OECD 492B: in vitro eye hazard identification assay (SkinEthic™ HCE TTT Test) Toxicology, In Vitro Alternate Industry MarketPhase Toxicology, In Vitro Alternate Industry MarketPhase

OECD 492B: SkinEthic™ is an in vitro reconstructed human corneal-like epithelium (HCE) model that closely mimics the human cornea. The validated Time-to-Toxicity (TTT) protocol employs the commercially available SkinEthicTM HCE tissues to assess the ocular hazards of chemicals.

The SkinEthicTM HCE TTT test identifies chemicals (substances and mixtures) as not requiring classification (No Category), requiring classification for eye irritation (Category 2) and requiring classification for serious eye damage (Category 1) according to UN GHS ocular hazard categories.

Irritant chemicals are identified by their ability to decrease cell viability in the SkinEthicTM HCE below defined threshold levels. Cell viability is measured by enzymatic conversion of the vital dye MTT into a blue formazan salt that is quantitatively measured.

The test method is applicable to substances and mixtures, to solids, liquids, semi-solids and waxes. The liquids may be aqueous or non-aqueous, solids may be soluble or insoluble in water. The current test method does not allow testing of gasses and aerosols.

Formal validation found the SkinEthicTM HCE TTT test to have an overall accuracy of 74.4%. Test substances are applied topically, so tissue exposures occur just as they do in the human eye.