Urinary excretion of benzidine in relation to the acetylator status of occupationally exposed subjects.

Twenty-four male workers engaged in the manufacture of benzidine dihydrochloride for 1-4 years were included in this study. Urinary levels of free benzidine were estimated by high-pressure liquid chromatography in all the workers. Acetylator status of the workers was determined with sulphamethazine. There was substantial absorption of benzidine over an 8-h work shift. A significant correlation was observed between the rate of sulphamethazine acetylation and urinary excretion of free benzidine.