In efforts to investigate possible toxic interactions between 1,2- dichloroethane (107062) (DCE) and an agent used in the management of chronic alcoholism, disulfiram (97778) (DSF), male Sprague-Dawley- rats were fed the AIN-76 semisynthetic diet containing 0.15 percent DSF followed 10 days later by inhalation exposure to DCE. Effects on urinary compounds measured by the thioether assay were studied. Urine samples were collected at the end of DCE exposure days one, seven, 12, 17, 22, and 30, each over a 17 hour period. DSF affected urinary excretion of DCE derived thioether compounds and also affected the elimination of urinary thio compounds derived from DSF. DCE levels used in this study were equivalent to dosages of 98, 194, and 291mg/kg per day for exposures at 153, 304, and 455 parts per million, respectively. Decreased urinary thio compound production was noted for DCE/DSF groups of rats. In rats receiving only DCE, urinary thio compounds were dose related in quantity. The authors suggest that this may by caused by several time dependent factors, including compromised hepatobiliary and/or kidney excretory functions or DSF inhibition or saturation of a microsome dependent reaction of the glutathione pathway. The authors conclude that this assay alone is not adequate as a biological monitor for DCE or DSF exposure at these exposure concentrations when confounding chemicals may also be present in the workplace. Measurements of specific urinary metabolites or thio compound content may require supplementation by other biochemical or parameter monitoring to be sufficient. In cases where there is no exposure to compounds which would confound results, monitoring of urinary thioethers still appears to be useful for screening purposes.