WAC 296-52-67105
Firing the blast. (1) A code of blasting
signals, equivalent to Table T-1, must be posted in one or more
conspicuous places at the blast area and all employees must
familiarize themselves with the code of blasting signals and use
it. Warning signs must be placed at suitable locations, see WAC 296-52-67075(1), Warning signs.
(2) All charges must be covered with blasting mats or other
protective material before firing, where blasting may cause
injury or damage by flying rock or debris.
(3) Before a blast is fired, the blaster in charge must give
a loud warning signal after they have verified all surplus
explosives are in a safe place and all employees, vehicles, and
equipment are at a safe distance or under sufficient cover.
(4) Flaggers must be safely stationed on highways that pass
through the danger zone, to stop traffic during blasting
operations on highways that pass.
(5) The blaster in charge must set the time of the blast and
conduct all blasting operations so no shots will be fired without
their approval.
TABLE T-1
WARNING SIGNAL
A 1 minute series of long blasts 5
minutes prior to blast signal.
BLAST SIGNAL
A series of short blasts 1 minute
prior to the shot.
ALL CLEAR SIGNAL
A prolonged blast following the
inspection of the blast.