1. (1) Employee evacuation. The blaster must make sure all employees are out of the blast area before firing a blast.

2. (2) Guarding entrances. All entrances:

   1. (a) Leading into the blasting area must be carefully guarded.
   2. (b) To any working place where a drift, raise, or other opening is about to hole through must be carefully guarded.

3. (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, § 296-52-67235, filed 1/23/02, effective 3/1/02.]