30 C.F.R. § 57.5015 Oxygen deficiency.
Title 30 - Mineral Resources
Air in all active workings shall contain at least 19.5 volume percent oxygen.
Title 30: Mineral Resources
PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES
Subpart D—Air Quality, Radiation, Physical Agents, and Diesel Particulate Matter
Air Quality—Underground Only
§ 57.5015 Oxygen deficiency.
