Potassium Bisulfite
The short version
A potassium sulfite used in winemaking and foods — releases SO2 and is a declared sulfite allergen.
A sulfite preservative. Like other sulfites it can trigger asthma and reactions in sensitive people and must be declared on labels, which is why we flag it.
Where it comes from
Potassium hydrogen sulfite, the potassium salt of sulfurous acid, usually handled in solution.
How it's used
Preservative and antioxidant releasing sulfur dioxide — used in winemaking and to protect some foods and beverages against browning and spoilage.
Safety profile
Sulfite group (group ADI 0.7 mg/kg as SO2). Triggers asthma and sensitivity reactions in some people; mandatory sulfite labelling above 10 mg/kg.
Physical & chemical properties
White crystals or solution, water-soluble, with a sulfurous odor.
Regulation worldwide
Permitted in the EU, the US, and globally with sulfite limits and labelling.
Educational information only. Not medical or dietary advice.