2,5-ジチオビ尿素

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical. [http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=142-46-1]

In the manufacture of rubber, irritant contact dermatitis may occur from a variety of acids, alkalies, detergents, and solvents used in the process. Allergic contact dermatitis occurs not infrequently and is almost always due to an organic accelerator or antioxidant. While the list of potential sensitizing accelerators and antioxidants is enormous, common allergens include ... thioureas. /Thioureas/

2,5-Dithiobiurea

TR-132: Bioassay of 2,5-Dithiobiurea for Possible Carcinogenicity (CASRN 142-46-1) (1979 )

10/25/78

No Evidence

No Evidence

No Evidence

ADMIN TO MALE & FEMALE MICE IN FEED FOR 78 WK @ CONCN OF 1 & 2%. AMONG FEMALE MICE HIGH INCIDENCE OF HEPATOCELLULAR CARCINOMA, WHILE THERE WAS NO INCREASE IN CARCINOGENICITY IN MALE MICE AND CONTROLS.

INCR WT OF ADRENAL GLANDS & OVARIES IF FED DURING ESTRUS CYCLE TO GILTS. LOWER FOLLICLE STIMULATING HORMONE INDICATED INHIBITION OF SYNTHESIS. RELEASE OF LUTEINIZING HORMONE WAS SUPPRESSED, THIS SUPPRESSION WAS SUPPORTED BY LACK OF OVULATION AND ESTRUS.

ADMIN TO MALE & FEMALE RATS IN FEED FOR 78 WK AT CONCN OF 0.6 OR 1.2%. THERE WAS NO CARCINOGENICITY FOR EITHER MALE OR FEMALE RATS.

2,5-Dithiobiurea was found to be negative when tested for mutagenicity using the Salmonella/microsome preincubation assay, using the standard protocol approved by the National Toxicology Program (NTP). 2,5-Dithiobiurea was tested in as many as 5 Salmonella typhimurium strains (TA1535, TA1537, TA97, TA98, and TA100) in the presence and absence of rat and hamster liver S9, at doses of 0.001, 0.0033, 0.010, 0.033, 0.100, 0.333, and 1.000 mg/plate. The highest ineffective dose tested in any Salmonella typhimurium strain was 1.000 mg/plate.

A bioassay of 2,5-dithiobiurea for possible carcinogenicity was conducted using Fischer 344 rats and B6C3F1 mice. 2,5-Dithiobiurea was administered in the feed, at either of two concentrations, to groups of 50 male and 50 female animals of each species, with the exception of high dose male rats, of which there were only 49. The dietary concentrations used in the chronic bioassay were 0.6% for the low dose rats and 1.2% for the high dose rats. The dietary concentrations used for low and high dose mice were 1.0 and 2.0%, respectively. After a 78 week dosing period, observation of the rats continued for an additional 31 weeks and observation of the mice continued for an additional 16 weeks. For each species, 50 animals of each sex were placed on test as controls. Among female mice, the Cochran-Armitage test indicated a significant positive association between the incidence of hepatocellular carcinoma and dietary concentration of 2,5-dithiobiurea. According to results of the Fisher exact test, the incidence of hepatocellular carcinoma was significantly higher in the high dose female mouse group when compared to the corresponding control group but not when compared to the laboratory historical control data. No neoplasms occurred at a significantly higher incidence in dosed male mice than in their controls. Under the conditions of this bioassay, the evidence suggested, but was insufficient to establish the carcinogenicity of 2,5-dithiobiurea for female B6C3F1 mice. The compound was not carcinogenic to male B6C3F1 mice or to male or female Fischer 344 rats.