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Cosmetic ingredient dictionary

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

Sodium 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 3,920 products, most often shampoos.

By Bravoora teamUpdated Sources checked 3 sourcesHow we check

What does Sodium Hydroxide do in a product?

In a cosmetic product, Sodium Hydroxide keeps the product's acidity steady and makes alcohol undrinkable. The EU’s CosIng database lists these jobs for it: buffering and denaturant.

bufferingdenaturant

What other names and numbers does Sodium Hydroxide have?

CAS number
1310-73-2
EC number
215-185-5
CosIng reference
37890

Is Sodium 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 Sodium Hydroxide?

Open Beauty Facts finds Sodium Hydroxide in the ingredient lists of 3,920 of the 22,021 products it has a list for, most often shampoos, hair care and shower gels.

  • Shampoos373
  • Hair care251
  • Shower gels203
  • Bath and shower194

Products with it, by country of sale: France 1,473 · Germany 561 · United States 362 · Spain 196.

Counted on 13 October 2026 from Open Beauty Facts, which volunteers fill from real packs: it shows where Sodium 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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