[Control of occupational exposure to benzene in a chemical plant].

Later on detection of several cases of acute myelotoxic intoxications the use of benzene as a solvent has been banned in Italy since 1963 (Law n. 245). Its consumption has therefore been confined to synthesys processes in petrolchemical industry. The hazards arising from the operations performed in an open air chemical plant which produces alkylbenzene were monitored by the AA. The synthesis occurs in a closed system which provides opportunities for benzene exposure during filling, control and maintenance operations. Nine environmental samples out of 10 showed benzene concentrations above 10 ppm with peaks up to 110 ppm. Long term air sampling showed values ranging from 12 to 75 ppm. Urinary phenol elimination has been measured showing values above 50 mg/1 for approximately 20% of workmen. The difficulties pertaining to an adequate control of benzene exposure in chemical plants are discussed. Being skin contact a mode of entry of apreciable concern, the AA. stress out that priority in exposure monitoring should be given to biological tests such as urinary phenol level and benzene concentration in expired air measurements.