Code of Federal Regulations (alpha)

CFR /  Title 30  /  Part 57  /  Sec. 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 Sec. 57.22226 and the methane level has been determined to be below 0.5 percent.