Calcium Stearate, Mallinckrodt ® 2249
A carboxylate of calcium, this compound is essentially a calcium soap used in some lubricants, surfactants, and various foodstuffs. It is a white waxy powder created by heating stearic acid and calcium oxide. It is also formed in many homes showers and bathtubs when soap is mixed with hard water, and is commonly referred to in this state as “soap scum”. Due to its insolubility in water, calcium stearate does not lather like soaps made with sodium and potassium, and is sold commercially as a 50 percent dispersion in water or as a spray dried powder. This waxy substance is cheap to procure, and so is used in numerous applications such as a surface conditioner in hard candies, waterproofing fabrics, lubricating pencils and crayons, and in concrete manufacturing for efflorescence control. The paper industry employs calcium stearate to add gloss to paper so that it becomes dust and fold cracking resistant.