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.