Calcium chloride (chemical formula CaCl₂) is the ionic compound of calcium and chlorine. It is a salt that behaves as a typical ionic halide, being solid at room temperature and highly soluble in water. Common applications include brine for refrigeration plants, ice and dust control on roads, and desiccation. Because of its hygroscopic nature, attracting and holding water, anhydrous calcium chloride must be kept in airtight containers.