Potassium acetate

Colourless soluble salt of acetic acid

Potassium acetate (also called potassium ethanoate), (CH3COOK) is the potassium salt of acetic acid. It is a hygroscopic solid at room temperature.

Potassium acetate is the extinguishing agent used in Class K fire extinguishers because of its ability to cool and form a crust over burning oils.

Potassium acetate is used in processed foods as a preservative and acidity regulator. In the European Union, it is labeled by the E number E261; it is also approved for usage in the USA, Australia, and New Zealand. Potassium hydrogen diacetate (CAS #) with formula KH(OOCCH3)2 is a related food additive with the same E number as potassium acetate.

In medicine, potassium acetate is used as part of electrolyte replacement protocols in the treatment of diabetic ketoacidosis because of its ability to break down to bicarbonate to help neutralize the acidotic state. In molecular biology, potassium acetate is used to precipitate dodecyl sulfate (DS) and DS bound proteins to extract ethanol from DNA. Potassium acetate is used in mixtures applied for tissue preservation, fixation, and mummification. Most museums today use a formaldehyde based method recommended by Kaiserling in 1897 which contains potassium acetate. This process was used to soak Lenin's corpse.

Potassium acetate was incorrectly used in place of potassium chloride when putting a prisoner to death in Oklahoma in January 2015. Charles Frederick Warner was executed on January 15, 2015 with potassium acetate; this was not public knowledge until the scheduled execution of Richard Glossip was called off. In August 2017, the U. S. state of Florida executed Mark James Asay using a combination of etomidate, rocuronium bromide, and potassium acetate. The drug was also used in the February 2023 execution of Donald Dillbeck, once again in combination with etomidate and rocuronium bromide.

Potassium acetate is used as a catalyst in the production of polyurethanes.

It is used as a diuretic and urinary alkalizer. Before modern chemistry, it was variously called terra foliata tartari, sal Sennerti, tartarus regeneratus, arcanum tartari and sal diureticus. In 1760 it was used in the preparation of Cadet's fuming liquid ((CH3)2As)2O, the first organometallic compound ever produced.