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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Key value for chemical safety assessment

Additional information

In a GLP conform Ames test according to OECD guideline 471 (and former OECD guideline 472), the test substance (purity 99.8%) was tested for gene mutations in Salmonella typhimurium strains TA100, TA1535, TA98, TA1537 and E. coli WP2 uvrA with or without metabolic activation. Here, a standard plate test (SPT) and a preincubation test (PIT) were performed in doses up to 5000 μg/plate in all strains; additionally, TA 1535 was tested up to 8000 µg/plate in the PIT. The test substance was weakly mutagenic in TA 1535 without metabolic activation system under the experimental conditions chosen, however, only in high doses >= 4000 µg/plate. Impurities rather than the test substance itself might be the cause for the effects observed. Therefore, the test substance Pyrazole ist finally considered as not mutagenic in the Ames test.

Another Ames test was performed with rather unconvenient Salmonella strains BA9 and BA13, the so called Ara mutation assay which is supposed to be highly sensitive to a wide variety of mutagens. With and without metabolic activation system, the test substance was not mutagen in doses up to 5000 µg/plate in the SPT and up to 5000 mg/mL in an LT (Duran et al. 1986).

In a further, narrowly described Ames test, the test substance was not mutagenic in S. typhimurium strains TA98, TA100, TA1535, TA1537 and TA1538 with and without metabolic activation system. No further information were given (Walsh and Claxton 1987).


Short description of key information:
in vitro
Gene mutation in bacteria
Ames test, S. typhimurium TA100, TA1535, TA98 and TA1537 and E. coli WP2 uvrA with and without metabolic activation: negative (weakly positive results in high doses were considered as caused by impurities; GLP, OECD 471; Rhone-Poulenc 1996)

Endpoint Conclusion:

Justification for classification or non-classification

The weakly positive result in the most valid Ames test is considered as caused by impurities since the increase of revertants appeared only at high doses. Based on that assessment and further negative results in other Ames tests, there is no indication given for a classification according to 67/548/EEC and GHS requirements, respectively.