Due to the interest in reducing the benzene exposure limit from 10 to 1 ppm, the benzene exposure data collected since 1977 were compiled and evaluated. Some 38,000 data points representing either time-weighted air samples or persons exposed were collected from five industries which produce and/or use benzene and two government organizations. Of the reported data, 87% represented exposure levels of 1.0 ppm or less. Petroleum and chemical operations where elevated exposure levels were reported included petrochemical and bulk loading operations. Benzol and by-product plants in the iron and steel industry showed similar elevated results.