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C.F.R.
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Title 30
» CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR › SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH › PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES › Subpart D—Air Quality, Radiation, Physical Agents, and Diesel Particulate Matter