Barium peroxide Barium peroxide Barium peroxide is the inorganic compound with the formula BaO. This white solid (gray when impure) is one of the most common inorganic peroxides, and it was the first peroxide compound discovered. Being an oxidizer and giving a vivid green colour upon ignition (as do all barium compounds), it finds some use in fireworks; historically, it was also used as a precursor for hydrogen peroxide. Barium peroxide is a peroxide, containing subunits. The solid is isomorphous to calcium carbide, CaC. Barium peroxide arises by the reversible reaction of O with barium oxide. The peroxide forms around 500 °C
Barium ("barium meals" and "barium enemas"). Lithopone, a pigment that contains barium sulfate and zinc sulfide, is a permanent white with good covering power that does not darken when exposed to sulfides. Other compounds of barium find only niche applications, limited by the toxicity of Ba ions (barium carbonate is a rat poison), which is not a problem for the insoluble BaSO. Because of the high reactivity of the metal, toxicological data are available only for compounds. Soluble barium compounds are poisonous. In low doses, barium ions act as a muscle stimulant, and higher doses affect the nervous system, causing cardiac