2-Phenylbenzimidazole-5-sulfonic acid, also called Ensulizole, the abbreviation is UV-T, which is a high-efficiency UVB absorber, with an ultraviolet absorption rate of at least 920 at about 302nm, and can also absorb a small part of the UVA band. It belongs to water-soluble chemical sunscreens. It is often used in combination with other ingredients such as avobenzone, titanium dioxide, zinc oxide, or tinosorb. Its protective power and quality of protection do not gradually decrease over time when exposed to sunlight, thus somewhat mitigating the breakdown of other UVB blockers in sunscreens. The non-greasy texture also converts ingested UV radiation into less harmful infrared radiation and heat.