PDFWAC 296-52-67235
Firing the blast.
(1) Employee evacuation. The blaster must make sure all employees are out of the blast area before firing a blast.
(2) Guarding entrances. All entrances:
(a) Leading into the blasting area must be carefully guarded.
(b) To any working place where a drift, raise, or other opening is about to hole through must be carefully guarded.
(3) Warning signals. A warning must be given before firing an underground blast. See Table T-1 for signaling requirements.
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. |
[Statutory Authority: RCW 49.17.010, [49.17].040, and [49.17].050. WSR 02-03-125, ยง 296-52-67235, filed 1/23/02, effective 3/1/02.]