What Is It?
Sodium Sulfite, Potassium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite and Potassium Metabisulfite are inorganic sulfite salts. In cosmetics and personal care products, these ingredients are used in the formulation of permanent waves, hair bleaches, hair dyes, colors and tints, and in some bath and skin care products.
Why Is It Used?
All these ingredients function as reducing agents, which means they donate hydrogen molecules to other substances in cosmetics and personal care products. With the exception of Sodium Metabisulfite, these ingredients also modify hair fibers to facilitate changes to the structure of the fibers, such as with permanent waves or with hair straightening. In addition, Sodium Sulfite, Potassium Sulfite, Sodium Bisulfite and Sodium Metabisulfite function as antioxidants preventing or slowing deterioration of cosmetics and personal care products caused by chemical reactions with oxygen.
Sodium Sulfite, Sodium Bisulfite, Potassium Bisulfite, Sodium Metabisulfite and Potassium Metabisulfite are referred to as sulfiting agents because they release sulfur dioxide under certain conditions.
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” is an acronym for the phrase Generally Recognized As Safe. Under sections 201(s) and 409 of the Federal Food, Drug, and Cosmetic Act (the Act), any substance that is intentionally added to food is a food additive, that is subject to premarket review and approval by FDA, unless the substance is generally recognized, among qualified experts, as having been adequately shown to be safe under the conditions of its intended use, or unless the use of the substance is otherwise excluded from the definition of a food additive.) 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 The Cosmetic Ingredient Review (CIR) was established in 1976 as an independent safety review program for cosmetic ingredients. The CIR Expert Panel consists of independent experts in dermatology, toxicology, pharmacolgy and veterinary medicine. The CIR includes participation by the U.S. Food & Drug Administration and the Consumer Federation of America. (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 Experiments performed in a test tube or another artificial, controlled environment, rather than in a whole animal., 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 A protein found in animal and plant cells that help to initiate or to accelerate specific chemical reactions., 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
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 Regulation 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 Cosmetic Regulation: http://europa.eu/legislation_summaries/consumers/product_labelling_and_p…
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.
More Scientific Information
Sodium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Potassium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite and Potassium Metabisulfite are all used as reducing agents in cosmetics and personal care products. All these ingredients, except Sodium Metabisulfite, also function as hair-waving/straightening agents. Sodium Sulfite, Potassium Sulfite, Sodium Bisulfite and Sodium Metabisulfite also function as antioxidants.
Find out more about the regulation of Food Additives by the Food and Drug Administration Food Ingredients and Packaging: http://www.fda.gov/Food/FoodIngredientsPackaging/default.htm
Food Contact Substances: http://www.fda.gov/food/foodingredientspackaging/foodcontactsubstancesfc…
Substances Generally Recognized As Safe (GRAS): http://www.fda.gov/Food/FoodIngredientsPackaging/GenerallyRecognizedasSa…
Search the Code of Federal Regulations http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm
The European Commission’s Scientific Committee on Cosmetic Products and Non-Food Products Intended for Consumers (SCCNFP) opinion concerning Inorganic Sulfites and Bisulfites http://ec.europa.eu/food/fs/sc/sccp/out_200.pdf
EU Cosmetics Inventory http://ec.europa.eu/consumers/cosmetics/cosing/