Barium chloride is one of the most popular salts of barium. Bacl2 in water is both hygroscopic and water-soluble. When exposed to an open flame, the compound gives a yellow-green coloration. The salt is produced by reacting hydrochloric acid with either barium carbonate or barium hydroxide. The result is hydrated BaCl2. Industrially, however, the salt is made in a two-step process. The first step entails reacting carbon and barium sulphate under high temperatures to produce BaS. In the second step, BaS is fused with calcium chloride to produce BaCl2 and CaS. The salt is used in laboratories to test for sulfate ions in the test sample. The salt is also used in caustic chlorine plants to purify brine solution. Other uses include; manufacture of pigments, case-hardening of steel, manufacture of heat-treatment salts as well as manufacturing other barium salts. The salt is also used to make fireworks as it gives the display a bright green color. Unfortunately, the toxicity of the salt limits its possible uses.