In the context of the 2013 ban given by EU Cosmetics Directive, the ability to identify and classify the skin sensitization potential of chemicals without animals is of high importance for the cosmetic industry. A range of different in vitro chemistry-based and cell-based methods have been developed and we are currently evaluating some of them for their applicability to cosmetic ingredients and their physicochemical diversity. Although these assays appear to be promising for hazard identification, potency assessment is still limited.
Immunosearch has developed SENS-IS, a new method, based on the quantitative analysis of specific biomarkers expressed in 3D reconstructed epidermis (Episkin®). This new assay provides a possible way to encompass the limitations of monolayer culture models (lack of skin bioavailability properties, different metabolism of the models compared to skin, inability to test water insoluble chemicals) and might therefore allow a better assessment of the sensitization potency of cosmetic ingredients.
With the aim to evaluate the predictive capacity of this approach on a panel of cosmetic ingredients, L’Oréal challenges this method with a blinded-set of 20 fragrance ingredients. We present here the result of this study and will analyze the genomic signature of those volatile weak/moderate sensitizers.