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Subchapter 7. General Industry Safety Orders
Group 18. Explosives and Pyrotechnics
Article 121. Snow Avalanche Blasting

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§5358. Management of Misfires.

The following requirements shall apply to all avalanche blasting:

(a) Each person who deploys a charge with any kind of apparatus shall record whether or not the charge actually detonates pursuant to subsection (i);

(b) A conscientious effort shall be made to retrieve all misfires;

(c) Where a deployed charge is suspected of misfire, the slope shall remain closed and the licensed blaster shall wait at least thirty minutes before approaching the blast site. After the thirty minutes has elapsed, one of the following shall be accomplished to abate the condition:

(1) Rearm the misfired charge and detonate.

(2) Place another charge alongside the misfired charge and detonate.

(3) Retrieve and disarm the misfired handcharge in accordance with subsection (h), and the misfired avalauncher/launcher charges in accordance with manufacturer's recommendations.

(d) If subsections (c)(1), (c)(2), or (c)(3) above are not immediately possible due to terrain or storm conditions, the location of the misfire shall be carefully documented and marked so a search for the misfire can be undertaken as soon as conditions permit.

(e) When searching for a misfire on an uncontrolled avalanche slope (a slope which has not released), the procedures used shall be consistent with good mountaineering practices.

(f) Any misfire which is aflame or emitting smoke shall not be approached for at least one hour after evidence of combustion ceases.

(g) When a fuse of a handcharge does not light properly on the first attempt, it shall be considered a misfire and no further attempt shall be made to light it. The resulting misfire shall be deployed, and recovered pursuant to subsection (c), or disarmed pursuant to subsection (h).

(h) If a misfire occurs before a charge is deployed, a licensed blaster may disarm the armed handcharge as follows:

(1) The blaster shall disarm the misfired charge within 20 seconds after the igniter has been installed on the fuse end;

(2) The capped fuse shall be carefully removed from the cartridge avoiding any excessive twisting or pulling force;

(3) After the capped fuse is removed from the cartridge pursuant to subsection (h)(2), the cap shall be cut from the fuse assembly as close to the cap as possible or the capped fuse shall be placed in a safe location for later retrieval;

(4) The cap shall be protected and separately transported to a safe area or destroyed by attaching it to another handcharge for immediate deployment.

(i) Records.

(1) Accurate records shall be maintained for every explosive device which does not detonate, and shall be made available to the Division upon request.

(2) Misfire records shall include the following information:

(A) The suspected location;

(B) A description and type of charge;

(C) The date the misfire occurred;

(D) The date the misfire was found and disposed of.

(E) Determination of the cause of the misfire.

(j) Misfire warning signs.

(1) Ski area operations which use any form of explosive device for avalanche blasting shall display warning and information placards and/or signs.

(2) Signs shall be posted at readily visible locations and in such a manner as to give both employees and the public ample opportunity to be informed of the potential existence of misfire avalanche charges. Sign locations shall include, but are not limited to:

(A) Ticket sales and ski lift loading areas;

(B) Food and beverage service facilities;

(C) Restrooms and locker rooms;

(D) Safety bulletin boards;

(E) Along general access routes.

(3) Signs shall be distinctive in appearance from the surrounding background where they are posted.

(4) Signs shall be maintained in legible condition.

(5) Signs shall include the following information:

(A) The word "warning" or "danger" at the top of the sign in the largest lettering on the sign;

(B) Sign wording indicating that unexploded explosives could be encountered;

(C) A colored pictorial illustration which also provides information on dimensions of each type of explosive device used in the area;

(D) The sign wording shall conclude with specific instructions to be followed by anyone who locates an unexploded explosive device.

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


1. Amendment of first paragraph and subsection (d) and new Notefiled 9-24-97; operative 10-24-97 (Register 97, No. 39).

2. Amendment filed 7-11-2003; operative 8-10-2003 (Register 2003, No. 28).

3. Repealer and new section heading and amendment of section filed 10-10-2007; operative 11-9-2007 (Register 2007, No. 41).

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