POTASSIUM METABISULFITE- ▸ Winemaking & brewing: Antioxidant and antimicrobial preservative; cask and vat sanitation
- ▸ Food preservation: Antioxidant and preservative for fruits and vegetables
- ▸ Bleaching: Bleaching agent for straw and other materials
- ▸ Photographic processing: Developing and antioxidant agent in film development
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
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Transport classification per the UN Model Regulations / 49 CFR 172.101 Hazardous Materials Table. Confirm against the grade-specific SDS (Section 14) before shipping.
Potassium metabisulfite (CAS 16731-55-8) is the potassium salt of disulfurous acid, K2S2O5, and a convenient solid source of sulfur dioxide. Established uses include antioxidant and preservative duty in winemaking, brewing, and the preservation of fruits and vegetables; bleaching; and use as a developing agent in photographic processing. It also serves as a source of sulfurous acid in dyeing and engraving.
Frequently Asked Questions
What is potassium metabisulfite used for?
Potassium metabisulfite (K2S2O5, CAS 16731-55-8) is a convenient solid source of sulfur dioxide used as an antioxidant and antimicrobial preservative in winemaking and brewing, in fruit and vegetable preservation, as a bleaching agent, and as a developing/antioxidant agent in photographic processing.
What is the chemical formula for potassium metabisulfite?
Potassium metabisulfite is K2S2O5 (listed formula K2O5S2), the potassium salt of disulfurous acid, CAS 16731-55-8. This is the technical grade.
How does potassium metabisulfite release sulfur dioxide?
In contact with water or acid it liberates sulfur dioxide, which provides its antioxidant, antimicrobial, and bleaching activity. This makes it a practical dry source of SO2 and of sulfurous acid for processing applications such as dyeing and engraving.
What are the DOT shipping details for potassium metabisulfite?
Potassium metabisulfite is assigned UN 1759. Refer to the SDS for the proper shipping name, packing group, and current transport requirements; we supply the SDS with each order so you can confirm classification for your shipment.
What is the cost of bulk potassium metabisulfite?
Bulk pricing depends on grade, packaging (bags, drums, supersacks), and volume. Submit a bulk RFQ with quantity and packaging for a current quote with CoA and SDS; we do not list fixed prices.