In underground blasting operations, explosives and blasting agents must be hoisted, lowered, or transported in a powder car.

1. (1) State approval. A state-approved powder car or conveyance must be used underground.

2. (2) Two-unit compartments. Compartments for transporting detonators and explosives together on the same conveyance must be physically separated by a:

   1. (a) Distance of twenty-four inches; or
   2. (b) Solid partition a minimum of six inches thick.
3. (3) Auxiliary lights prohibited. Auxiliary lights that are powered by an electrical system on a truck bed are prohibited.

4. (4) Daily inspection. The powder car or conveyance must be inspected daily for:

   1. (a) Properly working lights;
   2. (b) Properly working brakes;
   3. (c) External damage to electrical circuitry.

5. (5) Weekly inspection. Weekly inspections must:

   1. (a) Be conducted on the electrical system, to assess electrical hazards;

   2. (b) Include a written inspection certification record that:

      1. (i) Contains the date of inspection, the serial number, or other positive identification of the unit being inspected, and the signature of the person performing the inspection;
      2. (ii) Is kept on file for the duration of the job.

6. (6) Explosives warning sign. Powder cars or conveyance built for transporting explosives or blasting agents must have signs posted on each side of the car that:

   1. (a) State "EXPLOSIVES";
   2. (b) Use letters a minimum of four inches high;
   3. (c) Have a background color that sharply contrasts with the letters.

[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, and 49.17.060. WSR 17-16-132, § 296-52-68075, filed 8/1/17, effective 9/1/17. Statutory Authority: RCW 49.17.010, [49.17].040, and [49.17].050. WSR 02-03-125, § 296-52-68075, filed 1/23/02, effective 3/1/02.]