potassium hydroxide: meaning, definition, pronunciation and examples

Historically, 'lye' referred to solutions of potassium hydroxide (or sometimes sodium hydroxide) made from leaching wood ashes. In modern contexts, 'lye' often specifically means sodium hydroxide, but it can be ambiguous. Potassium hydroxide is more accurately called 'caustic potash'.

Yes, in very diluted forms in some soaps or hair relaxers. In concentrated forms, it is a main ingredient in some commercial oven and drain cleaners, which are highly corrosive and require careful handling.

Always wear appropriate personal protective equipment (PPE) including gloves, goggles, and a lab coat. Work in a well-ventilated area. Have access to running water and an acid neutraliser (like dilute acetic acid) for accidental skin contact. Never add water to solid KOH; always add KOH slowly to water to control the exothermic reaction.

Both are strong alkali metal hydroxides. Sodium hydroxide (NaOH) is more common and cheaper, used in many industrial processes and drain cleaners. Potassium hydroxide (KOH) is more soluble in alcohol and is preferred in liquid soap production and as an electrolyte in some batteries. Their chemical properties are similar but not identical in reactivity and resulting salts (potassium vs. sodium salts).

A strong inorganic chemical compound with the formula KOH, commonly known as caustic potash, used primarily in industry and laboratories.

Potassium hydroxide is usually technical / scientific in register.

Potassium hydroxide: in British English it is pronounced /pəˈtæs.i.əm haɪˈdrɒk.saɪd/, and in American English it is pronounced /pəˈtæs.i.əm haɪˈdrɑːk.saɪd/. Tap the audio buttons above to hear it.