Compounds are provided for reducing erythemal response which are photoreactive precursors to para-aminobenzoic acid or its physiologically acceptable esters. Upon exposure to ultraviolet radiation of greater than about 280nm, the compounds of this invention undergo a photoreactive degradation to provide a regulated amount of a sunscreen material which screens out ultraviolet radiation which could lead to erythema. The compounds are benzyl esters of p-carboxycarbanilic acid and the dermatological and physiological acceptable esters of the carboxy group.