StacksVerified U.S. regulatory reference

30 CFR §57.22233

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
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, no other work shall be permitted in affected areas.