Sulfite Information



Other Names

Sulphite; Sulfite ion

Chemical Formula


CAS Number

14265 – 45 – 3

Industry Uses

Food Additive; Antioxidant; Antimicrobial

Health Risks

Allergic Reaction

Sulfite MSDS

What is Sulfite?

Sulfite is not usually present in surface waters. If sulfite is discharged in effluents or from domestic wastewater, it oxidizes to form sulfate. Sodium sulfite is the most common form of sulfite and is an excellent reducing agent with applications as an oxygen scavenger. Sulfite concentrations in boiler and process waters must be monitored routinely to avoid over-treatment. Waste treatment plants that use sulfur dioxide to remove excess chlorine must monitor their effluents for sulfite. Sulfites have been used for centuries to sanitize and preserve foods. They are used worldwide in the wine industry as antioxidant and antimicrobial agents.

Sulfite Exposure and Health Risks

Sulfites have been proven to have caused allergic reactions suffered by asthmatics. Allergic reactions to sulfites are rare except for hyperallergic individuals. Some people have positive skin allergy tests, and chronic skin conditions in the hands, perineum, and face have been reported by individuals who regularly use cosmetics or medications containing sulfites. Anaphylaxis and life-threatening reactions are rare. Other potential symptoms include sneezing, throat swelling, hives, and migraine. High sulfite content in the blood and urine of babies can lead to neurological damage and even death.


The FDA and ATF have mandated that sulfites in foods and beverages, at levels of 10 ppm or higher, be identified on the label.

Measuring Sulfite

Dissolved Sulfite concentration in water can be measured in units of parts per million (ppm). We carry instrumental kits from CHEMetrics and monitors from ATI that determine Sulfite levels in water. All of our Sulfite products can be viewed HERE.

Contact us for help choosing the right monitor for your application