This information is provided free of charge by the Department of Industrial Relations from its web site at These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at

Subchapter 7. General Industry Safety Orders
Group 18. Explosives and Pyrotechnics
Article 120. Mixing Blasting Agents

Return to index
New query

§5344. Mix Room Equipment.

(a) Mixing facilities shall comply with the fire prevention requirements of this Section. The mixing equipment shall be designed to minimize the possibility of friction, heating, compaction, overloading, confinement, and the accumulation of static electricity.

(b) Bearings and gears shall be of the outboard type and protected from accumulation of explosive materials.

(c) All surfaces shall be accessible for cleaning. Mixers, pumps, valves and related equipment shall be designed to permit regular and periodic flushing, cleaning, dismantling and inspection.

(d) Mixing and packaging equipment shall be constructed of materials that are compatible with blasting agents.

(e) All electrical equipment in the mixing room shall conform to the requirements of the Electrical Safety Orders. The frame of the mixer and all other equipment used shall be effectively bonded.

(f) An automatic water-deluge system with adequate capacity shall be provided to protect mixers and the finished blasting agents storage area in the plant. The floors and equipment of the mixing and packaging room shall be washed down frequently to prevent accumulation of oxidizers, fuels, or sensitizers. The entire mixing and packaging plant shall be washed down periodically to prevent excessive accumulation of dust.

(g) Empty oxidizer bags shall be disposed of daily in a safe manner.

(h) Not more than 4 hours production of blasting agents or the limit determined by the Quantity and Distance Table, TABLE EX-1, Section 5252, whichever is less, shall be permitted in or near the mixing and packaging area. The total amount of oxidizer and blasting agents in the mix house shall be considered blasting agents in process.

(i) Equipment and handling procedures shall be designed to prevent the introduction of foreign objects or materials into the mix.

(j) Each day prior to starting operations, a visual inspection shall be made of the mixing, conveying, and electrical equipment to establish that such equipment is in good operating condition. A program of systematic maintenance sufficient to maintain the equipment in proper working order shall be conducted.


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 and new Note filed 7-11-2003; operative 8-10-2003 (Register 2003, No. 28).

Go BackGo Back to Article 120 Table of Contents