SAFETY EVALUATION OF PETROLEUM-PRODUCTS USING AN IN-VITRO EYE IRRITATION TEST BATTERY

An in vitro eye irritation test battery (IV Eye) composed of the EYTEX and Modified Agarose Diffusion Method (MADM) assays was evaluated for use as a predictive, economical screen and/or adjunct for the Draize eye test. EYTEX mimics corneal opacification using a synthetic matrix of proteins that is intended to produce measurable opacity on exposure to chemical irritants in proportion to their ocular irritation potential. MADM is a cytotoxicity-based assay consisting of NCTC clone 929 mouse fibroblasts overlayed with 1% agarose in culture medium. Potential eye irritation is measured macroscopically as the area of decolorization (neutral red release) around the area of chemical application and microscopically as the percentage of cell lysis resulting from chemical application. Of the 70 materials tested in the IV Eye for which Draize eye test data also exist, the battery correctly identified 38 materials as non-irritants and 30 as irritants, with two false positives and no false negatives. Non-parametric analysis of the data show the battery to have a sensitivity of 100%, a specificity of 95% and a predictive value of 94%. The irritation class correlation (equivalence; irritation ranking) between EYTEX alone and the Draize data was 85%. These data support the use of IV Eye as an accurate, reproducible and cost-effective in vitro method for identifying the eye irritation potential of petroleum products.