§ 33.193. Use.

 (a)  Open flame or fire. Each person in or about a cavern, before he opens or approaches after opening a magazine or box of dynamite or other explosive shall first place any lamp with open flame, or any lighted pipe, cigar or cigarette, or any other thing containing open fire, not less than 10 feet from this magazine or box and in the position that the air current cannot convey sparks to it.

 (b)  Opening containers of explosives. The provisions of §  33.15 (relating to use) applies to opening containers of explosives in mined underground storage caverns.

 (c)  Blasting. No blasting is permitted while men are underground in a cavern. No person may blast in a cavern unless he has a Commonwealth blaster’s license.

 (d)  Charging holes. In charging holes for blasting, only nonsparking tamping sticks shall be used. Holes shall be charged only in cartridge form. Nothing in this subchapter shall be construed to prohibit slitting dynamite cartridges nor dividing them into two or more pieces.

 (e)  Firing of charges. When dynamite is used in primary shooting, it shall be fired by means of electric current from a battery or switchboard. Electric blasting caps or detonators shall be used to explode dynamite. Each blaster or shooter using an electric battery or switchboard, before connecting the charge to the leading wires, shall first insure that these wires have been disconnected from the switchboard or battery. The practice of connecting a charge with the leading wires before placing the charge is prohibited. A safety break in the firing cable shall be installed. While shafts, slopes, winzes, drifts or other cavern outlets are being sunk or driven, all blasts shall be exploded by means of electric current.

 (f)  Safety precautions after firing. After the firing of each blast and before commencing work on the face or immediately adjacent to the face, the foreman shall examine daily the face of each working place, as well as the sides and roof of each place that has been shot, to ascertain its condition. No one except the person making the examination shall enter any working face until this examination has been made and a daily record has been filed.

 (g)  Misfired holes. A hole which has missed fire shall not have the charge withdrawn. In the event that an electric current from a battery or switchboard was used to explode a hole which missed fire, the waiting period shall be not less than 15 minutes, if the wires have been disconnected from the battery or switchboard. The handling of misfired holes shall be in accordance with the specifications of this subsection under the personal supervision of the cavern foreman. If the misfired hole has 18 inches or less of tamping, nothing in this subsection shall be construed to prohibit the recharging of the missed hole on top of the old tamping. If the unfilled portion of the missed hole is insufficient to accommodate the new charge and tamping, or if the missed hole has been tamped the full depth, a new hole shall be drilled, or water may be used to clean out the tamping in the old hole. The second hole shall be not less than 2 feet away from the missed hole.