P27) Validation study on a alternatives to skin irritation testing in Japan

As a second trial of validation on alternatives to skin irritation testing in Japan, we started a validation study of TESTSKIN(TM). In this validation, 6 laboratories per kit took part with the exclusion of kit suppliers (TOYOBO Co.Ltd.). Participants performed the pre-test and main trial and obtained an ET50 value (time causing 50% reduction in MTT from that of untreated control), in the period May to October, 2002. Forty cosmetic ingredients excluding 1% sodium lauryl sulphate solution (positive control), distilled water (solvent) and olive oil (solvent) were selected, coded and supplied to laboratories. The validation data have been analyzed by biostatisticians, I.Sonoda and Dr.I.Yoshimura.