Abstract: Disclosed herein are novel methods for reducing or preventing the harmful effects of solar radiation on skin. Also disclosed are novel sunscreen compositions comprising 3-[2-(4-diethylaminophenyl)-2-oxoethyl]thiazolium salt for reducing or preventing the harmful effects of solar radiation on skin. Agents that provide UV-A and UV-B filters are also included. The invention further discloses additional sunscreen active agents, emollients, humectants, dry-feel modifiers, waterproofing agents, insect repellants, antimicrobial preservatives, antioxidants, chelating agents, fragrances and moisturizers, suitable carriers for topical application and emulsions.