Diesel Particulate Matter Exposure of Underground Metal and Nonmetal Miners
This notice informs the public of MSHA's decision to implement the diesel particulate matter (DPM) final permissible exposure limit (PEL) of 160 micrograms of total carbon (TC) per cubic meter of air (160TC g/m3). MSHA has developed a practical sampling strategy to account for interferences from non-diesel exhaust sources when TC is used as a surrogate for measuring a miner's exposure to DPM. The Agency will begin enforcement of the 160 TC limit under existing 30 CFR 57.5060(b)(3) on May 20, 2008. MSHA will post details of its sampling strategy on the Agency's DPM Single Source Page prior to enforcement. The sampling strategy is based on the best available scientific evidence and will be specific to each mine.