Development of a defined approach for eye irritation or serious eye damage for neat liquids based on cosmetics Europe analysis of in vitro RhCE and BCOP test methods

The focus of Cosmetics Europe's ocular toxicity programme is on development of testing strategies and defined approaches for identification of ocular effects of chemicals in the context of OECD's Guidance Document on an Integrated Approach on Testing and Assessment (IATA) for Serious Eye Damage and Eye Irritation. Cosmetics Europe created a comprehensive database of chemicals for which in vitro data are available with corresponding historical in vivo Draize eye data and physicochemical properties. This database allowed further exploration of the initially proposed strategies from the CON4EI project and to identify opportunities for refinement. One key outcome of this project is that combining in vitro test methods (RhCE and BCOP LLBO) with physicochemical properties in a two-step Bottom-Up approach applicable to neat liquids, resulted in an improvement of the specificity, without reducing the sensitivity, when compared to the combination of in vitro methods alone. The Bottom-Up approach proposed here for neat liquids correctly predicted 58.3% (EpiOcular™ EIT followed by BCOP LLBO) to 62.6% (SkinEthic™ HCE EIT followed by BCOP LLBO) of No Cat., 59.1% to 68.7% of Cat. 2, and 76.5% of Cat. 1. Incorporating specific physicochemical properties with this Bottom-Up approach increased the correct identification of No Cat. neat liquids to between 72.7% and 79.7%.