and Aldy (2003)
lost-time injury willingness-to-pay estimate used in the proposed rule.
MSHA's preferred value for avoiding a case of CWP 2+ is $431,000. The
value for CWP 2+ is based on an Environmental Protection Agency (EPA)
final rule that estimated an avoided case of chronic bronchitis at
$410,000 in 2007 dollars (U.S. Environmental Protection Agency, Office
of Air and Radiation, 2011). MSHA revised the Agency's preferred dollar
values for CWP 2+ after reviewing literature, considering EPA's
assumption that the cases due to environmental causes were less severe
than occupational sources, and determining that CWP 2+ and chronic
bronchitis are similar. These diseases are similar in that, at early
stages, they cause minimal damage to lung tissue, and if further
exposure is prevented, progression to more serious forms of disease may
be avoided. Like chronic bronchitis, CWP 2+, while a material
impairment of health, is not disabling.
Valuation of Progressive Massive Fibrosis (PMF) and Severe Emphysema
As noted in the QRA, miners with PMF qualify as being presumptively
totally disabled under the Department of Labor criteria in 20 CFR
718.304(a). The Social Security Administration (SSA) also recognizes
PMF as a presumptively disabling condition (http://www.ssa.gov). Miners
with PMF are unable to work.
PMF is identified on chest x-rays by large lesions (nodular masses)
greater than 1 cm in diameter and often multiple and bilateral,
represent coalescence of smaller nodules. Disability is caused by
destruction of lung tissue that is incorporated into the nodules
(Rubin's Pathology, 2011). As PMF worsens, adjacent lung tissue
retracts towards the lesions, typically in the upper airways. Alveoli
and blood vessels are destroyed and airways become distorted and
inflexible as lung function is lost (Wade, 2011). PMF causes a mixed
obstructive and restrictive lung function pattern. Distortion of the
airways results in irreversible obstructive changes; the large masses
of fibrous tissue reduce the useful volume of the lung. Abnormally low
concentration of oxygen in the blood (hypoxemia), pulmonary heart
disease (cor pulmonale), and terminal respiratory failure may occur in
persons with PMF (Lyons and Campbell, 1981; Attfield and Wagner, 1992;
Miller and Jacobsen, 1985; West, 2011). The NIOSH Respiratory Disease
Research Program documented that PMF is a disabling and life-
threatening condition (NIOSH, 2007; Castranova and Vallyathan, 2000).
PMF is progressive, totally disabling, and incurable, and causes
premature death.
Severe emphysema also is progressive, disabling, and incurable, and
causes premature death (http://www.nhlbi.nih.gov, http://www.ssa.gov).
The QRA characterizes severe emphysema as a disabling loss of
respiratory function. Miners with severe emphysema are unable to work.
NIOSH defines a severe and disabling decrement in lung function as a
FEV1 of less than 65 percent of expected normal values. A
person with severe emphysema will have a lung function, as measured by
FEV1 numbers for severe emphysema reveal between 49 and 30
percent of normal lung function (FEV1/FVC <49-30 percent).
According to the National Heart, Lung, and Blood Institute, HHS
(http://www.nhlbi.nih.gov), although emphysema develops slowly, a
person's symptoms often worsen over time and can impair the ability to
perform any normal daily activity. Flare-ups (exacerbations) from the
disease become more frequent. These flare-ups can become increasingly
serious, even deadly, with FEV1 numbers during these
episodes revealing less than 30 percent of normal lung function
(FEV1/FVC <30 percent). Respiratory failure can occur, which
may also lead to effects on the heart such as right heart failure (cor
pulmonale).
For the final rule, MSHA reviewed the work of Magat, Viscusi and
Huber (1996), which measured willingness-to-pay values for reducing the
probability of contracting nerve disease (peripheral neuropathy) and
two forms of lymphoma (cancer of the lymph system). This study found
that the median amount persons would be willing to pay to avoid nerve
disease was 40 percent of what they would pay to avoid death in a car
crash, and was 58.3 percent to avoid non-fatal lymphoma.
MSHA also reviewed the work of Viscusi, Magat, and Huber (1991).
This earlier study laid the groundwork for the methodology used in
Magat et al. (1996). Viscusi et al. (1991) measured a willingness-to-
pay value for reducing
[[Page 24961]]
the probability of contracting chronic bronchitis. The study found that
the median amount persons would be willing to pay to avoid chronic
bronchitis was 32 percent of what they would pay to avoid death in a
car crash, although it found that the mean (average) amount was 68
percent.
In developing the estimates for the final rule, MSHA used both
Viscusi et al. 1991 and Magat et al. 1996, although MSHA believes that
the willingness-to-pay values in the Magat et al. 1996 study are more
closely related to those for PMF and severe emphysema. MSHA reevaluated
the diseases in the Magat et al. (1996) study and determined that
peripheral neuropathy (nerve disease) is a disabling disease like PMF
and severe emphysema and causes a more comparable degree of disability
than curable lymphoma.
The health consequences of nerve disease as described in this study
include, among other things, weakness, inability to move, constant
pain, depression, inability to work. Nerve disease also is incurable.
These health consequences of nerve disease, as described, are similar
to the health effects of PMF and severe emphysema discussed above. One
difference is that the end point of PMF and severe emphysema is the
probability of premature death; the authors stated that nerve disease
``is nonfatal in most cases.'' For this reason, it is possible that
subjects may be willing to pay more to avoid PMF and severe emphysema
than to avoid nerve disease.
Viscusi et al. (1991), on the other hand, measured a willingness-
to-pay value for reducing the probability of contracting chronic
bronchitis. Although chronic bronchitis is a respiratory disease, it is
a fundamentally different disease than PMF or severe emphysema in terms
of health effects. Generally, chronic bronchitis does not progress if
exposure is halted. The health implications listed by Viscusi et al.
(1991), while serious, are not totally disabling. Early diagnosis and
treatment can improve a person's quality of life (http://www.nhlbi.nih.gov). Chronic bronchitis may or may not cause airway
obstruction such as scarring or destruction of lung tissue. The health
implications of chronic bronchitis identified by Viscusi et al. (1991)
also did not include premature death, a well-known outcome of PMF and
severe emphysema. For these reasons MSHA concluded that the symptoms
expressed in Magat et al. (1996) are more comparable to the disabling
consequences and long-term health effects of PMF and severe emphysema.
However, both studies are methodologically imperfect. The authors
in Viscusi et al. 1991 stated that due to the need for further research
into the potential biases of their method, ``much further research is
needed before applying the methodology to give estimates precise enough
to be used in regulatory analyses.'' Specifically, the authors
identified that sensitivity analyses was needed to determine the degree
of familiarity persons must have with the health benefit being valued.
The authors in Magat et al. 1996 stated that their methodology was
limited and only valued one form of nerve disease and two forms of
lymphoma. The authors stated that ``specific results for nerve disease
and lymphoma cannot be directly used for the valuation of other
diseases.'' Moreover, although they described their 1991 study as
``elicit[ing] values for avoiding short term health risks'', their 1991
study described itself as focusing on ``the most severe chronic
morbidity effects of chronic bronchitis''.
MSHA evaluated both studies and for its benefit calculation and
concluded that the value of avoiding PMF and severe emphysema is in a
range between 32 percent of VSL (Viscusi et al. 1991) and 40 percent of
VSL (Magat et al. 1996); thus, MSHA chose (36 percent), the average of
the two, for the Agency's preferred value for PMF and severe emphysema.
Using this approach, the value for avoiding a case of PMF or severe
emphysema is $3.15 million (36.0 percent of $8.7 million) for a total
estimated value of $2.5 billion. This is an appropriate approach in
estimating the value of avoiding PMF and severe emphysema given the
methodological limitations of both studies.
MSHA monetized the total benefit estimates by multiplying the
number of adverse health effects in Tables V-1 and V-2 by the monetized
value of each adverse health effect. For example, MSHA estimates a
benefit of $221.5 million (as of age 73, 45-year working lifetime) for
avoided deaths based on: (1) Reducing the respirable dust standard; and
(2) basing determinations of noncompliance on single MSHA inspector
samples. MSHA multiplied the 25.5 deaths from NMRD (the estimates in
Tables V-1 and V-2 were rounded to the nearest whole number) by the
$8.7 million per death prevented. Based on this analysis, MSHA projects
that an estimated $2.2 billion in adverse health effects will be
prevented as of age 73 (45-year working lifetime) due to reducing the
respirable coal mine dust standards and basing determinations of
noncompliance on single MSHA inspector samples. MSHA also projects that
the final rule will result in an estimated $3.4 billion in adverse
health effects prevented as of age 73 (45-year working lifetime) due to
these two requirements plus the revised definition of normal production
shift. The net benefits and benefits sections of the REA include
additional details to explain the final steps in the benefit
calculation.
In the preamble to the proposed rule, MSHA noted several
limitations of the benefits analysis in the Preliminary Regulatory
Economic Analysis (PREA). The benefits analysis in the PREA was based
on the QRA for the proposed rule. As a result of comments received on
the QRA for the proposed rule and discussed in Section III.B. of this
preamble, MSHA revised the QRA for the final rule as follows:
The QRA for the proposed rule did not account for
uncertainties related to sampling error or the assumption that single-
shift exposures currently above the proposed limits of 1.0 mg/m\3\ (or
0.5 mg/m\3\ for part 90 miners) would be reduced no further than
necessary to achieve compliance with the proposed limits on each shift.
MSHA's QRA for the final rule contains an analysis of uncertainty with
respect to sampling error and a sensitivity analysis of MSHA's exposure
estimates.
MSHA's QRA for the proposed rule did not account for
measures that operators may take to avoid having exposures on any shift
exceed the proposed standard. The QRA for the final rule uses expected
reduction factors to project the impact that the final rule will have
on exposures at or below 1.5 mg/m\3\, or 0.5 mg/m\3\ for part 90
miners.
Some limitations in the benefits analysis in the REA may result in
underestimating the benefits for the final rule.
MSHA does not have data or quantitative models to quantify
the benefits associated with several provisions of the final rule
(e.g., full-shift sampling, quarterly sampling of designated
occupations (DOs), other designated occupations (ODOs), and part 90
miners using the CPDM; periodic medical surveillance examinations; and
extending the part 90 option to surface coal miners). The Agency
expects that these provisions will reduce the respirable dust levels
and further protect miners from the debilitating effects of
occupational respiratory disease. If the required data and quantitative
models were available, MSHA believes that the combined effect of these
provisions, particularly the requirements for full-shift sampling, and
requiring more frequent sampling of
[[Page 24962]]
selected occupations and locations using the CPDM in underground coal
mines would produce risk reductions beyond those projected in Table 28
of the QRA as well as an increase in the quantified benefits reported
in the REA.
As shown in Table 28 of the QRA for the final rule, since
MSHA does not have data on the smoking status of the mining population
specific to occupation and work location, the Agency assumed that all
miners were non-smokers when calculating the number of cases of severe
emphysema that would be reduced. Overall, Kuempel et al. (2009a)
established that exposure to coal mine dust can produce clinically
important levels of emphysema in coal miners regardless of smoking
status. Furthermore, Attfield and Seixas (1995) tested the effects of
smoking and CWP incidence and found that smoking contributed
substantially less to the incidence of disease than age.
In the REA, MSHA estimated the number of adverse health
effects prevented by multiplying the estimated risk reductions
presented in Table 28 of the QRA for the final rule by the current
number of coal miners in each occupation estimated to be directly
involved in or in the vicinity of operations that generate respirable
coal mine dust. However, because MSHA does not have the racial
composition of the mining population specific to occupation and work
location, the Agency applied the risk factor for whites to all miners
when calculating the number of cases of severe emphysema that would be
prevented. Results are summarized in Table V-2 of the REA. On average,
benefits would be underestimated for non-whites because the reduction
in excess risk for non-whites is greater than that for whites for 17 of
the 19 underground occupations, part 90 miners, and 11 of the 14
surface occupations (See Table 28 of the QRA).
On the other hand, in both the PREA and the REA, MSHA assumed a 45-
year working life which may yield larger estimates of the number of
cases of pneumoconiosis and possibly overestimate the benefits for the
final rule. MSHA's longstanding practice to use a 45-year working life
assumption for health standards is not based on empirical data that
most miners are exposed to respirable coal mine dust for 45 years.
Rather, it is based on the Mine Act's statutory directive that no miner
suffer material impairment of health or functional capacity even if
such miner is exposed to the hazard for the period of his or her
working life. To the extent that miners' careers are shorter than 45
years, the actual benefits may be lower. In order to compare the
estimate of benefits with the estimate of costs, it is necessary to
project the timing of the benefits. Risk assessments in the
occupational environment are generally designed to estimate the risk of
an occupationally related illness over the course of an individual
worker's lifetime. The estimate of benefits is calculated by comparing
the number of cases at the current occupational exposure level of 2.0
mg/m\3\ to the projected number of cases at the final dust level of 1.5
mg/m\3\. Current respirable coal mine dust occupational exposure
estimates were constructed from samples collected during the 2008
fiscal year. The number of projected cases anticipated under compliance
with the final dust standard was estimated by reducing any 2008 fiscal
year dust samples that were reported above the final dust standard to
1.5 mg/m\3\. In order to annualize the benefits for the period of time
after the final rule takes effect, it is necessary to create a timeline
of benefits for an entire active workforce over that period.
While there are various approaches that could be used for modeling
the workforce, there are two extremes. At one extreme, one could assume
that none of the benefits occur until after the current workforce
retires. Under this approach, workers with minimal cumulative exposure
(both in terms of years of exposure and levels of exposure) would be
assumed not to benefit from the revised standard. At the other extreme,
one could assume that the benefits occur immediately. However, based on
the various risk models, which reflect real-world experience with
development of disease over an extended period of time, neither extreme
is appropriate. MSHA estimated net benefits based on a 45-year working
lifetime as used in the QRA for the proposed and final rule.
In the proposed rule, MSHA estimated the timeline for benefits in
two different ways. First, benefits would begin immediately and annual
benefits equal lifetime benefits divided by 45 years; benefits would
begin to accrue in the first year after the provisions are put into
effect. Second, no benefits would occur for the first 10 years and the
annualized benefit for each of the next 35 years would be equal to the
projected benefits divided by 35 years. MSHA preferred the second
estimation method. In both methods under the proposed rule, MSHA
estimated that it would take 45 years to reach the benefits calculated
for the 45-year working lifetime.
For the final rule, net benefits are based on a single probability
distribution (Poisson distribution with mean of 20 years) that
represents the combined effects of worker turnover, disease
progression, and uncertainty. The use of a single probability
distribution to model the combined effects of employee turnover and the
progression of disease and morbidity creates a smooth benefit stream
rather than a discontinuous stream such as the one used for the
proposed rule, where annual benefits abruptly jumped from zero to 1/
35th of the total benefits in year 11. Under this approach, it would
take 65 years to reach the benefits calculated for the 45 year working
lifetime.
C. Compliance Costs
This section presents a summary of MSHA's estimate of costs that
will be incurred by operators of underground coal mines and surface
coal mines to comply with the final rule. These costs are based on
MSHA's assessment of the most likely actions that would be necessary to
comply with the final rule. Detailed analysis is provided in the cost
chapter (Chapter 4) of the REA. Several different discounting streams
are also presented in the net benefits chapter (Chapter 3).
MSHA estimates that the first year cost of the final rule will be
$61 million and the annualized cost of the final rule at a 7 percent
discount rate will be $28.1 million.
The estimated first year cost of the final rule for underground
coal mine operators will be $52.7 million. Costs associated with the
final requirement to use CPDMs ($34.1 million) and upgrading and
maintaining engineering controls and work practices ($10.7 million)
represent the most significant estimated first year costs for
underground coal operators.
The first year cost of the final rule for surface coal mine
operators will be $8.3 million. The part 90 option represents the most
significant estimated first year cost for surface operators ($3.9
million).
MSHA estimates that, at a 7% discount rate, the annualized cost of
the final rule for underground coal mine operators will be $26.2
million. Costs associated with the use of CPDMs ($14.6 million) and
upgrading and maintaining engineering controls and work practices ($5.1
million) represent the most significant estimated annualized costs for
underground coal operators.
MSHA estimates that the annualized cost of the rule for surface
coal operators will be $4.0 million. Costs associated with the use of
CMDPSUs (gravimetric samplers) ($1.1 million) and the extension of the
part 90 option ($1.1 million) represent the most significant annualized
estimated costs for surface coal miners.
[[Page 24963]]
D. Net Benefits
Net benefits are benefits minus costs. The long period to reach
full benefits requires consideration of inter-generational impacts with
discount rates such as 3 percent. MSHA estimates that the net benefits
of the final rule are positive, with annualized net benefits of $12.1
million at a discount rate of 3 percent, and negative with annualized
net benefits of -$8.1 million at a discount rate of 7 percent. Under
the Mine Act, MSHA is not required to use estimates of net benefits as
the basis for its regulatory decisions. The net benefits at both the 3
and 7 percent discount rates do not include the benefits associated
with sampling over a full-shift using the CPDM as well as several other
provisions (e.g. quarterly sampling of designated occupations, other
designated occupations, and part 90 miners using the CPDM; periodic
medical surveillance examinations; and extending the part 90 option to
surface coal miners) of the final rule. These provisions, although not
quantified, will significantly reduce coal mine dust exposures and the
incidences of other lung disease, and significantly increase benefits.
Congress realized that there ``is an urgent need to provide more
effective means and measures for improving the working conditions and
practices in the Nation's coal or other mines in order to prevent death
and serious physical harm, and in order to prevent occupational
diseases originating in such mines.'' 30 U.S.C. 801(c). In promulgating
mandatory standards dealing with toxic materials or harmful physical
agents, Section 101(a)(1)(A) of the Mine Act (30 U.S.C. 811(a)(6)(A))
requires MSHA to set standards ``which most adequately assure on the
basis of the best available evidence that no miner will suffer material
impairment of health . . . even if such miner has regular exposure to
the hazards dealt with by such standard for the period of his working
life.'' It further requires that to attain the highest degree of health
and safety protection for the miner, other considerations in setting
such standards shall be ``the latest available scientific data in the
field, the feasibility of the standards, and experience gained under
this and other health and safety laws.'' In adopting the language of
Section 101(a)(6)(A), the Senate Committee on Human Resources
emphasized that ``it rejects the view that cost benefit ratios alone
may be the basis for depriving miners of the health protection which
the law intended to insure.'' S. Rep. No. 95-181, 95th Cong. 1st Sess.
21 (1977).
VI. Regulatory Flexibility Act and Small Business Regulatory
Enforcement Fairness Act
In accordance with the Regulatory Flexibility Act (RFA) of 1980, as
amended by the Small Business Regulatory Enforcement Fairness Act
(SBREFA), MSHA has analyzed the compliance cost impact of the final
rule on small entities. Based on that analysis, MSHA has determined and
certifies that the final rule will not have a significant economic
impact on a substantial number of small entities.
The factual basis for this certification is presented in full in
Chapter VI of the REA and in summary form below.
A. Definition of a Small Mine
Under the RFA, in analyzing the impact of a rule on small entities,
MSHA must use the Small Business Administration's (SBA's) definition of
a small entity, or after consultation with the SBA Office of Advocacy,
establish an alternative definition for the mining industry by
publishing that definition in the Federal Register for notice and
comment. MSHA has not established an alternative definition and is
required to use SBA's definition. The SBA defines a small entity in the
mining industry as an establishment with 500 or fewer employees. There
are 412 underground mines and 1,119 surface mines that meet the SBA
definition.
MSHA has also examined the impact of the final rule on mines with
fewer than 20 employees, which MSHA and the mining community have
traditionally referred to as ``small mines.'' There are 81 underground
mines and 620 surface mines that meet this criterion as a small mine.
These small mines differ from larger mines not only in the number of
employees, but also in economies of scale in material produced, in the
type and amount of production equipment, and in supply inventory.
Therefore, their costs of complying with MSHA's rules and the impact of
the agency's rules on them will also tend to be different. This
analysis complies with the requirements of the RFA for an analysis of
the impact on ``small entities'' while continuing MSHA's traditional
definition of ``small mines.''
B. Factual Basis for Certification
MSHA's analysis of the economic impact on ``small entities'' begins
with a ``screening'' analysis. The screening compares the estimated
costs of the final rule for small entities to the estimated revenues.
When estimated costs are less than one percent of estimated revenues
(for the size categories considered), MSHA believes it is generally
appropriate to conclude that there is no significant economic impact on
a substantial number of small entities. If estimated costs are equal to
or exceed one percent of revenues, MSHA investigates whether further
analysis is required.
Estimated revenue for underground and surface coal mines is derived
from data on coal prices and tonnage. The 2010 price of coal was $60.73
per ton for underground coal and $24.13 per ton for surface coal.\63\
---------------------------------------------------------------------------
\63\ U.S. DOE, EIA, ``Annual Coal Report 2010,'' Table 28,
http://www.eia.gov/coal/annual/archive/05842010.pdf.
---------------------------------------------------------------------------
Throughout the economic analysis, MSHA used 2009 mine production to
remain consistent with the data used in the QRA for the final rule and
the output of the QRA used for the analysis of the benefits in the REA.
In addition, 2010 coal pricing was used to be consistent with wage
rates and costs used in the cost analysis. Overall coal production
tonnage did not vary significantly from 2009 to 2010.
For underground coal mines with 1-19 employees, coal production in
2009 was approximately 5.036 million tons. Multiplying the tonnage from
these small mines by the $60.73 price per ton in 2010 results in
estimated revenues of $305.8 million. The annualized cost of the final
rule, including penalty payments, for these mines is approximately $1.5
million. Dividing estimated costs for the final rule by estimated
revenues results in 0.5 percent of annual revenues. The average
compliance cost for an underground mine with 1-19 employees is $18,450
($1.5 million divided by 81 mines).
For underground coal mines with 1-500 employees, coal production in
2009 was approximately 241.6 million tons. Multiplying this tonnage by
the $60.73 price per ton in 2010 results in estimated revenues of $14.7
billion. The annualized cost of the final rule, including penalty
payments, for these mines is approximately $24.7 million. Dividing
estimated costs for the rule by estimated revenues results in 0.2
percent of annual revenues. The average compliance cost for an
underground mine with 1-500 employees is $59,950 ($24.7 million divided
by 412 mines).
For surface coal mines with 1-19 employees, coal production in 2009
was approximately 19.7 million tons. Multiplying this tonnage by the
$24.13 price per ton in 2010 results in estimated revenues of $475.7
million. The annualized cost of the final rule, including penalty
payments, for these mines is approximately $1.0 million.
[[Page 24964]]
Dividing estimated costs by estimated revenues results in 0.2 percent
of annual revenues. The average compliance cost for a surface mine with
1-19 employees is $1,625 ($1.0 million divided by 620 mines).
For surface coal mines with 1-500 employees, coal production in
2009 was approximately 494.8 million tons. Multiplying this tonnage by
the $24.13 price per ton in 2010 results in estimated revenues of $11.9
billion. The annualized cost of the final rule, including penalty
payment, for these mines is approximately $3.7 million. Dividing
estimated costs into estimated revenues results in 0.03 percent of
annual revenues. The average compliance cost for a surface mine with 1-
500 employees is $3,300 ($3.7 million divided by 1,119 mines).
Based on all analyses, the annualized costs of the final rule are
less than one percent of annual revenue for both small underground and
surface coal mines, as defined by SBA. Therefore, MSHA certifies that
the final rule will not have a significant impact on a substantial
number of small mining entities. Chapter VI of the REA to the final
rule contains a complete analysis of the cost impact on small mines.
VII. Paperwork Reduction Act of 1995
A. Summary
The Paperwork Reduction Act (PRA) provides for the Federal
government's collection, use, and dissemination of information. The
goals of the PRA include minimizing paperwork and reporting burdens and
ensuring the maximum possible utility from the information that is
collected under 5 CFR part 1320. There are provisions of this final
rule that take effect at different times after the final rule is
effective and there are provisions that have different burden hours,
burden costs, and responses each year. Because of this, MSHA shows the
estimates of burden hours, burden costs and responses in three separate
years.
In the first year that the final rule is in effect, the mining
community will incur 181,955 burden hours with related hour burden
costs of approximately $9,722,897 and 3,991,079 responses related to
the information collection.
In the second year that the final rule is in effect, the mining
community will incur 175,101 burden hours with related burden costs of
approximately $9,413,180 and 3,924,609 responses related to the
information collection.
In the third year that the final rule is in effect, the mining
community will incur 171,908 burden hours with related burden costs of
approximately $9,324,041 and 3,874097 responses related to the
information collection.
B. Procedural Details
The Department will, concurrent with publication of this rule,
submit the information collections contained in this final rule to the
Office of Management and Budget (OMB) for review under the PRA, as part
of a request for a new control number (Information Collection Review
(ICR) Reference No: 201012-1219-003) and will begin revisions to
Control Numbers 1219-0088, 1219-0011, 1219-0009. The Department will
publish an additional Notice on OMB's action on the ICR and when the
information collection requirements will take effect. The regulated
community is not required to respond to any collection of information
unless it displays a current, valid, OMB control number. MSHA displays
the OMB control numbers for the ICR in its regulations in 30 CFR part
3. The total information collection burden is summarized as follows:
Title of Collection: Ventilation Plans, Tests, and Examinations in
Underground Mines; OMB Control Number: 1219-0088.
Title of Collection: Mine Operator Dust Data Cards; OMB Control
Number: 1219-0011.
Title of Collection: Respirator Program Records; OMB Control
Number: 1219-0009.
Title of Collection: Medical Surveillance; OMB Control Number:
1219-0NEW.
Affected Public: Private sector-businesses or other for-profits.
Estimated Number of Respondents: 1,547 respondents.
Estimated Number of Responses: 3,991,079 responses in the first
year; 3,924,609 responses in the second year; and 3,874,097 responses
in the third year.
Estimated Number of Burden Hours: 181,955 hours in the first year;
175,101 hours in the second year; and 171,908 hours in the third year.
Estimated Hour Burden Costs: $9,722,897 in the first year;
$9,413,180 in the second year and $9,324,041 in the third year.
Estimated Capital Costs Related to the Information Collection
Package: $69,931 in the first year; $52,547 in the second year; and
$39,523 in the third year.
MSHA received comments on the information collection requirements
contained in the proposed rule. These comments are addressed in
applicable sections of Section IV, Section-by-Section Analysis, of this
preamble and in the Supporting Statement for the information collection
requirements for this final rule. The Information Collection Supporting
Statement is available at http://www.reginfo.gov/public/do/PRAMain, on
MSHA's Web site at http://www.msha.gov/regs/fedreg/informationcollection/informationcollection.asp, and at http://www.regulations.gov. A copy of the Statement is also available from
MSHA by request to Sheila McConnell at [email protected], by
phone request to 202-693-9440, or by facsimile to 202-693-9441.
VIII. Other Regulatory Considerations
A. National Environmental Policy Act (NEPA)
The National Environmental Policy Act (NEPA) of 1969 (42 U.S.C.
4321 et seq.) requires each Federal agency to consider the
environmental effects of final actions and to prepare an Environmental
Impact Statement on major actions significantly affecting the quality
of the environment. The final respirable coal mine dust rule has been
reviewed in accordance with the requirements of the National
Environmental Policy Act (NEPA) of 1969 (42 U.S.C. 4321 et seq.), the
regulations of the Council of Environmental Quality (CEQ) (40 CFR part
1500) and the Department of Labor's NEPA compliance procedures (29 CFR
part 11). In the Federal Register of October 19, 2010 (75 FR 64412),
MSHA made a preliminary determination that the proposed respirable coal
mine dust rule was of a type that does not have a significant impact on
the human environment. MSHA's preliminary determination was based on
its environmental assessment which considered the factors set forth in
29 CFR 11.11(c). MSHA has complied with the requirements of the NEPA,
including the Department of Labor's compliance procedures and the
regulations of the Council on Environmental Quality. The Agency has not
received any new information or comments that would affect its previous
determination. As a result of the Agency's review of the final
respirable coal mine dust rule, MSHA has concluded that the rule will
not have significant environmental impacts, and therefore an
environmental impact statement is not required.
B. The Unfunded Mandates Reform Act of 1995
MSHA has reviewed the final rule under the Unfunded Mandates Reform
Act of 1995 (2 U.S.C. 1501 et seq.). MSHA has determined that this
final rule does not include any federal mandate that may result in
increased
[[Page 24965]]
expenditures by State, local, or tribal governments; nor will it
increase private sector expenditures by more than $100 million
(adjusted for inflation) in any one year or significantly or uniquely
affect small governments. Accordingly, the Unfunded Mandates Reform Act
of 1995 (2 U.S.C. 1501 et seq.) requires no further Agency action or
analysis.
C. The Treasury and General Government Appropriations Act of 1999:
Assessment of Federal Regulations and Policies on Families
Section 654 of the Treasury and General Government Appropriations
Act of 1999 (5 U.S.C. 601) requires agencies to assess the impact of
Agency action on family well-being. MSHA has determined that the final
rule will have no effect on family stability or safety, marital
commitment, parental rights and authority, or income or poverty of
families and children. The final rule impacts the coal mine industry.
Accordingly, MSHA certifies that the final rule will not impact family
well-being.
D. Executive Order 12630: Government Actions and Interference With
Constitutionally Protected Property Rights
This final rule does not implement a policy with takings
implications. Accordingly, under E.O. 12630, no further Agency action
or analysis is required.
E. Executive Order 12988: Civil Justice Reform
The final rule was written to provide a clear legal standard for
affected conduct and was reviewed to eliminate drafting errors and
ambiguities, so as to minimize litigation and undue burden on the
Federal court system. Accordingly, the final rule meets the applicable
standards provided in Sec. 3 of E.O. 12988, Civil Justice Reform.
F. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
The final rule has no adverse impact on children. Accordingly,
under E.O. 13045, no further Agency action or analysis is required.
G. Executive Order 13132: Federalism
The final rule does not have ``federalism implications'' because it
does not ``have substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government.'' Accordingly, under E.O. 13132, no further Agency action
or analysis is required.
H. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
The final rule does not have ``tribal implications'' because it
does not ``have substantial direct effects on one or more Indian
tribes, on the relationship between the Federal government and Indian
tribes, or on the distribution of power and responsibilities between
the Federal government and Indian tribes.'' Accordingly, under E.O.
13175, no further Agency action or analysis is required.
I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
Executive Order 13211 requires agencies to publish a statement of
energy effects when a rule has a significant energy action that
adversely affects energy supply, distribution or use. The final rule
has been reviewed for its impact on the supply, distribution, and use
of energy because it applies to the coal mining industry. Insofar as
MSHA estimates that the final rule will result in annualized costs of
$27.1 million (includes costs to underground coal mine operators and
penalty costs) for the underground coal industry relative to annual
revenues of $20 billion in 2010 dollars and annualized costs of $4.0
million (includes costs to surface coal mine operators and penalty
costs) for the surface coal industry relative to annual revenue of
$17.9 billion in 2010 dollars, it is not a ``significant energy
action'' because it is not ``likely to have a significant adverse
effect on the supply, distribution, or use of energy * * * (including a
shortfall in supply, price increases, and increased use of foreign
supplies).'' Accordingly, Executive Order 13211 requires no further
Agency action or analysis.
J. Executive Order 13272: Proper Consideration of Small Entities in
Agency Rulemaking
MSHA has thoroughly reviewed the final rule to assess and take
appropriate account of its potential impact on small businesses, small
governmental jurisdictions, and small organizations. MSHA has
determined and certified that the final rule does not have a
significant economic impact on a substantial number of small entities.
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U.S. Department of Labor, Mine Safety and Health Administration.
1994. Notice. Mine Safety and Health Administration, Labor, National
Institute for Occupational Safety and Health, Centers for Disease
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1997. Response to Advisory Committee recommendations. 62 FR 3717,
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1998. Coal Mine Respirable Dust Standard Noncompliance
Determinations. 63 FR 5687, February 3, 1998.
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65 FR 42068, July 7, 2000.
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52708, October 14, 2009.
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18308, April 25, 1996.
U.S. Department of Labor, Mine Safety and Health Administration,
Pittsburgh Safety and Health Technology Center. 2011. Infrared
Determination of Quartz in Respirable Coal Mine Dust, MSHA Method P-
7, Sept. 2011.
U.S. Department of Labor, Mine Safety and Health Administration.
2011. Memorandum for the Record: E-Mail from Michael Attfield to
MSHA contractor (Jon Kogut) Re: Standard Errors Of Estimated
Coefficients Related To Cumulative Respirable Coal Mine Dust
Exposure in Attfield-Kuempel NMRD Mortality Model for Anthracite,
East Appalachia, West Appalachia, and Midwest Regions, December 21,
2011.
U.S. Department of Labor, Mine Safety and Health Administration,
Coal Division of Health. 2012a. CY 2009 Operator Dust Sample Count
by Void Code, March 20, 2012.
U.S. Department of Labor, Mine Safety and Health Administration,
Coal Health Division. 2012b. MSHA Longwall Surveys with Adjusted
Concentrations of 1.5 mg/m\3\ Dust Controls, Oct-Dec 2009, April 17,
2012.
U.S. Department of Labor, Mine Safety and Health Administration,
Coal Health Division. 2012c. MSHA Random Non-Longwall Surveys with
Adjusted Concentrations of 1.5 mg/m\3\ Dust Controls, Oct-Dec 2009,
April 17, 2012.
U.S. Department of Labor, Mine Safety and Health Administration.
2012. Program Policy Letter No. P12-V-01. Reissue of P09-V-08--
Procedures for Revoking MSHA Certifications To Take Respirable Dust
Samples Or To Maintain And Calibrate Approved Dust Sampling Devices,
3/8/2012.
U.S. Department of Labor, Mine Safety and Health Administration,
Pittsburgh Safety and Health Technology Center. 2012. Gravimetric
Determination of Mine Dust Collected on Tared Filter Cassettes. MSHA
Method No. P-19. November 2012.
U.S. Department of Labor, Mine Safety and Health Administration.
2009. Program Information Bulletin No. P09-31, Operator Respirable
Dust Sampling Requirements, August 25, 2009.
U.S. Department of Labor, Mine Safety and Health Administration.
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Quantitative Risk Assessment in Support of Proposed Respirable Coal
Mine Dust Rule. Jon Kogut, Statistical Methods and Analysis, MSHA
Contract DOLJ094R22516, September 2010.
U.S. Department of Labor, Mine Safety and Health Administration.
2010. Quantitative Risk Assessment, Dust Data Files, InspSamp.txt,
InspSamp.zip, OpSamp.txt and OpSamp.zip, March 2010.
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2013. Quantitative Risk Assessment in Support of Final Respirable
Coal Mine Dust Rule, 2013. December 2013.
U.S. Department of Labor, Mine Safety and Health Administration.
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Respirable Coal Mine Dust Including Continuous Personal Dust
Monitors Final Rule, March 2014.
U.S. Environmental Protection Agency, Office of Air and Radiation.
2011. Regulatory Impact Analysis for the Federal Implementation
Plans to Reduce Interstate Transport of Fine Particulate Matter and
Ozone in 27 States; Correction of SIP Approvals for 22 States.
Federal Register Notice, June 2011, http://www.epa.gov/airtransport/pdfs/FinalRIA.pdf.
U.S. Office of Management and Budget. 2002. Guidelines for Ensuring
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U.S. Office of Management and Budget. 2003. Subject: Circular A-4,
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X. Appendix A--Excessive Concentration Values
The Excessive Concentration Value (ECV) tables ensure that
noncompliance is cited only when there is a 95-percent level of
confidence that the applicable respirable dust standard has actually
been exceeded. All measurements of respirable coal mine dust
concentrations, whether taken using an approved CMDPSU or CPDM, are
subject to sampling and analytical (weighing) error. Such errors cause
individual concentration measurements to deviate above or below the
true concentration value in the mine atmosphere. Therefore, when
determining noncompliance, MSHA must ensure that the applicable
standard has actually been exceeded.
The final rule provides for a margin of error in each measurement
to reduce the risk of finding that a mine operator is in noncompliance
when the applicable standard was not exceeded. The ECV tables in the
final rule include this margin of error.
For example, when using a CMDPSU to sample an entity on a 2.0 mg/
m\3\ standard, a single-shift measurement of 2.14 mg/m\3\ would not,
according to Table 70-1, indicate noncompliance at a 95-percent
confidence level. Rather, this measurement indicates that the MMU was
probably out of compliance. However, because there is a small chance
that the measurement exceeded the respirable dust standard only because
of possible measurement error, a citation would not be issued.
Similarly, a single-shift measurement of 1.92 mg/m\3\ may not indicate
compliance at a 95-percent confidence level under a 2.0 mg/m\3\
standard.
Furthermore, even if a single-shift measurement showed that the
mine atmosphere was in compliance, at a 95-percent confidence level, at
the sampling location on a given shift, additional measurements would
be required to demonstrate compliance on each shift. For example, if S
= 2.0 mg/m\3\, then a valid measurement of 1.65 mg/m\3\ demonstrates
compliance on the particular shift and at the particular location
sampled. It would not, however, demonstrate compliance on other shifts
or at other locations.
In the final rule, the ECVs for a single, full-shift concentration
measurement are similar to the proposed rule except that the tables are
combined to be more user-friendly. The proposed ECV tables that were
based on CMDPSU sampling (proposed Tables 70-1, 71-1 and 90-1) and the
proposed ECV tables that were based on CPDM sampling (proposed Tables
70-2, 71-2 and 90-2) are combined into one table in each part in the
final rule. For example, Table 70-1 in the final rule combines proposed
Table 70-1, which established the ECVs based on single-shift
measurements taken with a CMDPSU, with proposed Table 70-2, which
established the ECVs based on single-shift measurements taken with a
CPDM. In addition, in response to comments, MSHA has established ECVs
based on the average of multiple samples. These ECVs are
[[Page 24970]]
included in final Tables 70-2, 71-2, and 90-2.
Each ECV, whether based on a single-shift CMDPSU or CPDM
measurement or on the average of multiple, full-shift CMDPSU or CPDM
concentration measurements, was calculated so that if the ECV is met or
exceeded, it can be inferred with at least 95-percent confidence that
the applicable standard has been exceeded on the particular shift
sampled or at the sampled occupation or location during the period
sampled.
The ECV tables do not depend on how the applicable standard was
established, or on any measurement uncertainties in the process of
setting the applicable standard.
Derivation of Final Tables 70-1, 71-1, and 90-1 Based on Single Full-
Shift Concentration Measurements
Dust concentration measurements vary partly because of measurement
error and partly because of differences in the dust concentration being
measured. Therefore, in deriving the ECVs, MSHA distinguished between
variability due to measurement (sampling and weighing) error and
variability due to actual differences in dust concentration. The
distinction between measurement error and variation in the true dust
concentration is more easily explained by defining some notational
abbreviations.
Dust samples are collected in the same MMU or other mine area on a
particular shift. Since it is necessary to distinguish between
different samples in the same MMU, let Xi represent the
equivalent MRE dust concentration measurement obtained from the ith
sample. The quantity being measured is the true, single-shift average
dust concentration at the ith sampling location and is denoted by
[mu]i. Because of potential measurement errors,
[mu]i can never be known with complete certainty. A
``sample,'' ``measurement,'' or ``observation'' always refers to an
instance of Xi rather than [mu]i.
The overall measurement error associated with an individual
measurement is the difference between the measurement (Xi)
and the quantity being measured ([mu]i). Therefore, this
error can be represented as
[egr]i = Xi - [mu]i.
Equivalently, any measurement can be regarded as the true
concentration in the atmosphere sampled, with a measurement error added
on:
Xi = [mu]i + [egr]i.
For two different measurements (X1 and X2),
it follows that X1 may differ from X2 because of
the combined effects of [egr]1 and [egr]2, and
because [mu]1 differs from [mu]2.
The probability distribution of Xi around
[mu]i depends only on the probability distribution of
[egr]i and should not be confused with the statistical
distribution of [mu]i, which arises from spatial and/or
temporal variability in dust concentration. This variability (i.e.,
among [mu]i for different values of i) is not associated
with inadequacies of the measurement system, but real variation in
exposures due to the fact that contaminant generation rates vary in
time and contaminants are heterogeneously distributed in workplace air.
If noncompliance determinations are made relative to individual
sampling locations on a shift, derivation of the tables require no
assumptions or inferences about the spatial or temporal pattern of
atmospheric dust concentrations--i.e., the statistical distribution of
[mu]i. MSHA is not evaluating dust concentrations averaged
across the different occupational sampling locations. Therefore, the
degree and pattern of variability observed among different measurements
obtained during MSHA sampling are not used in establishing any ECV.
Instead, the ECV for each applicable dust standard (S) is based
entirely on the distribution of measurement errors ([egr]i)
expected for the maximum dust concentration in compliance with that
standard--i.e., a concentration equal to S itself.
If control filters are used to eliminate potential biases as when
sampling using an approved CMDPSU, then each [egr]i arises
from a combination of four weighing errors (pre- and post-exposure for
both the control and exposed filter capsule) and a continuous summation
of instantaneous measurement errors accumulated over the course of the
full shift. Since the full shift being sampled can be subdivided into
an arbitrarily large number of sub-intervals, and some fraction of
[egr]i is associated with each sub-interval,
[egr]i can be represented as comprising the sum of an
arbitrarily large number of sub-interval errors. By the Central Limit
Theorem, such a summation tends to be normally distributed, regardless
of the distribution of sub-interval errors. This does not depend on the
distribution of [mu]i, which is generally represented as
being lognormal.
Any systematic error or bias in the weighing process attributable
to the laboratory is mathematically canceled out by subtraction. Any
bias that may be associated with day-to-day changes in laboratory
conditions or introduced during storage and handling of the filter
capsules is also mathematically canceled out. Elimination of the
sources of systematic errors identified above, together with the fact
that the concentration of respirable dust is defined by section 202(e)
of the Mine Act to mean the average concentration of respirable dust
measured by an approved sampler unit, indicates that the measurements
are unbiased. This means that [egr]i is equally likely to be
positive or negative and, on average, equal to zero.
Therefore, each [egr]i is assumed to be normally
distributed, with a mean value of zero and a degree of variability
represented by its standard deviation:
[sigma]i = [micro]i [middot] CVtotal
Since Xi = [mu]i + [egr]i, it
follows that for a given value of [mu]i, Xi is
normally distributed with expected value equal to [mu]i and
standard deviation equal to [sigma]i. CVtotal, is
the coefficient of variation in measurements corresponding to a given
value of [mu]i. CVtotal relates entirely to
variability due to measurement errors and not at all to variability in
actual dust concentrations.
The procedure for determining noncompliance with applicable
standards based on Tables 70-1, 71-1, and 90-1 consists of formally
testing a presumption of compliance at every location sampled.
Compliance with the applicable dust standard at the ith sampling
location is expressed by the relation [mu]i <= S.
Max{[mu]i{time} denotes the maximum dust concentration,
among all of the sampling locations within an MMU. Therefore, if
Max{[mu]i{time} <= S, none of the sampling devices in the
MMU were exposed to excessive dust concentrations. Since MSHA must
establish that the applicable standard has been exceeded, the
hypothesis being tested (called the null hypothesis, or H0,) is that
the concentration at every location sampled is in compliance with the
applicable standard. It follows that for an MMU, the null hypothesis
(H0) is that max{[mu]i{time} <= S. In other
areas, where only one, full-shift measurement is made, the null
hypothesis is simply that [mu]i <= S.
The test consists of evaluating the likelihood of measurements
under the assumption that H0 is true. Since Xi =
[mu]i + [egr]i, Xi (or
max{Xi{time} in the case of an MMU) can exceed S even under
that assumption. However, based on the normal distribution of
measurement errors, it is possible to calculate the probability that a
measurement error would be large enough to account for the
measurement's exceeding the standard. The greater the amount by which
Xi exceeds S, the less likely it is that this would be due
to measurement
[[Page 24971]]
error alone. If, under H0, this probability is less than
five percent, then H0 can be rejected at a 95-percent
confidence level and a finding of noncompliance with the applicable
standard is warranted. For an MMU, rejecting H0 (and
therefore issuing a finding of noncompliance) is equivalent to
determining that [mu]i > S for at least one value of i.
Each ECV listed was calculated to ensure that, if the ECV is met or
exceeded, it can be inferred with at least 95-percent confidence that
the applicable standard has been exceeded. As described in MSHA's
February 1994 notice, Coal Mine Respirable Dust Standard Noncompliance
Determinations (59 FR 8356, February 18, 1994) and explained further by
Kogut (Kogut, 1994), the tabled CMDPSU ECVs corresponding to each S
were calculated on the assumption that, at each sampling location:
[GRAPHIC] [TIFF OMITTED] TR01MY14.008
In July 2000, MSHA and NIOSH proposed a joint finding,
``Determination of Concentration of Respirable Coal Mine Dust'' (65 FR
42068, July 7, 2000). The joint finding stated that for valid
measurements made with an approved CMDPSU, CVtotal is, in
fact, less than CVCTV \64\ at all dust concentrations
([mu]i).
---------------------------------------------------------------------------
\64\ The term ``Concentration Threshold Value'' (CTV) used in
the July 7, 2000 Joint Finding was renamed the Excessive
Concentration Value (ECV) in the October 19, 2010 proposed rule (75
FR 64412).
---------------------------------------------------------------------------
The circumstance in which measurement error is most likely to cause
an erroneous noncompliance determination is the hypothetical case of
[mu]i = S for either a single-shift sample measurement or
for all of the occupational measurements made in the same MMU. In that
borderline situation--i.e., the worst case consistent with
H0--the standard deviation is identical for all measurement
errors. Therefore, the value of [sigma] used in constructing the CMDPSU
ECV table is the product of S and CVECV evaluated for a dust
concentration equal to S:
[GRAPHIC] [TIFF OMITTED] TR01MY14.009
Assuming a normal distribution of measurement errors as explained
above, it follows that the probability a single measurement would equal
or exceed the critical value
c = S + 1.645[sdot][sigma]
is five percent under H0 when CVtotal =
CVECV. The tabled CMDPSU ECV corresponding to S is derived
by raising the critical value c up to the next exact multiple of 0.01
mg/m\3\.
For example, at a dust concentration ([mu]i) just
meeting the applicable dust standard of S = 2 mg/m\3\, CVECV
is 9.95 percent for a CMDPSU measurement. Therefore, the calculated
value of c is 2.326 and the ECV is 2.33 mg/m\3\. Any valid single-shift
measurement at or above this ECV is unlikely to be this large simply
because of measurement error. Therefore, any such measurement should
result in MSHA finding the operator to be in noncompliance with the
applicable standard.
The probability that a measurement exceeds the ECV is even smaller
if [mu]i < S for any i. Furthermore, to the extent that
CVtotal is actually less than CVECV, [sigma] is
actually less than S[sdot]CVECV. This results in a lower
probability that the critical value would be exceeded under the null
hypothesis. Consequently, if any single-shift measurement equals or
exceeds c, then H0 can be rejected at confidence level of at
least 95-percent. Since rejection of H0 implies that
[mu]i > S for at least one value of i, this should result in
a finding of noncompliance.
When each of several measurements is separately compared to the ECV
table, the probability that at least one [egr]i will be
large enough to force Xi >= ECV when [mu]i <= S
is greater than the probability when only a single comparison is made.
For example (still assuming S = 2 mg/m\3\), if CVtotal is
actually 6.6%, then the standard deviation of [egr]i is 6.6%
of 2.0 mg/m\3\, or 0.132 mg/m\3\, when [mu]i = S. Using
properties of the normal distribution, the probability that any single
measurement would exceed the ECV in this borderline situation is
calculated to be 0.62%. However, the probability that at least one of
five such measurements results in a citation is 1 - (0.9938)\5\ = 3.1%.
Therefore, the confidence level at which a citation can be issued,
based on the maximum of five measurements made in the same MMU on a
given shift, is 97%.
The constant 1.645 used in calculating the ECV is a 1-tailed 95-
percent confidence coefficient and is derived from the standard normal
probability distribution. Since the purpose of the ECV tables is to
provide criteria for determining that the true dust concentration
strictly exceeds the applicable dust standard and such a determination
can occur only when a single-shift measurement is sufficiently high,
there is exactly zero probability of erroneously finding an operator to
be in noncompliance when a measurement falls below the lower confidence
limit. Consequently, the total probability of erroneously finding an
operator to be in noncompliance with the applicable standard equals the
probability that a standard normal random variable exceeds 1.645, which
is 5 percent.
The same statistical theory underlying the derivation of the CMDPSU
ECVs applies in constructing the CPDM ECVs listed in Tables 70-1, 71-1,
and 90-1 in the final rule. The initial step in the derivation process
involves addressing uncertainty due to potential measurement errors.
Measurement imprecision is quantified by the total coefficient of
variation for overall measurement error, or CVtotal, also
sometimes called relative standard deviation (RSD). CVtotal
corresponding to the CPDM has been estimated by NIOSH to be 7.8 percent
based on in-mine studies and is documented by Volkwein et al. (NIOSH RI
9669, 2006). The uncertainty due to measurement error is addressed by
applying a margin of error before issuing a finding that the applicable
standard was exceeded.
[[Page 24972]]
Applying this margin of error ensures that noncompliance determinations
are made only when there is at least 95-percent confidence that the
applicable standard has been exceeded. To achieve this confidence
level, the applicable margin of error is constructed by applying an
error factor appropriate for the measurement being considered. The
error factor is calculated as:
EF = 1 + (1.645 x CVtotal)
Therefore, when CVtotal = 7.8 percent, the calculated
value of EF is 1.128. If, for example, the sampled occupation is on a
1.5 mg/m\3\ standard, the operator would be in violation of the
applicable standard if a single, full-shift MRE-equivalent
concentration measurement times the EF exceeds 1.692 mg/m\3\ [1.5 x
1.128]. The ECV corresponding to each applicable standard is derived by
simply raising the calculated ECV to the next exact multiple of 0.01
mg/m\3\. Therefore, the ECV corresponding to the applicable standard of
1.5 mg/m\3\ is 1.70 mg/m\3\. Since it is unlikely that any valid CPDM
end-of shift equivalent concentration is this large simply because of
measurement error, it can be inferred with at least 95-percent
confidence that the applicable standard has been exceeded. The same
procedures were followed in calculating ECVs corresponding to other
applicable standards.
Derivation of Final Tables 70-2, 71-2, and 90-2 Based on Average of
Concentration Measurements
The ECVs in final Tables 70-2, 71-2 and 90-2 apply to the average
of all operators' valid representative samples. The ECVs in final
Tables 70-2, 71-2 and 90-2, like final Tables 70-1, 71-1 and 90-1,
provide a margin of error to address uncertainty due to measurement
error. When the ECV that corresponds to the applicable standard, the
particular sampling device used, and appropriate sample size is met or
exceeded, it can be inferred with at least 95-percent confidence that
the applicable standard has been exceeded at the particular MMU, or at
the sampled occupation or location, during the period sampled.
Tables 70-2, 71-2 and 90-2 in the final rule were developed in
response to commenters' concerns that MSHA failed to address
measurement errors when evaluating compliance with the proposed weekly
permissible accumulated exposure (WPAE) limit. The final rule does not
include the proposed WPAE approach. It includes an alternative method
of making a compliance determination based on the average of all
samples.
Under the final rule, the ECVs for 5 and 15 full-shift average
equivalent concentration measurements were calculated taking into
consideration measurement variability ([sigma]) and the probability
(95-percent confidence level) of not being in error when determining
noncompliance based on the multi-shift average. For both the CMDPSU and
CPDM, the measurement variabilities used were the same as those
previously estimated by the standard propagation-of-errors formula to
construct the single-sample ECVs in the proposal. These estimates of
measurement variability for the average of the respirable dust
concentration measurements just meeting the applicable standard were
then substituted into the following equation:
[GRAPHIC] [TIFF OMITTED] TR01MY14.010
Where c represents the Critical Value or quantity to be met or
exceeded to establish that the average of the respirable dust
concentration measurements exceeds the applicable standard.
S is the Applicable Standard; 1.645 is the 1-tailed 95-percent
confidence coefficient obtained from the standard normal probability
distribution; [sigma] is the appropriate measurement variability; and n
is the number of full-shift measurements included. The ECV
corresponding to S is derived by raising the critical value c up to the
next exact multiple of 0.01 mg/m\3\.
The following discussion illustrates when the 15-sample CMDPSU
average concentration exceeds the applicable standard of 2.0 mg/m\3\
standard. Assuming the average concentration is meeting the applicable
standard S = 2 mg/m\3\, which corresponds to a CVECV of 9.95
percent for a single, full-shift measurement, the value of measurement
variability [sigma] used in constructing the ECV tables is the product
of S and CVECV evaluated for an average concentration equal
to S:
[GRAPHIC] [TIFF OMITTED] TR01MY14.011
Substituting the appropriate value for [sigma] in this example
which equals 0.199 mg/m\3\ (2.0 mg/m\3\ x 9.95%) into the equation:
[GRAPHIC] [TIFF OMITTED] TR01MY14.012
yields the calculated value of c or 2.085 mg/m\3\. Therefore, a 15-
sample average CMDPSU concentration at or above 2.09 mg/m\3\ is
unlikely to be this large because of measurement error. If the average
concentration of the 15 CMDPSU samples meets or exceeds 2.09 mg/m\3\,
then the 2.0 mg/m\3\ standard is exceeded.
The following example illustrates when a 5-sample CPDM average
concentration exceeds the applicable standard for a part 90 miner on a
1.0 mg/m\3\ dust standard. For respirable dust levels that are
approximately 1.0 mg/m\3\, the estimate of measurement error [sigma] is
0.078 mg/m\3\. When substituted in the above equation, the calculated
value of c is 1.057 mg/m\3\ and the ECV is 1.06 mg/m\3\. If the average
concentration of the 5 CPDM samples meets or exceeds 1.06 mg/m\3\, then
the 1.0 mg/m\3\ standard is exceeded.
List of Subjects
30 CFR Part 70
Coal, Incorporation by reference, Mine safety and health, Reporting
and recordkeeping requirements, Respirable dust, Underground coal
mines.
30 CFR Part 71
Coal, Incorporation by reference, Mine safety and heath, Reporting
and recordkeeping requirements, Surface coal mines, Underground coal
mines.
30 CFR Part 72
Coal, Health standards, Mine safety and health, training,
Underground mines.
30 CFR Part 75
Coal, Mine safety and health, Reporting and recordkeeping
requirements, Underground coal mines, Ventilation.
30 CFR Part 90
Coal, Incorporation by reference, Mine safety and health.
Joseph A. Main,
Assistant Secretary of Labor for Mine Safety and Health.
For the reasons discussed in the preamble, the Mine Safety and
Health Administration is amending 30 CFR parts 70, 71, 72, 75 and 90 as
follows:
PART 70--MANDATORY HEALTH STANDARDS FOR UNDERGROUND COAL MINES
0
1. The authority citation for part 70 continues to read as follows:
Authority: 30 U.S.C. 811, 813(h), 957.
0
2. Subpart A to part 70 is revised to read as follows:
Subpart A--General
Sec.
[[Page 24973]]
70.1 Scope.
70.2 Definitions.
Subpart A--General
Sec. 70.1 Scope.
This part 70 sets forth mandatory health standards for each
underground coal mine subject to the Federal Mine Safety and Health Act
of 1977, as amended.
Sec. 70.2 Definitions.
The following definitions apply in this part.
Act. The Federal Mine Safety and Health Act of 1977, Public Law 91-
173, as amended by Public Law 95-164 and Public Law 109-236.
Active workings. Any place in a coal mine where miners are normally
required to work or travel.
Approved sampling device. A sampling device approved by the
Secretary and Secretary of Health and Human Services (HHS) under part
74 of this title.
Certified person. An individual certified by the Secretary in
accordance with Sec. 70.202 to take respirable dust samples required
by this part or certified in accordance with Sec. 70.203 to perform
the maintenance and calibration of respirable dust sampling equipment
as required by this part.
Coal mine dust personal sampler unit (CMDPSU). A personal sampling
device approved under part 74, subpart B, of this title.
Concentration. A measure of the amount of a substance contained per
unit volume of air.
Continuous personal dust monitor (CPDM). A personal sampling device
approved under part 74, subpart C of this title.
Designated area (DA). A specific location in the mine identified by
the operator in the mine ventilation plan under Sec. 75.371(t) of this
title where samples will be collected to measure respirable dust
generation sources in the active workings; approved by the District
Manager; and assigned a four-digit identification number by MSHA.
Designated occupation (DO). The occupation on a mechanized mining
unit (MMU) that has been determined by results of respirable dust
samples to have the greatest respirable dust concentration.
District Manager. The manager of the Coal Mine Safety and Health
District in which the mine is located.
Equivalent concentration. The concentration of respirable coal mine
dust, including quartz, expressed in milligrams per cubic meter of air
(mg/m\3\) as measured with an approved sampling device, determined by
dividing the weight of dust in milligrams collected on the filter of an
approved sampling device by the volume of air in cubic meters passing
through the filter (sampling time in minutes (t) times the sampling
airflow rate in cubic meters per minute), and then converting that
concentration to an equivalent concentration as measured by the Mining
Research Establishment (MRE) instrument. When the approved sampling
device is:
(1) The CMDPSU, the equivalent concentration is determined by
multiplying the concentration of respirable coal mine dust by the
constant factor prescribed by the Secretary.
(2) The CPDM, the device shall be programmed to automatically
report end-of-shift concentration measurements as equivalent
concentrations.
Mechanized mining unit (MMU). A unit of mining equipment including
hand loading equipment used for the production of material; or a
specialized unit which uses mining equipment other than specified in
Sec. 70.206(b) or in Sec. 70.208(b) of this part. Each MMU will be
assigned a four-digit identification number by MSHA, which is retained
by the MMU regardless of where the unit relocates within the mine.
However, when:
(1) Two sets of mining equipment are used in a series of working
places within the same working section and only one production crew is
employed at any given time on either set of mining equipment, the two
sets of equipment shall be identified as a single MMU.
(2) Two or more sets of mining equipment are simultaneously engaged
in cutting, mining, or loading coal or rock from working places within
the same working section, each set of mining equipment shall be
identified as a separate MMU.
MRE instrument. The gravimetric dust sampler with a four channel
horizontal elutriator developed by the Mining Research Establishment of
the National Coal Board, London, England.
MSHA. The Mine Safety and Health Administration of the U.S.
Department of Labor.
Normal production shift. A production shift during which the amount
of material produced by an MMU is at least equal to 80 percent of the
average production recorded by the operator for the most recent 30
production shifts or for all production shifts if fewer than 30 shifts
of production data are available.
Other designated occupation (ODO). Other occupation on an MMU that
is designated for sampling required by this part in addition to the DO.
Each ODO shall be identified by a four-digit identification number
assigned by MSHA.
Production shift. With regard to an MMU, a shift during which
material is produced; with regard to a DA of a mine, a shift during
which material is produced and routine day-to-day activities are
occurring in the DA.
Quartz. Crystalline silicon dioxide (SiO2) not
chemically combined with other substances and having a distinctive
physical structure.
Representative sample. A respirable dust sample, expressed as an
equivalent concentration, that reflects typical dust concentration
levels and with regard to an MMU, normal mining activities in the
active workings during which the amount of material produced is
equivalent to a normal production shift; or with regard to a DA,
material is produced and routine-day-to-day activities are occurring.
Respirable dust. Dust collected with a sampling device approved by
the Secretary and the Secretary of HHS in accordance with part 74 (Coal
Mine Dust Sampling Devices) of this title.
Secretary. The Secretary of Labor or a delegate.
Valid respirable dust sample. A respirable dust sample collected
and submitted as required by this part, including any sample for which
the data were electronically transmitted to MSHA, and not voided by
MSHA.
0
3. Subpart B to part 70 is revised to read as follows:
Subpart B--Dust Standards
Sec.
70.100 Respirable dust standards.
70.101 Respirable dust standard when quartz is present.
Subpart B--Dust Standards
Sec. 70.100 Respirable dust standards.
(a) Each operator shall continuously maintain the average
concentration of respirable dust in the mine atmosphere during each
shift to which each miner in the active workings of each mine is
exposed, as measured with an approved sampling device and expressed in
terms of an equivalent concentration, at or below:
(1) 2.0 milligrams of respirable dust per cubic meter of air (mg/
m\3\).
(2) 1.5 mg/m\3\ as of August 1, 2016.
(b) Each operator shall continuously maintain the average
concentration of respirable dust within 200 feet outby the working
faces of each section in the intake airways as measured with an
approved sampling device and
[[Page 24974]]
expressed in terms of an equivalent concentration at or below:
(1) 1.0 mg/m\3\.
(2) 0.5 mg/m\3\ as of August 1, 2016.
Sec. 70.101 Respirable dust standard when quartz is present.
(a) Each operator shall continuously maintain the average
concentration of respirable quartz dust in the mine atmosphere during
each shift to which each miner in the active workings of each mine is
exposed at or below 0.1 mg/m\3\ (100 micrograms per cubic meter or
[micro]g/m\3\) as measured with an approved sampling device and
expressed in terms of an equivalent concentration.
(b) When the equivalent concentration of respirable quartz dust
exceeds 100 [micro]g/m\3\, the operator shall continuously maintain the
average concentration of respirable dust in the mine atmosphere during
each shift to which each miner in the active workings is exposed as
measured with an approved sampling device and expressed in terms of an
equivalent concentration at or below the applicable dust standard. The
applicable dust standard is computed by dividing the percent of quartz
into the number 10. The application of this formula shall not result in
an applicable dust standard that exceeds the standard established by
Sec. 70.100(a).
Example: Assume the sampled MMU or DA is on a 1.5-mg/m\3\ dust
standard. Suppose a valid representative dust sample with an
equivalent concentration of 1.12 mg/m\3\ contains 12.3% of quartz
dust, which corresponds to a quartz concentration of 138 [micro]g/
m\3\. Therefore, the average concentration of respirable dust in the
mine atmosphere associated with that MMU or DA shall be maintained
on each shift at or below 0.8 mg/m\3\ (10/12.3% = 0.8 mg/m\3\).
0
4. Subpart C to part 70 is revised to read as follows:
Subpart C--Sampling Procedures
Sec.
70.201 Sampling; general and technical requirements.
70.202 Certified person; sampling.
70.203 Certified person; maintenance and calibration.
70.204 Approved sampling devices; maintenance and calibration.
70.205 Approved sampling devices; operation; air flowrate.
70.206 Bimonthly sampling; mechanized mining units.
70.207 Bimonthly sampling; designated areas.
70.208 Quarterly sampling; mechanized mining units.
70.209 Quarterly sampling; designated areas.
70.210 Respirable dust samples; transmission by operator.
70.211 Respirable dust samples; report to operator; posting.
70.212 Status change reports.
Tables to Subpart C
Table 70-1 Excessive Concentration Values (ECV) Based on Single,
Full-Shift CMDPSU/CPDM Concentration Measurements
Table 70-2 Excessive Concentration Values (ECV) Based on the Average
of 5 or 15 Full-Shift CMDPSU/CPDM Concentration Measurements
Subpart C--Sampling Procedures
Sec. 70.201 Sampling; general and technical requirements.
(a) Only an approved coal mine dust personal sampler unit (CMDPSU)
shall be used to take bimonthly samples of the concentration of
respirable coal mine dust from the designated occupation (DO) in each
MMU as required by this part until Janaury 31, 2016. On February 1,
2016, DOs in each MMU shall be sampled quarterly with an approved CPDM
as required by this part and an approved CMDPSU shall not be used,
unless notified by the Secretary to continue to use an approved CMDPSU
to conduct quarterly sampling.
(b) Only an approved CMDPSU shall be used to take bimonthly samples
of the concentration of respirable coal mine dust from each designated
area (DA) as required by this part until January 31, 2016. On February
1, 2016:
(1) DAs associated with an MMU shall be redesignated as Other
Designated Occupations (ODO). ODOs shall be sampled quarterly with an
approved CPDM as required by this part and an approved CMDPSU shall not
be used, unless notified by the Secretary to continue to use an
approved CMDPSU to conduct quarterly sampling.
(2) DAs identified by the operator under Sec. 75.371(t) of this
chapter shall be sampled quarterly with an approved CMDPSU as required
by this part, unless the operator notifies the District Manager in
writing that only an approved CPDM will be used for all DA sampling at
the mine. The notification must be received at least 90 days before the
beginning of the quarter in which CPDMs will be used to collect the DA
samples.
(c) Sampling devices shall be worn or carried directly to the MMU
or DA to be sampled and from the MMU or DA sampled and shall be
operated portal-to-portal. Sampling devices shall remain with the
occupation or DA being sampled and shall be operational during the
entire shift, which includes the total time spent in the MMU or DA and
while traveling to and from the mining section or area being sampled.
If the work shift to be sampled is longer than 12 hours and the
sampling device is:
(1) A CMDPSU, the operator shall switch-out the unit's sampling
pump prior to the 13th-hour of operation.
(2) A CPDM, the operator shall switch-out the CPDM with a fully
charged device prior to the 13th-hour of operation.
(d) If using a CMDPSU, one control filter shall be used for each
shift of sampling. Each control filter shall:
(1) Have the same pre-weight date (noted on the dust data card) as
the filters used for sampling;
(2) Remain plugged at all times;
(3) Be used for the same amount of time, and exposed to the same
temperature and handling conditions as the filters used for sampling;
(4) Be kept with the exposed samples after sampling and in the same
mailing container when transmitted to MSHA.
(e) Records showing the length of each production shift for each
MMU shall be made and retained for at least six months and shall be
made available for inspection by authorized representatives of the
Secretary and the representative of miners, and submitted to the
District Manager when requested in writing.
(f) Upon request from the District Manager, the operator shall
submit the date and time any respirable dust sampling required by this
part will begin. This information shall be submitted at least 48 hours
prior to the scheduled sampling.
(g) To establish a normal production shift, the operator shall
record the amount of run-of-mine material produced by each MMU during
each shift to determine the average production for the most recent 30
production shifts, or for all production shifts if fewer than 30 shifts
of production data are available. Production records shall be retained
for at least six months and shall be made available for inspection by
authorized representatives of the Secretary and the representative of
miners.
(h) Operators using CPDMs shall provide training to all miners
expected to wear a CPDM. The training shall be completed prior to a
miner wearing a CPDM and then every 12 months thereafter. The training
shall include:
(1) The importance of monitoring dust concentrations and properly
wearing the CPDM.
(2) Explaining the basic features and capabilities of the CPDM;
(3) Discussing the various types of information displayed by the
CPDM and how to access that information; and
(4) How to start and stop a short-term sample run during compliance
sampling.
[[Page 24975]]
(i) An operator shall keep a record of the CPDM training at the
mine site for 24 months after completion of the training. An operator
may keep the record elsewhere if the record is immediately accessible
from the mine site by electronic transmission. Upon request from an
authorized representative of the Secretary, Secretary of HHS, or
representative of miners, the operator shall promptly provide access to
any such training records. The record shall include:
(1) The date of training;
(2) The names of miners trained; and
(3) The subjects included in the training.
(j) An anthracite mine using the full box, open breast, or slant
breast mining method may use either a CPDM or a CMDPSU to conduct the
required sampling. The mine operator shall notify the District Manager
in writing of its decision to not use a CPDM.
(k) MSHA approval of the dust control portion of the operator's
mine ventilation plan may be revoked based on samples taken by MSHA or
in accordance with this part 70.
Sec. 70.202 Certified person; sampling.
(a) The respirable dust sampling required by this part shall be
performed by a certified person.
(b) To be certified, a person shall complete the applicable MSHA
course of instruction and pass the MSHA examination demonstrating
competency in sampling procedures. Persons not certified in sampling,
and those certified only in maintenance and calibration procedures in
accordance with Sec. 70.203(b), are not permitted to collect
respirable dust samples required by this part or handle approved
sampling devices when being used in sampling.
(c) To maintain certification, a person must pass the MSHA
examination demonstrating competency in sampling procedures every three
years.
(d) MSHA may revoke a person's certification for failing to
properly carry out the required sampling procedures.
Sec. 70.203 Certified person; maintenance and calibration.
(a) Approved sampling devices shall be maintained and calibrated by
a certified person.
(b) To be certified, a person shall complete the applicable MSHA
course of instruction and pass the MSHA examination demonstrating
competency in maintenance and calibration procedures for approved
sampling devices. Necessary maintenance of the sampling head assembly
of a CMDPSU, or the cyclone assembly of a CPDM, can be performed by
persons certified in sampling or in maintenance and calibration.
(c) To maintain certification, a person must pass the MSHA
examination demonstrating competency in maintenance and calibration
procedures every three years.
(d) MSHA may revoke a person's certification for failing to
properly carry out the required maintenance and calibration procedures.
Sec. 70.204 Approved sampling devices; maintenance and calibration.
(a) Approved sampling devices shall be maintained as approved under
part 74 of this title and calibrated in accordance with MSHA
Informational Report IR 1240 (1996) ``Calibration and Maintenance
Procedures for Coal Mine Respirable Dust Samplers'' or in accordance
with the manufacturer's recommendations, if using a CPDM. Only persons
certified in maintenance and calibration can perform maintenance work
on the CPDM or the pump unit of the CMDPSU.
(b) Sampling devices shall be calibrated at the flowrate of 2.0
liters of air per minute (L/min) if using a CMDPSU; at 2.2 L/min if
using a CPDM; or at a different flowrate recommended by the
manufacturer, before they are put into service and, thereafter, at time
intervals recommended by the manufacturer or prescribed by the
Secretary or Secretary of HHS.
(c) If using a CMDPSU, each sampling device shall be examined and
tested by a person certified in sampling or in maintenance and
calibration within 3 hours before the start of the shift on which the
approved sampling devices will be used to collect respirable dust
samples. This is to assure that the sampling devices are clean and in
proper working condition. This examination and testing shall include
the following:
(1) Examination of all components of the cyclone assembly to assure
that they are clean and free of dust and dirt. This includes examining
the interior of the connector barrel (located between the cassette
assembly and vortex finder), vortex finder, cyclone body, and grit pot;
(2) Examination of the inner surface of the cyclone body to assure
that it is free of scoring or scratch marks on the inner surface of the
cyclone where the air flow is directed by the vortex finder into the
cyclone body;
(3) Examination of the external hose connecting the pump unit to
the sampling head assembly to assure that it is clean and free of
leaks; and
(4) Examination of the clamping and positioning of the cyclone
body, vortex finder, and cassette to assure that they are rigid, in
alignment, firmly in contact, and airtight.
(5) Testing the voltage of each battery while under actual load to
assure the battery is fully charged. This requires that a fully
assembled and examined sampling head assembly be attached to the pump
inlet with the pump unit running when the voltage check is made. The
voltage for the batteries used in the CMDPSU shall not be lower than
the product of the number of cells in the battery multiplied by the
manufacturer's nominal voltage per cell value.
(d) If using a CPDM, the certified person in sampling or in
maintenance and calibration shall:
(1) Follow the pre-operational examinations, testing, and set-up
procedures, and perform necessary external maintenance recommended by
the manufacturer to assure the operational readiness of each CPDM
within 3 hours before the start of the shift on which the sampling
devices will be used to collect respirable dust samples; and
(2) Perform other required scheduled examinations and maintenance
procedures recommended by the manufacturer.
(e) You must proceed in accordance with ``Calibration and
Maintenance Procedures for Coal Mine Respirable Dust Samplers,'' MSHA
Informational Report IR 1240 (1996) referenced in paragraph (a) of this
section. The Director of the Federal Register approves this
incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. You may obtain a copy from the MSHA Web site at http://www.msha.gov and you may inspect or obtain a copy at MSHA, Coal Mine
Safety and Health, 1100 Wilson Blvd., Room 2424, Arlington, Virginia
22209-3939 and at each MSHA Coal Mine Safety and Health District
Office, or at the National Archives and Records Administration (NARA).
For information on the availability of this material at NARA, call 202-
741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
Sec. 70.205 Approved sampling devices; operation; air flowrate.
(a) Approved sampling devices shall be operated at the flowrate of
2.0 L/min if using a CMDPSU; at 2.2 L/min if using a CPDM; or at a
different flowrate recommended by the manufacturer.
(b) If using a CMDPSU, each approved sampling device shall be
examined each shift by a person certified in sampling during:
[[Page 24976]]
(1) The second hour after being put into operation to assure it is
in the proper location, operating properly, and at the proper flowrate.
If the proper flowrate is not maintained, necessary adjustments shall
be made by the certified person. This examination is not required if
the sampling device is being operated in an anthracite coal mine using
the full box, open breast, or slant breast mining method.
(2) The last hour of operation to assure that the sampling device
is operating properly and at the proper flowrate. If the proper
flowrate is not maintained, the respirable dust sample shall be
transmitted to MSHA with a notation by the certified person on the back
of the dust data card stating that the proper flowrate was not
maintained. Other events occurring during the collection of respirable
dust samples that may affect the validity of the sample, such as
dropping of the sampling head assembly onto the mine floor, shall be
noted on the back of the dust data card.
(c) If using a CPDM, the person certified in sampling shall monitor
the dust concentrations and the sampling status conditions being
reported by the sampling device at mid-shift or more frequently as
specified in the approved mine ventilation plan to assure: The sampling
device is in the proper location and operating properly; and the work
environment of the occupation or DA being sampled remains in compliance
with the applicable standard at the end of the shift. This monitoring
is not required if the sampling device is being operated in an
anthracite coal mine using the full box, open breast, or slant breast
mining method.
Sec. 70.206 Bimonthly sampling; mechanized mining units.
Until January 31, 2016:
(a) Each operator shall take five valid representative samples from
the designated occupation (DO) in each mechanized mining unit (MMU)
during each bimonthly period. DO samples shall be collected on
consecutive normal production shifts or normal production shifts each
of which is worked on consecutive days. The bimonthly periods are:
January 1-February 28 (29)
March 1-April 30
May 1-June 30
July 1-August 31
September 1-October 31
November 1-December 31
(b) Unless otherwise directed by the District Manager, the DO
samples shall be taken by placing the approved sampling device as
specified in paragraphs (b)(1) through (b)(10) of this section.
(1) Conventional section using cutting machine. On the cutting
machine operator or on the cutting machine within 36 inches inby the
normal working position;
(2) Conventional section blasting off the solid. On the loading
machine operator or on the loading machine within 36 inches inby the
normal working position;
(3) Continuous mining section other than auger-type. On the
continuous mining machine operator or on the continuous mining machine
within 36 inches inby the normal working position;
(4) Continuous mining machine; auger-type. On the jacksetter who
works nearest the working face on the return air side of the continuous
mining machine or at a location that represents the maximum
concentration of dust to which the miner is exposed;
(5) Scoop section using cutting machine. On the cutting machine
operator or on the cutting machine within 36 inches inby the normal
working position;
(6) Scoop section, blasting off the solid. On the coal drill
operator or on the coal drill within 36 inches inby the normal working
position;
(7) Longwall section. On the miner who works nearest the return air
side of the longwall working face or along the working face on the
return side within 48 inches of the corner;
(8) Hand loading section with a cutting machine. On the cutting
machine operator or on the cutting machine within 36 inches inby the
normal working position;
(9) Hand loading section blasting off the solid. On the hand loader
exposed to the greatest dust concentration or at a location that
represents the maximum concentration of dust to which the miner is
exposed;
(10) Anthracite mine sections. On the hand loader exposed to the
greatest dust concentration or at a location that represents the
maximum concentration of dust to which the miner is exposed.
(c) When the respirable dust standard is changed in accordance with
Sec. 70.101, the new applicable standard shall become effective 7
calendar days after the date of the notification of the change by MSHA.
(d) If a normal production shift is not achieved, the DO sample for
that shift may be voided by MSHA. However, any sample, regardless of
production, that exceeds the applicable standard by at least 0.1 mg/
m\3\ shall be used in the determination of the equivalent concentration
for that MMU.
(e) When a valid representative sample taken in accordance with
this section meets or exceeds the excessive concentration value (ECV)
in Table 70-1 that corresponds to the applicable standard and
particular sampling device used, the operator shall:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable dust to at or below the applicable respirable dust
standard; and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
(f) Noncompliance with the applicable standard is demonstrated
during the sampling period when:
(1) Two or more valid representative samples meet or exceed the ECV
in Table 70-1 that corresponds to the applicable standard and
particular sampling device used; or
(2) The average for all valid representative samples meets or
exceeds the ECV in Table 70-2 that corresponds to the applicable
standard and particular sampling device used.
(g) Unless otherwise directed by the District Manager, upon
issuance of a citation for a violation of the applicable standard
involving a DO in an MMU, paragraph (a) of this section shall not apply
to that MMU until the violation is abated and the citation is
terminated in accordance with paragraphs (h) and (i) of this section.
(h) Upon issuance of a citation for violation of the applicable
standard, the operator shall take the following actions sequentially:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable coal mine dust to at or below the applicable standard;
and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or
[[Page 24977]]
equivalent mine official, no later than the end of the mine foreman's
or equivalent official's next regularly scheduled working shift. The
record shall be made in a secure book that is not susceptible to
alteration or electronically in a computer system so as to be secure
and not susceptible to alteration. Such records shall be retained at a
surface location at the mine for at least 1 year and shall be made
available for inspection by authorized representatives of the Secretary
and the representative of miners.
(4) Begin sampling, within 8 calendar days after the date the
citation is issued, the environment of the affected occupation in the
MMU on consecutive normal production shifts until five valid
representative samples are taken.
(i) A citation for a violation of the applicable standard shall be
terminated by MSHA when:
(1) Each of the five valid representative samples is at or below
the applicable standard; and
(2) The operator has submitted to the District Manager revised dust
control parameters as part of the mine ventilation plan applicable to
the MMU in the citation, and the changes have been approved by the
District Manager. The revised parameters shall reflect the control
measures used by the operator to abate the violation.
Sec. 70.207 Bimonthly sampling; designated areas.
Until January 31, 2016:
(a) Each operator shall take one valid representative sample from
each designated area (DA) on a production shift during each bimonthly
period. The bimonthly periods are:
February 1-March 31
April 1-May 31
June 1-July 31
August 1-September 30
October 1-November 30
December 1-January 31.
(b) When the respirable dust standard is changed in accordance with
Sec. 70.101, the new applicable standard shall become effective 7
calendar days after the date of the notification of the change by MSHA.
(c) Upon notification from MSHA that any valid sample taken from a
DA to meet the requirements of paragraph (a) of this section exceeds
the applicable standard, the operator shall take five valid
representative samples from that DA within 15 calendar days. The
operator shall begin such sampling on the first day on which there is a
production shift following the day of receipt of notification.
(d) When a valid representative sample taken in accordance with
this section meets or exceeds the ECV in Table 70-1 that corresponds to
the applicable standard and particular sampling device used, the
operator shall:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable coal mine dust to at or below the applicable standard;
and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
(e) Noncompliance with the applicable standard is demonstrated
during the sampling period when:
(1) Two or more valid representative samples meet or exceed the ECV
in Table 70-1 that corresponds to the applicable standard and the
particular sampling device used; or
(2) The average for all valid representative samples meets or
exceeds the ECV in Table 70-2 that corresponds to the applicable
standard and the particular sampling device used.
(f) Unless otherwise directed by the District Manager, upon
issuance of a citation for a violation of the applicable standard,
paragraph (a) of this section shall not apply to that DA until the
violation is abated and the citation is terminated in accordance with
paragraphs (g) and (h) of this section.
(g) Upon issuance of a citation for violation of the applicable
standard, the operator shall take the following actions sequentially:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable coal mine dust to at or below the applicable standard;
and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
(4) Begin sampling, within 8 calendar days after the date the
citation is issued, the environment of the affected DA on consecutive
normal production shifts until five valid representative samples are
taken.
(h) A citation for a violation of the applicable standard shall be
terminated by MSHA when:
(1) Each of the five valid representative samples is at or below
the applicable standard; and
(2) The operator has submitted to the District Manager revised dust
control parameters as part of the mine ventilation plan applicable to
the DA in the citation, and the changes have been approved by the
District Manager. The revised parameters shall reflect the control
measures used by the operator to abate the violation.
Sec. 70.208 Quarterly sampling; mechanized mining units.
On February 1, 2016:
(a) The operator shall sample each calendar quarter:
(1) The designated occupation (DO) in each MMU on consecutive
normal production shifts until 15 valid representative samples are
taken. The District Manager may require additional groups of 15 valid
representative samples when information indicates the operator has not
followed the approved ventilation plan for any MMU.
(2) Each other designated occupation (ODO) specified in paragraphs
(b)(1) through (b)(10) of this section in each MMU or specified by the
District Manager and identified in the approved mine ventilation plan
on consecutive normal production shifts until 15 valid representative
samples are taken. Sampling of each ODO type shall begin after
fulfilling the sampling requirements of paragraph (a)(1) of this
section. When required to sample more than one ODO type, each ODO type
must be sampled over separate time periods during the calendar quarter.
(3) The quarterly periods are:
January 1-March 31
April 1-June 30
July 1-September 30
October 1-December 31.
(b) Unless otherwise directed by the District Manager, the approved
[[Page 24978]]
sampling device shall be worn by the miner assigned to perform the
duties of the DO or ODO specified in paragraphs (b)(1) through (b)(10)
of this section or by the District Manager for each type of MMU.
(1) Conventional section using cutting machine. DO--The cutting
machine operator;
(2) Conventional section blasting off the solid. DO--The loading
machine operator;
(3) Continuous mining section other than auger-type. DO--The
continuous mining (CM) machine operator or mobile bridge operator when
using continuous haulage; ODO--The roof bolting machine operator who
works nearest the working face on the return air side of the continuous
mining machine; the face haulage operators on MMUs using blowing face
ventilation; the face haulage operators on MMUs ventilated by split
intake air (``fishtail ventilation'') as part of a super-section; and
face haulage operators where two continuous mining machines are
operated on an MMU.
(4) Continuous mining section using auger-type machine. DO--The
jacksetter who works nearest the working face on the return air side of
the continuous mining machine;
(5) Scoop section using cutting machine. DO--The cutting machine
operator;
(6) Scoop section, blasting off the solid. DO--The coal drill
operator;
(7) Longwall section. DO--The longwall operator working on the
tailgate side of the longwall mining machine; ODO--The jacksetter who
works nearest the return air side of the longwall working face, and the
mechanic;
(8) Hand loading section with a cutting machine. DO--The cutting
machine operator;
(9) Hand loading section blasting off the solid. DO--The hand
loader exposed to the greatest dust concentration; and
(10) Anthracite mine sections. DO--The hand loader exposed to the
greatest dust concentration.
(c) When the respirable dust standard is changed in accordance with
Sec. 70.101, the new applicable standard shall become effective 7
calendar days after the date of notification of the change by MSHA.
(d) If a normal production shift is not achieved, the DO or ODO
sample for that shift may be voided by MSHA. However, any sample,
regardless of production, that exceeds the applicable standard by at
least 0.1 mg/m\3\ shall be used in the determination of the equivalent
concentration for that occupation.
(e) When a valid representative sample taken in accordance with
this section meets or exceeds the ECV in Table 70-1 that corresponds to
the applicable standard and particular sampling device used, the
operator shall:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable dust to at or below the applicable respirable dust
standard; and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
(f) Noncompliance with the applicable standard is demonstrated
during the sampling period when:
(1) Three or more valid representative samples meet or exceed the
ECV in Table 70-1 that corresponds to the applicable standard and the
particular sampling device used; or
(2) The average for all valid representative samples meets or
exceeds the ECV in Table 70-2 that corresponds to the applicable
standard and the particular sampling device used.
(g)(1) Unless otherwise directed by the District Manager, upon
issuance of a citation for a violation of the applicable standard
involving a DO in an MMU, paragraph (a)(1) shall not apply to the DO in
that MMU until the violation is abated and the citation is terminated
in accordance with paragraphs (h) and (i) of this section.
(2) Unless otherwise directed by the District Manager, upon
issuance of a citation for a violation of the applicable standard
involving a type of ODO in an MMU, paragraph (a)(2) shall not apply to
that ODO type in that MMU until the violation is abated and the
citation is terminated in accordance with paragraphs (h) and (i) of
this section.
(h) Upon issuance of a citation for violation of the applicable
standard, the operator shall take the following actions sequentially:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable coal mine dust to at or below the applicable standard;
and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
(4) Begin sampling, within 8 calendar days after the date the
citation is issued, the environment of the affected occupation in the
MMU on consecutive normal production shifts until five valid
representative samples are taken.
(i) A citation for violation of the applicable standard shall be
terminated by MSHA when:
(1) Each of the five valid representative samples is at or below
the applicable standard; and
(2) The operator has submitted to the District Manager revised dust
control parameters as part of the mine ventilation plan applicable to
the MMU in the citation and the changes have been approved by the
District Manager. The revised parameters shall reflect the control
measures used by the operator to abate the violation.
Sec. 70.209 Quarterly sampling; designated areas.
On February 1, 2016:
(a) The operator shall sample quarterly each designated area (DA)
on consecutive production shifts until five valid representative
samples are taken. The quarterly periods are:
January 1-March 31
April 1-June 30
July 1-September 30
October 1-December 31.
(b) When the respirable dust standard is changed in accordance with
Sec. 70.101, the new applicable standard shall become effective 7
calendar days after the date of the notification of the change by MSHA.
(c) When a valid representative sample taken in accordance with
this section meets or exceeds the ECV in Table 70-1 that corresponds to
the applicable standard and particular
[[Page 24979]]
sampling device used, the operator shall:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable dust to at or below the applicable respirable dust
standard; and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
(d) Noncompliance with the applicable standard is demonstrated
during the sampling period when:
(1) Two or more valid representative samples meet or exceed the ECV
in Table 70-1 that corresponds to the applicable standard and the
particular sampling device used; or
(2) The average for all valid representative samples meets or
exceeds the ECV in Table 70-2 that corresponds to the applicable
standard and particular sampling device used.
(e) Unless otherwise directed by the District Manager, upon
issuance of a citation for a violation of the applicable standard,
paragraph (a) of this section shall not apply to that DA until the
violation is abated and the citation is terminated in accordance with
paragraphs (f) and (g) of this section.
(f) Upon issuance of a citation for a violation of the applicable
standard, the operator shall take the following actions sequentially:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable coal mine dust to at or below the applicable standard;
and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
(4) Begin sampling, within 8 calendar days after the date the
citation is issued, the environment of the affected DA on consecutive
normal production shifts until five valid representative samples are
taken.
(g) A citation for a violation of the applicable standard shall be
terminated by MSHA when:
(1) Each of the five valid representative samples is at or below
the applicable standard; and
(2) The operator has submitted to the District Manager revised dust
control parameters as part of the mine ventilation plan applicable to
the DA in the citation, and the changes have been approved by the
District Manager. The revised parameters shall reflect the control
measures used by the operator to abate the violation.
Sec. 70.210 Respirable dust samples; transmission by operator.
(a) If using a CMDPSU, the operator shall transmit within 24 hours
after the end of the sampling shift all samples collected to fulfill
the requirements of this part, including control filters, in containers
provided by the manufacturer of the filter cassette to: Respirable Dust
Processing Laboratory, Pittsburgh Safety and Health Technology Center,
Cochrans Mill Road, Building 38, P.O. Box 18179, Pittsburgh,
Pennsylvania 15236-0179, or to any other address designated by the
District Manager.
(b) The operator shall not open or tamper with the seal of any
filter cassette or alter the weight of any filter cassette before or
after it is used to fulfill the requirements of this part.
(c) A person certified in sampling shall properly complete the dust
data card that is provided by the manufacturer for each filter
cassette. The card shall have an identification number identical to
that on the cassette used to take the sample and be submitted to MSHA
with the sample. Each card shall be signed by the certified person who
actually performed the required examinations under 70.205(b) of this
part during the sampling shift and shall include that person's MSHA
Individual Identification Number (MIIN). Respirable dust samples with
data cards not properly completed may be voided by MSHA.
(d) All respirable dust samples collected by the operator shall be
considered taken to fulfill the sampling requirements of part 70, 71,
or 90 of this title, unless the sample has been identified in writing
by the operator to the District Manager, prior to the intended sampling
shift, as a sample to be used for purposes other than required by part
70, 71, or 90 of this title.
(e) Respirable dust samples received by MSHA in excess of those
required by this part shall be considered invalid samples.
(f) If using a CPDM, the person certified in sampling shall (1)
validate, certify, and transmit electronically to MSHA within 24 hours
after the end of each sampling shift all sample data file information
collected and stored in the CPDM, including the sampling status
conditions encountered when sampling; and (2) not tamper with the CPDM
or its components in any way before, during, or after it is used to
fulfill the requirements of this part, or alter any sample data files.
All CPDM data files transmitted electronically to MSHA shall be
maintained by the operator for at least 12 months.
Sec. 70.211 Respirable dust samples; report to operator; posting.
(a) MSHA shall provide the operator, as soon as practicable, a
report with the following data on respirable dust samples submitted or
whose results were transmitted electronically, if using a CPDM, in
accordance with this part:
(1) The mine identification number;
(2) The locations within the mine from which the samples were
taken;
(3) The concentration of respirable dust, expressed as an
equivalent concentration for each valid sample;
(4) The average equivalent concentration of respirable dust for all
valid samples;
(5) The occupation code, where applicable; and
(6) The reason for voiding any sample.
(b) Upon receipt, the operator shall post this data for at least 31
days on the mine bulletin board.
(c) If using a CPDM, the person certified in sampling shall, within
12 hours after the end of each sampling shift, print, sign, and post on
the mine bulletin board a paper record (Dust Data Card) of the sample
run. This hard-copy record shall include the data entered when the
sample run was first programmed, and the following:
(1) The mine identification number;
(2) The locations within the mine from which the samples were
taken;
(3) The concentration of respirable dust, expressed as an
equivalent concentration reported and stored for each sample;
[[Page 24980]]
(4) The sampling status conditions encountered for each sample; and
(5) The shift length.
(d) The information required by paragraph (c) of this section shall
remain posted until receipt of the MSHA report covering these
respirable dust samples.
Sec. 70.212 Status change reports.
(a) If there is a change in operational status that affects the
respirable dust sampling requirements of this part, the operator shall
report the change in operational status of the mine, mechanized mining
unit, or designated area to the MSHA District Office or to any other
MSHA office designated by the District Manager. Status changes shall be
reported in writing or electronically within 3 working days after the
status change has occurred.
(b) Each specific operational status is defined as follows:
(1) Underground mine:
(i) Producing--has at least one MMU unit producing material.
(ii) Nonproducing--no material is being produced.
(iii) Abandoned--the work of all miners has been terminated and
production activity has ceased.
(2) MMU:
(i) Producing--producing material from a working section.
(ii) Nonproducing--temporarily ceased production of material.
(iii) Abandoned--permanently ceased production of material.
(3) DA:
(i) Producing--activity is occurring.
(ii) Nonproducing--activity has ceased.
(iii) Abandoned--the dust generating source has been withdrawn and
activity has ceased.
Tables to Subpart C
Table 70-1--Excessive Concentration Values (ECV) Based on Single, Full-
Shift CMDPSU/CPDM Concentration Measurements
------------------------------------------------------------------------
ECV (mg/m\3\)
Applicable standard (mg/m\3\) -------------------------
CMDPSU CPDM
------------------------------------------------------------------------
2.0........................................... 2.33 2.26
1.9........................................... 2.22 2.15
1.8........................................... 2.12 2.04
1.7........................................... 2.01 1.92
1.6........................................... 1.90 1.81
1.5........................................... 1.79 1.70
1.4........................................... 1.69 1.58
1.3........................................... 1.59 1.47
1.2........................................... 1.47 1.36
1.1........................................... 1.37 1.25
1.0........................................... 1.26 1.13
0.9........................................... 1.16 1.02
0.8........................................... 1.05 0.91
0.7........................................... 0.95 0.79
0.6........................................... 0.85 0.68
0.5........................................... 0.74 0.57
0.4........................................... 0.65 0.46
0.3........................................... 0.54 0.34
0.2........................................... 0.44 0.23
------------------------------------------------------------------------
Table 70-2--Excessive Concentration Values (ECV) Based on the Average of 5 or 15 Full-Shift CMDPSU/CPDM
Concentration Measurements
----------------------------------------------------------------------------------------------------------------
ECV (mg/m\3\) based on ECV (mg/m\3\) based on
5-sample average 15-sample average
Applicable standard (mg/m\3\) ---------------------------------------------------
CMDPSU CPDM CMDPSU CPDM
----------------------------------------------------------------------------------------------------------------
2.0......................................................... 2.15 2.12 2.09 2.07
1.9......................................................... 2.05 2.01 1.99 1.97
1.8......................................................... 1.94 1.91 1.89 1.87
1.7......................................................... 1.84 1.80 1.78 1.76
1.6......................................................... 1.74 1.70 1.68 1.66
1.5......................................................... 1.63 1.59 1.58 1.56
1.4......................................................... 1.53 1.49 1.48 1.45
1.3......................................................... 1.43 1.38 1.38 1.35
1.2......................................................... 1.33 1.27 1.28 1.25
1.1......................................................... 1.22 1.17 1.17 1.14
1.0......................................................... 1.12 1.06 1.07 1.04
0.9......................................................... 1.02 0.96 0.97 0.94
0.8......................................................... 0.92 0.85 0.87 0.83
0.7......................................................... 0.81 0.75 0.77 0.73
0.6......................................................... 0.71 0.64 0.67 0.63
0.5......................................................... 0.61 0.53 0.57 0.52
0.4......................................................... 0.51 0.43 0.47 0.42
0.3......................................................... 0.41 0.32 0.37 0.32
0.2......................................................... 0.31 0.22 0.27 0.21
----------------------------------------------------------------------------------------------------------------
Subpart D--[Removed and Reserved]
0
5. Subpart D to part 70 is removed and reserved.
PART 71--MANDATORY HEALTH STANDARDS FOR SURFACE COAL MINES AND
SURFACE WORK AREAS OF UNDERGROUND COAL MINES
0
6. The authority citation for part 71 is revised to read as follows:
Authority: 30 U.S.C. 811, 813(h), 957.
0
7. Subpart A to part 71 is revised to read as follows:
Subpart A--General
Sec.
71.1 Scope.
71.2 Definitions.
Subpart A--General
Sec. 71.1 Scope.
This part 71 sets forth mandatory health standards for each surface
coal mine and for the surface work areas of each underground coal mine
subject to the Federal Mine Safety and Health Act of 1977, as amended.
Sec. 71.2 Definitions.
The following definitions apply in this part.
[[Page 24981]]
Act. The Federal Mine Safety and Health Act of 1977, Public Law 91-
173, as amended by Public Law 95-164 and Public Law 109-236.
Active workings. Any place in a surface coal mine or the surface
work area of an underground coal mine where miners are normally
required to work or travel.
Approved sampling device. A sampling device approved by the
Secretary and Secretary of Health and Human Services (HHS) under part
74 of this title.
Certified person. An individual certified by the Secretary in
accordance with Sec. 71.202 to take respirable dust samples required
by this part or certified in accordance with Sec. 71.203 to perform
maintenance and calibration of respirable dust sampling equipment as
required by this part.
Coal mine dust personal sampler unit (CMDPSU). A personal sampling
device approved under part 74, subpart B, of this title.
Concentration. A measure of the amount of a substance contained per
unit volume of air.
Continuous personal dust monitor (CPDM). A personal sampling device
approved under part 74, subpart C, of this title.
Designated work position (DWP). A work position in a surface coal
mine and surface work area of an underground coal mine designated for
sampling to measure respirable dust generation sources in the active
workings. Each DWP will be assigned a four-digit number assigned by
MSHA identifying the specific physical portion of the mine that is
affected, followed by a three-digit MSHA coal mining occupation code
describing the location to which a miner is assigned in the performance
of his or her regular duties.
District Manager. The manager of the Coal Mine Safety and Health
District in which the mine is located.
Equivalent concentration. The concentration of respirable coal mine
dust, including quartz, expressed in milligrams per cubic meter of air
(mg/m\3\) as measured with an approved sampling device, determined by
dividing the weight of dust in milligrams collected on the filter of an
approved sampling device by the volume of air in cubic meters passing
through the filter (sampling time in minutes (t) times the sampling
airflow rate in cubic meters per minute), and then converting that
concentration to an equivalent concentration as measured by the Mining
Research Establishment (MRE) instrument. When the approved sampling
device is:
(1) The CMDPSU, the equivalent concentration is determined by
multiplying the concentration of respirable coal mine dust by the
constant factor prescribed by the Secretary.
(2) The CPDM, the device shall be programmed to automatically
report end-of-shift concentration measurements as equivalent
concentrations.
MRE instrument. The gravimetric dust sampler with a four channel
horizontal elutriator developed by the Mining Research Establishment of
the National Coal Board, London, England.
MSHA. The Mine Safety and Health Administration of the U.S.
Department of Labor.
Normal work shift. (1) A shift during which the regular duties of
the DWP are performed while routine day-to-day mining activities are
occurring in the rest of the mine and
(2) A shift during which there is no rain, or, if rain occurs, the
rain does not suppress the respirable dust to the extent that sampling
results will be measurably lower, in the judgment of the person
certified under this part to conduct sampling.
Quartz. Crystalline silicon dioxide (SiO2) not
chemically combined with other substances and having a distinctive
physical structure.
Representative sample. A respirable dust sample, expressed as an
equivalent concentration, that reflects typical dust concentration
levels in the working environment of the DWP when performing normal
duties.
Respirable dust. Dust collected with a sampling device approved by
the Secretary and the Secretary of HHS in accordance with part 74 (Coal
Mine Dust Sampling Devices) of this title.
Secretary. The Secretary of Labor or a delegate.
Surface area. A specific physical portion of a surface coal mine or
surface area of an underground coal mine. These areas are assigned a
four-digit identification number by MSHA.
Surface coal mine. A surface area of land and all structures,
facilities, machinery, tools, equipment, excavations, and other
property, real or personal, placed upon or above the surface of such
land by any person, used in, or to be used in, or resulting from, the
work of extracting in such area bituminous coal, lignite, or anthracite
from its natural deposits in the earth by any means or method, and the
work of preparing the coal so extracted, including custom coal
preparation facilities.
Surface installation. Any structure in which miners work at a
surface coal mine or surface work area of an underground coal mine.
Surface work area of an underground mine. The surface areas of land
and all structures, facilities, machinery, tools, equipment, shafts,
slopes, excavations, and other property, real or personal, placed in,
upon or above the surface of such land by any person, used in, or to be
used in, or resulting from, the work of extracting bituminous coal,
lignite, or anthracite from its natural deposits underground by any
means or method, and the work of preparing the coal so extracted,
including custom coal preparation facilities.
Surface worksite. Any area in which miners work at a surface coal
mine or surface work area of an underground coal mine.
Valid respirable dust sample. A respirable dust sample collected
and submitted as required by this part, including any sample for which
the data were electronically transmitted to MSHA, and not voided by
MSHA.
Work position. An occupation identified by an MSHA three-digit code
number describing a location to which a miner is assigned in the
performance of his or her normal duties.
0
8. Subpart B to part 71 is revised to read as follows:
Subpart B--Dust Standards
Sec.
71.100 Respirable dust standard.
71.101 Respirable dust standard when quartz is present.
Subpart B--Dust Standards
Sec. 71.100 Respirable dust standard.
Each operator shall continuously maintain the average concentration
of respirable dust in the mine atmosphere during each shift to which
each miner in the active workings of each mine is exposed, as measured
with an approved sampling device and expressed in terms of an
equivalent concentration, at or below:
(a) 2.0 milligrams of respirable dust per cubic meter of air (mg/
m\3\).
(b) 1.5 mg/m\3\ as of August 1, 2016.
Sec. 71.101 Respirable dust standard when quartz is present.
(a) Each operator shall continuously maintain the average
concentration of respirable quartz dust in the mine atmosphere during
each shift to which each miner in the active workings of each mine is
exposed at or below 0.1 mg/m\3\ (100 micrograms per cubic meter or
[mu]g/m\3\) as measured with an approved sampling device and expressed
in terms of an equivalent concentration.
(b) When the equivalent concentration of respirable quartz dust
exceeds 100
[[Page 24982]]
[mu]g/m\3\, the operator shall continuously maintain the average
concentration of respirable dust in the mine atmosphere during each
shift to which each miner in the active workings is exposed as measured
with an approved sampling device and expressed in terms of an
equivalent concentration at or below the applicable standard. The
applicable standard is computed by dividing the percent of quartz into
the number 10. The application of this formula shall not result in the
applicable standard that exceeds the standard established by Sec.
71.100(a) of this section.
Example: Assume the sampled DWP is on a 1.5-mg/m\3\ dust
standard. Suppose a valid representative dust sample with an
equivalent concentration of 1.09 mg/m\3\ contains 16.7% of quartz
dust, which corresponds to a quartz concentration of 182 [mu]g/m\3\.
Therefore, the average concentration of respirable dust in the mine
atmosphere associated with that DWP shall be maintained on each
shift at or below 0.6 mg/m\3\ (10/16.7% = 0.6 mg/m\3\).
0
9. Subpart C to part 71 is revised to read as follows:
Subpart C--Sampling Procedures
Sec.
71.201 Sampling; general and technical requirements.
71.202 Certified person; sampling.
71.203 Certified person; maintenance and calibration.
71.204 Approved sampling devices; maintenance and calibration.
71.205 Approved sampling devices; operation; air flowrate.
71.206 Quarterly sampling; designated work positions.
71.207 Respirable dust samples; transmission by operator.
71.208 Respirable dust samples; report to operator; posting.
71.209 Status change reports.
Subpart C--Sampling Procedures
Sec. 71.201 Sampling; general and technical requirements.
(a) Each operator shall take representative samples of the
concentration of respirable dust in the active workings of the mine as
required by this part only with an approved CMDPSU. On February 1,
2016, the operator may use an approved CPDM if the operator notifies
the District Manager in writing that only an approved CPDM will be used
for all DWP sampling at the mine. The notification must be received at
least 90 days before the beginning of the quarter in which CPDMs will
be used to collect the DWP samples.
(b) Sampling devices shall be worn or carried directly to and from
the DWP to be sampled. Sampling devices shall remain with the DWP and
shall be operational during the entire shift, which includes the total
time spent in the DWP and while traveling to and from the DWP being
sampled. If the work shift to be sampled is longer than 12 hours and
the sampling device is:
(1) A CMDPSU, the operator shall switch-out the unit's sampling
pump prior to the 13th-hour of operation.
(2) A CPDM, the operator shall switch-out the CPDM with a fully
charged device prior to the 13th-hour of operation.
(c) If using a CMDPSU, one control filter shall be used for each
shift of sampling. Each control filter shall:
(1) Have the same pre-weight data (noted on the dust data card) as
the filters used for sampling;
(2) Remain plugged at all times;
(3) Be used for the same amount of time, and exposed to the same
temperature and handling conditions as the filters used for sampling;
and
(4) Be kept with the exposed samples after sampling and in the same
mailing container when transmitted to MSHA.
(d) Records showing the length of each normal work shift for each
DWP shall be made and retained for at least six months and shall be
made available for inspection by authorized representatives of the
Secretary and the representative of miners, and submitted to the
District Manager when requested in writing.
(e) Upon request from the District Manager, the operator shall
submit the date and time any respirable dust sampling required by this
part will begin. This information shall be submitted at least 48 hours
prior to scheduled sampling.
(f) Upon written request by the operator, the District Manager may
waive the rain restriction for a normal work shift as defined in Sec.
71.2 for a period not to exceed two months, if the District Manager
determines that:
(1) The operator will not have reasonable opportunity to complete
the respirable dust sampling required by this part without the waiver
because of the frequency of rain; and
(2) The operator did not have reasonable opportunity to complete
the respirable dust sampling required by this part prior to requesting
the waiver.
(g) Operators using CPDMs shall provide training to all miners
expected to wear the CPDM. The training shall be completed prior to a
miner wearing the CPDM and then every 12 months thereafter. The
training shall include:
(1) The importance of monitoring dust concentrations and properly
wearing the CPDM;
(2) Explaining the basic features and capabilities of the CPDM;
(3) Discussing the various types of information displayed by the
CPDM and how to access that information; and
(4) How to start and stop a short-term sample run during compliance
sampling.
(h) An operator shall keep a record of the CPDM training at the
mine site for 24 months after completion of the training. An operator
may keep the record elsewhere if the record is immediately accessible
from the mine site by electronic transmission. Upon request from an
authorized representative of the Secretary, Secretary of HHS, or
representative of miners, the operator shall promptly provide access to
any such training records. The record shall include:
(1) The date of training;
(2) The names of miners trained; and
(3) The subjects included in the training.
Sec. 71.202 Certified person; sampling.
(a) The respirable dust sampling required by this part shall be
performed by a certified person.
(b) To be certified, a person shall complete the applicable MSHA
course of instruction and pass the MSHA examination demonstrating
competency in sampling procedures. Persons not certified in sampling,
and those certified only in maintenance and calibration procedures in
accordance with Sec. 71.203(b), are not permitted to collect
respirable dust samples required by this part or handle approved
sampling devices when being used in sampling.
(c) To maintain certification, a person must pass the MSHA
examination demonstrating competency in sampling procedures every three
years.
(d) MSHA may revoke a person's certification for failing to
properly carry out the required sampling procedures.
Sec. 71.203 Certified person; maintenance and calibration.
(a) Approved sampling devices shall be maintained and calibrated by
a certified person.
(b) To be certified, a person shall complete the applicable MSHA
course of instruction and pass the MSHA examination demonstrating
competency in maintenance and calibration procedures for approved
sampling devices. Necessary maintenance of the sampling head assembly
of a CMDPSU, or the cyclone assembly of a CPDM, can be performed by
persons certified in sampling or maintenance and calibration.
(c) To maintain certification, a person must pass the MSHA
examination demonstrating competency in maintenance and calibration
procedures every three years.
[[Page 24983]]
(d) MSHA may revoke a person's certification for failing to
properly carry out the required maintenance and calibration procedures.
Sec. 71.204 Approved sampling devices; maintenance and calibration.
(a) Approved sampling devices shall be maintained as approved under
part 74 of this chapter and calibrated in accordance with MSHA
Informational Report IR 1240 (1996) ``Calibration and Maintenance
Procedures for Coal Mine Respirable Dust Samplers'' or in accordance
with the manufacturer's recommendations if using a CPDM. Only persons
certified in maintenance and calibration can perform maintenance work
on the CPDM or on the pump unit of the CMDPSU.
(b) Sampling devices shall be calibrated at the flowrate of 2.0
liters of air per minute (L/min) if using a CMDPSU, or at 2.2 L/min if
using a CPDM, or at a different flowrate recommended by the
manufacturer, before they are put into service and, thereafter, at time
intervals recommended by the manufacturer or prescribed by the
Secretary or Secretary of HHS.
(c) If using a CMDPSU, sampling devices shall be examined and
tested by a person certified in sampling or in maintenance and
calibration within 3 hours before the start of the shift on which the
approved sampling devices will be used to collect respirable dust
samples. This is to assure that the sampling devices are clean and in
proper working condition. This examination and testing shall include
the following:
(1) Examination of all components of the cyclone assembly to assure
that they are clean and free of dust and dirt. This includes examining
the interior of the connector barrel (located between the cassette
assembly and vortex finder), vortex finder, cyclone body, and grit pot;
(2) Examination of the inner surface of the cyclone body to assure
that it is free of scoring or scratch marks on the inner surface of the
cyclone where the air flow is directed by the vortex finder into the
cyclone body;
(3) Examination of the external hose connecting the pump unit to
the sampling head assembly to assure that it is clean and free of
leaks; and
(4) Examination of the clamping and positioning of the cyclone
body, vortex finder, and cassette to assure that they are rigid, in
alignment, firmly in contact, and airtight.
(5) Testing the voltage of each battery while under actual load to
assure the battery is fully charged. This requires that a fully
assembled and examined sampling head assembly be attached to the pump
inlet with the pump unit running when the voltage check is made. The
voltage for the batteries used in the CMDPSU shall not be lower than
the product of the number of cells in the battery multiplied by the
manufacturer's nominal voltage per cell value.
(d) If using a CPDM, the certified person in sampling or in
maintenance and calibration shall:
(1) Follow the pre-operational examinations, testing, and set-up
procedures, and perform necessary external maintenance recommended by
the manufacturer to assure the operational readiness of the CPDM within
3 hours before the start of the shift on which the sampling devices
will be used to collect respirable dust samples; and
(2) Perform other required scheduled examinations and maintenance
procedures recommended by the manufacturer.
(e) You must proceed in accordance with ``Calibration and
Maintenance Procedures for Coal Mine Respirable Dust Samplers,'' MSHA
Informational Report IR 1240 (1996) referenced in paragraph (a) of this
section. The Director of the Federal Register approves this
incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. You may obtain a copy from the MSHA Web site at http://www.msha.gov and you may inspect or obtain a copy at MSHA, Coal Mine
Safety and Health, 1100 Wilson Blvd., Room 2424, Arlington, Virginia
22209-3939 and at each MSHA Coal Mine Safety and Health District
Office, or at the National Archives and Records Administration (NARA).
For information on the availability of this material at NARA, call 202-
741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
Sec. 71.205 Approved sampling devices; operation; air flowrate.
(a) Approved sampling devices shall be operated at the flowrate of
2.0 L/min, if using a CMDPSU; at 2.2 L/min, if using a CPDM; or at a
different flowrate recommended by the manufacturer.
(b) If using a CMDPSU, each sampling device shall be examined each
shift by a person certified in sampling during:
(1) The second hour after being put into operation to assure it is
in the proper location, operating properly, and at the proper flowrate.
If the proper flowrate is not maintained, necessary adjustments shall
be made by the certified person.
(2) The last hour of operation to assure that it is operating
properly and at the proper flowrate. If the proper flowrate is not
maintained, the respirable dust sample shall be transmitted to MSHA
with a notation by the certified person on the back of the dust data
card stating that the proper flowrate was not maintained. Other events
occurring during the collection of respirable dust samples that may
affect the validity of the sample, such as dropping of the sampling
head assembly onto the mine floor, shall be noted on the back of the
dust data card.
(c) If using a CPDM, the person certified in sampling shall monitor
the dust concentrations and the sampling status conditions being
reported by the sampling device at mid-shift or more frequently as
specified in the approved respirable dust control plan, if applicable,
to assure: The sampling device is in the proper location and operating
properly; and the work environment of the occupation being sampled
remains in compliance with the applicable standard at the end of the
shift.
Sec. 71.206 Quarterly sampling; designated work positions.
(a) Each operator shall take one valid representative sample from
the DWP during each quarterly period. The quarterly periods are:
January 1-March 31
April 1-June 30
July 1-September 30
October 1-December 31.
(b) When the respirable dust standard is changed in accordance with
Sec. 71.101, the new applicable standard shall become effective 7
calendar days after the date of the notification of the change by MSHA.
(c) Designated work position samples shall be collected at
locations to measure respirable dust generation sources in the active
workings. The specific work positions at each mine where DWP samples
shall be collected include:
(1) Each highwall drill operator (MSHA occupation code 384);
(2) Bulldozer operators (MSHA occupation code 368); and
(3) Other work positions designated by the District Manager for
sampling in accordance with Sec. 71.206(m).
(d) Operators with multiple work positions specified in paragraph
(c)(2) and (c)(3) of this section shall sample the DWP exposed to the
greatest respirable dust concentration in each work position performing
the same activity or task at the same location at the mine and exposed
to the same dust generation source. Each operator shall
[[Page 24984]]
provide the District Manager with a list identifying the specific work
positions where DWP samples will be collected for:
(1) Active mines--by October 1, 2014.
(2) New mines--Within 30 calendar days of mine opening.
(3) DWPs with a change in operational status that increases or
reduces the number of active DWPs--within 7 calendar days of the change
in status.
(e) Each DWP sample shall be taken on a normal work shift. If a
normal work shift is not achieved, the respirable dust sample shall be
transmitted to MSHA with a notation by the person certified in sampling
on the back of the dust data card stating that the sample was not taken
on a normal work shift. When a normal work shift is not achieved, the
sample for that shift may be voided by MSHA. However, any sample,
regardless of whether a normal work shift was achieved, that exceeds
the applicable standard by at least 0.1 mg/m\3\ shall be used in the
determination of the equivalent concentration for that occupation.
(f) Unless otherwise directed by the District Manager, DWP samples
shall be taken by placing the sampling device as follows:
(1) Equipment operator: On the equipment operator or on the
equipment within 36 inches of the operator's normal working position.
(2) Non-equipment operators: On the miner assigned to the DWP or at
a location that represents the maximum concentration of dust to which
the miner is exposed.
(g) Upon notification from MSHA that any valid representative
sample taken from a DWP to meet the requirements of paragraph (a) of
this section exceeds the applicable standard, the operator shall,
within 15 calendar days of notification, sample that DWP each normal
work shift until five valid representative samples are taken. The
operator shall begin sampling on the first normal work shift following
receipt of notification.
(h) When a valid representative sample taken in accordance with
this section meets or exceeds the excessive concentration value (ECV)
in Table 71-1 that corresponds to the applicable standard and
particular sampling device used, the operator shall:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable coal mine dust to at or below the applicable standard;
and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
(i) Noncompliance with the applicable standard is demonstrated
during the sampling period when:
(1) Two or more valid representative samples meet or exceed the ECV
in Table 71-1 that corresponds to the applicable standard and the
particular sampling device used; or
(2) The average for all valid representative samples meets or
exceeds the ECV in Table 71-2 that corresponds to the applicable
standard and the particular sampling device used.
(j) Unless otherwise directed by the District Manager, upon
issuance of a citation for a violation of the applicable standard,
paragraph (a) of this section shall not apply to that DWP until the
violation is abated and the citation is terminated in accordance with
paragraphs (k) and (l) of this section.
(k) Upon issuance of a citation for violation of the applicable
standard, the operator shall take the following actions sequentially:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable coal mine dust to at or below the applicable standard;
and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the representative of miners.
(4) Begin sampling, within 8 calendar days after the date the
citation is issued, the environment of the affected DWP on consecutive
normal work shifts until five valid representative samples are taken.
(l) A citation for violation of the applicable standard shall be
terminated by MSHA when the equivalent concentration of each of the
five valid representative samples is at or below the applicable
standard.
Table 71-1--Excessive Concentration Values (ECV) Based on Single, Full-
Shift CMDPSU/CPDM Concentration Measurements
------------------------------------------------------------------------
ECV (mg/m\3\)
Applicable standard (mg/m\3\) -------------------------------
CMDPSU CPDM
------------------------------------------------------------------------
2.0..................................... 2.33 2.26
1.9..................................... 2.22 2.15
1.8..................................... 2.12 2.04
1.7..................................... 2.01 1.92
1.6..................................... 1.90 1.81
1.5..................................... 1.79 1.70
1.4..................................... 1.69 1.58
1.3..................................... 1.59 1.47
1.2..................................... 1.47 1.36
1.1..................................... 1.37 1.25
1.0..................................... 1.26 1.13
0.9..................................... 1.16 1.02
0.8..................................... 1.05 0.91
0.7..................................... 0.95 0.79
0.6..................................... 0.85 0.68
0.5..................................... 0.74 0.57
0.4..................................... 0.65 0.46
0.3..................................... 0.54 0.34
0.2..................................... 0.44 0.23
------------------------------------------------------------------------
Table 71-2--Excessive Concentration Values (ECV) Based on the Average of
5 Full-Shift CMDPSU/CPDM Concentration Measurements
------------------------------------------------------------------------
ECV (mg/m\3\)
Applicable standard (mg/m\3\) -------------------------------
CMDPSU CPDM
------------------------------------------------------------------------
2.0..................................... 2.15 2.12
1.9..................................... 2.05 2.01
1.8..................................... 1.94 1.91
1.7..................................... 1.84 1.80
1.6..................................... 1.74 1.70
1.5..................................... 1.63 1.59
1.4..................................... 1.53 1.49
1.3..................................... 1.43 1.38
1.2..................................... 1.33 1.27
1.1..................................... 1.22 1.17
1.0..................................... 1.12 1.06
0.9..................................... 1.02 0.96
0.8..................................... 0.92 0.85
0.7..................................... 0.81 0.75
0.6..................................... 0.71 0.64
0.5..................................... 0.61 0.53
0.4..................................... 0.51 0.43
0.3..................................... 0.41 0.32
0.2..................................... 0.31 0.22
------------------------------------------------------------------------
(m) The District Manager may designate for sampling under this
section additional work positions at a
[[Page 24985]]
surface coal mine and at a surface work area of an underground coal
mine where a concentration of respirable dust exceeding 50 percent of
the standard in effect at the time the sample is taken, or a
concentration of respirable dust exceeding 50 percent of the standard
established in accordance with Sec. 71.101, has been measured by one
or more MSHA valid representative samples.
(n) The District Manager may withdraw from sampling any DWP
designated for sampling under paragraph (m) of this section upon
finding that the operator is able to maintain continuing compliance
with the applicable standard. This finding shall be based on the
results of MSHA and operator valid representative samples taken during
at least a 12-month period.
Sec. 71.207 Respirable dust samples; transmission by operator.
(a) If using a CMDPSU, the operator shall transmit within 24 hours
after the end of the sampling shift all samples collected to fulfill
the requirements of this part, including control filters, in containers
provided by the manufacturer of the filter cassette to: Respirable Dust
Processing Laboratory, Pittsburgh Safety and Health Technology Center,
Cochrans Mill Road, Building 38, P.O. Box 18179, Pittsburgh,
Pennsylvania 15236-0179, or to any other address designated by the
District Manager.
(b) The operator shall not open or tamper with the seal of any
filter cassette or alter the weight of any filter cassette before or
after it is used to fulfill the requirements of this part.
(c) A person certified in sampling shall properly complete the dust
data card that is provided by the manufacturer for each filter
cassette. The card shall have an identification number identical to
that on the cassette used to take the sample and be submitted to MSHA
with the sample. Each card shall be signed by the certified person who
actually performed the required examinations under 71.205(b) of this
part during the sampling shift and shall include that person's MSHA
Individual Identification Number (MIIN). Respirable dust samples with
data cards not properly completed may be voided by MSHA.
(d) All respirable dust samples collected by the operator shall be
considered taken to fulfill the sampling requirements of part 70, 71,
or 90 of this title, unless the sample has been identified in writing
by the operator to the District Manager, prior to the intended sampling
shift, as a sample to be used for purposes other than required by part
70, 71, or 90 of this title.
(e) Respirable dust samples received by MSHA in excess of those
required by this part shall be considered invalid samples.
(f) If using a CPDM, the person certified in sampling shall (1)
validate, certify, and transmit electronically to MSHA within 24 hours
after the end of each sampling shift all sample data file information
collected and stored in the CPDM, including the sampling status
conditions encountered when sampling each DWP; and (2) not tamper with
the CPDM or its components in any way before, during, or after it is
used to fulfill the requirements of this part, or alter any sample data
files. All CPDM data files transmitted electronically to MSHA shall be
maintained by the operator for at least 12 months.
Sec. 71.208 Respirable dust samples; report to operator; posting.
(a) MSHA shall provide the operator, as soon as practicable, a
report with the following data on respirable dust samples submitted or
whose results were transmitted electronically, if using a CPDM, in
accordance with this part:
(1) The mine identification number;
(2) The DWP at the mine from which the samples were taken;
(3) The concentration of respirable dust, expressed as an
equivalent concentration for each valid sample;
(4) The average equivalent concentration of respirable dust for all
valid samples;
(5) The occupation code; and
(6) The reason for voiding any sample.
(b) Upon receipt, the operator shall post this data for at least 31
days on the mine bulletin board.
(c) If using a CPDM, the person certified in sampling shall, within
12 hours after the end of each sampling shift, print, sign, and post on
the mine bulletin board a paper record (Dust Data Card) of each sample
run. This hard-copy record shall include the data entered when the
sample run was first programmed, and the following:
(1) The mine identification number;
(2) The DWP at the mine from which the samples were taken;
(3) The concentration of respirable dust, expressed as an
equivalent concentration reported and stored for each sample;
(4) The sampling status conditions encountered for each sample; and
(5) The shift length.
(d) The information required by paragraph (c) of this section shall
remain posted until receipt of the MSHA report covering these
respirable dust samples.
Sec. 71.209 Status change reports.
(a) If there is a change in operational status that affects the
respirable dust sampling requirements of this part, the operator shall
report the change in operational status of the mine or DWP to the MSHA
District Office or to any other MSHA office designated by the District
Manager. Status changes shall be reported in writing or electronically
within 3 working days after the status change has occurred.
(b) Each specific operational status is defined as follows:
(1) Underground mine:
(i) Producing--has at least one mechanized mining unit producing
material.
(ii) Nonproducing--no material is being produced.
(iii) Abandoned--the work of all miners has been terminated and
production activity has ceased.
(2) Surface mine:
(i) Producing--normal activity is occurring and coal is being
produced or processed or other material or equipment is being handled
or moved.
(ii) Nonproducing--normal activity is not occurring and coal is not
being produced or processed, and other material or equipment is not
being handled or moved.
(iii) Abandoned--the work of all miners has been terminated and all
activity has ceased.
(3) DWP:
(i) Producing--normal activity is occurring.
(ii) Nonproducing--normal activity is not occurring.
(iii) Abandoned--the dust generating source has been withdrawn and
activity has ceased.
0
10. Subpart D to part 71 is revised to read as follows:
Subpart D--Respirable Dust Control Plans
Sec.
71.300 Respirable dust control plan; filing requirements.
71.301 Respirable dust control plan; approval by District Manager
and posting.
Subpart D--Respirable Dust Control Plans
Sec. 71.300 Respirable dust control plan; filing requirements.
(a) Within 15 calendar days after the termination date of a
citation for violation of the applicable standard, the operator shall
submit to the District Manager for approval a written respirable dust
control plan applicable to the DWP identified in the citation. The
respirable dust control plan and revisions thereof shall be suitable to
the conditions and the mining system of the
[[Page 24986]]
coal mine and shall be adequate to continuously maintain respirable
dust to at or below the applicable standard at the DWP identified in
the citation.
(1) The mine operator shall notify the representative of miners at
least 5 days prior to submission of a respirable dust control plan and
any revision to a dust control plan. If requested, the mine operator
shall provide a copy to the representative of miners at the time of
notification;
(2) A copy of the proposed respirable dust control plan, and a copy
of any proposed revision, submitted for approval shall be made
available for inspection by the representative of miners; and
(3) A copy of the proposed respirable dust control plan, and a copy
of any proposed revision, submitted for approval shall be posted on the
mine bulletin board at the time of submittal. The proposed plan or
proposed revision shall remain posted until it is approved, withdrawn,
or denied.
(4) Following receipt of the proposed plan or proposed revision,
the representative of miners may submit timely comments to the District
Manager, in writing, for consideration during the review process. Upon
request, a copy of these comments shall be provided to the operator by
the District Manager.
(b) Each respirable dust control plan shall include at least the
following:
(1) The mine identification number and DWP number assigned by MSHA,
the operator's name, mine name, mine address, and mine telephone number
and the name, address, and telephone number of the principal officer in
charge of health and safety at the mine;
(2) The specific DWP at the mine to which the plan applies;
(3) A detailed description of the specific respirable dust control
measures used to abate the violation of the respirable dust standard;
and
(4) A detailed description of how each of the respirable dust
control measures described in response to paragraph (b)(3) of this
section will continue to be used by the operator, including at least
the specific time, place and manner the control measures will be used.
Sec. 71.301 Respirable dust control plan; approval by District
Manager and posting.
(a) The District Manager will approve respirable dust control plans
on a mine-by-mine basis. When approving respirable dust control plans,
the District Manager shall consider whether:
(1) The respirable dust control measures would be likely to
maintain concentrations of respirable coal mine dust at or below the
applicable standard; and
(2) The operator's compliance with all provisions of the respirable
dust control plan could be objectively ascertained by MSHA.
(b) MSHA may take respirable dust samples to determine whether the
respirable dust control measures in the operator's plan effectively
maintain concentrations of respirable coal mine dust at or below the
applicable standard.
(c) The operator shall comply with all provisions of each
respirable dust control plan upon notice from MSHA that the respirable
dust control plan is approved.
(d) The approved respirable dust control plan and any revisions
shall be:
(1) Provided upon request to the representative of miners by the
operator following notification of approval;
(2) Made available for inspection by the representative of miners;
and
(3) Posted on the mine bulletin board within 1 working day
following notification of approval, and shall remain posted for the
period that the plan is in effect.
(e) The operator may review respirable dust control plans and
submit proposed revisions to such plans to the District Manager for
approval.
PART 72--HEALTH STANDARDS FOR COAL MINES
0
11. The authority citation for part 72 is revised to read as follows:
Authority: 30 U.S.C. 811, 813(h), 957.
0
12. Add subpart B to part 72 to read as follows:
Subpart B--Medical Surveillance
Sec.
72.100 Periodic examinations.
Subpart B--Medical Surveillance
Sec. 72.100 Periodic examinations.
(a) Each operator of a coal mine shall provide to each miner
periodic examinations including chest x-rays, spirometry, symptom
assessment, and occupational history at a frequency specified in this
section and at no cost to the miner.
(1) Each operator shall use facilities approved by the National
Institute for Occupational Safety and Health (NIOSH) to provide
examinations specified in paragraph (a) of this section.
(2) The results of examinations or tests made pursuant to this
section shall be furnished only to the Secretary, Secretary of Health
and Human Services (HHS), and at the request of the miner, to the
miner's designated physician.
(b) Voluntary examinations. Each operator shall provide the
opportunity to have the examinations specified in Sec. 72.100(a) at
least every 5 years to all miners employed at a coal mine. The
examinations shall be available during a 6-month period that begins no
less than 3.5 years and not more than 4.5 years from the end of the
last 6-month period.
(c) Mandatory examinations. For each miner who begins work at a
coal mine for the first time, the operator shall provide examinations
specified in Sec. 72.100(a) as follows:
(1) An initial examination no later than 30 days after beginning
employment;
(2) A follow-up examination no later than 3 years after the initial
examination in paragraph (c)(1); and
(3) A follow-up examination no later than 2 years after the
examinations in paragraph (c)(2) if the chest x-ray shows evidence of
pneumoconiosis or the spirometry examination indicates evidence of
decreased lung function. For this purpose, evidential criteria will be
defined by NIOSH.
(d) Each mine operator shall develop and submit for approval to
NIOSH a plan in accordance with 42 CFR part 37 for providing miners
with the examinations specified in Sec. 72.100(a) and a roster
specifying the name and current address of each miner covered by the
plan.
(e) Each mine operator shall post on the mine bulletin board at all
times the approved plan for providing the examinations specified in
Sec. 72.100(a).
0
13. Add Sec. Sec. 72.700, 72.701, and 72.800 to subpart E of part 72
to read as follows:
Subpart E--Miscellaneous
Sec. 72.700 Respiratory equipment; respirable dust.
(a) Respiratory equipment approved by NIOSH under 42 CFR part 84
shall be made available to all persons as required under parts 70, 71,
and 90 of this chapter. Use of respirators shall not be substituted for
environmental control measures in the active workings. Each operator
shall maintain an adequate supply of respiratory equipment.
(b) When required to make respirators available, the operator shall
provide training prior to the miner's next scheduled work shift, unless
the miner received training within the previous 12 months on the types
of respirators made available. The training shall include: The care,
fit, use, and limitations of each type of respirator.
(c) An operator shall keep a record of the training at the mine
site for 24 months after completion of the training.
[[Page 24987]]
An operator may keep the record elsewhere if the record is immediately
accessible from the mine site by electronic transmission. Upon request
from an authorized representative of the Secretary, Secretary of HHS,
or representative of miners, the operator shall promptly provide access
to any such training records. The record shall include:
(1) The date of training;
(2) The names of miners trained; and
(3) The subjects included in the training.
Sec. 72.701 Respiratory equipment; gas, dusts, fumes, or mists.
Respiratory equipment approved by NIOSH under 42 CFR part 84 shall
be provided to persons exposed for short periods to inhalation hazards
from gas, dusts, fumes, or mists. When the exposure is for prolonged
periods, other measures to protect such persons or to reduce the hazard
shall be taken.
Sec. 72.800 Single, full-shift measurement of respirable coal mine
dust.
The Secretary will use a single, full-shift measurement of
respirable coal mine dust to determine the average concentration on a
shift since that measurement accurately represents atmospheric
conditions to which a miner is exposed during such shift. Noncompliance
with the applicable respirable dust standard or the applicable
respirable dust standard when quartz is present, in accordance with
subchapter O of this chapter, is demonstrated when a single, full-shift
measurement taken by MSHA meets or exceeds the applicable ECV in Table
70-1, 71-1, or 90-1 that corresponds to the applicable standard and the
particular sampling device used. Upon issuance of a citation for a
violation of the applicable standard, and for MSHA to terminate the
citation, the operator shall take the specified actions in subchapter O
of this chapter.
PART 75--MANDATORY SAFETY STANDARDS--UNDERGROUND COAL MINES
0
14. The authority citation for part 75 is revised to read as follows:
Authority: 30 U.S.C. 811, 813(h), 957.
0
15. Amend Sec. 75.325 by revising paragraph (a)(2) to read as follows:
Sec. 75.325 Air quantity.
(a) * * *
(2) The quantity of air reaching the working face shall be
determined at or near the face end of the line curtain, ventilation
tubing, or other ventilation control device. If the curtain, tubing, or
device extends beyond the last row of permanent roof supports, the
quantity of air reaching the working face shall be determined behind
the line curtain or in the ventilation tubing at or near the last row
of permanent supports. When machine-mounted dust collectors are used in
conjunction with blowing face ventilation systems, the quantity of air
reaching the working face shall be determined with the dust collector
turned off.
* * * * *
0
16. Amend Sec. 75.350 by revising paragraph (b)(3)(i) and (ii) to read
as follows:
Sec. 75.350 Belt air course ventilation.
* * * * *
(b) * * *
(3)(i) The average concentration of respirable dust in the belt air
course, when used as a section intake air course, shall be maintained
at or below:
(A) 1.0 mg/m\3\.
(B) 0.5 mg/m\3\ as of August 1, 2016.
(ii) Where miners on the working section are on a reduced standard
below that specified in Sec. 75.350(b)(3)(i), the average
concentration of respirable dust in the belt entry must be at or below
the lowest applicable standard on that section.
* * * * *
0
17. Amend Sec. 75.362 by revising paragraphs (a)(2) and (g)(2) and
adding paragraphs (g)(3) and (g)(4) to read as follows:
Sec. 75.362 On-shift examinations.
(a)(1) * * *
(2) A person designated by the operator shall conduct an
examination and record the results and the corrective actions taken to
assure compliance with the respirable dust control parameters specified
in the approved mine ventilation plan. In those instances when a shift
change is accomplished without an interruption in production on a
section, the examination shall be made anytime within 1 hour after the
shift change. In those instances when there is an interruption in
production during the shift change, the examination shall be made
before production begins on a section. Deficiencies in dust controls
shall be corrected before production begins or resumes. The examination
shall include: Air quantities and velocities; water pressures and flow
rates; excessive leakage in the water delivery system; water spray
numbers and orientations; section ventilation and control device
placement; roof bolting machine dust collector vacuum levels; scrubber
air flow rate; work practices required by the ventilation plan; and any
other dust suppression measures. Measurements of the air velocity and
quantity, water pressure and flow rates are not required if continuous
monitoring of these controls is used and indicates that the dust
controls are functioning properly.
* * * * *
(g) * * *
(2) The certified person directing the on-shift examination to
assure compliance with the respirable dust control parameters specified
in the approved mine ventilation plan shall:
(i) Certify by initials, date, and time on a board maintained at
the section load-out or similar location showing that the examination
was made prior to resuming production; and
(ii) Verify, by initials and date, the record of the results of the
examination required under (a)(2) of this section to assure compliance
with the respirable dust control parameters specified in the mine
ventilation plan. The verification shall be made no later than the end
of the shift for which the examination was made.
(3) The mine foreman or equivalent mine official shall countersign
each examination record required under (a)(2) of this section after it
is verified by the certified person under (g)(2)(ii) of this section,
and no later than the end of the mine foreman's or equivalent mine
official's next regularly scheduled working shift. The record shall be
made in a secure book that is not susceptible to alteration or
electronically in a computer system so as to be secure and not
susceptible to alteration.
(4) Records shall be retained at a surface location at the mine for
at least 1 year and shall be made available for inspection by
authorized representatives of the Secretary and the representative of
miners.
0
18. Amend Sec. 75.371 by revising paragraphs (f), (j), and (t) to read
as follows:
Sec. 75.371 Mine ventilation plan; contents.
* * * * *
(f) Section and face ventilation systems used and the minimum
quantity of air that will be delivered to the working section for each
mechanized mining unit, including drawings illustrating how each system
is used, and a description of each different dust suppression system
used on equipment, identified by make and model, on each working
section, including:
(1) The number, types, location, orientation, operating pressure,
and flow rate of operating water sprays;
(2) The maximum distance that ventilation control devices will be
[[Page 24988]]
installed from each working face when mining or installing roof bolts
in entries and crosscuts;
(3) Procedures for maintaining the roof bolting machine dust
collection system in approved condition; and
(4) Recommended best work practices for equipment operators to
minimize dust exposure.
* * * * *
(j) The operating volume of machine mounted dust collectors or
diffuser fans, if used (see Sec. 75.325(a)(3)), including the type and
size of dust collector screen used, and a description of the procedures
to maintain dust collectors used on equipment.
* * * * *
(t) The locations where samples for ``designated areas'' will be
collected, including the specific location of each sampling device, and
the respirable dust control measures used at the dust generating
sources for these locations (see Sec. Sec. 70.207 and 70.209 of this
chapter).
* * * * *
PART 90--MANDATORY HEALTH STANDARDS--COAL MINERS WHO HAVE EVIDENCE
OF THE DEVELOPMENT OF PNEUMOCONIOSIS
0
19. The authority citation for part 90 is revised to read as follows:
Authority: 30 U.S.C. 811, 813(h), 957.
0
20. Subpart A to part 90 is revised to read as follows:
Subpart A--General
Sec.
90.1 Scope.
90.2 Definitions.
90.3 Part 90 option; notice of eligibility; exercise of option.
Subpart A--General
Sec. 90.1 Scope.
This part 90 establishes the option of miners who are employed at
coal mines and who have evidence of the development of pneumoconiosis
to work in an area of a mine where the average concentration of
respirable dust in the mine atmosphere during each shift is
continuously maintained at or below the applicable standard as
specified in Sec. 90.100. The rule sets forth procedures for miners to
exercise this option, and establishes the right of miners to retain
their regular rate of pay and receive wage increases. The rule also
sets forth the operator's obligations, including respirable dust
sampling for part 90 miners. This part 90 is promulgated pursuant to
section 101 of the Act and supersedes section 203(b) of the Federal
Mine Safety and Health Act of 1977, as amended.
Sec. 90.2 Definitions.
The following definitions apply in this part:
Act. The Federal Mine Safety and Health Act of 1977, Public Law 91-
173, as amended by Public Law 95-164 and Public Law 109-236.
Active workings. Any place in a coal mine where miners are normally
required to work or travel.
Approved sampling device. A sampling device approved by the
Secretary and Secretary for Health and Human Services (HHS) under part
74 of this title.
Certified person. An individual certified by the Secretary in
accordance with Sec. 90.202 to take respirable dust samples required
by this part or certified in accordance with Sec. 90.203 to perform
the maintenance and calibration of respirable dust sampling equipment
as required by this part.
Coal mine dust personal sampler unit (CMDPSU). A personal sampling
device approved under part 74, subpart B, of this title.
Concentration. A measure of the amount of a substance contained per
unit volume of air.
Continuous personal dust monitor (CPDM). A personal sampling device
approved under part 74, subpart C, of this title.
District Manager. The manager of the Coal Mine Safety and Health
District in which the mine is located.
Equivalent concentration. The concentration of respirable coal mine
dust, including quartz, expressed in milligrams per cubic meter of air
(mg/m\3\) as measured with an approved sampling device, determined by
dividing the weight of dust in milligrams collected on the filter of an
approved sampling device by the volume of air in cubic meters passing
through the filter (sampling time in minutes (t) times the sampling
airflow rate in cubic meters per minute), and then converting that
concentration to an equivalent concentration as measured by the Mining
Research Establishment (MRE) instrument. When the approved sampling
device is:
(1) The CMDPSU, the equivalent concentration is determined by
multiplying the concentration of respirable coal mine dust by the
constant factor prescribed by the Secretary.
(2) The CPDM, the device shall be programmed to automatically
report end-of-shift concentration measurements as equivalent
concentrations.
Mechanized mining unit (MMU). A unit of mining equipment including
hand loading equipment used for the production of material; or a
specialized unit which uses mining equipment other than specified in
Sec. 70.206(b) or in Sec. 70.208(b) of this chapter. Each MMU will be
assigned a four-digit identification number by MSHA, which is retained
by the MMU regardless of where the unit relocates within the mine.
However, when:
(1) Two sets of mining equipment are used in a series of working
places within the same working section and only one production crew is
employed at any given time on either set of mining equipment, the two
sets of equipment shall be identified as a single MMU.
(2) Two or more sets of mining equipment are simultaneously engaged
in cutting, mining, or loading coal or rock from working places within
the same working section, each set of mining equipment shall be
identified as a separate MMU.
MRE instrument. The gravimetric dust sampler with a four channel
horizontal elutriator developed by the Mining Research Establishment of
the National Coal Board, London, England.
MSHA. The Mine Safety and Health Administration of the U.S.
Department of Labor.
Normal work duties. Duties which the part 90 miner performs on a
routine day-to-day basis in his or her job classification at a mine.
Part 90 miner. A miner employed at a coal mine who has exercised
the option under the old section 203(b) program (36 FR 20601, October
27, 1971), or under Sec. 90.3 of this part to work in an area of a
mine where the average concentration of respirable dust in the mine
atmosphere during each shift to which that miner is exposed is
continuously maintained at or below the applicable standard, and who
has not waived these rights.
Quartz. Crystalline silicon dioxide (SiO2) not
chemically combined with other substances and having a distinctive
physical structure.
Representative sample. A respirable dust sample, expressed as an
equivalent concentration, that reflects typical dust concentration
levels in the working environment of the part 90 miner when performing
normal work duties.
Respirable dust. Dust collected with a sampling device approved by
the Secretary and the Secretary of HHS in accordance with part 74 (Coal
Mine Dust Sampling Devices) of this title.
Secretary. The Secretary of Labor or a delegate.
Secretary of Health and Human Services. The Secretary of Health and
[[Page 24989]]
Human Services (HHS) or the Secretary of Health, Education, and
Welfare.
Transfer. Any change in the work assignment of a part 90 miner by
the operator and includes: (1) Any change in occupation code of a part
90 miner; (2) any movement of a part 90 miner to or from an MMU; or (3)
any assignment of a part 90 miner to the same occupation in a different
location at a mine.
Valid respirable dust sample. A respirable dust sample collected
and submitted as required by this part, including any sample for which
the data were electronically transmitted to MSHA, and not voided by
MSHA.
Sec. 90.3 Part 90 option; notice of eligibility; exercise of option.
(a) Any miner employed at a coal mine who, in the judgment of the
Secretary of HHS, has evidence of the development of pneumoconiosis
based on a chest X-ray, read and classified in the manner prescribed by
the Secretary of HHS, or based on other medical examinations shall be
afforded the option to work in an area of a mine where the average
concentration of respirable dust in the mine atmosphere during each
shift to which that miner is exposed is continuously maintained at or
below the applicable standard. Each of these miners shall be notified
in writing of eligibility to exercise the option.
(b) Any miner who is a section 203(b) miner on January 31, 1981,
shall be a part 90 miner on February 1, 1981, entitled to full rights
under this part to retention of pay rate, future actual wage increases,
and future work assignment, shift and respirable dust protection.
(c) Any part 90 miner who is transferred to a position at the same
or another coal mine shall remain a part 90 miner entitled to full
rights under this part at the new work assignment.
(d) The option to work in a low dust area of the mine may be
exercised for the first time by any miner employed at a coal mine who
was eligible for the option under the old section 203(b) program (36 FR
20601, October 27, 1971), or is eligible for the option under this part
by signing and dating the Exercise of Option Form and mailing the form
to the Chief, Division of Health, Coal Mine Safety and Health, MSHA,
1100 Wilson Boulevard, Arlington, Virginia 22209.
(e) The option to work in a low dust area of the mine may be re-
exercised by any miner employed at a coal mine who exercised the option
under the old section 203(b) program (36 FR 20601, October 27, 1971),
or exercised the option under this part by sending a written request to
the Chief, Division of Health, Coal Mine Safety and Health, MSHA, 1100
Wilson Boulevard, Arlington, Virginia 22209. The request should include
the name and address of the mine and operator where the miner is
employed.
(f) No operator shall require from a miner a copy of the medical
information received from the Secretary or Secretary of HHS.
0
21. Subpart B to part 90 is revised to read as follows:
Subpart B--Dust Standards, Rights of Part 90 Miners
Sec.
90.100 Respirable dust standard.
90.101 Respirable dust standard when quartz is present.
90.102 Transfer; notice.
90.103 Compensation.
90.104 Waiver of rights; re-exercise of option.
Subpart B--Dust Standards, Rights of Part 90 Miners
Sec. 90.100 Respirable dust standard.
After the 20th calendar day following receipt of notification from
MSHA that a part 90 miner is employed at the mine, the operator shall
continuously maintain the average concentration of respirable dust in
the mine atmosphere during each shift to which the part 90 miner in the
active workings of the mine is exposed, as measured with an approved
sampling device and expressed in terms of an equivalent concentration,
at or below:
(a) 1.0 milligrams of respirable dust per cubic meter of air (mg/
m\3\).
(b) 0.5 mg/m\3\ as of August 1, 2016.
Sec. 90.101 Respirable dust standard when quartz is present.
(a) Each operator shall continuously maintain the average
concentration of respirable quartz dust in the mine atmosphere during
each shift to which a part 90 miner in the active workings of each mine
is exposed at or below 0.1 mg/m\3\ (100 micrograms per cubic meter or
[micro]g/m\3\) as measured with an approved sampling device and
expressed in terms of an equivalent concentration.
(b) When the mine atmosphere of the active workings where the part
90 miner performs his or her normal work duties exceeds 100 [micro]g/
m\3\ of respirable quartz dust, the operator shall continuously
maintain the average concentration of respirable dust in the mine
atmosphere during each shift to which a part 90 miner is exposed as
measured with an approved sampling device and expressed in terms of an
equivalent concentration at or below the applicable standard. The
applicable standard is computed by dividing the percent of quartz into
the number 10. The application of this formula shall not result in an
applicable standard that exceeds the standards specified in Sec.
90.100.
Example: Assume the part 90 miner is on a 0.5 mg/m\3\ dust
standard. Suppose a valid representative dust sample with an
equivalent concentration of 0.50 mg/m\3\ contains 25.6% of quartz
dust, which corresponds to a quartz concentration of 128 [micro]g/
m\3\. Therefore, the average concentration of respirable dust in the
mine atmosphere associated with that part 90 miner shall be
maintained on each shift at or below 0.4 mg/m\3\ (10/25.6% = 0.4 mg/
m\3\).
Sec. 90.102 Transfer; notice.
(a) Whenever a part 90 miner is transferred in order to meet the
applicable standard, the operator shall transfer the miner to an
existing position at the same coal mine on the same shift or shift
rotation on which the miner was employed immediately before the
transfer. The operator may transfer a part 90 miner to a different coal
mine, a newly-created position or a position on a different shift or
shift rotation if the miner agrees in writing to the transfer. The
requirements of this paragraph do not apply when the respirable dust
concentration in a part 90 miner's work position complies with the
applicable standard but circumstances, such as reductions in workforce
or changes in operational status, require a change in the miner's job
or shift assignment.
(b) On or before the 20th calendar day following receipt of
notification from MSHA that a part 90 miner is employed at the mine,
the operator shall give the District Manager written notice of the
occupation and, if applicable, the MMU unit to which the part 90 miner
shall be assigned on the 21st calendar day following receipt of the
notification from MSHA.
(c) After the 20th calendar day following receipt of notification
from MSHA that a part 90 miner is employed at the mine, the operator
shall give the District Manager written notice before any transfer of a
part 90 miner. This notice shall include the scheduled date of the
transfer.
Sec. 90.103 Compensation.
(a) The operator shall compensate each part 90 miner at not less
than the regular rate of pay received by that miner immediately before
exercising the option under Sec. 90.3.
(b) Whenever a part 90 miner is transferred, the operator shall
compensate the miner at not less than the regular rate of pay received
by that miner immediately before the transfer.
[[Page 24990]]
(c) Once a miner has been placed in a position in compliance with
the provisions of part 90, paragraphs (a) and (b) of this section do
not apply when the part 90 miner initiates and accepts a change in work
assignment for reasons of job preference.
(d) The operator shall compensate each miner who is a section
203(b) miner on January 31, 1981, at not less than the regular rate of
pay that the miner is required to receive under section 203(b) of the
Act immediately before the effective date of this part.
(e) In addition to the compensation required to be paid under
paragraphs (a), (b), and (d) of this section, the operator shall pay
each part 90 miner the actual wage increases that accrue to the
classification to which the miner is assigned.
(f) If a miner is temporarily employed in an occupation other than
his or her regular work classification for two months or more before
exercising the option under Sec. 90.3, the miner's regular rate of pay
for purposes of paragraph (a) and (b) of this section is the higher of
the temporary or regular rates of pay. If the temporary assignment is
for less than two months, the operator may pay the part 90 miner at his
or her regular work classification rate regardless of the temporary
wage rate.
(g) If a part 90 miner is transferred, and the Secretary
subsequently notifies the miner that notice of the miner's eligibility
to exercise the part 90 option was incorrect, the operator shall retain
the affected miner in the current position to which the miner is
assigned and continue to pay the affected miner the applicable rate of
pay provided in paragraphs (a), (b), (d), and (e) of this section,
until:
(1) The affected miner and operator agree in writing to a position
with pay at not less than the regular rate of pay for that occupation;
or
(2) A position is available at the same coal mine in both the same
occupation and on the same shift on which the miner was employed
immediately before exercising the option under Sec. 90.3 or under the
old section 203(b) program (36 FR 20601, October 27, 1971).
(i) When such a position is available, the operator shall offer the
available position in writing to the affected miner with pay at not
less than the regular rate of pay for that occupation.
(ii) If the affected miner accepts the available position in
writing, the operator shall implement the miner's reassignment upon
notice of the miner's acceptance. If the miner does not accept the
available position in writing, the miner may be reassigned and
protections under part 90 shall not apply. Failure by the miner to act
on the written offer of the available position within 15 days after
notice of the offer is received from the operator shall operate as an
election not to accept the available position.
Sec. 90.104 Waiver of rights; re-exercise of option.
(a) A part 90 miner may waive his or her rights and be removed from
MSHA's active list of miners who have rights under part 90 by:
(1) Giving written notification to the Chief, Division of Health,
Coal Mine Safety and Health, MSHA, that the miner waives all rights
under this part;
(2) Applying for and accepting a position in an area of a mine
which the miner knows has an average respirable dust concentration
exceeding the applicable standard; or
(3) Refusing to accept another position offered by the operator at
the same coal mine that meets the requirements of Sec. Sec. 90.100,
90.101 and 90.102(a) after dust sampling shows that the present
position exceeds the applicable standard.
(b) If rights under part 90 are waived, the miner gives up all
rights under part 90 until the miner re-exercises the option in
accordance with Sec. 90.3(e) (Part 90 option; notice of eligibility;
exercise of option).
(c) If rights under part 90 are waived, the miner may re-exercise
the option under this part in accordance with Sec. 90.3(e) (Part 90
option; notice of eligibility; exercise of option) at any time.
0
22. Subpart C to part 90 is revised to read as follows:
Subpart C--Sampling Procedures
Sec.
90.201 Sampling; general and technical requirements.
90.202 Certified person; sampling.
90.203 Certified person; maintenance and calibration.
90.204 Approved sampling devices; maintenance and calibration.
90.205 Approved sampling devices; operation; air flowrate.
90.206 Exercise of option or transfer sampling.
90.207 Quarterly sampling.
90.208 Respirable dust samples; transmission by operator.
90.209 Respirable dust samples; report to operator.
90.210 Status change reports.
Subpart C--Sampling Procedures
Sec. 90.201 Sampling; general and technical requirements.
(a) An approved coal mine dust personal sampler unit (CMDPSU) shall
be used to take samples of the concentration of respirable coal mine
dust in the working environment of each part 90 miner as required by
this part. On February 1, 2016, part 90 miners shall be sampled only
with an approved continuous personal dust monitor (CPDM) as required by
this part and an approved CMDPSU shall not be used, unless notified by
the Secretary to continue to use an approved CMDPSU to conduct
quarterly sampling.
(b) If using a CMDPSU, the sampling device shall be worn or carried
to and from each part 90 miner. If using a CPDM, the sampling device
shall be worn by the part 90 miner at all times. Approved sampling
devices shall be operated portal-to-portal and shall remain operational
during the part 90 miner's entire shift, which includes the time spent
performing normal work duties and while traveling to and from the
assigned work location. If the work shift to be sampled is longer than
12 hours and the sampling device is:
(1) A CMDPSU, the operator shall switch-out the unit's sampling
pump prior to the 13th-hour of operation.
(2) A CPDM, the operator shall switch-out the CPDM with a fully
charged device prior to the 13th-hour of operation.
(c) Unless otherwise directed by the District Manager, the
respirable dust samples required under this part using a CMDPSU shall
be taken by placing the sampling device as follows:
(1) On the part 90 miner;
(2) On the piece of equipment which the part 90 miner operates
within 36 inches of the normal working position; or
(3) At a location that represents the maximum concentration of dust
to which the part 90 miner is exposed.
(d) If using a CMDPSU, one control filter shall be used for each
shift of sampling. Each control filter shall:
(1) Have the same pre-weight date (noted on the dust data card) as
the filter used for sampling;
(2) Remain plugged at all times;
(3) Be used for the same amount of time, and exposed to the same
temperature and handling conditions as the filter used for sampling;
and
(4) Be kept with the exposed samples after sampling and in the same
mailing container when transmitted to MSHA.
(e) The respirable dust samples required by this part and taken
with a CMDPSU shall be collected while the part 90 miner is performing
normal work duties.
(f) Records showing the length of each shift for each part 90 miner
shall be made and retained for at least six months, and shall be made
available for inspection by authorized representatives
[[Page 24991]]
of the Secretary and submitted to the District Manager when requested
in writing.
(g) Upon request from the District Manager, the operator shall
submit the date and time any respirable dust sampling required by this
part will begin. This information shall be submitted at least 48 hours
prior to scheduled sampling.
(h) Operators using CPDMs shall provide training to all part 90
miners. The training shall be completed prior to a part 90 miner
wearing a CPDM and then every 12 months thereafter. The training shall
include:
(1) The importance of monitoring dust concentrations and properly
wearing the CPDM;
(2) Explaining the basic features and capabilities of the CPDM;
(3) Discussing the various types of information displayed by the
CPDM and how to access that information; and
(4) How to start and stop a short-term sample run during compliance
sampling.
(i) An operator shall keep a record of the CPDM training at the
mine site for 24 months after completion of the training. An operator
may keep the record elsewhere if the record is immediately accessible
from the mine site by electronic transmission. Upon request from an
authorized representative of the Secretary or Secretary of HHS, the
operator shall promptly provide access to any such training records.
The record shall include:
(1) The date of training;
(2) The names of miners trained; and
(3) The subjects included in the training.
(j) An anthracite mine using the full box, open breast, or slant
breast mining method may use either a CPDM or a CMDPSU to conduct the
required sampling. The mine operator shall notify the District Manager
in writing of its decision to not use a CPDM.
Sec. 90.202 Certified person; sampling.
(a) The respirable dust sampling required by this part shall be
performed by a certified person.
(b) To be certified, a person shall complete the applicable MSHA
course of instruction and pass the MSHA examination demonstrating
competency in sampling procedures. Persons not certified in sampling
and those certified only in maintenance and calibration procedures in
accordance with Sec. 90.203(b) are not permitted to collect respirable
dust samples required by this part or handle approved sampling devices
when being used in sampling.
(c) To maintain certification, a person must pass the MSHA
examination demonstrating competency in sampling procedures every three
years.
(d) MSHA may revoke a person's certification for failing to
properly carry out the required sampling procedures.
Sec. 90.203 Certified person; maintenance and calibration.
(a) Approved sampling devices shall be maintained and calibrated by
a certified person.
(b) To be certified, a person shall complete the applicable MSHA
course of instruction and pass the MSHA examination demonstrating
competency in maintenance and calibration procedures for approved
sampling devices. Necessary maintenance of the sampling head assembly
of a CMDPSU, or the cyclone assembly of a CPDM, can be performed by
persons certified in sampling or in maintenance and calibration.
(c) To maintain certification, a person must pass the MSHA
examination demonstrating competency in maintenance and calibration
procedures every three years.
(d) MSHA may revoke a person's certification for failing to
properly carry out the required maintenance and calibration procedures.
Sec. 90.204 Approved sampling devices; maintenance and calibration.
(a) Approved sampling devices shall be maintained as approved under
part 74 of this title and calibrated in accordance with MSHA
Informational Report IR 1240 (1996) ``Calibration and Maintenance
Procedures for Coal Mine Respirable Dust Samplers'' or in accordance
with the manufacturer's recommendations if using a CPDM. Only persons
certified in maintenance and calibration can perform maintenance on the
CPDM or the pump unit of the CMDPSU.
(b) Approved sampling devices shall be calibrated at the flowrate
of 2.0 liters of air per minute (L/min) if using a CMDPSU; at 2.2 L/min
if using a CPDM; or at a different flowrate recommended by the
manufacturer, before they are put into service and, thereafter, at time
intervals recommended by the manufacturer or prescribed by the
Secretary or Secretary of HHS.
(c) If using a CMDPSU, sampling devices shall be examined and
tested by a person certified in sampling or in maintenance and
calibration within 3 hours before the start of the shift on which the
approved sampling devices will be used to collect respirable dust
samples. This is to assure that the sampling devices are clean and in
proper working condition. This examination and testing shall include
the following:
(1) Examination of all components of the cyclone assembly to assure
that they are clean and free of dust and dirt. This includes examining
the interior of the connector barrel (located between the cassette
assembly and vortex finder), vortex finder, cyclone body, and grit pot;
(2) Examination of the inner surface of the cyclone body to assure
that it is free of scoring or scratch marks on the inner surface of the
cyclone where the air flow is directed by the vortex finder into the
cyclone body;
(3) Examination of the external hose connecting the pump unit to
the sampling head assembly to assure that it is clean and free of
leaks; and
(4) Examination of the clamping and positioning of the cyclone
body, vortex finder, and cassette to assure that they are rigid, in
alignment, firmly in contact, and airtight.
(5) Testing the voltage of each battery while under actual load to
assure the battery is fully charged. This requires that a fully
assembled and examined sampling head assembly be attached to the pump
inlet with the pump unit running when the voltage check is made. The
voltage for batteries used in the CMDPSU shall not be lower than the
product of the number of cells in the battery multiplied by the
manufacturer's nominal voltage per cell.
(d) If using a CPDM, the certified person in sampling or in
maintenance and calibration shall:
(1) Follow the pre-operational examinations, testing, and set-up
procedures, and perform necessary external maintenance recommended by
the manufacturer to assure the operational readiness of the CPDM within
3 hours before the start of the shift on which the sampling device will
be used to collect respirable dust samples; and
(2) Perform other required scheduled examinations and maintenance
procedures recommended by the manufacturer.
(e) You must proceed in accordance with ``Calibration and
Maintenance Procedures for Coal Mine Respirable Dust Samplers,'' MSHA
Informational Report IR 1240 (1996) referenced in paragraph (a) of this
section. The Director of the Federal Register approves this
incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. You may obtain a copy from the MSHA Web site at http://www.msha.gov and you may inspect or obtain a copy at MSHA, Coal Mine
Safety and Health, 1100 Wilson Blvd., Room 2424, Arlington, Virginia
22209-3939 and at each MSHA Coal Mine Safety and Health District
Office, or at
[[Page 24992]]
the National Archives and Records Administration (NARA). For
information on the availability of this material at NARA, call 202-741-
6030, or go to:http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
Sec. 90.205 Approved sampling devices; operation; air flowrate.
(a) Approved sampling devices shall be operated at the flowrate of
2.0 L/min if using a CMDPSU; at 2.2 L/min if using a CPDM; or at a
different flowrate recommended by the manufacturer.
(b) If using a CMDPSU, each approved sampling device shall be
examined each shift, by a person certified in sampling during:
(1) The second hour after being put into operation to assure it is
in the proper location, operating properly, and at the proper flowrate.
If the proper flowrate is not maintained, necessary adjustments shall
be made by the certified person. This examination is not required if
the sampling device is being operated in an anthracite coal mine using
the full box, open breast, or slant breast mining method.
(2) The last hour of operation to assure that the sampling device
is operating properly and at the proper flowrate. If the proper
flowrate is not maintained, the respirable dust sample shall be
transmitted to MSHA with a notation by the certified person on the back
of the dust data card stating that the proper flowrate was not
maintained. Other events occurring during the collection of respirable
dust samples that may affect the validity of the sample, such as
dropping of the sampling head assembly onto the mine floor, shall be
noted on the back of the dust data card.
(c) If using a CPDM, the person certified in sampling shall monitor
the dust concentrations and the sampling status conditions being
reported by the sampling device at mid-shift or more frequently as
specified in the approved respirable dust control plan, if applicable,
to assure: The sampling device is in the proper location and operating
properly; and the work environment of the part 90 miner being sampled
remains in compliance with the applicable standard at the end of the
shift. This monitoring is not required if the sampling device is being
operated in an anthracite coal mine using the full box, open breast, or
slant breast mining method.
Sec. 90.206 Exercise of option or transfer sampling.
(a) The operator shall take five valid representative dust samples
for each part 90 miner within 15 calendar days after:
(1) The 20-day period specified for each part 90 miner in Sec.
90.100; and
(2) Implementing any transfer after the 20th calendar day following
receipt of notification from MSHA that a part 90 miner is employed at
the mine.
(b) Noncompliance with the applicable standard shall be determined
in accordance with Sec. 90.207(d) of this part.
(c) Upon issuance of a citation for a violation of the applicable
standard, the operator shall comply with Sec. 90.207(f) of this part.
Sec. 90.207 Quarterly sampling.
(a) Each operator shall take five valid representative samples
every calendar quarter from the environment of each part 90 miner while
performing normal work duties. Part 90 miner samples shall be collected
on consecutive work days. The quarterly periods are:
January 1-March 31
April 1-June 30
July 1-September 30
October 1-December 31.
(b) When the respirable dust standard is changed in accordance with
Sec. 90.101, the new applicable standard shall become effective 7
calendar days after the date of notification of the change by MSHA.
(c) When a valid representative sample taken in accordance with
this section meets or exceeds the excessive concentration value (ECV)
in Table 90-1 that corresponds to the applicable standard and
particular sampling device used, the operator shall:
(1) Make approved respiratory equipment available to affected
miners in accordance with Sec. 72.700 of this chapter;
(2) Immediately take corrective action to lower the concentration
of respirable coal mine dust to at or below the applicable standard;
and
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the part 90 miner.
(d) Noncompliance with the applicable standard is demonstrated
during the sampling period when:
(1) Two or more valid representative samples meet or exceed the ECV
in Table 90-1 that corresponds to the applicable standard and the
particular sampling device used; or
(2) The average for all valid representative samples meets or
exceeds the ECV in Table 90-2 that corresponds to the applicable
standard and the particular sampling device used.
(e) Unless otherwise directed by the District Manager, upon
issuance of a citation for a violation of the applicable standard,
paragraph (a) of this section shall not apply to that part 90 miner
until the violation is abated and the citation is terminated in
accordance with paragraphs (f) and (g) of this section.
(f) Upon issuance of a citation for a violation of the applicable
standard, the operator shall take the following actions sequentially:
(1) Make approved respiratory equipment available to the affected
part 90 miner in accordance with Sec. 72.700 of this chapter.
(2) Immediately take corrective action to lower the concentration
of respirable dust to at or below the applicable standard. If the
corrective action involves:
(i) Reducing the respirable dust levels in the work position of the
part 90 miner identified in the citation, the operator shall implement
the proposed corrective actions and begin sampling the affected miner
within 8 calendar days after the date the citation is issued, until
five valid representative samples are taken.
(ii) Transferring the part 90 miner to another work position at the
mine to meet the applicable standard, the operator shall comply with
Sec. 90.102 of this part and then sample the affected miner in
accordance with Sec. 90.206(a) of this part.
(3) Make a record of the corrective actions taken. The record shall
be certified by the mine foreman or equivalent mine official, no later
than the end of the mine foreman's or equivalent official's next
regularly scheduled working shift. The record shall be made in a secure
book that is not susceptible to alteration or electronically in a
computer system so as to be secure and not susceptible to alteration.
Such records shall be retained at a surface location at the mine for at
least 1 year and shall be made available for inspection by authorized
representatives of the Secretary and the part 90 miner.
[[Page 24993]]
(g) A citation for a violation of the applicable standard shall be
terminated by MSHA when the equivalent concentration of each of the
five valid representative samples is at or below the applicable
standard.
Table 90-1--Excessive Concentration Values (ECV) Based on Single, Full-
Shift CMDPSU/CPDM Concentration Measurements
------------------------------------------------------------------------
ECV (mg/m\3\)
Applicable standard (mg/m\3\) -------------------------------
CMDPSU CPDM
------------------------------------------------------------------------
1.0..................................... 1.26 1.13
0.9..................................... 1.16 1.02
0.8..................................... 1.05 0.91
0.7..................................... 0.95 0.79
0.6..................................... 0.85 0.68
0.5..................................... 0.74 0.57
0.4..................................... 0.65 0.46
0.3..................................... 0.54 0.34
0.2..................................... 0.44 0.23
------------------------------------------------------------------------
Table 90-2--Excessive Concentration Values (ECV) Based on the Average of
5 Full-Shift CMDPSU/CPDM Concentration Measurements
------------------------------------------------------------------------
ECV (mg/m\3\)
Applicable standard (mg/m\3\) -------------------------------
CMDPSU CPDM
------------------------------------------------------------------------
1.0..................................... 1.12 1.06
0.9..................................... 1.02 0.96
0.8..................................... 0.92 0.85
0.7..................................... 0.81 0.75
0.6..................................... 0.71 0.64
0.5..................................... 0.61 0.53
0.4..................................... 0.51 0.43
0.3..................................... 0.41 0.32
0.2..................................... 0.31 0.22
------------------------------------------------------------------------
Sec. 90.208 Respirable dust samples; transmission by operator.
(a) If using a CMDPSU, the operator shall transmit within 24 hours
after the end of the sampling shift all samples collected to fulfill
the requirements of this part, including control filters, in containers
provided by the manufacturer of the filter cassette to: Respirable Dust
Processing Laboratory, Pittsburgh Safety and Health Technology Center,
Cochrans Mill Road, Building 38, P.O. Box 18179, Pittsburgh,
Pennsylvania 15236-0179, or to any other address designated by the
District Manager.
(b) The operator shall not open or tamper with the seal of any
filter cassette or alter the weight of any filter cassette before or
after it is used to fulfill the requirements of this part.
(c) A person certified in sampling shall properly complete the dust
data card that is provided by the manufacturer for each filter
cassette. The card shall have an identification number identical to
that on the cassette used to take the sample and be submitted to MSHA
with the sample. Each card shall be signed by the certified person who
actually performed the required examinations under 90.205(b) of this
part during the sampling shift and shall include that person's MSHA
Individual Identification Number (MIIN). Respirable dust samples with
data cards not properly completed may be voided by MSHA.
(d) All respirable dust samples collected by the operator shall be
considered taken to fulfill the sampling requirements of part 70, 71,
or 90 of this title, unless the sample has been identified in writing
by the operator to the District Manager, prior to the intended sampling
shift, as a sample to be used for purposes other than required by part
70, 71, or 90 of this title.
(e) Respirable dust samples received by MSHA in excess of those
required by this part shall be considered invalid samples.
(f) If using a CPDM, the person certified in sampling shall (1)
validate, certify, and transmit electronically to MSHA within 24 hours
after the end of each sampling shift all sample data file information
collected and stored in the CPDM, including the sampling status
conditions encountered when sampling each part 90 miner; and (2) not
tamper with the CPDM or its components in any way before, during, or
after it is used to fulfill the requirements of this part, or alter any
data files. All CPDM data files transmitted electronically to MSHA
shall be maintained by the operator for at least 12 months.
Sec. 90.209 Respirable dust samples; report to operator.
(a) MSHA shall provide the operator, as soon as practicable, a
report with the following data on respirable dust samples submitted or
whose results were transmitted electronically, if using a CPDM, in
accordance with this part:
(1) The mine identification number;
(2) The locations within the mine from which the samples were
taken;
(3) The concentration of respirable dust, expressed as an
equivalent concentration for each valid sample;
(4) The average equivalent concentration of respirable dust for all
valid samples;
(5) The occupation code;
(6) The reason for voiding any sample; and
(7) The part 90 miner's MSHA Individual Identification Number
(MIIN).
(b) Upon receipt, the operator shall provide a copy of this report
to the part 90 miner. The operator shall not post the original or a
copy of this report on the mine bulletin board.
(c) If using a CPDM, the person certified in sampling shall print,
sign, and provide to each part 90 miner, a paper record (Dust Data
Card) of the sample run within one hour after the start of the part 90
miner's next work shift. This hard-copy record shall include the data
entered when the sample run was first programmed, and the following:
(1) The mine identification number;
(2) The location within the mine from which the sample was taken;
(3) The concentration of respirable dust, expressed as an
equivalent concentration reported and stored for each sample;
(4) The sampling status conditions encountered for each sample;
(5) The shift length; and
(6) The part 90 miner's MSHA Individual Identification Number
(MIIN).
(d) The operator shall not post data on respirable dust samples for
part 90 miners on the mine bulletin board.
Sec. 90.210 Status change reports.
If there is a change in the status of a part 90 miner (such as
entering a terminated, injured, or ill status, or returning to work),
the operator shall report the change in the status of the part 90 miner
to the MSHA District Office or to any other MSHA office designated by
the District Manager. Status changes shall be reported in writing or by
electronic means within 3 working days after the status change has
occurred.
0
23. Subpart D to part 90 is revised to read as follows:
Subpart D--Respirable Dust Control Plans
Sec.
90.300 Respirable dust control plan; filing requirements.
90.301 Respirable dust control plan; approval by District Manager;
copy to part 90 miner.
Subpart D--Respirable Dust Control Plans
Sec. 90.300 Respirable dust control plan; filing requirements.
(a) If an operator abates a violation of the applicable standard by
reducing the respirable dust level in the position of the part 90
miner, the operator shall submit to the District Manager for approval a
written respirable dust
[[Page 24994]]
control plan for the part 90 miner in the position identified in the
citation within 15 calendar days after the citation is terminated. The
respirable dust control plan and revisions thereof shall be suitable to
the conditions and the mining system of the coal mine and shall be
adequate to continuously maintain respirable dust to at or below the
applicable standard for that part 90 miner.
(b) Each respirable dust control plan shall include at least the
following:
(1) The mine identification number assigned by MSHA, the operator's
name, mine name, mine address, and mine telephone number and the name,
address and telephone number of the principal officer in charge of
health and safety at the mine;
(2) The name and MSHA Individual Identification Number of the part
90 miner and the position at the mine to which the plan applies;
(3) A detailed description of the specific respirable dust control
measures used to continuously maintain concentrations of respirable
coal mine dust at or below the applicable standard; and
(4) A detailed description of how each of the respirable dust
control measures described in response to paragraph (b)(3) of this
section will continue to be used by the operator, including at least
the specific time, place, and manner the control measures will be used.
Sec. 90.301 Respirable dust control plan; approval by District
Manager; copy to part 90 miner.
(a) The District Manager will approve respirable dust control plans
on a mine-by-mine basis. When approving respirable dust control plans,
the District Manager shall consider whether:
(1) The respirable dust control measures would be likely to
maintain concentrations of respirable coal mine dust at or below the
applicable standard; and
(2) The operator's compliance with all provisions of the respirable
dust control plan could be objectively ascertained by MSHA.
(b) MSHA may take respirable dust samples to determine whether the
respirable dust control measures in the operator's plan effectively
maintain concentrations of respirable coal mine dust at or below the
applicable standard.
(c) The operator shall comply with all provisions of each
respirable dust control plan upon notice from MSHA that the respirable
dust control plan is approved.
(d) The operator shall provide a copy of the current respirable
dust control plan required under this part to the part 90 miner. The
operator shall not post the original or a copy of the plan on the mine
bulletin board.
(e) The operator may review respirable dust control plans and
submit proposed revisions to such plans to the District Manager for
approval.
[FR Doc. 2014-09084 Filed 4-23-14; 11:15 am]
BILLING CODE 4510-43-P