StacksVerified U.S. regulatory reference

30 CFR §57.22239

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
If methane reaches 2.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from the mine until methane is reduced to less than 0.5 percent. MSHA shall be notified immediately.