NTP Toxicology and Carcinogenesis Studies of C.I. Disperse Blue 1 (A commercial dye containing approximately 50% 1,4,5,8-tetraaminoanthraquinone, and 20% water) (CAS No. 2475-45-8) in F344/N Rats and B6C3F1 Mice (Feed Studies).
C.I. Disperse Blue 1, a component of several semipermanent hair dyes, was studied as a commercial-grade product (minus lignosulfonate dispersants) containing approximately 50% 1,4,5,8-tetraaminoanthraquinone, 30% other compounds structurally related to 1,4,5,8-tetraaminoanthraquinone, and 20% water. C.I. Disperse Blue 1 was studied for toxicity and carcinogenicity in single-administration gavage, 14-day feed, 13-week feed, and 104-week feed studies. All studies used F344/N rats and B6C3F1 mice. In the single-administration gavage studies, no deaths occurred within 14 days at doses up to 3,000 mg/kg C.I. Disperse Blue 1 in rats or up to 2,000 mg/kg in mice. In the 14-day studies, rats and mice received dietary concentrations of up to 50,000 ppm. All male rats survived, and 2/5 female rats in the 50,000-ppm group died. All mice receiving 25,000 ppm or more died. Three of five males and 2/5 female mice in the 12,500-ppm groups died. In the 13-week studies, diets containing concentrations up to 20,000 ppm C.I. Disperse Blue 1 were fed to rats, and diets containing concentrations up to 10,000 ppm were fed to mice. No compound-related deaths of rats occurred; however, pathologic changes occurred at 2,500 ppm and higher and included urinary tract calculi, urinary bladder inflammation, hyperplasia of the urinary bladder transitional epithelium, and nephrosis, Compound-related deaths occurred at 10,000 ppm in mice of each sex. Pathologic changes included chronic inflammation and hyperplasia of the urinary bladder transitional epithelium and urinary tract calculi at dietary concentrations of 2,500 ppm and higher and nephrosis, myocardial necrosis, and testicular degeneration at 10,000 ppm. The renal lesions at 5,000 ppm were considered to be potentially life threatening. These composite findings from the short-term studies were used to identify target organs and to help select dietary concentrations for the longer term studies. In the 2-year studies in rats, groups of 50 animals of each sex were administered C.I. Disperse Blue 1 at dietary concentrations of 0, 1,250, 2,500, or 5,000 ppm. These dietary concentrations corresponded to 0, 45, 95, and 217 mg/kg per day for males and 0, 56, 111, and 240 mg/kg per day for females. Survival of males and females in the 5,000 ppm groups and males in the 2,500-ppm group was significantly reduced. Final body weights, as percent of controls, were: male-- low dose 100%; mid dose, 94%; high dose, 85%; female-- low dose, 99%; mid dose, 94%; high dose, 87%. Compound-related effects of feeding diets containing C.I. Disperse Blue 1 for 104 weeks to F344/N rats included urinary bladder neoplasms and calculi at the incidences noted in the table. Positive statistical associations existed between the presence of calculi and transitional cell neoplasms of the urinary bladder in male and female rats, leiomyomas or leiomyosarcomas (combined) in female rats, and squamous cell neoplasms in male rats. The increased incidence of pancreatic islet cell adenomas or carcinomas (combined) in high dose male rats was significant by survival-adjusted analyses (overall incidences: control, 1/49; low dose, 2/50; mid dose, 5/50; high dose, 3/50). In the 2-year studies in mice, 50 animals of each sex were administered diets containing C.I. Disperse Blue 1 at 0, 600, 1,200, or 2,500 ppm. These dietary concentrations corresponded to doses of 0, 112, 239, and 540 mg/kg per day for males and 0, 108, 235, and 520 mg/kg per day for females. Survival was comparable among control and dosed male or female mice. Final body weights, as percent of controls, were as follows: male-- low dose, 97%; mid dose, 98%; high dose, 101%; female-- low dose, 110%; mid dose, 104%; high dose, 91%. The incidences of hepatocellular adenomas or carcinomas (combined) were increased for dosed male mice (9/50; 21/50; 16/50) and for low dose female mice (3/50; 13/49; 3/50; 4/50). Alveolar/bronchiolar adenomas or carcinomas (combined) occurred with an increased incidence in high dose male mice (4/50; 9/49; 5/50; 11/50). Several nonneoplastic effects were increased incidence in high dose male mice (4/50; 9/49; 5/50; 11/50). Several nonneoplastic effects were detected in the kidneys of mid dose and high dose male and high dose female rats and of all dosed groups of male and female mice. These effects on the kidney included calculi, hydronephrosis, and epithelial hyperplasia in rats and casts and renal tubular degeneration in mice. C.I. Disperse Blue 1 was studied for mutagenicity in Salmonella typhimurium in the presence or absence of Aroclor 1254-induced male Sprague-Dawley rat or male Syrian hamster liver S9. C.I. Disperse Blue 1 was mutagenic in strain TA1535 in the presence of S9 and in strains TA97 and TA98 in the presence or absence of S9; it was not mutagenic in strain TA100. An audit of the experimental data was conducted for the 2-year toxicology and carcinogenesis studies of C.I. Disperse Blue 1. No data discrepancies were found that influenced the final interpretations. Under the conditions of these feed studies of C.I. Disperse Blue 1, there was clear evidence of carcinogenicity for male and female F344/N rats as shown by the increased occurrence of transitional cell papillomas and carcinomas, of leiomyomas and leiomyosarcomas, and of squamous cell papillomas and carcinomas of the urinary bladder. Urinary bladder calculi were observed in the groups of rats in which urinary bladder neoplasms were increased. Positive associations existed between the presence of calculi and transitional cell neoplasms in male and female rats, leiomyomas or leiomyosarcomas (combined) in female rats, and squamous cell neoplasms in male rats. A marginally increased occurrence of pancreatic islet cell adenomas or carcinomas (combined) was observed in male rats exposed to C.I. Disperse Blue 1. There was equivocal evidence of carcinogenicity of C.I. Disperse Blue 1 in male B6C3F1 mice as shown by marginally increased incidences of hepatocellular adenomas or carcinomas (combined) in dosed male mice and a marginally increased occurrence of alveolar/bronchiolar adenomas or carcinomas (combined) in high dose male mice. There was no evidence of carcinogenicity of C.I. Disperse Blue 1 in female B6C3F1 mice. Synonyms: C.I. 64500; 1,4,5,8-tetraamino-9,10-anthracenedione; 1,4,5,8-tetraaminoanthraquinone