053-4 Wyo. Code R. § 75.322
Concentrations of noxious or poisonous gases, other than carbon dioxide, shall not exceed the threshold limit values (TLV) as specified and applied by the American Conference of Governmental Industrial Hygienists in -Threshold Limit Values for Substance in Workroom Air- (1972). Detectors or laboratory analysis of mine air samples shall be used to determine the concentrations of harmful, noxious, or poisonous gases. This incorporation by reference has been approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies are available from the Mine Safety and Health Administration, Department of Labor, 4015 Wilson Boulevard, Arlington, VA 22203 and at every Coal Mine Health and Safety District and Subdistrict Office. The material is available for examination at the Office of the Federal Register, 800 N. Capitol Street, NW., 7th Floor, Suite 700, Washington, D.C. 20408
053-4 Wyo. Code R. § 75.322