The project to develop a new Defined Approach for Skin Sensitisation (DASS) based on the Reconstructed Human Epidermis-based Test Strategy (RTS) was included in the OECD Test Guideline (TG) Work Plan in 2025 based on a proposal from Japan. The aim of the project is to update the OECD TG 497 on DASS with inclusion of a new DA that can be used for hazard and potency classification under the UN GHS Classification and Labelling of Chemicals.
First commenting round on the Reconstructed Human Epidermis-based Test Strategy (RTS)-based Defined Approach for Skin Sensitisation
- Submission period
- 8 October - 19 November 2026
Background public consultation
Project description
The new RTS DA uses the Epidermal Sensitisation Assay (EpiSensA) from OECD TG 442D on In Vitro Skin Sensitisation and the OECD QSAR Toolbox (TB) Automated Workflow (AW) for DASS as information sources. The score-based information transferred from EpisensA and QSAR TB AW for DASS is used in the RTS DA for prediction of hazard and potency categories of skin sensitisation according to the UN GHS Classification and Labelling of Chemicals.
How to contribute
The draft Updated TG 497 on Defined Approaches for Skin Sensitisation and the relevant annexes to the Supporting Document of TG 497 are currently under a commenting round by the Working Party of the National Coordinators of the Test Guidelines Programmes and open for comments from the public at the same time. Note that for the draft Updated TG 497, only the revisions showing in track change are subject to the review. Interested parties are invited to contact their National Coordinators at least a week before 19 November 2026.
