Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

The genotoxic and carcinogenic activity of chromium derives from Cr(IV), which in physiological solutions exist as chromate-anion.  

- There exist clear evidence that solubilised zinc potassium chromate has genotoxic effects.

- The numerous studies on Cr(VI)-compounds have given the evidence that chromium(VI) is genotoxic

- There exist some positive data on experimental germ cell mutagenicity, but not on zinc potassium chromate. These data are not considered to have significant effect on classification due to low bioavailability.

Chromium-induced DNA damage is thought to be the primary mechanism of chromate genotoxicity and mutagenicity, but it is only clearly observed at doses that are also capable of producing cell death. Recently, data has been presented to the EPA’s Cancer Assessment Review Committee (CARC) to support mutagenicity as the initiating step in Cr(VI)-induced carcinogenesis (McCarroll N, Keshava N et al. An evaluation of the mode of action framework for mutagenic carcinogens case study II: Chromium (VI). Environ Mol Mutag 51;2010;89 -111). Structural genetic lesions produced by Cr(VI) include DNA adducts, DNA-strand breaks, DNA–protein crosslinks, oxidized bases, abasic sites, and DNA inter- and intrastrand crosslinks

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Short description of key information:
- There exist clear evidence that solubilised zinc potassium chromate has genotoxic effects.
- The numerous studies on Cr(VI)-compounds have given the evidence that chromium(VI) is genotoxic

Endpoint Conclusion: Adverse effect observed (positive)

Justification for classification or non-classification

 The genotoxicity tests of Zn-K-chromate, and the genotoxicity of chromate anion in general, lead to the conclusion that there are good evidence that Zn-K-chromate should be classified as genotoxic –Muta 2 according to CLP system.

No additional studies on genotoxicity/mutagenicity are needed.