Absorption, metabolism, and disposition of 1,3-diphenyl-1-triazene in ratsand mice after oral, IV, and dermal administration

1,3-Diphenyl-1-triazene (DPT) is used in the synthesis of polymers and dyes , and has been found as an impurity in the color additives D&C Red 33 and F D&C Yellow 5. [C-14]DPT, randomly labeled in the phenyl rings, was used to investigate its disposition in rodents. Dermal doses to rats and mice (2 an d 20 mg/cm(2)) were poorly absorbed (less than or equal to 7%) in 72 h of e xposure. Oral doses of DPT (20 mg/kg) to male rats and mice were well absor bed and excreted mainly in the urine, with exhalation of volatile organics accounting for about 1% of the dose. The sole volatile component present in breath was benzene, and all of the metabolites present in urine were compo sed of those known for the differential metabolism of benzene and for anili ne in the two species. Benzene and aniline were detected in the blood of ra ts administered oral doses of DPT, and relatively high circulating levels o f their metabolites were measured as early as 15 min postdosing. Metabolite s of these two carcinogens were also formed in human liver slices, indicati ng a carcinogenic potential for DPT in humans.