Nickel dichloride

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:

No positive animal studies were identified characterizing skin sensitization following exposure to nickel chloride. Nickel chloride has been shown to elicit an allergic reaction in nickel sensitive humans (Nielsen et al. 1999). The Ni²⁺ ion is considered exclusively responsible for the immunological effects of nickel (Menné 1994). Sufficient data from human studies exists to warrant classification of Ni chloride as a dermal sensitizer.

 

For risk characterization data was read across from nickel suphate. In addition to animal data for nickel sulphate, information on human dermal sensitization to nickel sulphate is summarized in the Nickel Sulphate IUCLID dossier Section 7.10.4. One of these studies, a meta-analysis of published patch test studies by Fischer et al. (2005) has been used as the basisfor 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 for nickel sulphateand read-across to nickel chloride based on similar solubilities in bioaccessibility testing in synthetic sweat. A comprehensive summary on this topic is provided in Appendix B3.

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

Sufficient data from human studies exists to warrant classification of Ni chloride as a dermal sensitizer.

Value used for CSA:sensitising

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Data on the potential to cause respiratory sensitization are being read-across from Ni sulphate. 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:

 

Data on the potential to cause respiratory sensitization are being read-across from Ni sulphate. Based on a recent literature review (Appendix B5), the available data for Ni sulphate may not be sufficient for classification of either compound as a respiratory sensitizer but the possibility cannot be ruled out due to association of soluble nickel compounds with type 1 allergic reactivity and respiratory reactions.

Value used for CSA:sensitising

Justification for classification or non-classification

Ni chlorideis classified as Skin Sens. 1;H317 in the 1st ATP to the CLP Regulation. Background information can be found in the discussion section.

Ni chloride 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).