Potassium Hydroxide

poh-TASS-ee-um hy-DROX-ide

pH Adjuster 6/10 Safety Not CGControversial Synthetic Vegan

What Is Potassium Hydroxide?

A strong alkaline compound similar to sodium hydroxide, used as a pH adjuster and in the production of liquid soaps and some hair products.

Source: Synthesized from potassium chloride electrolysis

Origin: Synthetic

Also known as: KOH, Caustic Potash, Potassium Lye

What Does Potassium Hydroxide Do to Your Hair?

Adjusts pH in hair product formulations, similar to sodium hydroxide. Used in the saponification process to create liquid Castile soaps. Also used in some chemical straightening treatments.

Best For

All hair types (as pH adjuster); curly hair (in relaxers)

Not Recommended For

Damaged hair, sensitive scalp (at high concentrations)

Concentration Matters

Trace amounts as pH adjuster; higher in liquid soap manufacture

Hair Type Compatibility

1A Straight Fine
1B Straight Medium
1C Straight Coarse
2A Wavy Fine
2B Wavy Medium
2C Wavy Coarse
3A Curly Loose
3B Curly Tight
3C Curly Corkscrew
4A Coily S-Shaped
4B Coily Z-Shaped
4C Coily Tight
Heat-damaged: Not recommended

Method Compatibility

Curly Girl (CG) Method: Avoid
CG Avoid

Safety & Regulation

6/10
AvoidCautionSafe

Same caustic potential as sodium hydroxide at high concentrations. As a trace pH adjuster in products, perfectly safe. In chemical treatments, requires professional handling. Never apply directly to skin or hair.

FDA Status: Generally Recognized As Safe

FDA permits use as pH adjuster in cosmetics.

EWG Score: 5/10

HairAide Verdict

Functionally identical to sodium hydroxide as a pH adjuster. Safe at trace amounts in regular hair products. The same precautions apply for concentrated use in chemical treatments.

Products That Contain Potassium Hydroxide

Liquid soaps, pH-adjusted products, some straightening treatments

Alternatives to Potassium Hydroxide

If you want to avoid Potassium Hydroxide, look for products with these ingredients instead:

Sodium Hydroxide, Citric Acid, Triethanolamine

Frequently Asked Questions

Is Potassium Hydroxide safe for hair?

Potassium Hydroxide has a safety rating of 6/10. It's generally acceptable but may cause issues for some hair types. Same caustic potential as sodium hydroxide at high concentrations. As a trace pH adjuster in products, perfectly safe. In chemical treatments, requires professional handling. Never apply directly to skin or hair.

Is Potassium Hydroxide bad for curly hair?

Potassium Hydroxide is not CG-method approved. Curly hair types may want to avoid this ingredient or use products containing it sparingly.

Is Potassium Hydroxide CG-method approved?

No, Potassium Hydroxide is not approved for the Curly Girl method.

What can I use instead of Potassium Hydroxide?

Some alternatives to Potassium Hydroxide include: Sodium Hydroxide, Citric Acid, Triethanolamine

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