In vitro skin corrosivity test using human skin

The in vitro skin corrosivity test (IVSCT) has been shown to be a reliable alternative for detecting substances that would be classified as corrosive in the standard in vivo test. The assay is based on the observation that corrosive substances produce a significant reduction in the transcutaneous electrical resistance (TER) of ex vivo rat skin. The use in the test of human skin to provide a means of direct assessment of potential corrosive substances in humans has been assessed. The testing of 12 substances allowed a TER threshold for in vitro classification as corrosive to be established. In further testing of 15 surfactants (three classified as corrosive) and eight fatty acid substances (four corrosive), the three surfactants but none of the fatty acids were identified as corrosive in vitro. Thus the fatty acids labelled as corrosive, on the basis of animal data, may be incorrectly classified (i.e. in humans the substances would not lead to a corrosive effect following skin contact). It is envisaged that the IVSCT using human skin will be used together with human patch testing and lead to a reduction in animal testing and a more relevant classification of skin irritation potential to humans.