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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

  • Concerning the Ames test

Tests in bacterial systems are not appropriate for metal and metal compounds due to a lack of sensitivity related to either probable mechanism of action or lack of metal uptake.The high prevalence of false negatives for metal compounds might suggest that mutagenesis essay with mammalian cells, as opposed to bacterial cells, would be preferred starting point.

 

  • Concerning the in vitro mammalian cells tests

Although no data is available on the genotoxic potential of hafnium dioxide, one may safely assume that HfO2 as such cannot cross cellular membranes, but instead only the hafnium cation, the active form. Therefore, read across with reference to information on the mutagenicity of other similar substances (like ZrO2) is clearly warranted.

 

An in vitro cytogenicity study in mammalian cells with ZrO2 (according to OECD 473 guideline) and in vitro gene mutation study in mammalian cells with ZrO2 (OECD 476 guideline) were realised. The soluble Zr cation, the active form, was tested, so the results could be used to read across. The result of the two tests performed with ZrO2 was negative: under the experimental conditions, no chromosome aberration or gene mutation was induced in mammalian cells.

 


Short description of key information:
Mutagenicity testing in bacterial systems is not appropriate for metal (see discussion below). So, testing is not required.
No relevant articles is available for HfO2 to assess in vitro cytogenicity/ mutagenicity in mammalian cells. Nevertheless, an in vitro cytogenicity studies in mammalian cells with ZrO2 and in vitro gene mutation study in mammalian cells with ZrO2 (according to OECD 473 and 476 guideline) have been performed. Their results were negative.

Endpoint Conclusion:

Justification for classification or non-classification

Based on the available data, the substance was not classified under the CLP Regulation 1272/2008 and the directive Classification and Labelling 67/548.