Pennsylvania Statutes Title 52 P.S. Mines and Mining § 70-628. Thirty minute waiting period before returning to misfired hole

Where misfires occur with electric detonators, a waiting period of at least thirty minutes shall elapse before anyone returns to the misfired hole or holes. Before returning to the misfire, the blasting wires shall be disconnected from the blasting battery and the ends of the blasting wires short-circuited.