US EPA

2755503 

Technical Report 

Toxicology and carcinogenesis studies of C.I. Pigment Red 3 in F344/N rats and B6C3F1 mice (feed studies) 

Ntp working group 

1992 

RISKLINE/1992050060 

407 

1992 

English 

Conclusions: Under the conditions of these 2-year feed studies, there was some evidence of carcinogenic activity of C.I. Pigment Red 3 in male F344/N rats as exhibited by increased incidences of benign pheochromocytomas of the adrenal gland. The marginal increase in the incidences of squamous cell papillomas of the skin and Zymbal's gland carcinomas may have been related to C.I. Pigment Red 3 administration. There was some evidence of carcinogenic activity of C.I. Pigment Red 3 in female F344/N rats as indicated by the increased incidence of hepatocellular adenomas. There was some evidence of carcinogenicity activity of C.I. Pigment Red 3 in male B6C3F1 mice as exhibited by the increased incidences of tubule adenomas of the renal cortex and follicular cell adenomas of the thyroid gland. There was no evidence of carcinogenic activity of C.I. Pigment Red 3 in female B6C3F1 mice that received 12,500, 25,000 or 50,000 ppm. The incidences of mononuclear cell leukemia and preputial gland tumors in male rats and mononuclear cell leukemia, mammary gland fibroadenoma, and clitoral gland tumors in female rats were lower in the exposed groups. The incidences of liver foci were markedly increased in exposed male and female rats. The severity of chronic nephropathy was increased in male rats and to a lesser extent in female rats given C.I. Pigment Red 3. An increase in the severity of nephropathy was observed in male and female mice; cytomegaly (karyomegaly) of renal tubule epithelium was observed in male mice. Thyroid follicular cell hyperplasia occurred with an increased incidence in male and female mice receiving C.I. Pigment Red 3.