Sodium Metabisulfite

Sodium metabisulfite or sodium pyrosulfite (IUPAC spelling; Br. E. sodium metabisulphite or sodium pyrosulphite) is an inorganic compound of chemical formula Na₂S₂O₅. The substance is sometimes referred to as disodium metabisulfite. It is used as a disinfectant, antioxidant, and preservative agent.\

It is used as a preservative and antioxidant in food and is also known as E223.^[4]

It may cause allergic reactions in those who are sensitive to sulfites, including respiratory reactions in asthmatics, anaphylaxis, and other allergic reactions in sensitive individuals

The anion metabisulfite is a hybrid of dithionite (S₂O₄^{2−}) and dithionate (S₂O₆^{2−}). The anion consists of an SO₂ group linked to an SO₃group, with the negative charge more localized on the SO₃ end. The S–S bond length is 2.22 Ã…, and the "thionate" and "thionite" S–O distances are 1.46 and 1.50 Ã… respectively.^[3]

• Molecular Formula : Na2S2O5
• CAS No. : 7681-57-4
• Accurate compositions