Phosphoric Acid or orthophosphoric acid is a mineral (inorganic) acid having the chemical formula H3PO4. Phosphoric Acid molecules can combine with themselves to form a variety of compounds which are also referred to as phosphoric acids, but in a more general way.

Food-grade Phosphoric Acid is used to acidify foods and beverages such as various colas, but not without controversy regarding its health effects. It provides a tangy or sour taste and, being a mass-produced chemical, is available cheaply and in large quantities. The low cost and bulk availability is unlike more expensive seasonings that give comparable flavors, such as citric acid which is obtainable from lemons and limes. However, most citric acid in the food industry is not extracted from citrus fruit, but fermented by Aspergillus niger mold from scrap molasses, waste starch hydrolysates and Phosphoric Acid.