(a) The provisions governing the handling, storage, transportation and use of permissible explosives shall apply to all other blasting devices employing a heater element when used underground.
(b) Where compressed air is used for blasting, the airlines shall be grounded at the compressor and, if practical, at other low-resistant ground connections along the lines. They shall not be connected in any way to rails, waterlines or other electric return conductors and shall be adequately insulated and protected where they cross electric wires, underneath track or at places where equipment passes over or under. Steel, copper or other airlines connected therewith shall not be handled or repaired when air pressure is in the line. Shutoff valves shall be installed every thousand feet in all compressed-air blasting lines and at all points where branch lines leave the main line and blowdown valves shall not be less than fifty feet from the face and shall be around a corner.
(c) When misfires occur with any other blasting devices, they shall be handled in a safe manner and under the supervision of the mine foreman or a certified person designated by him