Eye irritation: Reference chemicals data bank.

A list of 55 chemicals has been developed for which comprehensive in vivo rabbit eye irritation data are available. No new in vivo testing has been carried out to qualify a chemical for inclusion in the list. The 55 chemicals selected are available at high and consistent purity and are expected to be stable on storage. They have been tested undiluted in in vivo studies, except those chemicals where high concentrations of the substance could be expected to cause severe effects. The in vivo data have been generated since 1981 in studies carried out according to OECD Test Guideline 405 and following the principles of Good Laboratory Practice. The data were obtained from tests normally using at least three rabbits evaluated at the same time, involving instillation of 0.1 ml (or equivalent weight) into the conjunctival sac, and in which observations were made at least at 24, 48 and 72 hr after instillation. The chemicals represent a range of chemical classes (acetates, acids, alcohols, alkalis, aromatics, hydrocarbons, inorganics and surfactants) and different degrees of irritancy. They are ranked for eye irritation potential on the basis of a 'modified maximum average score'. The reference data bank should be of use in validation tests for promising alternatives to the in vivo rabbit eye irritation test. This is an essential step in the progression to regulatory acceptance of alternative procedures.