Earlier editions: 2020-112018-11
DIVISION 5. SAFETY IN EMPLOYMENT 6300-9254›PART 9. TUNNEL AND MINE SAFETY 7950-8004›CHAPTER 2. Gassy and Extrahazardous Tunnels 7965-7985
§ 7979
California Labor Code · 2026 edition · updated 2026-10-04 · California
In tunnels or underground mines classified extrahazardous, sufficient air shall be supplied to maintain an atmosphere of all of the following conditions:
(a) Not less than 19 percent oxygen.
(b) Not more than 0.5 percent carbon dioxide.
(c) Not more than 5 parts per million nitrogen dioxide.
(d) No petroleum vapors or other toxic gases in concentrations exceeding the threshold limit values established annually by the American Conference of Governmental Industrial Hygienists.
(Added by Stats. 1972, Ch. 1430.)
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