A case of leukemia attributable to occupational benzene (71432) exposure was examined. A male laboratory technician who had used benzene to calibrate spectrophotometers from 1971 through 1975 developed leukemia 15 years later. He died 1 year later at the age of 42. Details of his work practices and benzene handling procedures described in a deposition taken from him in 1990, a year before he died, were reviewed. Replicates of the technician's benzene handling practices, as described in his deposition, were performed to estimate his benzene exposure. The technician's workplace was a laboratory with no windows or ventilation fans. He typically poured two or three drops of benzene from a pint bottle with a mouth opening of approximately 1 inch into a small glass cuvette that had a 0.15 inch square opening. The cuvette was then placed into the spectrophotometer for calibration. The technician also reported four or five sizable spills, one in which the benzene ran down his left arm and fell onto the floor. He usually mopped up the benzene with paper towels and discarded the towels in an uncovered trash can. The replicate pouring procedure was performed three times by a technician wearing a charcoal filter respirator in a well ventilated laboratory. This revealed that the pouring procedure was awkward and frequently resulted in skin contact with liquid and vaporized benzene occurring. Breathing zone benzene vapor exposures as high as 17 parts per million were measured. With the aid of published dermal exposure data, it was estimated that the technician may have absorbed 5 to 6 milligrams of benzene through the palm of his hand for every five calibrations he performed. The author concludes that the technician's benzene exposure was high and that this placed him at considerable risk for developing leukemia.