Sodium metabisulfite or sodium pyrosulfite (IUPAC spelling; Br. E. sodium metabisulphite or sodium pyrosulphite) is an inorganic compound of chemical formula Na2S2O5. Sodium metabisulfite powder food grade is a white crystalline powder commonly used as a food preservative and antioxidant. It is also used in the production of wine, beer, and other fermented beverages to prevent oxidation and bacterial growth. Additionally, it is used in the pharmaceutical industry as a reducing agent and in the textile industry as a bleaching agent. Its ability to prevent spoilage and extend shelf life makes it a popular ingredient in the food industry.