Section 57.22234 - Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines)(a) If methane reaches 1.0 percent in the mine atmosphere, ventilation changes shall be made to reduce the methane. Until such changes are achieved-(1) All persons other than competent persons necessary to make the ventilation changes shall be withdrawn from affected areas;(2) Electrical power shall be deenergized in affected areas, except power to monitoring equipment determined by MSHA to be intrinsically safe under 30 CFR part 18 ; and(3) Diesel equipment shall be shut off or immediately removed from the area.(b) If methane reaches 1.0 percent at a main exhaust fan, electrical power underground shall be deenergized, except power to monitoring equipment determined by MSHA to be intrinsically safe under 30 CFR part 18, and all persons shall be withdrawn from the mine.(c) If methane reaches 1.0 percent at a work place and there has been a failure of the main ventilation system, all persons shall be withdrawn from the mine.52 FR 24941, July 1, 1987, as amended at 53 FR 9615, Mar. 24, 1988