Abstract

Sherwood, R. J. (1972).Brit. J. industr. Med.,29, 65-69. Evaluation of exposure to benzene vapour during loading of petrol. The exposure of three workers to benzene vapour has been determined by personal air sampling, and has been related to their intake (assessed by sampling exhaled breath), and to their metabolism of benzene (evaluated from the concentration of phenol in urine.) The results obtained agree in general with those already published in the literature and with a preliminary experimental exposure undertaken as part of the development of techniques.

The two loaders who handled the loading arms were exposed to mean concentrations of 1·6 and 2·5 p.p.m. over the 5-hour period of loading. The probability of their exposure to concentrations greater than 25 p.p.m. was about 0·1 and 1%. The weigher working between the tracks was exposed to a mean concentration of 20 p.p.m. over the same period and had a total exposure of 114 p.p.m.-hour. Samples of exhaled breath taken at the end of work showed 0·14 and 0·18 p.p.m. benzene for the loaders and 0·84 p.p.m. for the weigher. The following morning the latter showed 0·19 p.p.m. Urine samples taken from the loaders at the end of work contained 12 and 25 mg/l total phenol and for the weigher 83 mg/l. The following morning the phenol was not above natural levels in the loaders' urine, and was 38 mg/l in a sample from the weigher.

It is suggested that any or all of the methods developed for this study could be used in conjunction with appropriate clinical studies to provide a more quantitative basis for determining the hazard of occupational exposure to benzene.