77.1910—Explosives and blasting; general.
(a)
Light and power circuits shall be disconnected or removed from the blasting area before charging and blasting.
(b)
All explosive materials, detonators, and any other related blasting material employed in the development of any slope or shaft shall be stored, transported, carried, charged, and fired in accordance with the provision of Subpart N, “Explosives and Blasting,” of this Part 77. Except as provided in paragraph (c) of this section, all shots shall be fired from the surface.
(c)
Where tests for methane have been conducted and methane has not been found and only permissible blasting units are being employed, shots may be fired from an upper level of the slope or shaft.
(d)
Except as provided in paragraph (c) of this section, all men shall be removed from the slope or shaft prior to blasting.
(e)
Blasting areas in slopes or shafts shall be covered with mats or other suitable material when the excavation is too shallow to retain blasted material.
(f)
Where it is impracticable to prepare primers in the blasting area, primers may be prepared on the surface and carried into the shaft in specially constructed, insulated, covered containers.
(g)
No other development operation shall be conducted in a shaft or at the face of a slope while drill holes are being charged and until after all shots have been fired.
(h)
The sides of the slope or shaft between the overhead platform and the bottom where men are working shall be examined after each blast and loose material removed.
(i)
Loose rock and other material shall be removed from timbers and platforms after each blast before men are lowered to the shaft bottom.