Sodium bicarbonate, commonly known as baking soda, is a crystalline salt that often appears as a white powder. It is perhaps most commonly known as a key raising agent used to bake bread, as it reacts to acidic components in the dough or batter, causing the release of carbon dioxide bubbles. Sodium bicarbonate can be produced through the solvay process; the natural mineral form is nahcolite, which is found in many natural springs. Its use is wide, including in cooking, cleaning and medicine. It has gentle cleansing properties, and has been shown to be an effective whitening agent when used in toothpaste.