Barium oxalate Barium oxalate Barium oxalate (BaCO), a barium salt of oxalic acid, is a white odorless powder that is sometimes used as a green pyrotechnic colorant generally in specialized pyrotechnic compositions containing magnesium. Though largely stable, barium oxalate can be reactive with strong acids. A mild skin irritant, the substance is considered toxic when ingested, causing nausea, vomiting, renal failure, and injury to the gastrointestinal tract. It is different from most pyrotechnic colorants in that it is a reducing agent and not an oxidizing agent. It is extremely insoluble in water and converts to the oxide form when heated. The raw
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