Integrated approach for skin corrosion and skin irritation using in vitro SkinEthic RHE test methods

Acute dermal integrated approach on testing and assessment (IATA) include adopted in vitro skin corrosion and irritation test methods. As such, the SkinEthic Reconstructed Human Epidermis (RHE) test method is considered in the current OECD guidance document.

Illustration of IATA is provided by combining and evaluating both SkinEthic RHE skin corrosion and irritation methods in the stepwise top-down and bottom-up approaches. Concordant classification between runs has been demonstrated for both toxicological endpoints amongst the 83 tested substances. Only 1/83 false negative was defined (consistently false negative in all in vitro tests). High accuracy (90%) was obtained when discriminating corrosives versus irritants versus non-classified substances. Furthermore, similar classifications were defined by discriminating the UN GHS subcategories Cat.1A, versus Cat.1B-and-1C versus irritants (Cat.2) versus not-classified (NC) substances applying both the top down and bottom up approaches.

In conclusion, assessment of in vitro skin corrosion and irritation results for 83 commercially available substances using SkinEthic RHE methods in stepwise approaches shows that a combination of Guidelines (irritation and corrosion) allows the determination of the potential hazard of tested substances. The sequence of the prospective testing in either a top-down or a bottom-up approach should be guided by all available information of the substance.