Registration Dossier

Administrative data

Description of key information

The release of ytterbium, zirconium or hafnium from the target substance Ytterbium stabilized Zirconium and Hafnium Oxide in simulated body fluids indicated that the bio-accessibility is very low for all routes (see section 7.1.1). The hafnium release was below the detection limit, the zirconium release was 0.02 µg/mL and the ytterbium release was 3.24 µg/mL from the target substance within 24 hours in artificial perspiration fluid. Thus, the bioavailability of hafnium, zirconium and/or ytterbium after administration to the skin can expected to be very low. No information was found in the public domain, which would have indicated any skin sensitising properties of hafnium, zirconium and/or ytterbium. Based on the results and in line with the 3R principles, the study is scientifically unjustified.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vitro
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)

Justification for classification or non-classification

The release of ytterbium, zirconium or hafnium from the target substance Ytterbium stabilized Zirconium and Hafnium Oxide in simulated body fluids indicated that the bio-accessibility is very low for all routes (see section 7.1.1). The hafnium release was below the detection limit, the zirconium release was 0.02 µg/mL and the ytterbium release was 3.24 µg/mL from the target substance within 24 hours in artificial perspiration fluid. Thus, the bioavailability of hafnium, zirconium and/or ytterbium after administration to the skin can expected to be very low. No information was found in the public domain, which would have indicated any skin sensitising properties of hafnium, zirconium and/or ytterbium. Based on the results and in line with the 3R principles, the study is scientifically unjustified.