Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

It was concluded that H-CB is not mutagenic in the bacterial reverse mutation assay (JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals) carried out under the experimental conditions.

The test material did not induce any statistically significant, dose-related increases in the frequency of cells with structural or numerical chromosome aberrations either in the presence or absence of a liver enzyme metabolising system or after various exposure times. The test material was therefore considered to be non-c1astogenic to CHL cells in vitro (OECD Guideline 473 (In vitro Mammalian Chromosome Aberration Test)).

The test material was not mutagenic to L5178Y cells following a 4-hour exposure in the absence and presence of metabolic activation under the conditions of the test. However, the test material was considered to be mutagenic to L5178Y cells following a 24-hour exposure in the absence of metabolic activation at dose levels with significant levels of test material-induced toxicity under the conditions of the test (OECD Guideline 476 (In vitro Mammalian Cell Gene Mutation Test)).

The test material was considered to be non-genotoxic under the conditions of the test (OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)).


Short description of key information:
Four genetic toxicity studies have been conducted on the test material H-CB Sodium salt, three in vitro (Ames, Chromesome abberration and Mouse lymphoma) and one in vivo (Mouse micronucleus).

All studies indicated negative results however the mouse lymphoma also produced a positive result with metabolic activation.

All studies have been ranked 'reliability 1' according to the Klimisch et al scale as they were conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of relevant results.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Negative results were indicated in three of the genetic toxicity studies however a positive result was also noted in the mouse lymphoma study following a 24-hour exposure in the absence of metabolic activation.

Due to the positive result in the mouse lymphoma study an in vivo mouse micronucleus study was conducted, this gave a negative result indicating that the test material is not genetoxic and as a result would not be classifed according to Regulation (No.) EC 1272/2008 or Council Directive 67/548/EEC.