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Skincare Ingredient

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Potassium Hydroxide

In Skincare: Is Potassium Hydroxide Safe? Comedogenic Rating & Side Effects

Safety (overall safety)
3/5 — Moderate risk
Irritancy (skin irritation)
4/5 — High risk

Safety Information

Potassium hydroxide is a strong alkali and pH adjuster that can be caustic at high concentrations, causing burns or irritation; in rinse-off products and at low levels, it is typically neutralized but may still cause stinging in individuals with sensitive or compromised skin, such as those with eczema. The Cosmetic Ingredient Review (CIR) Expert Panel has assessed potassium hydroxide as safe for use in cosmetics under the listed conditions of use.

Overview

Ingredient Profile

Potassium hydroxide is a strong alkali utilized in cosmetics to adjust product pH and, less commonly, as a cleansing agent primarily found in soaps. While effective at these functions, it is used in minimal concentrations to prevent irritation. Due to its alkaline nature, potassium hydroxide can cause skin aggravation if present in higher concentrations or used on sensitive skin.
Classifications
pH Adjuster/Stabilizer
Texture Enhancer

Data & Research

Scientific Facts

Potassium hydroxide is commonly known as potash lye or caustic potash. It’s a strong alkali that attracts water molecules and dissolves in water it absorbs. Historically, it has been used to hydrolyze fats and create soaps. Calcium hydroxide is also known as hydrated lime, while magnesium hydroxide is often referred to as milk of magnesia. Portlandite is the mineral form of calcium hydroxide, and brucite is the mineral form of magnesium hydroxide.

Common Uses

Formulation in Potassium Hydroxide

Potassium hydroxide is primarily used to control the pH of cosmetic and personal care products, ensuring they are within a desired range for stability and efficacy. It can also act as an absorbent in certain formulations.

Role of Potassium Hydroxide

Active Cosmetic Mechanisms

BUFFERING

pH Stabilizer

Maintains stable pH levels in products

SCIENTIFIC ANALYSIS

// Evidence: Buffering systems resist pH changes through weak acid-conjugate base pairs (citric acid/sodium citrate, lactic acid/sodium lactate, phosphate salts) that operate within specific pH ranges based on their pKa values. The mechanism follows the Henderson-Hasselbalch equation, with buffer components neutralizing added H⁺ or OH⁻ ions. Proper buffering prevents pH drift and maintains efficacy.

Products

containing Potassium Hydroxide

4272 formulations
Olive Real Cleansing Foam
Olive Real Cleansing Foam
innisfree · cleanser
Plantscription™ Anti-Aging Cleanser
Plantscription™ Anti-Aging Cleanser
Origins · cleanser
Moisturizing Cream Cleanser
Moisturizing Cream Cleanser
Laneige · cleanser
White Seed Exfoliating Foam Cleanser
White Seed Exfoliating Foam Cleanser
The Face Shop · cleanser
Egg Cleansing Foam
Egg Cleansing Foam
Esfolio · cleanser
White Washing Cream
White Washing Cream
Sekkisui · cleanser
Suncut UV Perfect Essence Super Waterproof SPF 50+ PA++++
Suncut UV Perfect Essence Super Waterproof SPF 50+ PA++++
Kose Cosmeport · sunscreen
All Day Fine Pore Mint Paste
All Day Fine Pore Mint Paste
SCINIC · masks
Soothing Foam Cleanser - Cica & Sunflower
Soothing Foam Cleanser - Cica & Sunflower
Watsons · cleanser
Rice Water Bright Cleansing Wipes
Rice Water Bright Cleansing Wipes
The Face Shop · makeup
See all products with Potassium Hydroxide

References

Scientific sources

[1]

Ullman's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim.

[2]
toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+1234
Semantic Analysis

Similar Ingredients

Ingredients with similar chemical profiles and skincare properties.

Frequently Asked Questions

Potassium Hydroxide — common questions

What is Potassium Hydroxide in skincare?

Potassium hydroxide is a white, crystalline solid. It’s used in cosmetics and personal care products as a pH adjuster across a wide range of formulations, including bath products, cleansing products, fragrances, foot powders, hair dyes and colors, makeup, nail products, personal cleanliness products, shampoos, shaving products, depilatories, skin care products, and suntan lotions. It’s also utilized in hair straightening and wave setting products.

What does Potassium Hydroxide do? / Functions of Potassium Hydroxide?

Common functions: BUFFERING.

What is the comedogenic rating of Potassium Hydroxide? / Is Potassium Hydroxide comedogenic?

The comedogenic rating of Potassium Hydroxide has not been established in our database.

Does it clog pores?
No Rating Available

Whether Potassium Hydroxide clogs pores depends on the formulation and concentration.

Is Potassium Hydroxide safe for skin?
3 3/5 — Moderate risk

Potassium Hydroxide has a safety rating of 3 out of 5. A rating of 3 indicates moderate safety considerations. Note: Potassium hydroxide is a strong alkali and pH adjuster that can be caustic at high concentrations, causing burns or irritation; in rinse-off products and at low levels, it is typically neutralized but

Is Potassium Hydroxide good for sensitive skin?
4 4/5 — High risk

Potassium Hydroxide has an irritancy rating of 4 out of 5. A rating of 4 means it has high irritation potential.

What are the side effects of Potassium Hydroxide in skincare?

Known considerations: Potassium hydroxide is a strong alkali and pH adjuster that can be caustic at high concentrations, causing burns or irritation; in rinse-off products and at low levels, it is typically neutralized but may still cause stinging in individuals with sensitive or compromised skin, such as those with eczema. The Cosmetic Ingredient Review (CIR) Expert Panel has assessed potassium hydroxide as safe for use in cosmetics under the listed conditions of use. Additional risks: skin irritation (irritancy rating 4/5).

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