Nickel sulphate

Endpoint summary

Description of key information

Value used for CSA: sensitising (skin and respiratory)

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Human clinical data (e.g. Santucci et al., 1998, Fischer et al., 2005) clearly demonstrate that nickel sulphate is a skin sensitizer, summarized in the Nickel Sulphate IUCLID dossier Section 7.10.4. A number of studies on skin sensitisation in guinea pigs have been performed with nickel sulphate. The dose-response relationship for nickel sulphate hexahydrate has been studied in the guinea pig maximization test with varying results due to the diificulty in sensitizing lab animals. Basketter & Scholes (1992) tested nickel sulphate in the local lymph node assay (LLNA) in mice at concentrations of 0.5, 1 and 2.5%. Nickel sulphate was negative in the LLNA. 

 

One of these studies, a meta-analysis of published patch test studies by Fischer et al. (2005) has been used as the basis for the derivation of a DNEL for dermal elicitation/sensitization with nickel sulphate as described in Section  5.11.  The aim of the study by Fischer et al. (2005) was to assess thresholds of response by making a statistical analysis of available dose-response studies with a single occluded exposure and comparing the results to thresholds from other modes of exposure. Eight occluded Ni dose-response studies were selected based on statistical considerations. The statistical analysis showed that 5% of a sensitized population reacts to 0.44 µg Ni/cm² and 10% react to 1.04 µg Ni/cm². In another study with a single open application, 7.8% of sensitized persons responded to a dose 6x higher than the dose to which 10% reacted in occluded exposure. The NOAEL of 0.00044 mg Ni/cm² from the Fischer et al. (2005) study is carried forward as the basis for the derivation of DNEL for dermal elicitation/sensitization. This DNEL was used as the basis to derive a DNEL for other nickel substances based on relative nickel ion release to nickel sulphate in bioaccessibility testing. See Appendix B3.

 

The following information is taken into account for any hazard / risk assessment:

 

Data demonstrate that nickel sulphate is a skin sensitiser in humans and in experimental animals.

Value used for CSA: sensitising

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

A few case reports in the 1970s and 1980s suggest that nickel sulphate may be a respiratory sensitiser in humans. Considering the number of workers that have been exposed to soluble nickel compounds in the refining and metal finishing industry over the years, the number of reported cases is very small. No data regarding respiratory sensitisation in animals have been located. A recent comprehensive review of the available literature regarding the potential of soluble Ni compounds to induce respiratory sensitization can be found in the attached background document entitled, "Background-Soluble Nickel Respiratory Sensitization" (Section 7.4.2 of IUCLID) and in Appendix B5 of the CSR.

 

The following information is taken into account for any hazard / risk assessment:

Based on a recent literature review (Appendix B5), the available data for Ni sulphate may not be sufficient for classification as a respiratory sensitizer.

Justification for classification or non-classification

Ni sulphate is classified as Skin Sens. 1;H317  in the 1st ATP to the CLP Regulation. Background information regarding this classification is provided in the discussion section above.

Ni sulphate is classified as Resp. Sens. 1; H334 in the 1st ATP to the CLP Regulation. A comprehensive review of the available literature regarding the potential of soluble Ni compounds to induce respiratory sensitization can be found in the attached background document entitled, "Background-Soluble Nickel Respiratory Sensitization" (Appendix B5).