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Subchapter 20. Tunnel Safety Orders
Article 14. Fire Prevention and Control

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§8445. General.

(a) Combustible structures shall not be erected over shafts or tunnel openings.
Exception: Head frames, bins, and doors or hatches required for closing the opening.
(b) All shafts and tunnel openings used as a normal means of access and egress or as the main intake of fresh air for underground workings shall be constructed of noncombustible material or designed with a fire-resistance rating of 1 1/2 hours or more.
(c) Combustible framing sheds, storage buildings or change houses shall not be located within 100 feet of any tunnel opening, shaft house, hoisting engine house or ventilating fan house.
Temporary stockpiles of timber, or buildings that are as fire resistant as a change house with concrete floor, wood frame and corrugated iron sheathing may be located within the 100-foot limit if they are as far as practicable from the tunnel opening. Other combustible material shall not be stored or permitted within 100 feet of any tunnel opening.
(d) Fire protection shall be provided in accordance with Title 8, Group 27 of the General Industry Safety Orders commencing with Section 6150.
(e) Oils and other dangerous flammable material shall be stored at least 100 feet from any shaft or tunnel opening, or building over a tunnel opening, and at least one hundred feet from any powder magazine. Where oils are stored in buildings, such buildings shall not be used for other purposes. LPG storage tanks shall be located away from tunnel openings to prevent the contents from flowing into the tunnel.
Tanks and drums containing flammable or combustible liquids shall be so located that the escaping liquid cannot run over the surface from such tank to any powder magazine or to any building, within 100 feet of any tunnel opening. Under no circumstances shall oxygen or any flammable gas be stored in proximity to oil.
(f) Lubricating oils, greases and rope dressings taken underground shall be in closed metal containers that will not permit the contents to leak out or spill. When taken underground, they shall be stored in a fire resistant secluded place at least 100 feet from shafts, winzes, hoists, and tunnel timbers and at least 300 feet from powder magazines and stored in such manner that the oil from a ruptured or overturned container will not flow from its storage place. Quantities of oil and grease underground shall be limited to a one-day supply.
(g) Welding, cutting, and other hot work shall be conducted in accordance with Title 8, Article 4 and Article 32 of the Construction Safety Orders. Where welding, cutting and other hot work operations are employed, and when such operations may cause fires, suitable shields shall be provided to isolate flammable materials. Appropriate fire extinguishers shall be provided and maintained. Thorough inspections for fire hazards shall be made immediately after welding, cutting and other hot work is completed and a fire watch maintained at the location for at least one hour.
(h) No petroleum based product shall be taken underground for illuminating or heating purposes.
(i) The use of volatile solvents (below 100 degrees F. flash point) such as gasoline underground are prohibited.
(j) No more than the amount of acetylene and oxygen cylinders necessary to perform welding, cutting or other hot work during any 24-hour period shall be permitted underground.
(k) Noncombustible barriers shall be installed below welding, cutting, or other hot work being done over a shaft or deep excavation associated with a tunnel.
(l) All oily waste or rags used underground shall be stored in metal receptacles with secure covers. The contents of the receptacles shall be sent to the surface every week or when the receptacle is full.
(m) Waste materials for which no underground storage facilities are provided shall be promptly removed from the tunnel. Leaks and spills of flammable or combustible fluids shall be cleaned up immediately.
(n) Fire resistant hydraulic fluids shall be used in hydraulically-actuated underground machinery and equipment unless such equipment is protected by a fire suppression system or by a multi-purpose fire extinguisher(s) rated at a sufficient capacity for the type and size of hydraulic equipment involved, and rated at least 4A:40B:C.
(o) A fire extinguisher of at least 4A:40B:C rating or other equivalent extinguishing means shall be provided at the head pulley and at the tail pulley of underground belt conveyors and at 300 foot intervals along the belt line.
(p) Fires which may cause serious injury to employees or threatening occupied tunnel workings shall be reported to the Division within 24 hours.
(q) Suitable fire extinguishers or other fire protection equipment shall be provided at appropriate locations. Such equipment shall be inspected monthly and maintained in operating condition.
(r) Straw, hay or similar material shall not be taken underground.
(s) Excelsior when used underground shall be made fire resistant and shall not be used in any place where welding or cutting is anticipated.
(t) Readily visible sign prohibiting smoking and open flames shall be posted in areas having fire or explosive hazards.
Note: Authority cited: Sections 142.3 and 7997, Labor Code. Reference: Sections 142.3 and 7997, Labor Code.
1. Amendment of section heading and subsection (a), new subsection (b) and subsection relettering, amendment of newly designated subsection (c), new subsection (d), renumbering and amendment of former section 8446 as new subsections (e)-(t) and new Note filed 3-5-96; operative 4-4-96 (Register 96, No. 10).

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