(a) A separate instantaneous detonator shall be used to fire each
sheathed explosive unit.
(b) Sheathed explosive units shall be primed and placed in position
for firing only by a qualified person or a person working in the presence of
and under the direction of a qualified person. To prime a sheathed explosive
unit, the entire detonator shall be inserted into the detonator well of the
unit and be held securely in place.
(c) Sheathed explosive units shall not be primed until immediately
before the units are placed where they are to be fired. A sheathed explosive
unit shall not be primed if it is damaged or deteriorated.
(d) Except in anthracite mines, rock dust shall be applied to the
roof, ribs and floor within a 40-foot radius of the location where the
sheathed explosive units are to be fired.
(e) No more than three sheathed explosive units shall be fired at one
time.
(f) No sheathed explosive unit shall be fired in contact with another
sheathed explosive unit.
