E525

Potassium hydroxide

What the research shows

Not enough

published research on this page yet

A white solid also called caustic potash.

It is used to make soft and liquid soaps.1

  • Vegan
  • Vegetarian
  • EU permitted

What research says

Single cases of misuse or overdose

One person or one incident, such as an accidental overdose or a mistake in a kitchen or factory. They are real, but a single case does not show what happens at normal amounts, so the signal does not count them.

  • Harm from a supplement2

    A person was poisoned after eating potassium hydroxide used as a nutrient in a supplement.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.

What expert reviews concluded

Expert panels that weigh all the research. Shown for context: the signal at the top does not count them.

Regulatory status

Checked Sep 2026

Status reflects the named register on the date checked. It is not a safety rating.

How we check

Products

The 6 most-scanned of 530 products on Open Food Facts that list potassium hydroxide.

  • Fine Dark Cocoa Powder Dr. Oetker · 190 g 2 additives
  • Cocoa Dr. Oetker · 100 g 2 additives
  • Original nutrition shake Ensure · 237 ml 5 additives
  • Alkaline Ionized Hydration Member's Mark 0 additives
  • Cacao Dr. Oetker · 50 grame 2 additives
  • Cocoa Asda · 250 g 2 additives

References

  1. 1Potassium hydroxide. Wikipedia. Accessed September 26, 2026. CC BY-SA 4.0.
  2. 2Zovi A, Ferrara F. Is Potassium Hydroxide Safe as a Source of Nutrient in Food Supplements? An Expert Opinion. Int J Vitam Nutr Res. 2025;95(2):31370. doi:10.31083/IJVNR31370