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Subchapter 7. General Industry Safety Orders
Group 18. Explosives and Pyrotechnics
Article 114. Storage of Explosives
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§5256. Storage Within Magazines.

(a) Magazines shall be kept clean and free from rubbish. They shall not be used as storerooms for anything except explosive materials and transfer conveyors or other magazine tools while explosive materials are stored therein.

Sweepings from floors of magazines shall be properly disposed of. Magazine floors stained by leakage from explosive materials shall be cleaned according to instructions by the explosives manufacturer.

(b) Smoking, matches, open flames, spark producing devices and unauthorized fire arms shall be prohibited inside of or within 50 feet of magazines. Combustible materials shall not be stored within 50 feet of magazines.

(c) Fixed electric wiring in a magazine shall be equivalent to the requirements of Class II, Division 1, Hazardous Location, Electrical Safety Orders or may be more restrictive upon classification materials. The electric switch must be located outside of the magazine.

(d) When portable lights are necessary inside the magazine, permissible flash lights or permissible lanterns shall be used.

(e) Corresponding grades and brands of explosive materials shall be stored together in such a manner that brands and grade marks show. All stocks shall be stored so as to be easily counted and checked. Packages shall be piled in a stable manner and laid flat with top side up. Black powder, when stored in magazines with other explosive materials, shall be segregated by a sandbag barricade not less than 2 bags thick.

(f) When explosive materials are removed from a magazine, the oldest explosive materials of that kind in the magazine shall be taken and used first.

(g) Containers of bulk explosives shall not be unpacked or repacked in a magazine nor within 50 feet of a magazine or in close proximity to other explosive materials, except for manufacturing processes. Opened containers of bulk explosives shall be securely closed before being returned to a magazine.

(h) When magazines need inside repairs, all explosive materials shall be removed therefrom and the floors cleaned before work is started. In making outside repairs, if there is a possibility of causing sparks or fire, the explosive materials shall first be removed from the magazine.

(i) Explosive materials removed from a magazine under repair shall either be placed in another magazine or placed a safe distance from the magazine where they shall be properly guarded and protected until repairs have been completed and the explosive materials returned to the magazine.

(j) Every magazine used for the storage of explosive materials shall be under the supervision of a competent person who shall be not less than 21 years of age.

(k) Explosive materials shall not be piled/stored against interior walls so as not to interfere with ventilation.

(l) If buffer material is used to isolate the explosive material from the masonry walls, brick-lined or sand filled metal walls and single-thickness walls, it shall be so placed/ positioned as to not interfere with the ventilation provisions of the side and walls.

(m) Ammonium nitrate fuel oil (ANFO) blasting agent shall be physically separated from other explosives stored in the same magazine and in such a manner that oil does not contaminate other explosives.

(n) Magazine interiors shall be of a smooth finish without cracks or crevices with all nails, screws, bolts and nuts countersunk. Exposed metal or materials capable of emitting sparks shall be covered so as not to come in contact with packages of explosive materials.

Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.


1. Amendment filed 10-17-75; effective thirtieth day thereafter (Register 75, No. 42).

2. Amendment filed 7-16-76; effective thirtieth day thereafter (Register 76, No. 29).

3. Amendment of section heading and section and newNote filed 7-11-2003; operative 8-10-2003 (Register 2003, No. 28).

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