1. (1) Separation distance. When two or more storage magazines are located on the same property, each magazine must comply with the minimum quantity of explosives and separation distance requirements for:

   1. (a) Magazines (Table H-21);
   2. (b) Inhabited buildings, railways, and highways (Table H-20).

2. (2) Distances that do not meet requirements. If the separation distance between two or more magazines is less than the distance required (Table H-21), the magazines must:

   1. (a) Be considered one magazine; and
   2. (b) Comply with the minimum distance requirements for inhabited buildings, railways, and highways (Table H-20).
3. (3) Distance of grouped magazines to other magazines. Each magazine in a group must comply with minimum magazine distance requirements (Table H-21) in relation to other magazines not considered part of the group.

4. (4) Quantity of explosives.

   1. (a) Magazine group. The total quantity of explosives stored in a magazine group (two or more) must:

      1. (i) Be considered one magazine;
      2. (ii) Not exceed the requirements of Table H-21 for one magazine.
   2. (b) Detonator magazine. The quantity of explosives contained in a detonator magazine takes precedence over the minimum magazine distance requirements (Table H-21) when determining the separation distance required between a detonator magazine and magazines that contain other types of explosives.

   3. (c) Detonator strength. Strengths of blasting and electric detonators:

      1. (i) Up to #8 detonators must be rated as one and one-half pounds of explosives per one thousand detonators;
      2. (ii) Detonators greater than #8 must be computed on the combined weight of explosives.

[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, and 49.17.060. WSR 17-16-132, § 296-52-69085, 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, § 296-52-69085, filed 1/23/02, effective 3/1/02.]