Potassium metabisulfite

Potassium metabisulfite (CAS 16731-55-8), also sold as potassium pyrosulfite and approved as E224, is an inorganic sulfite salt used industrially as a preservative, antioxidant, and reducing agent.

Where is Potassium metabisulfite used?

• Food: prevents enzymatic browning in dried fruits, potato products, and seafood processing
• Beverage: sanitizes equipment, inhibits wild yeast, and protects finished products from oxidative spoilage during storage
• Water treatment: dechlorinates potable water and treats process streams before discharge or further treatment
• Textile and leather processing: bleaching and reducing agent during fabric preparation
• It releases sulfur dioxide upon contact with moisture or acids, enabling microbial control and oxidation prevention.

Commercial specifications

• Purity levels typically range from 97% to 99%
• Food and pharma grades carry tighter sulfur dioxide content specifications