Technical Report

TR 087 – Contact Sensitisation: Classification According to Potency

TR 087 : Contact Sensitisation: Classification According to Potency | April 2003

Contact allergens vary substantially with regard to the relative potency with which they are able to induce skin sensitisation. It is therefore appropriate to establish what is known of potency and thresholds in the induction of skin sensitisation and the elicitation of allergic contact dermatitis, and to identify approaches that might be available for assessment of relative potency for the purposes of categorising chemical allergens. This report was prepared by a Task Force with the remit 'to recommend approaches for the measurement of potency and definition of thresholds for both the induction and elicitation of contact sensitisation.'

Building on the recommendations of an ECETOC Task Force that reviewed the conduct of standard skin sensitisation test methods for the purposes of hazard identification and risk assessment (ECETOC, Monograph No. 29), the present report also focused on standard and accepted methods for the assessment of skin sensitisation, and for which OECD guidelines are available: the local lymph node assay (LLNA), the guinea pig maximisation test and the occluded patch test of Buehler. For various reasons, discussed in detail in this report, attention focused primarily on consideration of categorisation of chemical allergens and the identification of thresholds with respect to the induction of skin sensitisation, rather than the elicitation of allergic contact dermatitis.

The conclusions drawn in the earlier report (Monograph No.29) are reflected by recommendations made here. Thus, although the LLNA is the method of choice for the determination of skin sensitisation potency for the purposes of categorisation, judicious interpretation of existing data from appropriate guinea pig tests may provide information of value in determinations of potency and categorisation. The report includes detailed and specific recommendations on how best the results of the three test methods considered can be used for the categorisation of chemical allergens as a function of skin sensitisation potency.