Sulfites occur naturally in wine. They are also added to wine. In the US, wine bottled after mid-1987 must have a label stating that they contain sulfites if they contain more than 10 parts per million. In the EU an equivalent regulation came into force in November 2005. Organic wines are not necessarily sulfite-free but they have no added sulfites. Wines made with organic grapes, however, may contain up to 100 ppm, compared to conventional wines which may contain up to 350 ppm. Most beers no longer contain sulfites. Although shrimp is sometimes treated with sulfites on fishing vessels, the chemical may not appear on the label. In 1986, the Food and Drug Administration in the United States banned the addition of sulfites to all fresh fruit and vegetables which are usually eaten raw.
Sodium sulfite (sodium sulphite) is a soluble compound of sodium. Its chemical formula is Na2SO3. It has a molecular weight of 126.04. It is a product of SO2 scrubbing, a part of the flue gas desulfurization process. It is also used as a preservative to prevent dried fruit from discoloring, and for preserving meats, and is used in the same way as sodium thiosulfate to convert elemental halides to their respective acids, in photography and for reducing chlorine levels in pools.
Inhalation: Remove to fresh air. Get medical attention for any breathing difficulty. Ingestion: Induce vomiting immediately as directed by medical personnel. Never give anything by mouth to an unconscious person.
Skin Contact: Remove any contaminated clothing. Wash skin with soap and water for at least 15 minutes. Get medical attention if irritation develops or persists. Eye Contact: Immediately flush eyes with plenty of water for at least 15 minutes, lifting lower and upper eyelids occasionally. Get medical attention immediately.