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Phenylbenzimidazole sulfonic acid

CAS 27503-81-7 · 20/100 · High conf.

Also registered as 1 other CAS number

165659-93-8

Phenylbenzimidazole sulfonic acid chemical structure

Concern score

20/100Minor concern based on regulatory listings.
High confidence

Phenylbenzimidazole sulfonic acid in plain language

What it is

On cosmetic ingredient lists it appears as “Potassium phenylbenzimidazole sulfonate”.

Also known as Potassium phenylbenzimidazole sulfonate · Sodium phenylbenzimidazole sulfonate · Tea-phenylbenzimidazole sulfonate · Ensulizole · 2-PHENYLBENZIMIDAZOLE-5-SULFONIC acid · 1H-BENZIMIDAZOLE-5-SULFONIC ACID-2-PHENYL-

Show all 21 names

2-Phenyl-1H-benzimidazole-5-sulfonic acid · 2-phenyl-3H-benzimidazole-5-sulfonic acid · 1H-Benzimidazole-6-sulfonic acid, 2-phenyl- · 2-Phenyl-1H-benzimidazol-5-sulfonsaure · 2-Phenyl-1H-benzimidazole-5-sulphonic acid · 2-Phenyl-5-sulfobenzimidazole · 2-phenyl-1H-1,3-benzodiazole-6-sulfonic acid · 5-Benzimidazolesulfonic acid, 2-phenyl- · Covergirl Outlast Stay Fabulous 3in1 Foundation · Covergirl Queen Collection All Day Flawless 3in1 Foundation · Ensulizole (INN) · Full spectrum matte ambition skin primer SPF 20 · ensulizol · ensulizolum · novantisol

What it does

Used in cosmetics as a UV filter and a light stabiliser. Phenylbenzimidazole Sulfonic Acid is the aromatic organic compound.

  • UV filter
  • UV absorber
  • Light stabilizer
  • Fragrance
Is it a concern?
Minor concern: no hazard classifications on record. It is listed for cosmetic use in the EU.

What the listings say

Permitted, with conditions — Phenylbenzimidazole sulfonic acid appears on published "allowed" regulatory lists rather than on a restriction list.

2-Phenylbenzimidazole-5-sulphonic acid and its potassium, sodium and triethanolamine salts / Ensulizole is listed in Annex VI of the EU Cosmetics Regulation (EC) 1223/2009 (UV filters allowed in cosmetic products).

The score describes this ingredient's chemical identity — its hazard profile from published classifications and regulatory status — not the safety of any product it appears in.

Regulation

No restrictions found. Phenylbenzimidazole sulfonic acid appears in these published regulatory listings.

  • In marketed US drugs
  • EU Annex VI — permitted UV filter
  • EU permitted UV filter

Recorded in these product areas

  • Found in consumer products
  • Beauty
  • Cleaning
  • Pharma
  • Food
  • EUCosIngActive2 entries
    • Cosmetics Regulation annex VI / ref 6.Source →
    • Phenylbenzimidazole Sulfonic Acid is the aromatic organic compound that conforms to the formula: Restriction: VI/6Source →
  • USFDAmarketed drug occurrence2 entries
    • FDA NDC lists this ingredient in 87 active drug products and 90 total products.Source →
    • FDA NDC lists this ingredient in 9 active drug products and 9 total products.Source →
  • EUECallowed_listedAnnex VI of EU Cosmetics Regulation (EC) 1223/2009: UV filters allowed in cosmetic products. Maximum concentration: 8%(as acid)
    • Annex VI of EU Cosmetics Regulation (EC) 1223/2009: UV filters allowed in cosmetic products. Maximum concentration: 8%(as acid)Source →
  • USEPAcommercial use observedEPA CPDat observed this chemical in 152 composition records across product categories including Personal care, Food and drug. EPA CPDat classifies this chemical for functional uses including UV stabilizer, Fragrance.
    • EPA CPDat observed this chemical in 152 composition records across product categories including Personal care, Food and drug. EPA CPDat classifies this chemical for functional uses including UV stabilizer, Fragrance.Source →
  • USFDAlisted in openFDA substanceopenFDA substance registry classifies this ingredient as chemical.
    • openFDA substance registry classifies this ingredient as chemical.Source →

Expert safety opinions

No expert opinion on file for Phenylbenzimidazole sulfonic acid. These are the independent scientific bodies that assess ingredients like this one; we show an opinion only when a record we hold cites it.

  • SCCS

    EU Scientific Committee on Consumer Safety

    No SCCS opinion on file.

  • CIR

    Cosmetic Ingredient Review (US expert panel)

    No CIR safety assessment on file.

Evidence & sources

No graded research studies for Phenylbenzimidazole sulfonic acid yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.

8 data sources

Where this comes from

  • CosIng

    regulatory · updated 2026-09-23

    Open →

  • EU CosIng Cosmetics Regulation Annexes

    regulatory · updated 2011-03-08

    Open →

  • EPA Chemical and Products Database

    exposure · updated November 2014

    Open →

  • EPA DSSTox Identifiers

    chemistry · updated 2025-12-29

    Open →

  • FDA National Drug Code Directory

    regulatory · updated 2027-12-31

    Open →

  • FDA GSRS UNII

    registry · updated 2026-02-26

    Open →

  • openFDA Substance

    registry · updated 2026-05-24

    Open →

  • PubChem Live Enrichment

    chemistry · updated 2026-05-17

    Open →

Allergen profile

Canonical allergen markers detected on this ingredient. Each row is derived from the ingredient’s name or synonyms matching a known allergen class — useful when scanning a label for a specific allergy context.

  • DairyContains · Oral (ingested)

    Source: chemindex_name_match

Suitability

Context-specific fit derived from published classifications and the current ingredient evidence profile.

Food use

Food-use source coverage is present in the current record.

Good fit

The ingredient appears in food-oriented source coverage or allowed-use references, which makes food use easier to support than a context with no domain signal at all.

Fragrance avoidance

Not a strong fit for fragrance avoidance because it carries Fragrance.

Avoid

The ingredient itself is a fragrance-linked signal, so it is better treated as an avoid case when fragrance exposure is the main concern.

Where it has been recorded

How often EPA CPDat has listed Phenylbenzimidazole sulfonic acid in a product composition. These are source records, not Greenveil catalog products.

Source records

152

Named organisations

6

Personal careFood and drug

Typical roles

UV filterUV absorberLight stabilizerFragrance
See products using Phenylbenzimidazole sulfonic acid →

Catalog

Found in these products

Their ingredient lists include Phenylbenzimidazole sulfonic acid; each product's own rating depends on its whole formula, so it is shown on the product page, not here.

See all 318 →Find products without it →

Co-occurrence

Often appears with

Ingredients that frequently appear alongside Phenylbenzimidazole sulfonic acid in the catalog.