{"data":{"id":"us-ca/lab-7979","jurisdiction":"us-ca","citation":"LAB § 7979","heading":"","body":"In tunnels or underground mines classified extrahazardous, sufficient air shall be supplied to maintain an atmosphere of all of the following conditions:\n(a) Not less than 19 percent oxygen.\n(b) Not more than 0.5 percent carbon dioxide.\n(c) Not more than 5 parts per million nitrogen dioxide.\n(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.","path":["Labor Code - LAB","DIVISION 5. SAFETY IN EMPLOYMENT [6300. - 9254.]","PART 9. TUNNEL AND MINE SAFETY [7950. - 8004.]","CHAPTER 2. Gassy and Extrahazardous Tunnels [7965. - 7985.]"],"source_url":"https://downloads.leginfo.legislature.ca.gov/pubinfo_2025.zip","current_through":"2026-09-13","vintage":"","retrieved_at":"2026-09-14T05:56:33Z","sha256":"26c4c8723605c23120cf52108482c79e88933f488227f84d82b58cd5eeeff3d4","source_id":"us-ca","stale":false,"prev":"us-ca/lab-7978","next":"us-ca/lab-7980"},"notice":"GroundRules: Original legal text. Not legal advice."}