Prediction of severe or corrosive chemically-induced dermal reactions was evaluated in an in vitro model. TESTSKIN-TM, a human living skin equivalent consisting of differentiated human keratinocytes grown on a human fibroblast and bovine collagen matrix coated filter support, provided a model system that resembles many aspects of mammalian skin. Cellular viability and mitochondrial function, as well as histological and ultrastructural characterization of tissue morphology, were evaluated following incubation of TESTSKIN with nine test articles chosen based on their previously reported animal dermal irritation category. Various incubation times, doses, and dose administration techniques were evaluated. Morphologica changes were observed to precede measurable differences in cellular viability or mitochondrial function. Viability measurements and mitochondrial function were generally correlative. A single test article dose of 25 mg or 25 mu-l of each of nine test articles provided data that best correlated with the established test article dermal irritation category.