Potassium Hydroxide

AKA: 1310-58-3, Caustic potash, Potash lye, Potassium hydrate, Potassium hydroxide (K(OH)), Hydroxyde de potassium, Potassa, Potasse caustique, Caustic-potash
Synthetic
Not Clean
OriginProduced from the alkali metal potassium through oxidation and hydration processes in industrial synthesis. Manufactured by electrolyzing potassium chloride solution or through reactions between potassium compounds and water.
Potassium hydroxide, also known as lye is an inorganic compound with the chemical formula KOH. Also commonly referred to as caustic potash, it is a potent base that is marketed in several forms including pellets, flakes, and powders. It is used in various chemical, industrial and manufacturing applications. Potassium hydroxide is also a precursor to other potassium compounds. Potassium hydroxide is used in food to adjust pH, as a stabilizer, and as a thickening agent. This ingredient has been considered as generally safe as a direct human food ingredient by the FDA, based upon the observance of several good manufacturing practice conditions of use. In addition to the above uses, potassium hydroxide is also used in making soap, as an electrolyte in alkaline batteries and in electroplating, lithography, and paint and varnish removers. Liquid drain cleaners contain 25 to 36% of potassium hydroxide. Medically, potassium hydroxide (KOH) is widely used in the wet mount preparation of var
Solubility 107 g/100 cc at 59 °F (NTP, 1992)
Formula
HKO
Mol. Weight
56.11
CAS #
1310-58-3
Form
Powder
State
Potassium hydroxide, solution appears as an clear aqueous solution. Corrosive to metals and tissue. Noncombustible. Used in chemical manufacturing, petroleum refining, cleaning compounds.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
Functions
Buffering
Stabilizes pH
Reduces Inflammation
Brightens Skin
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
5
CIR
Safe as used
Pregnancy
Caution
CIR Safety Findings
Not a Sensitizer
1 study / 1 not sensitizing (CIR 703)
Skin Irritant in Testing
2 studies / 2 irritating / reactions corrosive (CIR 703)
Eye Irritant in Testing
1 study / 1 irritating / reactions severe (CIR 703)
Concentration Guide
Leave-on0.0000049–7%
Rinse-off0.00048–10%
0%50%100%
Reg. limit 5%
CIR reported use · report published 2021
EU regulatory limit: 5.0%. (a) 5% (5) (b) 1. 2% (5) 2. 4.5% (5). (a) Contains alkali Avoid contact with eyes Can cause blindness Keep out of reach of children (b) 1. Contains alkali Avoid contact with eyes Can cause blindness Keep out of reach of children 2. F... Source: EU Cosmetics Regulation (EC) 1223/2009, Annex III (Restricted Substances), Entry 15a.
Regulatory Status
USA✔ permitted
EU✔ permitted
JAPAN✔ permitted
CANADA✔ permitted
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR