Barium chlorate
From PyroGuide
Formula: BaClO3
Description: Barium chlorate is used as an oxidiser in green color compositions and can produce intense greens. Fierce burning and high color purity compositions can be made with it.
Hazards: Barium chlorate is poisonous and a dust mask should be worn at all times when handling it. Barium chlorate should never be mixed with sulfur or sulfides or allowed to come in contact with mixtures containing sulfur or sulfides since this could result in spontaneous ignition. Sulfur reacts with water and air to form small amounts of sulfuric acid. Sulfuric acid and chlorates react producing ClO2, an explosive gas that will ignite many organic materials on contact. Mixtures made with barium chlorate are often especially sensitive to friction and shock (even more so than potassium chlorate based mixtures) and should be handled with extra care.
Sources: Barium chlorate is usually purchased from chemical suppliers or from dedicated pyro suppliers. It can be made at home from sodium chlorate and barium chloride by double decomposition however purifying the product by recrystallising can be a lot of work because all traces of the sodium must be removed so as to not interfere with pure green colors. Barium chlorate can also be prepared from barium chloride by electrolysis in a process analogous to that used for preparing sodium chlorate.