What Is Sodium Metabisulfite?

Sodium metabisulfite is a white, crystalline powder with the chemical formula Na2S2O5. It is commonly used as a food preservative, antioxidant, and disinfectant. When added to food or beverages, it prevents oxidation and helps maintain the product's color and flavor. In addition, it is used in the production of paper and pulp, as well as in the water treatment industry to remove chlorine and other harmful chemicals. However, it can also cause allergic reactions in some individuals, particularly those who are sensitive to sulfites. Therefore, it is required by law in many countries to be listed on food labels if it is present above certain concentrations.