Loading boreholes.

§ 75.1318 Loading boreholes. (a) Explosives shall be loaded by a qualified person or a person working in the presence of and under the direction of a qualified person. (b) When boreholes are being loaded, no other work except that necessary to protect persons shall be done in the working place or other area where blasting is to be performed. (c) When loading boreholes drilled at an angle of 45 degrees or greater from the horizontal in solid rock or loading long holes drilled upward in anthracite mines— (1) The first cartridge in each borehole shall be the primer cartridge with the end of the cartridge containing the detonator facing the back of the borehole; and (2) The explosive cartridges shall be loaded in a manner that provides contact between each cartridge in the borehole. (d) When loading other boreholes— (1) The primer cartridge shall be the first cartridge loaded in the borehole; (2) The end of the cartridge in which the detonator is inserted shall face the back of the borehole; and (3) The primer cartridge and other explosives shall be pushed to the back of the borehole in a continuous column with no cartridge being deliberately crushed or deformed. (e) An explosive shall not be loaded into a borehole if it is damaged, deteriorated or if the cartridge is incompletely filled. (f) Explosives of different brands, types or cartridge diameters shall not be loaded in the same borehole. (g) Only nonconductive, nonsparking tamping poles shall be used for loading and tamping boreholes. The use of nonsparking connecting devices for extendable tamping poles is permitted. [53 FR 46786, Nov. 18, 1988; 54 FR 888, Jan. 10, 1989]