MSHA - Code of Federal Regulations - 30 CFR 57.22105
Skip to content
MSHA - Title 30 CFR
30 CFR § 57.22105
Smoking and open flames (IV mines).

Smoking or open flames shall not be permitted in a face or raise, or during release of gas from a borehole until tests have been conducted in accordance with §57.22226 and the methane level has been determined to be below 0.5 percent.