Cesium, Silver-colored solid, 99.8% (Metals basis)

Moderately toxic by intraperitoneal route. Cesium is quite similar to potassium in its elemental state. It has been shown, however, to have pronounced physiological action in experimentation with animals. Hyper-irritability, including marked spasms, has been shown to follow the administration of cesium in amounts equal to the potassium content of the diet. It has been found that replacing the potassium in the diet of rats with cesium caused death after 10–17 days. Ignites spontaneously in air. Violent reaction with water, moisture, or steam releases hydrogen gas which explodes. Violent reaction with acids, halogens, and other oxidizing materials. Incandescent reaction with nonmetals (e.g., sulfur, phosphorus). See also SODIUM.