Cal. Labor Code - LAB § 7950. Section 7950.
This part shall be known and may be cited as “The Tom Carrell Memorial Tunnel and Mine Safety Act of 1972.”
CHAPTER 1. Tunnels and Mines [7950. - 7964.5.]
Cal. Labor Code - LAB 1.
in effectCal. Labor Code - LAB § 7951. Section 7951.
As used in this part:
(a)
Tunnel shall include excavation, construction, alteration, repairing, renovating, or demolishing of any tunnel except tunnel work covered under the compressed air safety orders adopted by the Occupational Safety and Health Standards Board and manhole construction.
(b)
“Tunnel” means an underground passageway, excavated by men and equipment working below the earth’s surface, that provides a subterranean route along which men, equipment, or substances can move.
(c)
“Mine” means any excavation or opening above or below ground used for removal of ore, minerals, gravel, sand, rock, or other materials intended for manufacturing or sale. It shall include quarries and open pit operations, other than a gravel pit or other pit where material is removed by a contractor or other person for his own use and not for sale to others. The term “mine” shall not include a mine that is operated exclusively by persons having a proprietary interest in such mine or by persons who are paid only a share of the profits from the mine, nor shall it include during any calendar year, any mine that produced less than five thousand dollars ($5,000) in ore, minerals, sand, rock, or other material during the preceding calendar year.
(d)
“Access shaft” means a vertical shaft used as a regular means of worker access to underground mines and tunnels under construction, renovation, or demolition.
(e)
“Lower explosive limit” means the lowest concentration at which a gas or vapor can be ignited or will explode.
(f)
“Face” means the head of the tunnel where soil is being removed, or that area in a mine where digging is underway.
(g)
“Muck” means excavated dirt, rock, or other material.
(h)
“Permissible equipment” means equipment tested and approved by the U.S. Bureau of Mines or acceptable to other authorities recognized by the division, and acceptable by the division, which is safe for use in gassy or extrahazardous tunnels or underground mines.
(i)
“Division” means the Division of Occupational Safety and Health.
(j)
“Board” means the Occupational Safety and Health Standards Board.
(k)
“Underground mine” means a mine that consists of a subterranean excavation.
Cal. Labor Code - LAB § 7952. Section 7952.
There shall be within the division a separate unit of safety engineers trained to inspect all tunnel construction and mine operations.
Cal. Labor Code - LAB § 7953. Section 7953.
Sufficient manpower shall be maintained to provide for four annual inspections of underground mines, one inspection of surface mines or quarries annually, and six inspections of tunnels under construction annually.
Cal. Labor Code - LAB § 7954. Section 7954.
To assist the unit of safety engineers in determining the safety of tunnel construction and mine operation, the division shall make available at least one industrial hygiene engineer and one chemist. A laboratory for analysis of dust, gas, vapors, soil, or other materials shall be available to members of this unit. Contracts to provide for geological and other services may be signed by the division whenever it is necessary to assure safety for employees engaged in mining or tunnel work.
Cal. Labor Code - LAB § 7955. Section 7955.
The division and the owner of a mine, if he is not the operator of the mine, shall be notified before any initial mining operation or construction may be started at any mines or tunnels. A prejob safety conference shall be held with an authorized representative of the division for all underground operations. Representatives of the tunnel or mine owner, the employer, and employees shall be included in the prejob safety conference.
The division shall classify all tunnels or underground mines operating on the effective date of this section, or which commence operation thereafter, as one of the classifications set forth in subdivisions (a) to (d), inclusive. Such classification shall be made prior to the request for bids on all public works projects, whenever possible. This shall not, however, prevent the division from reclassifying such mines or tunnels when conditions warrant it.
(a)
Nongassy, which classification shall be applied to tunnels or underground mines where there is little likelihood of encountering gas during the construction of the tunnel or operation of an underground mine. Such tunnels shall be constructed or underground mines operated under regulations, rules, and orders developed by the division and board and approved by the board. This subdivision shall not prohibit the division chief or his representatives from establishing any special orders that they feel are necessary for safety.
(b)
Potentially gassy, which classification shall be applied to tunnels or underground mines where there exists a possibility gas will be encountered.
(c)
Gassy, which classification shall be applied to tunnels or underground mines where it is likely gas will be encountered. Special safety measures, including those set forth in Sections 7965 to 7976, inclusive, those established by the division and board and adopted by the board, or special orders written by the chief or his representatives shall be observed in construction of gassy tunnels in addition to regular rules, orders, special orders, or regulations.
(d)
Extrahazardous, which classification may, when the division finds that there is a serious danger to the safety of the employees, be applied to tunnels or underground mines where gas or vapors have caused an explosion or fire, where the likelihood of encountering petroleum vapors exists, or where tests show, with normal ventilation, a concentration of hydrocarbon petroleum vapors in excess of 20 percent of the lower explosive limit within three inches of the roof, face, floor, or walls of any open workings. Construction in extrahazardous tunnels or operation in extrahazardous underground mines shall conform to safety measures set forth in Sections 7977 to 7985, inclusive, any rules, regulations, orders, or special orders of the division, or any special rules, orders, or regulations adopted by the board.
The division shall not be required to reclassify any tunnel or underground mine that is shut down seasonally, when such tunnel or underground mine is put back into operation in not less than six months after date of the shutdown.
Cal. Labor Code - LAB § 7956. Section 7956.
All personnel, including both employees working above ground and those in the tunnel or underground mine, shall be informed of the classification designated by the division for that job. A notice of the classification and any special orders, rules, or regulations to be used in construction, remodeling, demolition, or operation of the tunnel or underground mine shall be prominently posted at the site.
Cal. Labor Code - LAB § 7957. Section 7957.
An emergency rescue plan shall be developed by the employer for every tunnel or underground mine. Such plan, including a current map of the tunnel or underground mine, shall be provided to local fire and rescue units, to the division, and to every employee at the place of employment.
Cal. Labor Code - LAB § 7958. Section 7958.
A trained rescue crew of at least five men shall be provided at underground mines with more than 25 men or tunnels with 10 or more men underground at any one time. Smaller mines shall have one man for each 10 men underground who receives annual training in the use of breathing apparatus. Two trained crews shall be provided at mines with more than 50 men underground and at tunnels with more than 25 men underground.
Cal. Labor Code - LAB § 7959. Section 7959.
Rescue crews shall be familiar with all emergency equipment necessary to effect a rescue or search for missing employees in case of an accident or explosion. Such rescue crews shall hold practices with equipment and using emergency rescue plan procedures at least once monthly during construction or operation of the tunnel or underground mines. At least one rescue crew shall be maintained above ground at all times and within 30 minutes travel of the tunnel or underground mine site classified as gassy or extrahazardous.
Cal. Labor Code - LAB § 7960. Section 7960.
In any tunnel or underground mine classified as potentially gassy, tests for gas or vapors shall be made prior to start of work at each shift. If any concentration of gas at or above 10 percent of the lower explosive limit is recorded, the division shall be notified immediately.
Cal. Labor Code - LAB § 7961. Section 7961.
The division shall investigate immediately any notification of a gas reading 10 percent of the lower explosive limit or higher by an employer in a tunnel or underground mine classified as potentially gassy. If the inspection determines the likelihood of encountering more gas or vapor, the division may halt operations until the tunnel or mine can be reclassified.
Cal. Labor Code - LAB § 7962. Section 7962.
A safety representative qualified to recognize hazardous conditions and certified by the division shall be designated by the employer in any tunnel or underground mine. He shall have the authority to correct unsafe conditions and unsafe practices, and shall be responsible for directing the required safety programs.
Cal. Labor Code - LAB § 7963. Section 7963.
All underground mines and tunnels with more than five men underground at one time shall have telephone or other communication systems to the surface in operation at any time there are persons underground. Such systems shall be installed in such a manner that destruction or removal of one phone or communication device does not make other phones or communication devices inoperative.
Cal. Labor Code - LAB § 7964. Section 7964.
Whenever an access shaft is used as the normal means of entrance or exit to an underground mine or tunnel, it shall be constructed of fireproof material or fireproofed by chemical or other means.
Cal. Labor Code - LAB § 7964.5. Section 7964.5.
Nothing contained in this part shall restrict the division in contracting with the Secretary of the Interior for an approved state plan for mines under P.L. 89-577 (30 U.S.C. 721 et seq.).
Source: CA Legislative Counsel Bulk DataURL: https://downloads.leginfo.legislature.ca.gov/pubinfo_2025.zipFetched: 6/27/2026