Sodium Hydrosulfite

What Is It?

Sodium Hydrosulfite is a white to grayish crystalline powder. In cosmetics and personal care products, Sodium Hydrosulfite is used in the formulation of body and hand products, deodorants, hair dyes and colors, and moisturizers.

Why Is It Used?

Sodium Hydrosulfite is a chemical which reacts with oxidizing agents to lose electrons. Reducing agents such as Sodium Hydrosulfite commonly contribute hydrogen to other substances. They can be used as an antioxidantIngredients that prevent or slow deterioration due to chemical reaction with oxygen. to scavenge oxygen and they have the ability to split disulfide bonds in hair and, therefore, find use as hair waving/straightening agents.

Scientific Facts

Sodium Hydrosulfite is often referred to as Sodium Dithionate. Water-soluble salts such as Sodium Hydrosulfite contain equivalent amounts of sodium cations and hydrosulfite anions in order to maintain electroneutrality.

Safety Information

The Food and Drug Administration (FDA) includes Sodium Hydrosulfite on its list of substances considered Generally Recognized As Safe (GRAS“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.) as a substance migrating to food from paper and paperboard products. Sodium Hydrosulfite is also approved for use as an indirect food additiveIndirect food additives are additives that may become part of the food in trace amounts due to its packaging, storage or other handling. For example, minute amounts of packaging substances may find their way into foods during storage.. It may be used as a component of textiles and textile fibers intended for repeated use.

The FDA’s Select Committee on GRAS Substances (SCOGS) concluded that there was no evidence in the available information on Sodium Hydrosulfite (packaging) that demonstrates, or suggests reasonable grounds to suspect, a hazard to the public when it is used at levels that are now current or might reasonably be expected in the future.
http://www.cfsan.fda.gov/~dms/opascogc.html

Link to FDA Code of Federal Regulations for Sodium Hydrosulfite

Sodium Hydrosulfite may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European UnionUnder the general provisions of the cosmetics regulation of the EU, ingredients appearing on the following function-specific annexes must comply with the listed restrictions and/or specifications: colorants (Annex IV), preservatives (Annex V), UV filters (Annex VI) and other ingredients with specific concentration limits and/or other restrictions (Annex III). Ingredients specifically prohibited from use in cosmetic products are listed in Annex II. Other ingredients listed in the EU cosmetic ingredient database (CosIng) may be used without restrictions..

Link to the EU Cosmetic Regulation:
http://europa.eu/legislation_summaries/consumers/product_labelling_and_p…

More Scientific Information

Sodium Hydrosulfite is an inorganic salt. In cosmetics and personal care products, Sodium Hydrosulfite functions as a reducing agentReducing agents are ingredients which during their reaction with oxidizing agents lose electrons. Reducing agents commonly contribute hydrogen to other substances. They can be used as antioxidants since they scavenge oxygen. In addition, reducing agents have the ability to split disulfide bonds in hair..

Resources

Find out more about the regulation of Food Additives by the Food and Drug Administration

Food Ingredients and Packaging: http://www.fda.gov/Food/IngredientsPackagingLabeling/default.htm

Food Contact Substances: http://www.fda.gov/Food/IngredientsPackagingLabeling/PackagingFCS/defaul…

Substances Generally Recognized As Safe (GRAS): http://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/default.htm

Search the Code of Federal Regulations http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm

EU Cosmetics Inventory http://ec.europa.eu/consumers/cosmetics/cosing/