SODIUM HYDROXIDE
Official label name (INCI name, EU glossary of cosmetic ingredient names), No 26674
- Allowed with restrictions (Annex III)
SODIUM HYDROXIDE: Allowed with restrictions, with limits depending on the product type (Annex III, entry 15a), under Regulation (EC) No 1223/2009.
In plain words
What it is used for
Functions declared by manufacturers:
Buffering: stabilises the pH of cosmetics.
Denaturant: renders cosmetics unpalatable. Mostly added to cosmetics containing ethyl alcohol.
What the rules say
Allowed, with restrictions: Annex III sets a maximum concentration, the product types allowed and a warning to be printed on the packaging. Ingredient lists do not give quantities, so the concentration cannot be checked on the label; the warning can.
The text of the annexes
Allowed with restrictions
| Product type | Maximum concentration | Other conditions | Warning to print |
|---|---|---|---|
| (a) Nail cuticle solvent | 5% | not set | Contains alkali Avoid contact with eyes Can cause blindness Keep out of reach of children |
| (b) Hair straightener | 2% (General use) and 4.5% (Professional use) Entry 15d: 1,5% | 1. General use 2. Professional use | 1. Contains alkali Avoid contact with eyes Can cause blindness Keep out of reach of children 2. For professional use only Avoid contact with eyes Can cause blindness |
| (c) pH adjuster for depilatories | not set | up to pH 12.7 | Keep out of reach of children Avoid contact with eyes |
| (d) Other uses as pH adjuster Callosity softener/remover (entry 15d) | not set | up to pH 11 15 d Contains alcakali, Avoid contact with eyes Keep out of reach of chindren ans Read directions for use carefully | not set |
- Entry
- Annex III, No 15a
- Substance
- Potassium or sodium hydroxide
- Glossary names
- POTASSIUM HYDROXIDE / SODIUM HYDROXIDE
- CAS
- 1310-58-3 / 1310-73-2
- EC
- 215-181-3 / 215-185-5
Dates in the act (1)
- Entry into force on 12 May 2016
Excerpts from the English text published in the Official Journal. A date may concern only some substances of the act: the excerpt says so.
Identity
- CosIng identifier
- 37890
- CAS (according to CosIng)
- 1310-73-2
- EC (according to CosIng)
- 215-185-5
- Declared functions
- Buffering, Denaturant
- Wikidata
- Q102769
- PubChem
- 14798
- ECHA InfoCard
- 100.013.805
- InChIKey
- HEMHJVSKTPXQMS-UHFFFAOYSA-M
Classified hazard (CLP Regulation)
The harmonised classification is the one set by the European Union for the whole Union. H codes refer to the hazard statements of Annex III of Regulation (EC) No 1272/2008.
sodium hydroxide; caustic soda
No harmonised CMR classification
- Hazard classes
- Skin Corr. 1A
- Hazard statements
- H314
EU product alerts (Safety Gate)
3 alerts on cosmetic products cite this name in their hazard description. An alert targets a specific product, not the ingredient itself; each alert states the reason (prohibited substance, limit exceeded, missing labelling, and so on).
Elsewhere in the world
Information on other jurisdictions. What is covered, and what is not yet.
United Kingdom (Great Britain)
- Allowed with restrictions (Annex III)
Same entries as in the European Union. Conditions (concentrations, warnings) may differ: they are not compared here.
Switzerland
Regulation (EC) No 1223/2009 applies in Switzerland (Article 54 of the Ordinance on Foodstuffs and Utility Articles).
United States, federal rules
None of the integrated sections of the federal code (21 CFR 700.11 to 700.27 and 250.250) targets this name. The FDA does not publish a list of allowed ingredients.
South Korea
- Restricted: 포타슘하이드록사이드 또는 소듐하이드록사이드 (SODIUM HYDROXIDE)
별표 2, 기타 (other substances with limits), entry 76, page 42-43. Limit: ․손톱표피 용해 목적일 경우 5%, pH 조정 목적으로 사용되고 최종 제품이 제5조제5항에 pH기준이 정하여 있지 아니한 경우에도 최종 제품의 pH는 11이하 ․제모제에서 pH조정 목적으로 사용되는 경우 최종 제품의 pH는 12.7이하.
Conditions, source text, in Korean
화학물질명: 포타슘하이드록사이드 (CAS No. 1310-58-3) | 화학물질명: 소듐하이드록사이드 (CAS No. 1310-73-2)
Australia
- Prohibited for the stated use: SODIUM HYDROXIDE
Poisons Standard, Schedule 10 (formerly Appendix C), page 318.
Conditions, source text
(excluding its salts and derivatives), in liquid or semi-solid food additive preparations, for domestic use, the pH of which is more than 11.5.
Recorded cosmetics that contain it
3,910 recorded products list it, according to Open Beauty Facts contributors. Records are dated: the formula may have changed. See the list (page in French).
Glossary: Commission Implementing Decision (EU) 2025/1175. Page updated on 21 October 2026.