Phenylbenzimidazole sulfonic acid
Encyclopedia
Phenylbenzimidazole sulfonic acid (C13H10N2O3S) 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
. Phenylbenzimidazole sulfonic acid is primarily a UV
B 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. 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 and . Because phenylbenzimidazole sulfonic acid 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. The free acid is poorly soluble in water, so it is only used as its soluble salts.
Sunscreen
Sunblock is a lotion, spray, gel or other topical product that absorbs or reflects some of the sun's ultraviolet radiation on the skin exposed to sunlight and thus helps protect against sunburn...
agent. In 1999, the United States Food and Drug Administration regulated that the name ensulizole be used on sunscreen labels in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Phenylbenzimidazole sulfonic acid is primarily a UV
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
B 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. For better UVA protection, it must be paired with avobenzone
Avobenzone
Avobenzone is an oil soluble ingredient used in sunscreen products to absorb the full spectrum of UVA rays....
, titanium dioxide
Titanium dioxide
Titanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...
, or zinc oxide
Zinc oxide
Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
; outside of the United States it can also be paired with and . Because phenylbenzimidazole sulfonic acid 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. The free acid is poorly soluble in water, so it is only used as its soluble salts.