The Lab
Specimen No. 0128
ClearedSyntheticsunscreenuv filter

Ensulizole

phenylbenzimidazole sulfonic acid · 2-phenylbenzimidazole-5-sulfonic acid · pbsa

A water-soluble UVB filter approved in the US (up to 4%) and EU (up to 8%). Regulatory safety reviews from multiple authorities confirm its safety profile, with only occasional mild local skin reactions and no evidence of systemic toxicity or endocrine activity.

medium confidence
Researched April 18, 2026
Ensulizole molecular structure
Specimen 0128Ensulizole

Concerns

  • Provides UVB protection only — must be combined with a UVA filter
  • Rare allergic contact dermatitis reported in sensitized individuals

Commonly found in

Daily SPF moisturizersLightweight facial sunscreenTinted SPF formulasSensitive skin sunscreen

Last researched: April 18, 2026

Research disclaimer: This rating is based on available peer-reviewed research and regulatory assessments at the time of publication. It is not medical advice. Consult a qualified professional for personal health or skin concerns.

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