Topically applicable UVA photoprotective cosmetic/dermatological compositions comprise an effective photoprotecting amount of at least one UVA screening agent substituted by at least one optionally neutralized sulfo functional group, and an effective UVA photoprotecting-enhancing amount of at least one otherwise non-UVA photoprotecting iron chelating agent, thereby imparting a synergistic protection factor (PF) effect thereto, in a cosmetically/dermatologically acceptable topical vehicle, carrier or diluent therefor.