Sodium metabisulfite

Sodium metabisulfite (CAS 7681-57-4), also known as sodium pyrosulfite and sold under the abbreviation SMBS, is an inorganic sulfite salt used across food, industrial, and water treatment sectors. It serves as a preservative, antioxidant, and reducing agent. As E223, it is a regulated food additive recognized in major international markets. Its ability to release sulfur dioxide under controlled conditions underpins its function across multiple industries and specialized chemical processes.

In food and beverage production, E223 prevents oxidative browning and microbial spoilage in dried fruits, wines, seafood, and fruit juices. This ensures product longevity and maintains the aesthetic quality of processed goods. Water treatment plants use SMBS to neutralize residual chlorine in municipal and industrial effluent streams before discharge or further processing. This step is critical for environmental safety and protecting downstream equipment.

Textile and leather processors apply it as a bleaching and reducing agent in dye stripping and chrome tanning operations. It provides consistent results in heavy industrial manufacturing environments requiring high-purity chemical inputs. In pharmaceutical manufacturing, it functions as an antioxidant stabilizer in injectable formulations and oral solutions. This is essential where oxygen-sensitive active ingredients require protection to maintain their therapeutic efficacy.

Sodium metabisulfite is supplied as a white to off-white crystalline powder or fine granules. Standard commercial grades include food-grade (FCC-compliant), USP/BP pharmaceutical grade, and technical grade for industrial applications. Bulk supply is available in 25 kg bags, with food and pharma grades accompanied by full compliance documentation. Our logistics network ensures reliable delivery for large-scale manufacturing and chemical processing facilities worldwide.