PLDEFRESITJęzyk: polski
INCI name

SODIUM HYDROXIDE

Lye

BufferingDenaturantreviewed

Used in small amounts to adjust pH or neutralise acids.

What it is

Sodium hydroxide is a strong base. In cosmetic formulas it is used to raise pH or to neutralise acidic ingredients such as carbomer or fatty acids; in soap making it reacts with oils to form soap.

Where it is used

Gels, creams, cleansers and soaps.

Limits of interpretation

The INCI list shows which ingredients are present, not how much of each. Above 1%, ingredients are listed in descending order of weight; below 1% the order is free.

In the finished product it is normally neutralised; its presence on the label does not mean the product is highly alkaline.

Functions

Buffering
Stabilising the pH of an aqueous medium in a narrow range even if an acid or base is added. Altering and/or maintaining a cosmetic product's pH at the desired level.
Denaturant
Rendering cosmetics unpalatable. Mostly added to cosmetics containing ethyl alcohol to make it unsuitable for ingestion.

EU regulation

EU · Annex III, entry 15aPotassium or sodium hydroxide
Product type
(a) Nail cuticle solvent (b) Hair straightener (c) pH adjuster for depilatories (d) Other uses as pH adjuster Callosity softener/remover (entry 15d)
Maximum concentration
(a) 5% (b) 2% (General use) and 4.5% (Professional use) Entry 15d: 1,5%
Conditions and warnings
(a) Contains alkali Avoid contact with eyes Can cause blindness Keep out of reach of children (b) 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) Keep out of reach of children Avoid contact with eyes
As of
3 November 2026 · (EU) 2016/622

Products with this ingredient (4200)

Check a full ingredient list