Approaches now approved offer prospect of fully replacing skin sensitisation tests on animals for many chemicals
We are excited to report that the Organisation for Economic Co-operation and Development (OECD) has adopted a new groundbreaking guideline on Defined Approaches for Skin Sensitisation (DASS), employing a selection of non-animal methods in approved combinations for predicting if chemical substances could cause human skin sensitisation.
Working within ICAPO (International Council on Animal Protection in OECD programs), we have contributed to the efforts since work began in 2017 and are delighted to see the guideline published.
This guideline is the first of its kind, offering a set procedure for combining in chemico and in vitro test methods, as well as the use of in silico tools, to provide more information and better predictions than can be delivered by the individual techniques. The Defined Approaches also shows the overall confidence associated with the results from the combined methods.
This development is a crucial step forward in avoiding new tests on animals. These Defined Approaches have been shown to perform better than the commonly used test on mice (the Local Lymph Node Assay) for predicting effects in humans. Not only are these approaches capable of replacing animal-based test methods, they also open the door for further OECD approved non-animal approaches for predicting skin sensitisation as well as other types of toxicity.
Dr Emma Grange, our Senior Science Advisor, said: “The DASS guideline formalises the combined use of existing, standardised non-animal methods. Rigorous evaluation of the performance of these set approaches has involved extensive and highly curated human-derived reference chemical data, along with data from tests on mice, lending great confidence in the use of these non-animal approaches.
It has now been shown that the Defined Approaches perform very well and in fact outperform the established mouse test on animals, providing data at least on a par with that generated by testing on animals. It is anticipated that for many chemical substances, the Defined Approaches will be accepted as a full replacement to testing on animals, either as a stand-alone tool or along with other information sources in order to satisfy a regulatory need to supply data on skin sensitisation.”