Ensulizole

Names
IUPAC name 2-Phenyl-3H-benzimidazole-5-sulfonic acid
Identifiers
CAS Number	27503-81-7 Y
3D model (JSmol)	Interactive image
ChemSpider	31267 Y
ECHA InfoCard	100.044.078
KEGG	D10005 N
PubChem CID	33919
UNII	9YQ9DI1W42 Y
CompTox Dashboard (EPA)	DTXSID3038852
InChI InChI=1S/C13H10N2O3S/c16-19(17,18)10-6-7-11-12(8-10)15-13(14-11)9-4-2-1-3-5-9/h1-8H,(H,14,15)(H,16,17,18) Y Key: UVCJGUGAGLDPAA-UHFFFAOYSA-N Y InChI=1/C13H10N2O3S/c16-19(17,18)10-6-7-11-12(8-10)15-13(14-11)9-4-2-1-3-5-9/h1-8H,(H,14,15)(H,16,17,18) Key: UVCJGUGAGLDPAA-UHFFFAOYAY
SMILES O=S(=O)(O)c3ccc2[nH]c(c1ccccc1)nc2c3
Properties
Chemical formula	C13H10N2O3S
Molar mass	274.29 g·mol−1
Hazards
Safety data sheet (SDS)	Cole Parmer Material Safety Data Sheet
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Ensulizole (INN;^[1] also known as phenylbenzimidazole sulfonic acid) is a common sunscreen agent. In 1999, the United States Food and Drug Administration regulated that the name ensulizole be used on sunscreen labels in the United States. Ensulizole is primarily a UVB protecting agent providing only minimal UVA protection. The scope of UVB is 290 to 340 nanometers whereas the UVA range is 320 to 400 nanometers.^[2] For better UVA protection, it must be paired with avobenzone, titanium dioxide, or zinc oxide; outside of the United States it can also be paired with a UV absorber of the Tinosorb or Mexoryl types. Because ensulizole is water-soluble, it has the characteristic of feeling lighter on skin. As such, it is often used in sunscreen lotions or moisturizers whose aesthetic goal is a non-greasy finish.^[3] The free acid is poorly soluble in water, so it is only used as its soluble salts.^[4]

• Thomson MICROMEDEX - Sunscreen Agents (Topical)
• Phenylbenzimidazole sulfonic acid