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DOL Press Release - 05-1641-NAT
U.S. Department of Labor
Contact: Suzy Bohnert    Dirk Fillpot
Phone: (202) 693-9420    (202) 693-4676

Released Wednesday, September 7, 2005

MSHA Issues Proposed Rule to Phase in Lower Limit of Exposure to Diesel Particulate Matter for Miners

ARLINGTON, Va -The U.S. Department of Labor's Mine Safety and Health Administration (MSHA) today issued a proposed rule to phase in, over a five-year period, a lower permissible exposure limit to diesel particulate matter (DPM) in underground metal and nonmetal mines.

A final rule MSHA issued in June converted the unit of measure for the interim permissible exposure limit (PEL) to DPM from 400 micrograms of total carbon to a more accurate measure of 308 micrograms of elemental carbon.

The proposed rule published today in the Federal Register would phase in the lower final PEL of 160 micrograms of total carbon over a five-year period. A separate rulemaking would convert the final PEL to an equivalent measure of elemental carbon. Extensions could be granted to mines if compliance is not technologically or economically feasible.

The proposed rule also seeks comment on a number of questions, including whether miners should be transferred to an existing job if it is determined that they are medically unable to wear a respirator.

Written comments on this proposed rulemaking should be submitted by October 14, 2005 to the MSHA Office of Standards, Regulations and Variances, 1100 Wilson Blvd., Room 2350, Arlington, Va. 22209-3939; fax 202-693-9441. Comments may be submitted at, or by e-mail to, inserting RIN: 1219-AB29 in the subject line. Public hearings are scheduled for September 26, 28 and 30, 2005.

MSHA's Web site at has a hearing schedule and a link to the proposed rule.