Belguard PBSA (Phenylbenzimidazole sulfonic acid) is a UV-B filter that absorbs UV light between 280-340 nm to protect skin from sunburn and cancer. Due to its water solubility, it fits perfectly for sun care without oil or exceeding the contents of oil. It is compatible with almost all cosmetic ingredients. It is always used in combination with other UV filters like Avobenzone, Titanium oxide, Zinc Oxide etc.