The phototoxicity test measures the potential of test products to produce phototoxic reactions by a single exaggerated exposure of human volunteer subjects to a test product, with and without UVR, followed by scoring of responses. Comparison of responses to test product alone, test product irradiated with UV radiation and an irradiated, untreated site will permit assessment of the potential for phototoxicity of test products.

The photoallergenicity test measures the potential of test products to produce allergic reactions in the presence of UVR. This study consists of a 24 hour duplicate occluded exposure to up to 6 test products on the backs of healthy volunteers, followed by an evaluation and irradiation of one set of sites with UVR and 5 additional applications and irradiations of one set of sites over a 2 week Induction phase.

After a 9 day resting phase, another 24 hour occluded exposure, irradiation of one set of sites and 24 and 48 hour evaluation constitute a Challenge phase. The inclusion of evaluations of 24 and 48 hour responses of sites treated with test products, with and without UVR, in the Induction Phase and again in the Challenge Phase, permits simultaneous evaluation of the potential for contact irritation, phototoxicity, contact allergy and photoallergy.