Potassium sulfite

Potassium sulfite (K2SO3) is a chemical compound which is the salt of potassium cation and sulfite anion. As a food additive it is used as a preservative under the E number E225 (INS number 225). It is approved for use in Australia and New Zealand and is not approved in the EU or US. Potassium sulfite (K2SO3) is a chemical compound which is the salt of potassium cation and sulfite anion. As a food additive it is used as a preservative under the E number E225 (INS number 225). It is approved for use in Australia and New Zealand and is not approved in the EU or US. Potassium sulfite is produced by the thermal decomposition of potassium metabisulfite at 190°C:K2S2O5 → K2SO3 + SO2