Abstract
Benzene and total hydrocarbon (as hexane) exposures were measured during removal, cleaning, pumping, and testing of underground gasoline storage tanks at five gasoline retail outlets in New Jersey during 1988. Personal air samples were collected using 3M 3500 Organic Vapor Monitors with sampling times ranging from 15 minutes to 6.5 hours. Benzene exposures to the observer ranged from 0.12 to 0.43 ppm (sampling times ranging from 4.75 to 6.5 hours). Benzene exposures to laborers during tank removal (including cutting and cleaning) ranged from 0.43 to 3.84 ppm (sampling times ranging from 1.5 to 6 hours). The highest short-term benzene exposure was 9.14 ppm (sampling time 15 minutes) for a tank cleaning assistant. Benzene exposures during tank cutting ranged from 2.16 to 4.57 ppm (sampling times ranged from 0.5 to 3 hours). Benzene exposure to a tank tester was 0.23 ppm (sampling time of 4.75 hours). Total hydrocarbons as hexane were also determined. The mean ratio of benezene to total hydrocarbon concentrations was 0.028 (n = 21, S.D. 0.02). Gasoline tanks were not purged of vapors prior to being removed, cut open, and cleaned. This raises a safety issue (flammable/combustible vapor hazard) in addition to changing the time, duration, and magnitude of benzene exposure during the tank removal process. Dermal exposure to gasoline was frequent.