(NH4)2CO3 – ammonium carbonate – consists of white, water-soluble crystals. It is very unstable and can spontaneously decompose, even in ordinary air, with a release of ammonia. When heated to 60 oC it rapidly decomposes into NH3, CO2, and H2O. Due to this property, it is used in the baking and confectionery industry as a leavening agent, and additionally serves as an acidity regulator in cookies, cakes, chocolate products, bagels, and more. As ammonium carbonate can irritate the respiratory system, it was traditionally used to revive those who had lost consciousness, and is perhaps the main compound in smelling salts.