Sodium Sulfite

The Food and Drug Administration (FDA) includes Sodium Sulfite, Sodium Bisulfite, Potassium Bisulfite, Sodium Metabisulfite and Potassium Metabisulfite on its list of substances considered Generally Recognized As Safe (GRAS) for use as chemical preservatives in food. They are not to be used in meats, in foods recognized as sources of vitamin B1, or on raw fruits and vegetables. Because some people are sensitive to sulfites, food containing these ingredients must be clearly labeled. More information about the use of sulfites in food can be found at
http://www.cfsan.fda.gov/~dms/fdsulfit.html

The safety of Sodium Sulfite, Potassium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite and Potassium Metabisulfite has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that all seven ingredients were safe as used in cosmetics and personal care products.CIR Safety Review: Sodium Sulfite, Sodium Metabisulfite and Potassium Metabisulfite were negative in mutagenicity studies. Some positive results were noted for Sodium Bisulfite in in vitro, but not in in vivo studies. In was noted that in in vitro assays, an equilbrium would exist between sulfurous acid, sulfur dioxide, bisulfite, sulfite and metabisulfite. The CIR Expert Panel concluded that the positive results in the in vitro assays were a result of the presence of the bisulfite form. In cosmetic and personal care products, even with the addition of bisulfite, the sulfite form would predominate. In mammals, the presence of the enzyme, sufate oxidase, would convert all sulfite to sulfate. In addition, the highly charged nature of these ingredients would result in relatively low dermal penetration. As used in cosmetics and personal care products, the CIR Expert Panel concluded that Sodium Sulfite, Potassium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Sodium Metabisulfite and Potassium Metabisulfte were safe.

FDA: Link to Code of Federal Regulations for Sodium Sulfite, Sodium Bisulfite, Potassium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...

Sodium Sulfite, Potassium Sulfite, and Ammonium Sulfite are listed as inorganic sulphites and hydrogen sulphites in Annex VI, Part I (preservatives which cosmetic products may contain) of the Cosmetics Directive of the European Union and may be used at a maximum authorized concentration of 0.2%, expressed as free sulfur dioxide.
Link to the EU Cosmetics Directive: http://ec.europa.eu/enterprise/cosmetics/html/consolidated_d...

The Joint FAO/WHO Expert Committee on Food Additives has established a group Acceptable Daily Intake of 0.7 mg/kg body weight for sulfur dioxide and sulfites expressed as sulfur dioxide, which includes Sodium Sulfite, Sodium Metabisulfite and Potassium Metabisulfite.
http://www.inchem.org/documents/jecfa/jecmono/v042je25.htm