A strong alkali used in controlled amounts to adjust product pH or neutralize acidic ingredients.
Sources: 1, 2Caustic soda, Lye
Not assessed
No pregnancy- or breastfeeding-specific assessment has been completed for this record. A cosmetic safety review is not a pregnancy rating.
Not assessed
Sodium Hydroxide
What it does
Helps a formulator reach the intended pH or develop a neutralized gel. Its appearance on a label does not reveal the finished product's pH or residual free alkali.
Sources: 1, 2Good for
- Controlled formula pH
How to use it
Use only the finished product as labeled. Do not add sodium hydroxide to cosmetics or apply a raw alkali to skin.
Sources: 1, 2Who should be careful
Concentrated sodium hydroxide is corrosive and can cause severe skin or eye burns. Ingredient-list presence alone does not mean a correctly formulated product is caustic.
Sources: 1, 2Pairs well with
No supported pairings have been documented for this record.
Usage, safety and formulation details
Mechanism of action
Hydroxide ions react with acids during neutralization. The chemistry of the finished buffered product differs from that of concentrated raw sodium hydroxide.
Sources: 1, 2Potential adverse effects
An excessively alkaline or improperly made product can irritate or burn. Exposure to concentrated raw material is a separate chemical hazard.
Sources: 1, 2Formulation considerations
Verify measured final pH, buffering and adequate processing. Neutralizing an acidic polymer or fatty acid changes the chemical species present.
Sources: 1, 2Pregnancy and breastfeeding
Not assessed
No pregnancy- or breastfeeding-specific assessment has been completed for this record. A cosmetic safety review is not a pregnancy rating.
Safety tags
- Fragrance allergen
- Not assessed
Not separately assessed in this draft.
- Essential oil
- Not assessed
Not separately assessed in this draft.
- Drying alcohol
- Not assessed
Not separately assessed in this draft.
- May irritate sensitive skin
- Not assessed
Not separately assessed in this draft.
What remains uncertain
- Exact concentration, final pH and the full composition of any unprovided finished product
Clinical evidence and research
Clinical evidence
Evidence for its main benefitNot assessed
The cited references support identity, formulation role or safety context. No standalone clinical efficacy rating has been completed for the main benefit in this draft.
Sources: 1, 2Regulation and ingredient label names
Regulatory information
No jurisdiction-specific assessment is recorded. An inventory listing is not blanket approval.
Names on ingredient lists
sodium hydroxide
Chemical identity and molecular structure
Chemical information
Chemical structure
| Detail | Value | Source |
|---|---|---|
| PubChem CID | 14798 | PubChem compound 14798: chemical identity |
| molecular formula | HNaO | PubChem compound 14798: chemical identity |
| molecular weight | 40.00 g/mol | PubChem compound 14798: chemical identity |
| iupac name | sodium hydroxide | PubChem compound 14798: chemical identity |
Content updated 9 November 2026.
Sources (3)
Scientific sources
- CIR: Safety assessment of inorganic hydroxides as used in cosmeticssafety assessment · 2021
- PubChem: Sodium hydroxide identity and concentrated-material hazardschemical identity and safety
- PubChem compound 14798: chemical identitychemical identity
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