Cal. Code Regs. tit. 8, § 7063
(a) One or more fire extinguishers of a type suitable for use underground shall be provided at all locations where electrical equipment is in service in the mine.
Carbon tetrachloride fire extinguishers shall not be permitted in a mine because of danger to men who may breathe the vapor.
(d) Every mine with a fire hazard as outlined below shall be protected against fire in accordance with the provisions of subsection (e) of this section:
(e) Mines required by subsection (d) of this section to be protected against fire shall be provided with water and equipment for fighting fires as follows: