Section 7057 - Mine Exit Protection(a) Each mine required to maintain an escape exit shall protect underground employees against the hazard of all exits becoming impassable because of fire or fire gases by one or more of the following methods: (1) By fireproofing the main shaft and shaft stations where there is a fire hazard sufficient to interrupt use of the main shaft hoist for rescue purposes.(2) By maintaining a connecting passageway between working levels of such mine and an adjoining mine which has a safe access to the surface.(3) By mechanical control of the air currents that will permit good air to be supplied through any shaft or escapeway by reversal of air currents.(4) By installation of fire doors and ventilation doors satisfactory to the Division.(5) If none of the foregoing methods can be made applicable to a particular mine, such mine may be required by the Division to install a hoist in an escape exit and keep it in a usable condition.Cal. Code Regs. Tit. 8, § 7057