30 CFR Part 57Public Domain
§ 57.22232 — Actions at 0.5 percent methane (I-B, II-A, II-B, IV, V-B, and VI mines)
Subpart T — Safety Standards for Methane in Metal and Nonmetal Mines
If methane reaches 0.5 percent in the mine atmosphere, ventilation changes shall be made to reduce the level of methane. Until methane is reduced to less than 0.5 percent, electrical power shall be deenergized in affected areas, except power to monitoring equipment determined by MSHA to be intrinsically safe under 30 CFR part 18. Diesel equipment shall be shut off or immediately removed from the area and no other work shall be permitted in affected areas.
Public Domain: 30 CFR Part 57 (MSHA Safety and Health Standards — Underground Metal and Nonmetal Mines) is a U.S. government publication and is not subject to copyright. Text extracted from the official source ↗. Figures are served from the eCFR; if one does not load, use the link in its place.