{"code":"LAB","codeName":"Labor Code","section":"7979","citation":"Lab. Code, § 7979","status":"in-force","lawOn":"2026-09-28","headings":[{"name":"DIVISION 5. SAFETY IN EMPLOYMENT [6300. - 9254.]","url":"https://blackletter.si/labor-code/division-5"},{"name":"PART 9. TUNNEL AND MINE SAFETY [7950. - 8004.]","url":"https://blackletter.si/labor-code/division-5/part-9"},{"name":"CHAPTER 2. Gassy and Extrahazardous Tunnels [7965. - 7985.]","url":"https://blackletter.si/labor-code/division-5/part-9/chapter-2"}],"history":"Added by Stats. 1972, Ch. 1430.","effective":null,"html":"<p>In tunnels or underground mines classified extrahazardous, sufficient air shall be supplied to maintain an atmosphere of all of the following conditions:</p><p>(a) Not less than 19 percent oxygen.</p><p>(b) Not more than 0.5 percent carbon dioxide.</p><p>(c) Not more than 5 parts per million nitrogen dioxide.</p><p>(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.</p>","text":"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.","otherVersions":[],"url":"https://blackletter.si/labor-code/gassy-and-extrahazardous-tunnels-7979","source":"California Legislative Information bulk export (pubinfo)"}