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Administrative data

Key value for chemical safety assessment

Additional information

A key bacterial reversion assay (Ames test) was conducted on Diurea 8 together with a chromosomal aberration assay in human lymphocytes. In the Ames test, no significant increases in the frequency of revertant colonies were recorded for any of the strains of bacteria at any dose level, up to the maximum recommended, either with or without metabolic activation or exposure method. In the chromosome aberration test there was no increase in the frequency of cells with chromosome aberrations in either the presence or absence of a liver enzyme metabolising system in either of the experiments. In the case of both studies the results were negative, therefore Diurea 8 was considered to be non-mutagenic and non-clastogenic under the conditions of these tests.

As a consequence of the negative Ames test and chromosome aberration assay an in vitro mammalian cell mutation assay was undertaken, under Annex VIII requirements, to determine the potential for mutagenicity on the thymidine kinase locus of mouse lymphoma cells. In this study, dose levels up to the maximum, chosen on the basis of toxicity demonstrated in previous tests, did not induce any toxicologically significant dose-related increases in the mutant frequency at any dose level either with or without metabolic activation.


Justification for selection of genetic toxicity endpoint
No single study is selected as Diurea 8 has been subjected to three good quality guideline studies for genotoxocity covering three different genotoxicity mechanisms; an Ames in vitro reverse mutation study in bacteria, an in vitro chromosome aberration study in human lymphocytes and an in vitro mammalian cell gene mutation test in mouse lymphoma cells, all of which were negative.

Short description of key information:
in vitro:
- gene mutation (bacterial reversion assay/Ames test): Negative
- cytogenicity (chromosomal aberration assay in human lymphocytes): Negative
- gene mutation (mouse lymphoma cells): Negative

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Not classified for genetic toxicity based on negative results in all three in vitro studies conducted.