Investigation of possible metabolism of pigment yellow 17, a 3,3'-dichlorobenzidine-based pigment, after inhalation exposure in rats.

Rats were exposed by inhalation to the technically highest administrable concentration of 230 mg Pigment Yellow 17/m3 air for 4 h. Inhalability of the dust was guaranteed by a mass-median aerodynamic diameter of 1.0-1.1 microns. For 14 days after exposure, urine and serum samples were analysed for 3,3'-dichlorobenzidine, the parent carcinogenic amine of the test compound. No 3,3'-dichlorobenzidine could be detected either in urine or blood, the detection limit being 5 ng/ml for both media. Based on the results of this study there is no evidence for metabolic cleavage of Pigment Yellow 17 to 3,3'-dichlorobenzidine in the rat.