[Federal Register Volume 59, Number 48 (Friday, March 11, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-5752]
[[Page Unknown]]
[Federal Register: March 11, 1994]
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DEPARTMENT OF LABOR
Occupational Safety and Health Administration
29 CFR Parts 1910, 1915 and 1926
[Docket No. H-071A]
Occupational Exposure to Methylene Chloride
AGENCY: Occupational Safety and Health Administration (OSHA),
Department of Labor.
ACTION: Proposed rule; limited reopening of the rulemaking record.
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SUMMARY: The Occupational Safety and Health Administration (OSHA) is
reopening the record for the proposed revision (NPRM) of the regulation
of methylene chloride (MC) (56 FR 57036, November 7, 1991) to
incorporate (1) information regarding engineering controls for MC
exposure in the furniture stripping industry; (2) a National Cancer
Institute study of occupational exposure to chlorinated aliphatic
hydrocarbons and the risk of astrocytic brain cancer; and (3)
information regarding the use of MC as a solvent in adhesive
formulations in flexible foam manufacturing. The NPRM and hearing
notice (57 FR 24438, June 9, 1992) raised concerns and solicited
information regarding the ability of furniture stripping operations to
comply with the proposed PELs through the use of engineering controls;
human cancer risk from exposure to MC; and any applications of MC not
addressed by OSHA's Preliminary Regulatory Impact Assessment. The
Agency generated a considerable amount of information regarding these
and other MC-related issues at public hearings (September 16-24, 1992
and October 14-16, 1992) and in post-hearing comment periods that ended
on March 15, 1993. OSHA subsequently received the materials covered by
this notice.
OSHA has determined that the above-mentioned information is
relevant to full consideration of issues raised by the MC rulemaking.
Therefore, OSHA is reopening the record to incorporate the pertinent
materials and to allow the public an opportunity to comment.
DATES: Written comments on the materials incorporated through the
notice of reopening must be postmarked by April 25, 1994.
ADDRESSES: Comments are to be submitted in quadruplicate to the Docket
Office, Docket No. H-071A, U.S. Department of Labor, room N-2634, 200
Constitution Avenue, NW., Washington, DC 20210. Telephone (202) 219-
7894. Written comments limited to 10 pages or less in length also may
be transmitted by facsimile to (202) 219-5046, provided that the
original and three copies are sent to the Docket Office thereafter.
FOR FURTHER INFORMATION CONTACT:
Mr. James F. Foster, Occupational Safety and Health Administration,
U.S. Department of Labor, room N-3647, 200 Constitution Avenue, NW.,
Washington, DC 20210. Telephone (202) 219-8148.
SUPPLEMENTARY INFORMATION:
I. Background
On November 7, 1991, OSHA issued a notice of proposed rulemaking
(NPRM) (56 FR 57036) to address the significant risks of MC-induced
health effects. The proposed rule required employers to reduce
occupational exposure to MC and to institute ancillary measures, such
as employee training and medical surveillance, for further protection
of MC-exposed workers.
OSHA convened public hearings in Washington, DC on September 16-24,
1992 and in San Francisco, CA on October 14-16, 1992. The post-hearing
period for the submission of additional briefs, arguments and
summations ended on March 15, 1993.
The Agency has subsequently obtained information which OSHA
believes should be considered in the drafting of the final rule.
Accordingly, the Agency is reopening the rulemaking record so the
public has an opportunity to comment on that information. The materials
being added to the record are discussed below.
A. Feasibility Analysis for the Furniture Stripping Sector
OSHA conducted a Preliminary Regulatory Impact Analysis and
preliminarily determined that it would be feasible for the furniture
stripping sector to comply with the proposed standard of 25 ppm as an
8-hour time-weighted average (TWA) permissible exposure limit (PEL)
with a 125 ppm short-term exposure limit (as measured over 15 minutes)
(STEL) and ancillary provisions (e.g., exposure monitoring, medical
surveillance and training). Several commenters and hearing participants
questioned the feasibility determination (Exs. 29, 30, 73 and 86). In
response to issues raised during the hearings and comment periods, OSHA
contracted with Mr. Richard Green to reexamine the technical and
economic feasibility of the proposed rule for the furniture stripping
industry. In order to give interested parties an opportunity to comment
on this analysis, it is being introduced into the rulemaking record at
this time.
Mr. Green determined that the proposed standard would be
technically and economically feasible for furniture refinishers. The
cost of engineering controls and additional heating (of make-up air)
needed to comply with the proposed rule were estimated to be
approximately $300 per establishment per year. Total compliance costs
would be higher than this figure and include costs for ancillary
provisions, such as exposure monitoring, medical surveillance and
training.
Mr. Green determined the amount of ventilation that would be needed
based upon the rate of evaporation of methylene chloride, principles of
dilution ventilation, and estimates of costs for heating make-up air.
Mr. Green's analysis utilized data in the MC docket and general
reference materials such as the ACGIH Industrial Ventilation Manual for
ventilation recommendations, and the 1993 Statistical Abstract of the
United States to obtain monthly average, high and low temperatures.
Based on theoretical and empirical models, Mr. Green determined
that the average-sized firm will need to install an approximately 5,000
cubic feet per minute (cfm) fan in both the stripping and rinse areas
to ensure that the proposed PEL could be met in both areas. This would
ensure good air mixing in both areas and provide adequate ventilation
capacity. Mr. Green also recommended that the fans should be located
near each process to provide a local spot ventilation effect.
OSHA solicits comments on Mr. Green's analysis and the
appropriateness of using this analysis as a basis for the Agency's
final determination of feasibility in the furniture stripping sector.
B. National Cancer Institute Study on Methylene Chloride Exposure and
the Risk of Developing Astrocytic Brain Cancer
After the post-hearing comment period closed, OSHA received a copy
of a study on the risk of developing brain cancer after exposure to
chlorinated solvents conducted by researchers at the National Cancer
Institute. This study was accepted for publication as two journal
articles to be published in the American Journal of Industrial Medicine
as ``Occupational exposure to chlorinated aliphatic hydrocarbons and
risk of astrocytic brain cancer'' by Ellen F. Heineman et al. and
``Occupational exposure to chlorinated aliphatic hydrocarbons: job
exposure matrix'' by M.R. Gomez et al.
The abstract for the Heineman et al. paper reads as follows,
Chlorinated aliphatic hydrocarbons (CAHs) were evaluated as
potential risk factors for astrocytic brain tumors. Job-exposure
matrices for six individual CAHs and for the general class of
organic solvents were applied to data from a case-control study of
brain cancer among white men. The matrices indicated whether the
CAHs were likely to have been used in each industry and occupation
by decade (1920-1980), and provided estimates of probability and
intensity of exposure for ``exposed'' industries and occupations.
Cumulative exposure indices were calculated for each subject.
Associations of astrocytic brain cancer were observed with
likely exposure to carbon tetrachloride, methylene chloride,
tetrachloroethylene, and trichloroethylene, but were strongest for
methylene chloride. Exposure to chloroform or methy chloroform
showed little indication of an association with brain cancer. Risk
of astrocytic brain tumors increased with probability and average
intensity of exposure, and with duration of employment in jobs
considered exposed to methylene chloride, but not with a cumulative
exposure score. These trends could not be explained by exposures to
the other solvents.
The Gomez et al. paper explains in detail the job-exposure matrix
used to determine whether exposure to a particular solvent was likely
for the subjects of the study. OSHA solicits comments on this study and
its implications for the MC risk assessment.
C. Information Regarding the Use of Methylene Chloride as a Solvent in
Adhesive Formulations in Flexible Foam Manufacturing
During the rulemaking proceedings, OSHA solicited information on
the feasibility of compliance with the proposed standard. After the
post-hearing comment period had closed, the Center for Emissions
Control sent OSHA materials with a cover letter from Mr. Stephen P.
Risotto, detailing an ongoing analysis of adhesive use in foam
manufacturing facilities and a request for OSHA to ``consider the
inability of foam adhesive operations to meet the proposed occupational
limits before issuing a final rule.'' The CEC submission also included
a document entitled ``Foam Adhesive--Ventilation Project Description,''
which outlined the protocol for investigating potential engineering
controls and feasibility for this sector, and a preliminary report
entitled ``Foam Adhesive Fabrication Ventilation Study,'' conducted by
Rust Engineering Company, which outlined recommendations to improve the
ventilation systems for the spray booths, including costs of
modifications.
OSHA preliminarily determined that it was technologically and
economically feasible for establishments that use adhesives to comply
with the proposed standard or substitute away from MC. In this Federal
Register notice, OSHA is soliciting comments on the submitted protocol
and report and requesting information on the technological and economic
feasibility of compliance with the proposed standard for adhesive use
in this situation.
II. Public Participation
Comments
Written comments regarding the materials incorporated into the
methylene chloride rulemaking record through this notice must be
postmarked by April 25, 1994. Four copies of these comments must be
submitted to the Docket Office, Docket No. H-071A, U.S. Department of
Labor, room N-2625, 200 Constitution Avenue, NW., Washington, DC 20210.
(202) 219-7894. All materials submitted will be available for
inspection and copying at the above address. Materials previously
submitted to the Docket for this rulemaking need not be resubmitted.
III. Authority
This document was prepared under the direction of Joseph A. Dear,
Assistant Secretary of Labor for Occupational Safety and Health, U.S.
Department of Labor, 200 Constitution Avenue, NW., Washington, DC
20210.
It is issued under section 6(b) of the Occupational Safety and
Health Act (29 U.S.C. 655), and 29 CFR part 1911.
Signed at Washington, DC, this 8th day of March 1994.
Joseph A. Dear,
Assistant Secretary of Labor.
[FR Doc. 94-5752 Filed 3-10-94; 8:45 am]
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