[Federal Register Volume 79, Number 84 (Thursday, May 1, 2014)]
[Rules and Regulations]
[Pages 24813-24994]
From the Federal Register Online via the Government Printing 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 mcconnell.sheila.a@dol.gov (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 mcconnell.sheila.a@dol.gov, 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 mcconnell.sheila.a@dol.gov, 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'

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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,

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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

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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

[[Page 24885]]

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) an