The effects of occupational exposure to benzene (71432) on human health were discussed. After a brief mention of earlier findings, most of this testimony revolved around an ongoing mortality pattern study of workers exposed to benzene during the manufacture of a natural rubber cast film with the trade name Pliofilm. The cohort demonstrated a five fold excessive risk of total leukemia and a ten fold excess of myelogenous and monocytic leukemias combined. Except for the natural rubber base employed, benzene was the only solvent used in this process. Employees' 8 hour time weighted average exposures were fairly consistent with the recommended standard in effect at that time. In areas where excessive concentrations of benzene occurred, respiratory protection was required. A modification was recommended in the sampling and analytical method recommended by NIOSH in the criteria document. The sample should be collected on a standard charcoal adsorption tube at a sampling rate of 1 liter per minute and a sampling time of 1 hour, and desorbed with 0.5 milliliters of carbon-disulfide; benzene should be determined by gas chromatography using a flame ionization detector and a 5 microliter aliquot. According to this testimony, employees should be educated as to the potential dangers from benzene exposure, continuing education programs should be in place, and monitoring and recording of engineering control data should be emphasized to assure that engineering controls are effective and working properly.