Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 279-093-7 | CAS number: 79135-92-5
In Main Assay I neither precipitation of the test item, nor toxicity was observed at the end of the incubation period, with any tester strain, at any concentration tested, in the absence or presence of S9 metabolism. In the absence of S9 metabolism, an increase in revertant numbers (2.4-fold) was seen with TA1537 tester strain at an intermediate dose level. A slight increase was also observed with TA100 tester strain at higher concentrations. Based on these equivocal results, Main Assay II was performed using the Prival modification method and the same concentration range.
No precipitation of the test item was observed at the end of the incubation period, with any tester strain, at any concentration tested, in the absence or presence of S9 metabolism. Toxicity, as indicated by thinning of the background lawn and reduction in revertant colonies, was observed with TA1537 and TA100 tester strains at the two highest dose levels in the absence of S9 metabolism.
Dose-related increases in revertant numbers were observed with TA1537 (1.9-fold), TA98 (2.3-fold) and TA100 (2.0-fold) tester strains in the presence of S9 metabolism. At higher dose levels, the number of revertant colonies fell out the current historical control range for negative controls. No relevant increases were observed with the remaining tester strains.
VALIDITY CRITERIA FULFILLED
The estimated numbers of viable bacteria/plate (titre) fell in the range of 100 - 500 million for each strain. No plates were lost through contamination or cracking. The study was accepted as valid.
The test item was examined for the ability to induce gene mutations in tester strains of Salmonella typhimurium and Escherichia coli, as measured by reversion of auxotrophic strains to prototrophy. The test was performed according to the OECD Guideline 471 (1997) and the EU method B.13/14 of EC 440/2008. The five tester strains TA1535, TA1537, TA98, TA100 and WP2 uvrA were used. Experiments were performed both in the absence and presence of metabolic activation, using liver S9 fraction from rats pre-treated with phenobarbital and 5,6 -benzoflavone (standard metabolic activation) in Main Assay I, and liver S9 fraction from uninduced hamsters (reductive metabolic activation system using the Prival modification method), in Main Assay II. The test item was used as a solution/suspension in sterile water for injection. As limited by solubility, the test item was assayed in the toxicity test at a maximum concentration of 2500 µg/plate and at four lower concentrations.
On the basis of toxicity test results, in order to evaluate a potential mutagenic effect up to cytotoxic or insoluble concentrations, in the Main Assays an additional dose level of 5000 µg/plate was employed. In Main Assay I, using the plate incorporation method and the standard S9 metabolic activation system, the test item was assayed at five dose levels from 313 to 5000 µg/plate. Neither precipitation of the test item, nor toxicity was observed at the end of the incubation period, with any tester strain, at any concentration tested, in the absence or presence of S9 metabolism.
As no relevant increase in revertant numbers was observed at any concentration tested, Main Assay II was carried out using the pre-incubation method in the presence of a reductive metabolic system. The test item was assayed at the same dose levels. No precipitation of the test item was observed at the end of the incubation period, with any tester strain, at any concentration tested, in the absence or presence of S9 metabolism. Toxicity was observed with TA1537 and TA100 tester strains at the two highest dose levels in the absence of S9 metabolism. Dose-related and biologically relevant increases in revertant numbers were observed with TA1537, TA98 and TA100 tester strains in the presence of S9 metabolism. These increases were greater than twice the control values with TA98 and TA100 tester strains and so can be considered as clear evidence of mutation induction.
Thus, the test item induces reverse mutation in bacteria in the presence of a reductive metabolic activation system, under the reported experimental conditions.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Close Do not show this message again