Monitoring surveys of gasoline vapor exposures were conducted on truck drivers and terminal operators from five terminal loading facilities, on dockmen and seamen at two tanker/barge loading facilities, and on attendants at a single expressway service plaza. Results revealed wide variations in total C6+ hydrocarbon exposures for each location, with overall 8-hr time-weighted averaged (TWA) geometric means of 5.7 mg/m3 (1.4 ppm) for the terminals, and 4.0 mg/m3 (1.0 ppm) for the service plaza, respectively. The exposures ranged from 0.8 to 120.8 mg/m3 (0.2-30.1 ppm) for the terminals, and from 1.1 to 130.3 mg/m3 (0.3-32.5 ppm) for the service plaza. For the terminals, exposures were not significantly different regardless of loading method or the presence or absence of vapor recovery systems. Comprehensive chemical analyses of terminal employee exposure samples revealed that the C4 and C5 hydrocarbon components constituted 74.8 +/- 9.2% of the total exposure sample on a microgram/sample basis. The C6, C7, and C8+ components constituted 13.0 +/- 1.9, 6.2 +/- 3.0, and 5.9 +/- 7.2% of the total samples, respectively. Comprehensive analyses of the marine employee exposure samples resulted in a similar distribution of components; that is, 66.6 +/- 7.9, 17.5 +/- 4.7, 9.2 +/- 3.1, and 6.4 +/- 1.9% for the C4/C5, C6, C7, and C8+ components, respectively. The composition of the exposures, however, was weighted more toward the C5, C6 and C7 components when compared to the bulk terminal employee exposures.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of workplace exposures to gasoline vapors revealed that C4 and C5 hydrocarbons constitute anywhere from 67 to 74% by weight of a typical vapor. Furthermore, it was found that n-butane, isobutane, n-pentane, and isopentane together comprise greater than 90% of all the C4/C5 vapor components and approximately 61 to 67% by weight of the total vapor. Accordingly, a 21-day inhalation toxicity study of a blend consisting of 25% (w/w) each of these four hydrocarbons was conducted using rats to assess the potential for these major gasoline vapor components to induce kidney damage. No evidence of the kidney lesions typically associated with hydrocarbon-induced nephropathy was observed in rats exposed at up to 11 800 mg/m3 (4437 ppm) of the blend.