CaCl2 – calcium chloride – is a white, odorless, crystalline solid. It can form crystals together with 1, 2, 4, and 6 molecules of water. Calcium chloride with 6 molecules of water is called antarcticite, and was discovered in Antarctica as a crystalline precipitate from a highly saline brine in Don Juan Pond. As it releases heat when dissolved in water, it is often used to initiate the heating process required for industrial purposes. Its ability to lower the melting point of ice led to its use as a de-icer on roads. Calcium chloride is sometimes used as an additive in fire extinguishers. Moreover, it can be used to stave off food spoilage and is often utilized as a preservative in packed foods. Calcium chloride is added in small amounts to pasteurized milk to aid in coagulation and form quality yogurt.