The Measurement of Phenol in Urine As An Index of Benzene Exposure

The measurement of phenol as a metabolic product of benzene was investigated in relation to its usefulness in evaluating exposures to benzene. Phenol was distilled from the urine and determined colorimetrically by a p-nitroaniline procedure. The average phenol content of normal urine is 30 mg/liter as determined by this method. Concentrations of phenol found in the urine of workers exposed to benzene and benzene-containing solvents were correlated with benzene concentrations in the air of the workrooms. A urinary phenol value of about 200 mg/liter was found for workers exposed to an average of 25 ppm of benzene in air.