4-Hydroxy Pyridine-3- Sulfonic Acid is an organosulfur compounds. This is a free acid, which is widely used as the catalysts in organic syntheses. Also, this is suited to manufacture catalysts, detergents and water-soluble dyes. 4-Hydroxy Pyridine-3- Sulfonic Acid is functional as an ion-exchange resin. In many applications, it works as a proton-shutting agent of high effectiveness. This pharmaceutical intermediate has good shelf life.