Registration Dossier

Administrative data

Description of key information

There are no non-human data on repeated dose effects of zinc potassium chromate. Read-across from sparingly water soluble chromates and from highly water soluble chromates are suggested. Human evidence in several studies with highly water soluble chromates show irritant and corrosive responses in relation to inhalation and dermal exposure.

Key value for chemical safety assessment

Mode of Action Analysis / Human Relevance Framework

Additional information

There are no non-human data on repeated dose effects of zinc potassium chromate. Information on the repeated dose toxicity of other sparingly soluble hexavalent chromium compounds is limited to studies conducted with mainly zinc chromate (one old study of exposure via oral route and showing effects of zinc chromate and a highly water soluble potassium chromate, as well as four studies of exposure via other routes with zinc chromate).

There are, however, several animal studies with highly water soluble chromates via oral or inhalation route. Therefore, in lack of representative data with zinc potassium chromate or other sparingly soluble chromates, it is justified to utilise highly water soluble chromates for read-across purposes. There were no studies available on systemic effects arising from repeated percutaneous exposure to chromium (VI) compounds.

A large number of studies are available relating to repeated exposure of workers to highly water-soluble Cr(VI) (EU RAR 2005). The main effects reported are irritant and corrosive responses in relation to inhalation and dermal exposure. These include inflammation in the lower respiratory tract, and nasal septum perforation in the upper respiratory tract. However, it is not possible to relate these effects to reliable measures of Cr(VI) exposure.

Nasal ulceration and perforation caused by exposure to chromates were recognized already in the 19th century. However, based on the available reports on nasal ulceration and perforation it is not possible to locate threshold doses for these effects (see reports described under title 'human information').

According to Cross et al. (1997) and EU RAR (2005), two reviews also covering the repeated inhalation experiments, it is not possible to identify with confidence a no observed adverse effect level (NOAEL) for Cr(VI) compounds. NOAELs for repeated oral toxicity are suggested in studies with highly water soluble chromates, but these values are received in studies mainly focusing on other effects (e.g., reprotoxicity).

Justification for classification or non-classification

Conclusion: There are no non-human zinc potassium chromate specific data on repeated dose toxicity. Based on the data with mainly highly water soluble chromates, zinc potassium chromate is not suggested to be classified. There is no need for further testing.