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Cosmetic ingredient dictionary

Potassium Hydroxide in cosmetics: what it is and what it does

Potassium Hydroxide is a cosmetic ingredient that keeps the product's acidity steady. The EU allows it only with limits or conditions. Open Beauty Facts finds it in 365 products, most often sunscreen.

By Bravoora teamUpdated Sources checked 3 sourcesHow we check

What does Potassium Hydroxide do in a product?

In a cosmetic product, Potassium Hydroxide keeps the product's acidity steady. The EU’s CosIng database lists this job for it: buffering.

buffering

What other names and numbers does Potassium Hydroxide have?

CAS number
1310-58-3
EC number
215-181-3
CosIng reference
36981

Is Potassium Hydroxide restricted in the EU?

Yes, it has limits. The EU allows it only with limits or conditions of use, such as a maximum amount or a warning on the label (Annex III of Regulation 1223/2009, entry 15a).

The annex entry sets the exact limits, the products it may be used in and any warning the label must carry.

Which products contain Potassium Hydroxide?

Open Beauty Facts finds Potassium Hydroxide in the ingredient lists of 365 of the 22,021 products it has a list for, most often sunscreen and soaps.

  • Sunscreen23
  • Soaps16

Products with it, by country of sale: France 96 · United States 56 · Germany 47 · Norway 27.

Counted on 13 October 2026 from Open Beauty Facts, which volunteers fill from real packs: it shows where Potassium Hydroxide turns up, not how much of the market it is.

On these listsRestricted in the EU

Bravoora reads this ingredient for everyone you shop for: an allergy or intolerance, a vegan or vegetarian diet, a calorie or protein goal, and the labels on supplements and skincare too. Build a profile · For dermatologists, dietitians and doctors

Sources

The job, the description and the EU annex entry are CosIng’s; the fragrance allergens are the EU Annex III names Bravoora’s label checker reads; the product counts are Open Beauty Facts’.

  1. European Commission: CosIng cosmetic ingredient database (functions, description, EU annex entry)
  2. Open Beauty Facts: product database, 77,506 products, read 13 October 2026, ODbL
  3. EU Regulation 1223/2009 on cosmetic products (the annexes)

Contains information from Open Beauty Facts, which is made available here under the Open Database License (ODbL). Read the licence · Download this dictionary’s data · How we check

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