Measurements were taken of airborne contaminants during the bulking of waste liquids at the United States EPA Chemdyne Cleanup Site in Hamilton, Ohio. Respiratory protection was worn during drum sampling and bulking operations. After testing for waste compatibility classification, drums containing compatible liquids were staged near one of three bulking chambers categorized as acid, base/neutral, or organic bulking chambers. Records indicated that several classes of chemical contaminants were on the site including volatile organics, polychlorinated biphenyls (1336363) (PCBs), strong acids and bases, pesticides, and polynuclear aromatics. Air samples were taken over a 2 day period and analyzed by Fourier transform infrared spectroscopy, gas chromatography/mass spectrometry, or a total hydrocarbon analyzer with photoionization detection. During the sampling period, a drum grappler dropped a drum of flammable organic, non PCB waste sludge. However, no significant exposure was demonstrated under this condition. General area monitoring revealed that concentrations were in the range of 0 to 5 parts per million except when showers occurred, which caused the measuring equipment to behave erratically. Vapors of organic volatiles and acid anions were detected downwind of the bulking chamber. The authors suggest that a proper evaluation of the potential inhalation exposure to hazardous materials for workers at hazardous waste sites with contaminants generated by unit processes or unit operations located outside a particular work area must be considered as well as contaminants generated by operations or processes where they work.