This test method is the first single non-animal eye irritation test method which can be used to distinguish between GHS Category 1, Category 2, and non-categorized substances and mixtures. Until recently, resolving GHS Category 2 Ocular Irritants had relied on a Weight-of-Evidence approach as the use of no single in vitro assay had been able to distinguish between Category 1, Category 2 and non-categorized test materials.With the approval of the OECD 492B test guideline, the determination of these classifications is now possible.
Test substances are classified for eye irritation hazards within the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS) according to the following categories:
- GHS Category 1 – test substances or mixtures that induce serious eye damage, or decay of vision which is not fully reversible after a single exposure
- GHS Category 2 – eye irritation and changes in the eye, which are fully reversible after a single exposure to a test substance
- GHS No Category (No Cat) – test substances not classified for eye irritation or serious eye damage are defined as those that do not meet the requirements for classification.
SkinEthic™ HCE (Human Corneal Epithelium) tissues are treated with test substances following a time-to-toxicity protocol. Since corneal cell damage and loss of viability are highly related to adverse impacts on corneal function and visual acuity, viability of the HCE tissues is measured following test substance exposure using the MTT reduction viability endpoint.
Based on the Prediction Models presented below, a definitive categorization can be obtained. IIVS now offers this evaluation – please contact clientservices@iivs.org for further information.