Pennsylvania Statutes Title 52 P.S. Mines and Mining § 690-314. Storage battery equipment

(a) General rule.--All storage battery equipment and charging stations shall be designed, operated and ventilated so that gas from the batteries will be safely diluted. Storage battery charging stations shall be on a separate split of air. The split of air ventilating a storage battery charging station may be ventilated to a belt entry when the belt entry air is not used to ventilate working faces and a carbon monoxide monitoring system is in place in the belt entry.

(b) Flammable materials.--The presence of flammable materials is not permitted in any storage battery room or charging station. Signs to this effect shall be posted in all battery rooms or charging stations.

(c) Use in face areas.--Storage battery-operated equipment may be used in face areas when all electrical parts that are practicable to enclose are enclosed in explosion-proof casings and the batteries are adequately ventilated.