Phenylbenzimidazole Sulfonic Acid (Ensulizole, Wksorb970) is a common UV filter used in sunscreen or other cosmetics with sunscreen functions. It can block UVB rays and some UVA rays. Under sunlight, its protective ability and quality will not decrease gradually over time, so to a certain extent it can alleviate the decomposition of other UVB blocking agents in sunscreen. Ensulizole can also convert incoming ultraviolet radiation into less harmful infrared radiation or heat energy. Because Ensuizole is water-soluble and has a light, non-greasy texture, it is often used in sunscreen lotions or moisturizers to make the skin feel lighter.