Validation of the SkinEthic HCE Time-to-Toxicity test method for eye hazard classification of chemicals according to UN GHS

This study describes the within- and between-laboratory reproducibility (WLR and BLR) of a Time-to-Toxicity (TTT) approach for chemicals based on the SkinEthic™ HCE tissue construct, capable to distinguish chemicals that do not require classification for serious eye damage/eye irritation (No Cat.) from chemicals that require classification for eye irritation (Cat. 2), and serious eye damage (Cat. 1). The WLR and BLR was assessed with three participating laboratories. Each laboratory tested 40 coded chemicals in three independent runs. The predictive capacity of the method was assessed on a larger set of 150 chemicals (70 liquids and 80 solids) by combining the results of this study with the results of the test method developer. The WLR for the 20 liquids ranged from 85% to 95% with a BLR of 90%. For the 20 solids, a WLR and BLR of 100% was obtained. The test method developer obtained a WLR of 80% and 95%, based on 50 liquids and 48 solids tested in three independent runs, respectively. Regarding the predictive capacity, the SkinEthic™ HCE TTT test method identified 80.8% Cat. 1, 69.2% Cat. 2, and 74.9% No Cat. correctly. An independent peer review panel concluded that based on all available data, the relevance and reliability of the SkinEthic™ HCE TTT has been demonstrated for discriminating the three UN GHS eye hazard categories. •SkinEthic HCE Time-to-Toxicity evaluate the eye hazard potential of chemicals.•A validation study was conducted with three laboratories on 40 coded substances.•Within- and between laboratory reproducibility was achieved of ≥85.0% and 90%.•Balanced accuracy of 74.4% with 79% Cat. 1, 69% Cat. 2 and 75% No Cat. was achieved.•The method distinguishes on its own the 3 UN GHS ocular hazard categories.