30 C.F.R. § 57.22237 Actions at 2.0 to 2.5 percent methane in bleeder systems (I-A and III mines).
Title 30 - Mineral Resources
If methane reaches 2.0 percent in bleeder systems at the point where a bleeder split enters a main return split, mining shall not be permitted on ventilation splits affected by the bleeder system. If methane has not been reduced to less than 2.0 percent within 30 minutes, or if methane levels reach 2.5 percent, all persons other than competent persons necessary to take corrective action shall be withdrawn from affected areas.
Title 30: Mineral Resources
PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES
Subpart T—Safety Standards for Methane in Metal and Nonmetal Mines
Ventilation
§ 57.22237 Actions at 2.0 to 2.5 percent methane in bleeder systems (I-A and III mines).
