GASOLINE

      Previously, OSHA had no PEL for gasoline. The ACGIH has a 300-ppm 8-hour TWA and a 500-ppm 15-minute STEL for this substance. OSHA proposed a TWA PEL of 300 ppm and a STEL of 500, and these limits are established in the final rule.

       Studies have shown that exposure to 2000 ppm of gasoline for 30 minutes produces mild anesthesia, while exposure to concentrations between 500 and 900 ppm for one hour produces dizziness (Gerarde 1963a and Runion 1975, both as cited in ACGIH 1986/Ex. 1-3, p. 283). However, these authors also found that people exposed to gasoline at concentrations of 160 to 270 ppm for several hours do not experience any symptoms of narcosis but may, as Dr. Liem (Ex. 46) points out, experience eye and throat irritation.

       Several commenters noted that gasoline, or specific types of gasoline (i.e., unleaded), may cause kidney and liver damage and cancer, in addition to CNS effects (Exs. 3-746, 8-47, 194, 197; Tr. VII, pp. 70-76). Dr. Franklin Mirer, Director of the Health and Safety Department of the United Auto Workers, made the following statement, which is typical of the views of this group of commenters:

The crucial study in redefining the toxicity of aliphatic hydrocarbons is an inhalation bioassay of unleaded gasoline conducted by the American Petroleum Institute in 1984. The study found increased kidney tumors in male rats and liver tumors in female mice. The rat portion of the study gave definitely clear evidence of carcinogenic activity. Kidney tumors appeared in a group of rats exposed at 292 parts per million, although a statistical analysis was not documented in the published report. Of greater concern to me than the carcinogenic effect was that male rats also suffered a characteristic toxic kidney effect[s]. Indications of this toxicity appeared as early as three to six months in rats exposed at 47 parts per million (Tr. VII, pp. 70-71).

      NIOSH shares these concerns and commented (Ex. 8-47, Table N6B) that gasoline would be an appropriate candidate for a full Section 6(b) rulemaking.

       OSHA is aware that there is a recent and rapidly developing body of evidence about other health effects associated with exposure to gasoline and other petroleum materials and that this is an active area of toxicological research. However, the Agency agrees with the American Petroleum Institute (Ex. 124, p. 4) that complex and difficult scientific questions remain to be answered before conclusions can be drawn about these other potentially toxic effects of gasoline exposure. OSHA believes that it would be inappropriate to delay action on this substance at the present time. NIOSH representatives at the hearing (Tr. pp. 3-130, 3-131) agreed that, in the absence of a NIOSH REL for gasoline, promulgation of the proposed limits would constitute an appropriate first step in affording exposed workers protection against these health effects.

       OSHA is establishing an 8-hour TWA of 300 ppm, supplemented with a STEL of 500 ppm, to ensure that workplace exposure levels to gasoline do not exceed the TWA level for any length of time; these limits are intended to protect against narcosis. OSHA concludes that the 8-hour TWA and STEL being promulgated in the final rule will substantially reduce the significant risks posed to workers exposed to gasoline in their places of work. These exposure-related health effects, which include narcosis and liver and kidney damage, clearly constitute material impairments of health within the meaning of the Act.