Potassium chloride is a chemical compound with the formula KCl. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water and its solutions have a salt-like taste. Potassium chloride can be obtained from ancient dried lake deposits. It is present in the sea, and occurs naturally as sylvite. It is mined from sylvinite ore, which also contains sodium chloride (NaCl) and other minerals.
The majority of potassium chloride produced is used for making fertilizer, since the growth of many plants is limited by their potassium intake. As a fertilizer, it is often applied either to the soil or directly to the leaves of plants (foliar feeding). Other major applications include use as an electrolyte replenisher in sports drinks and oral rehydration therapy for treatment of dehydration caused by diarrheal diseases; it also finds uses in medicine, scientific applications, food processing, and industrial processes where it forms caustic potassium hydroxide when dissolved in water or neutralized with acid.
Potassium chloride has been used as part of lethal injection to execute prisoners on death row in the United States since 1977. A three-drug lethal injection protocol typically begins with an anesthetic such as sodium thiopental or pentobarbital followed by pancuronium bromide (a muscle relaxant) and finally potassium chloride to stop the prisoner's heart