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Subchapter 7. General Industry Safety Orders
Group 18. Explosives and Pyrotechnics
Article 116. Handling and Use of Explosives--Blasting Operations

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§5293. Misfires.

(a) After each shot the blast area shall be examined for misfires. If any are found, or suspected to exist, they shall be reported to the person in charge. Steps shall be taken to eliminate all undetonated explosive materials.

(b) In case of a detonator misfire, the shot area shall be made safe under competent supervision by one of the following means after a 30-minute wait following electric or non-electric shock tube blasting, or a 60-minute wait following fuse cap blasting:

(1) Where practical a new primer shall be inserted into the hole and the hole reblasted, or

(2) Where the hole cannot be reblasted, the stemming and explosive shall be washed out with water, or

(3) Where blasting agents are used, try to remove the detonator and cap sensitive explosive materials.

(4)(A) Where reblasting, washing, or removing explosive materials is unsafe or impracticable in a geophysical operation, the Division and surface owners shall be notified within 24 hours. The notice shall include the location, depth and the amount of the undetonated explosive material; and

(B) Following concurrence by the Division that retrieval of the explosive material in a misfired geophysical operation is impractical or unsafe, a substantial concrete cap capable of containing the explosion shall be placed above the explosive material at least 3 feet below the ground surface, or other permanent protection shall be installed.

(c) If explosive materials are suspected of burning in a hole, all persons in the endangered area shall move to a safe location and no one shall return to the hole until the danger has passed, but in no case within 1 hour.

(d) Holes shall not be drilled where there is danger of intersecting a charged hole of misfired explosives.

(e) No other work shall be performed in the danger area except that necessary to remove the hazard of the misfire. No other employees except the licensed blaster and the necessary crew shall be in the danger area when a misfire hazard is being removed.


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


1. New subsection (e) filed 3-28-75; effective thirtieth day thereafter (Register 75, No. 13).

2. Amendment of section and new Note filed 9-24-97; operative 10-24-97 (Register 97, No. 39).

3. Amendment of subsection (b), new subsection (c) and subsection relettering filed 7-11-2003; operative 8-10-2003 (Register 2003, No. 28).

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