Exposure Assessment of 3,3′-Dichlorobenzidine (DCB) at Two Chemical Plants

Abstract 3,3′-Dichlorobenzidine (DCB), an analogue of benzidine, has been an Occupational Safety and Health Administration (OSHA)-regulated carcinogen since 1974. This article presents a limited case study evaluating worker exposure to DCB at two pigment manufacturing plants. In each plant, exposure to DCB was estimated by personal breathing-zone (PBZ) and general area (GA) air samples, by skin patch and surface wipe samples, and by analysis of urine collected before and after the DCB-charging operation. Plant A performs the DCB-charging operation in a dedicated 12-ft × 10-ft enclosed room. Two workers perform the operation, each wearing full protective clothing and an air-supplied hood. After decontaminating the work area with a sodium hypochlorite bleach solution, the workers enter a “dirty” change room to undress, and then shower and change into clean work clothes in a “clean” change room. The levels of DCB found averaged 0.45 μg/m3, PBZ; 0.18 μg/m3, GA; and 0.04 μg/cm2, skin. Detectable levels of urin...