Potassium hydroxide
HKO56.106 g/mol Calculated
Also called caustic potash, KOH, lye and potassium hydrate.
Caustic potash, the base that makes liquid and soft soaps where sodium hydroxide makes hard bars. It is also the electrolyte in alkaline batteries.
Sources and notes
- The introductionfrom sourceMoleculeFinder curated
- Other namesfrom sourceWikidataIts English label and aliases on Wikidata.
- Formula and weightcomputedPubChem
- 2D drawingcomputedPubChem structure, drawn by RDKit
Where you encounter it
Potassium hydroxide on the product labels we hold.
Medicines
Personal care
Every product and list we hold
Sources and notes
- The product labels and their strengthsfrom sourceDailyMed (FDA label)Each label lists the molecule as an ingredient, and an active ingredient at the strength shown.
- How it gets therefrom sourceMoleculeFinder curatedEach mark is set by hand on our lists, never inferred; a label's ingredient is added by the maker. A row with no mark data says Not marked.
Properties and sources
Calculated by PubChem
- Molecular formula
- HKO
- Molecular weight
- 56.106 g/mol
- Polar surface areatopological
- 1 Ų
- H-bond donors
- 1
- H-bond acceptors
- 1
- Rotatable bonds
- 0
- Complexity
- 2
Measured LD50, HSDB via PubChem
273 mg/kg pure potassium hydroxide, rat, oral
An LD50 is an animal study measurement, not a dose for a person.
Reported Hazard label (GHS), ECHA, EU CLP Regulation, Safe Work Australia, HSDB via PubChem
Danger Corrosive pictogram (GHS05) and Irritant pictogram (GHS07); hazard statements H290, H302, H314, H318, H402
Groups it belongs to
- Category
- Everyday chemistry
- Family
- Inorganic compounds
- Elements
- Potassium
- Hazard classes
- Corrosive, Irritant, GHS Danger
- Size
- Under 100 g/mol
SMILES
[OH-].[K+]PubChem CID 14797 · Wikidata Q132298 · InChIKey KWYUFKZDYYNOTN-UHFFFAOYSA-M · Data refreshed
Questions
- What is Potassium hydroxide?
- Caustic potash, the base that makes liquid and soft soaps where sodium hydroxide makes hard bars. It is also the electrolyte in alkaline batteries.
- How toxic is Potassium hydroxide?
- The reported LD50 of Potassium hydroxide is 273 mg/kg (rat, oral). An LD50 is an animal study measurement, not a dose for a person. Its GHS hazard label carries the signal word Danger and the hazard pictograms Corrosive and Irritant. from sourcefrom source
- What kind of molecule is Potassium hydroxide?
- Potassium hydroxide has the formula HKO and a molecular weight of 56.106 g/mol. MoleculeFinder files it under inorganic compounds, in the everyday chemistry group. from sourcefrom sourcefrom sourcefrom source
- What else is Potassium hydroxide called?
- Potassium hydroxide is also called KOH, caustic potash, lye and potassium hydrate. from source
Sources and notes
- Calculated valuescomputedPubChemComputed from the structure, so no laboratory conditions apply; complexity is PubChem's own structural score.
- LD50from sourceHSDB via PubChemOther values the sources report: rat, oral, 363 mg/kg; rat, oral, 1,230 mg/kg. The page shows the one LD50 the site uses everywhere.
- Hazard labelfrom sourceECHA, EU CLP Regulation, Safe Work Australia, HSDB via PubChemThe label combines these classifications.
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- EU CLP Regulationfrom sourceAttributionSource: EUR-Lex, Regulation (EC) No 1272/2008, © European Union.
- Safe Work Australiafrom sourceAttributionSource: Safe Work Australia, Hazardous Chemical Information System, © Commonwealth of Australia, CC BY 4.0.
- Data refreshedfrom sourceMoleculeFinder2026-11-09