Potassium metabisulfite

Potassium metabisulfite (CAS 16731-55-8), also known as potassium disulfite or dipotassium disulfite, is an inorganic sulfite salt that releases sulfur dioxide upon contact with moisture or acids. It carries no E-number designation and is commercially identified under synonyms including Dikaliumdisulfit and potassium disulphite.

In winemaking and brewing, it inhibits oxidative enzymes and suppresses microbial growth by releasing active SO2, protecting color and flavor stability. Water treatment operations use it to neutralize residual chlorine in process streams through direct chemical reduction. In textile processing, it functions as a reducing bleach to strip unwanted dyes or prepare fiber surfaces prior to dyeing.

Potassium metabisulfite is sourced in food-grade and technical-grade powder form, with food applications governed by FCC specifications and pharmaceutical use by Ph.Eur. monograph standards. The product falls under REACH registration requirements within the EU. It is classified under HS code 28322000 and is typically available in 25 kg bags or bulk quantities.