Sulfite is rarely found in natural waters because it oxidizes quickly to sulfate.

However, sulfite is commonly used in industry, in particular, in the food sector for its preservative properties. Sulfite is also utilized in water heating systems as an oxygen scavenger. High concentrations of sulfite however lowers the pH of a solution, hence facilitating corrosion.

Sulfite is also monitored in environmental analysis as it is toxic to aquatic life. Its ability to eliminate oxygen from water disrupts the ecologic equilibrium of rivers, ponds and lakes. Method Titration Range 0.0-20.0 mg/L
0-200 mg/L Smallest Increment 0.2 mg/L
2 mg/L Chemical Method Iodometric Number of Tests approx. 110 Weight 910 g