Sodium Hydroxide — Allergy Risk & Safety Profile
INCI: SODIUM HYDROXIDE
Also known as: Lye, NaOH, Caustic Soda
Key Facts
- CAS Number
- 1310-73-2
- Category
- ph adjuster
- Risk Level
- low
- Common Allergen
- No
- Found In
- all
Is Sodium Hydroxide safe in cosmetics?
Sodium Hydroxide is rated low risk in cosmetic products. It is not classified as a common allergen and is generally well-tolerated by most skin types. Commonly found in all.
What is Sodium Hydroxide?
Lye — used in tiny amounts to adjust pH. Not harmful at cosmetic concentrations.
Allergy & Safety Information
Sodium Hydroxide is considered safe for cosmetic use. No significant safety concerns have been identified at typical use concentrations. As with any cosmetic ingredient, discontinue use if irritation occurs.
This ingredient is considered low risk from an allergenicity perspective. Reactions are uncommon at typical cosmetic use concentrations. However, no ingredient is universally safe — if you notice redness, itching, or irritation after using a product containing this ingredient, discontinue use and monitor whether symptoms resolve.
How to Identify Sodium Hydroxide in Products
Cosmetic ingredients are listed by their INCI (International Nomenclature of Cosmetic Ingredients) name in descending order of concentration. To check whether a product contains Sodium Hydroxide, scan the ingredient list for its INCI name exactly as it appears above. Ingredients present at 1% or less may appear in any order after the 1% threshold.
Product types to prioritise checking: All. These product categories are the most common sources of Sodium Hydroxide exposure based on formulation data.
Not sure if your products contain Sodium Hydroxide? Paste the ingredient list into the free ingredient checker to scan for Sodium Hydroxide and other allergens automatically.
Frequently Asked Questions
Is Sodium Hydroxide safe for sensitive skin?
Sodium Hydroxide is generally well-tolerated, even by sensitive skin types.
What products contain Sodium Hydroxide?
Sodium Hydroxide is commonly found in all.
What does Sodium Hydroxide do in cosmetics?
Sodium Hydroxide functions as a ph_adjuster in formulations.
Related Guides
Is Sodium Hydroxide causing YOUR skin reactions?
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