Characteristics: Soft, silvery metal; rapidly oxidized in moist air. Soluble in liquid ammonia, aniline, mercury, and sodium.
Hazards: Dangerous fire risk; reacts with moisture to form potassium hydroxide and hydrogen. The reaction evolves much heat causing the potassium to melt and splatter. It also ignites the hydrogen. Burning potassium is difficult to extinguish; dry powdered soda ash or graphite or special mixtures of dry chemical is recommended. It can ignite spontaneously in moist air. Moderate explosion risk by chemical reaction. Potassium metal will form the peroxide and the superoxide at room temperature even when stored under mineral oil; may explode violently when handled or cut. Oxide-coated potassium should be destroyed by burning. Store in inert atmospheres, such as argon or nitrogen, or under liquids which are oxygen-free, such as toluene or kerosene, or in glass capsules which have been filled under vacuum or inert atmosphere.