Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

No skin sensitisation studies are available for zirconium basic sulfate. Therefore, data from two studies performed with other insoluble zirconium compounds were included in a weight of evidence approach to cover the endpoint.

Harrisson et al. (1951) examined the skin sensitisation potential of hydrated zirconium carbonate, another water insoluble zirconium compound, using white guinea pigs. The animals were exposed epicutaneously to an ointment containing 21% of the test substance, using a rubber (occlusive) sleeve. After 9 days they were again exposed and observed for a total period of 60 days. The result was negative; no vascularization under the treated areas was observed.

The test was not conducted according to current standard methods and was therefore assigned a Klimisch 3 score, but can be used in a weight of evidence approach.

Another water insoluble zirconium compound is yttrium zirconium dioxide (zirconium dioxide with a small amount of yttrium in the crystal lattice), which was tested for skin sensitisation in a guinea pig maximisation test (CITI, 1999). This test was conducted according to OECD guideline 406. Intradermal and occlusive epicutaneous induction (2.5% and 25% test item, respectively), followed by occlusive epicutaneous challenge exposure at 2.5 and 25% test item, induced no positive effects in 10 female Hartley guinea pigs. The positive control (0.1% DNCB) was clearly positive, indicating the validity of the test system.

Taking both studies together in a weight of evidence approach, it can be reasonably concluded that zirconium basic sulfate, which is a similar water insoluble zirconium compound, will not cause skin sensitisation either.


Migrated from Short description of key information:
A weight of evidence approach using data for other insoluble zirconium substances is presented to cover the skin sensitisation endpoint for zirconium basic sulfate.
One study (Harrisson et al., 1951) assessed the skin sensitisation potential of zirconium basic carbonate in guinea pigs. The outcome was negative.
The other study used in the weight of evidence approach is a Japanese GPMT study on yttrium zirconium oxide (CITI, 1999) which was also negative. Both read across substances are water insoluble zirconium compounds, as is zirconium basic sulfate. The justification for the read across approach is given in IUCLID Section 13.

Justification for selection of skin sensitisation endpoint:
Due to the absence of data for the substance itself, a read across approach was followed using a study performed with zirconium basic carbonate and a study performed with yttrium zirconium oxide, i.e. two other insoluble zirconium compounds.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

A weight of evidence approach using studies performed with other water insoluble zirconium compounds indicated that zirconium basic sulfate does not need to be classified as a skin sensitiser.