Toxicity Sodium hydride and potassium hydride react with the moisture on skin and other tissues to form highly corrosive sodium and potassium hydroxide. Flammability and Explosibility Potassium hydride and sodium hydride are flammable solids that ignite on contact with moist air.
Potassium hydride presents a more serious fire hazard than sodium hydride.
The mineral oil dispersions do not ignite spontaneously on exposure to the atmosphere. Water or CO extinguishers must never be used on sodium and potassium hydride fires . Reactivity and Incompatibility Potassium hydride and sodium hydride react violently with water, liberating hydrogen, which can ignite. Oil dispersions of these hydrides are much safer to handle because the mineral oil serves as a barrier to moisture and air. Potassium hydride may react violently with oxygen, CO, dimethyl sulfoxide, alcohols, and acids.