There is no OSHA standard or permissible exposure level of asphalt fumes, although a 5 mg/m3 permissible exposure limit (PEL) was proposed in 1992. OSHA’s quantitative risk assessment estimated a significant risk of lung cancer among exposed workers at levels as low as 0.2 mg/m3. The American Conference of Governmental Industrial Hygienists (ACGIH) currently recommends a Threshold Limit Value (TLV) of 0.5 mg/m3 as an 8-hour time weighted average. NIOSH currently recommends no more than 5 mg/m3 for a maximum exposure per 15-minute short-term exposure in addition to assigning a carcinogenicity designation. Some states do have their own limits. For example, Cal/OSHA’s permissible exposure level (PEL) for asphalt fumes is 5mg/M3 with additives having their own PELs.