Terephthalylidene Dicamphor Sulfonic Acid
Terephthalylidene Dicamphor Sulfonic Acid, commonly known as Ecamsule or Mexoryl SX, is a L'Oréal-group exclusive sunscreen agent with CAS # 92761-26-7 / 90457-82-2. Unlike most sunscreen agents, it is water soluble and functions as a UVA filter with a peak absorbance at 345 nm. It is listed under Cosmetic Restrictions VI/7 and is officially classified as a UV absorber and UV filter.
Protects skin in the UVA range, with documented evidence that it shields human skin from the effects of repeated suberythemal doses of UVA radiation. Its water-soluble nature distinguishes it from many other UVA filters used in sunscreen formulations.
Subject to cosmetic use restrictions (VI/7). A 2019 JAMA clinical trial found that sunscreen active ingredients, including this compound, can be absorbed into the bloodstream under maximal use conditions; clinical significance of systemic absorption is not yet fully established.
