IN-VITRO ALTERNATIVES FOR THE DETECTION OF PHOTOIRRITANT CHEMICALS - THE EEC COLIPA TRIAL

The effects of UV irradiation on the cytotoxicities of selected chemic als were investigated in cultures of Balb/c 3T3 cells, normal human ke ratinocytes and Jurkat cells. The chemicals were chosen according to t heir reported photoirritancy, or lack thereof, and the abilities of th e in Ditto tests to distinguish between these photoirritants and non-p hotoirritants were assessed. The data obtained suggest that the neutra l red uptake assay with Balb/c 3T3 cells can be used to provide some i ndication of the potential photoirritancy of these particular chemical s. However, similar results were also obtained using the human keratin ocytes and these should provide a more relevant in vitro model for inv estigating mechanisms of chemical-induced photoirritation.