Currently, the OECD has adopted three defined approaches (DAs) for eye hazard identification of non-surfactant liquids and solids (TG 467) according to the three UN GHS categories. We are now expanding the applicability domain with a new DA for chemicals having surfactant properties (DASF). It is based on a combination of recombinant human cornea-like epithelium test methods (TG 492: EpiOcular™ EIT or SkinEthic™ HCE EIT) and a modification of the Short Time Exposure (TG 491) method. The aim of the current study was to compare the performance of the DASF with the performance of other NAMs currently included in the OECD TGs and with the classification based on the Draize eye test to identify potential additional DAs. The minimum performance criteria (75% Cat. 1, 50% Cat. 2, 70% No Cat.) used for the adoption of the DAs currently included in TG 467 were used for this purpose. The DASF identified 90.9% of Cat. 1 (N = 23), 77.8% of Cat. 2 (N = 9), and 76.0% of No Cat. (N = 17) surfactants, meeting the minimum performance criteria. Some of the NAMs that are currently included in the TGs seem promising methods to become part of a DA to identify Cat. 1 or No Cat. for eye hazard assessment of surfactants. However, the number of surfactants that have been tested to evaluate their reliability and relevance was often too low. To date, the DASF is the only DA that has evaluated a sufficiently large number of surfactants and whose performance meets the minimum performance criteria.
Keywords: EpiOcular™ EIT; SkinEthic™ HCE EIT; UN GHS classification; full replacement test; modified STE.
Three non-animal testing strategies called “defined approaches” for eye hazard assessment have been adopted by the OECD as full replacements for the rabbit eye test. To date they can be used for non-surfactant liquid and solid chemicals. We built a new defined approach to test surfactants, which reduce a liquid’s surface tension, that combines OECD-adopted eye models using human cells and a method using rabbit corneal cells. This new defined approach, the DASF, reliably predicted the eye irritation potential of 50 surfactants for which historical data from the rabbit eye test were available for comparison. Combinations of other OECD-adopted non-animal methods did not have sufficient data for a reliable appraisal. To date, the DASF is the best predictive human-relevant DA that covers the whole range of eye irritation responses across the different classes of surfactants.