Potassium hydrogen sulfite or potassium bisulfite is a chemical compound with the chemical formula KHSO3. It is used during the production of alcoholic beverages as a sterilising agent.

Sodium bisulfite (sodium hydrogen sulfite) is a chemical compound with the chemical formula NaHSO3. Sodium bisulfite is a food additive with E number E222. Sodium bisulfite can be prepared by bubbling sulfur dioxide in a solution of sodium carbonate in water.