Researched by Helena DeMaria-Williams
Formula IngredientUV FilterPhenylbenzimidazole Sulfonic Acid
INCI: Phenylbenzimidazole Sulfonic Acid
Phenylbenzimidazole sulfonic acid, commonly known as ensulizole, is a water-soluble UVB-absorbing sunscreen agent with peak absorbance at 306 nm (280–320 nm range). Unlike most chemical UV filters which are oil-soluble, its unique water solubility makes it ideal for creating lightweight, non-greasy sunscreen formulations that are well-suited to oily skin. It is also photostable and can help stabilise less stable UV filters like avobenzone in combined formulations.
Category
UV Filter
Irritation Risk
Low
Skin Types
all skin types, oily, acne-prone, combination, sensitive
What does this do in a formula?
UVB protection, lightweight non-greasy formulations, photostability, stabilises avobenzone, suitable for oily skin sunscreens
Is Phenylbenzimidazole Sulfonic Acid safe? Key considerations
Can Phenylbenzimidazole Sulfonic Acid cause irritation?
Low RiskEnsulizole is generally well tolerated with a low irritation profile. EU CosIng lists it under Annex VI (entry 6) as a permitted UV filter. Some in vitro studies have raised questions about potential photogenotoxicity, but regulatory bodies (EU SCCS, FDA) continue to approve its use at permitted concentrations. Individuals with very sensitive skin should patch test.
Does Phenylbenzimidazole Sulfonic Acid increase sun sensitivity?
No RiskEnsulizole is itself a UV-absorbing sunscreen agent and does not increase photosensitivity. It actively protects skin from UVB radiation.
Is Phenylbenzimidazole Sulfonic Acid safe during pregnancy?
CautionAs a chemical UV filter, ensulizole may be absorbed systemically at low levels. While no specific reproductive toxicity data have raised alarms, mineral sunscreens are generally preferred during pregnancy as a precaution. Consult a healthcare provider.
How does Phenylbenzimidazole Sulfonic Acid work?
Phenylbenzimidazole sulfonic acid, commonly known as ensulizole, is a water-soluble UVB-absorbing sunscreen agent with peak absorbance at 306 nm (280–320 nm range). Unlike most chemical UV filters which are oil-soluble, its unique water solubility makes it ideal for creating lightweight, non-greasy sunscreen formulations that are well-suited to oily skin. It is also photostable and can help stabilise less stable UV filters like avobenzone in combined formulations.
Individuals with known allergy to benzimidazole derivatives should review the considerations above before use.
Which products contain Phenylbenzimidazole Sulfonic Acid?
Shop products that contain Phenylbenzimidazole Sulfonic Acid
