INTRODUCTION To prevent skin damage from the suns radiation, many skin care products, such as lipstick, makeup, and lotions contain one or more compounds to block UV radiation. The lotions containing these compounds are commonly referred to as sunscreens and other products that contain one or more of these compounds are said to contain sunscreen. The active ingredients in sunscreens are usually aromatic compounds conjugated with carbonyl groups (e.g. homosalate) and rather than literally blocking the UV radiation, they absorb it and release it as lower-energy UV radiation. The FDA allows over 15 different compounds to be used as the active ingredient in sunscreens and sunscreen-containing products. Additional compounds have been approved for use in the European Union and other parts of the world.