Lactic acid (C3H6O3 or CH3CHOHCOOH or HC3H5O3) is an organic compound which is acidic. Also know as 2-hydroxypropanoic or milk acid, this substance is produced by the breakdown of glucose inside a living creature or by some kinds of bacteria. It is an odorless, colorless or yellow syrupy liquid. It is corrosive to metals and body tissue. Small, diluted amounts are typically considered safe to eat, and it is used in the production of cultured dairy products and as a food preservative. However, excessive amounts in the human body can be harmful. Lactic acid is also used in some industrial processes to make chemicals.