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

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§5348. On-Site Mixed Water Gels and Blasting Agents.

(a) The composition of field mixed blasting agents and water gels shall comply with Section 5340.

(b) Liquid fuels shall be stored in separate tanks with shut-off valves. Solid fuels shall be stored in separate containers until mixed.

(c) Ingredients in themselves classified as explosive materials, shall be stored in compliance with Article 114.

(d) Liquid ammonium nitrate spills or leaks shall be cleaned up immediately.

(e) Mixing equipment shall comply with the following requirements:

(1) If electric power is used, it may be furnished by cable from an outside source or by a self-contained motor generator. In case of a self-contained power source, it shall be located at the end of the storage container opposite that which the blasting agent is discharged. It shall have adequate capacity for the loads to be expected and be equipped with suitable overload protection devices.

(2) Electric wiring and motors shall conform to the requirements of the Electrical Safety Orders.

(3) All exposed metal parts, electric equipment and personnel shall be placed at the same potential by electrical bonding.

(4) All moving parts of the mixing system shall be designed to prevent a heat build up. Shafts or axles which contact the product shall have outboard bearings with one-inch minimum clearance between the bearings and the outside of the product container. Particular attention shall be given to the clearances on all moving parts.

(5) Mixing equipment and other transfer equipment shall be compatible with blasting agents.

(f) Sensitized blasting agents shall not be pulverized or crushed.

(g) Each mixer unit shall be equipped with an operable, UL approved fire extinguisher, 4-A:20-B:C or equivalent.

(h) All unused explosives shall be returned to their proper magazines or designated storage area, upon completion of loading operations.

(i) A warning sign shall be posted on the front, sides, and rear of the mixing unit reading: “EXPLOSIVES” in red letters at least 4 inches high, with a 5/8-inch stroke, on a white background.

(j) Repairs to bulk delivery and/or mixing vehicles shall conform with the following requirements:

(1) No welding or open flames shall be used on or around any part of the delivery equipment unless it has been completely washed down and all oxidizer material removed.

(2) Before welding or repairs to hollow loading shafts, the shaft shall be thoroughly cleaned inside and out and vented.

(k) The entire loading and mixing equipment shall be cleaned to prevent hazardous accumulations of ingredients and before open flame work is performed on the unit.

(l) Intransit mixing of blasting agents shall not be performed.

(m) The operator shall be trained in the safe operation of the vehicle together with its mixing, conveying, and related equipment and shall be familiar with the commodities being delivered and the general procedure for handling emergency situations.

(n) Caution shall be exercised in the movement of the vehicle in the blasting area to avoid driving the vehicle over or dragging hoses over firing lines, detonator wires, or explosive materials. The driver in moving the vehicle shall obtain the assistance of a second person to guide the movements.

(o) The location chosen for water gel or ingredient transfer from a support vehicle into the borehole loading vehicle shall be away from the blast hole site when the bore holes are loaded or in the process of being loaded.

(p) No person shall smoke, carry matches or any flame-producing device, or carry any fire arms while in or about bulk vehicles effecting the mixing transfer or down-the-hole loading of blasting agents at or near the blasting site.


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 of subsection (d) filed 11-18-76; effective thirtieth day thereafter (Register 76, No. 47).

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

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