Sodium Citrate
What Is It?
Citric acid is a weak acid that is widely found in both plants and animals. It is a natural ingredient that is common in citrus fruits, for example, lemon juiceThe liquid obtained by expressing various plants or plant parts, usually fruits. , which contains about 5-8 percent citric acid. The dominant use of citric acid is as a natural flavoring and preservativeIngredients that prevent or retard bacterial growth, and thus protect cosmetic products from spoilage. in food and beverages, especially soft drinks. Citric acid is also a central compound in the citric acid cycle. The citric acid cycle is the pathway in many organisms, including humans, that produces nearly two-thirds of all of the energy used by cells.
Why Is It Used?
Products containing citric acid and some of its salts and esters can be safely formulated for specific application to baby skin or use near the eye area or on mucous membranes. In addition, they may be used in cosmetic sprays, including hair, deodorant, body and other propellantCompressed gases that are used to expel products from aerosols. and pump spray products. Citric acid is also one of a group of ingredients known as alpha hydroxy acids that are used as the active ingredients in chemical skin peels. Sodium citrate may be used in all types of cosmetic products, including baby products, make-up, lipstick, bath products, soaps and detergents, hair dyes and colors, and hair and skin care products. Tributyl citrate and triethyl citrate may be used in bath products, other cleansing products, and creams and lotions.
Citric acid and its diammonium, potassium and sodium salts are all used to help preserve cosmetics and personal care products by chelating (complexing) metals. Citric acid and its salts are also added to cosmetics to help adjust the acid/base balance. Other functions of the citrate ingredients include: Buffering agentIngredients that minimize the change in the pH of a solution when an acid or a base is added to the solution. , Cosmetic astringentIngredients that induce a tightening or tingling sensation of the skin. , Cosmetic biocideIngredients that help to cleanse the skin or to prevent odor by destroying or inhibiting the growth of microorganisms. , Hair fixativeIngredients that help hair hold its style by inhibiting the hair?s ability to absorb moisture. , Oral care agentIngredients that polish the teeth, reduce oral odor, or otherwise cleanse or deodorize the teeth and mouth. , PlasticizerMaterials that soften synthetic polymers by reducing brittleness and cracking. , Skin-conditioning agent – emollient , Skin-conditioning agent – miscellaneous , Skin-conditioning agent – occlusive , and SolventSubstances, usually liquids, that are used to dissolve other substances. .
The citric acid ingredients most commonly used in cosmetics are citric acid, sodium citrate, tributyl citrate and triethyl citrate. According to the 2016 U.S. Food and Drug Administration’s (FDA) Voluntary Cosmetic Registration Program (VCRP), citric acid was used in almost every category of cosmetic product with over 10,000 reported uses. The next most commonly used citric acid-derived ingredients were sodium, tributyl and triethyl citrate.
Scientific Facts
Sodium citrate is a salt derived from citric acid that is commonly used in cosmetics and personal care products. Other natural salts of citric acid that are used in cosmetics and personal care products include potassium citrate, aluminum citrate, diammonium citrate, ferric citrate, magnesium citrate, monosodium citrate and zinc citrate.
Tributyl citrate and triethyl citrate may also be used in cosmetics and personal care products. These ingredients are made by combining butyl or ethyl alcoholAlcohols are a large class of important cosmetic ingredients but only ethanol needs to be denatured to prevent it from being redirected from cosmetic applications to alcoholic beverages. with citric acid and are called organic esters of citric acid. Other citric acid esters that may be used in cosmetics include Tri-C12-13 Alkyl Citrate, Tri-C14-15 Alkyl Citrate, tricaprylyl citrate, triethylhexyl citrate, triisocetyl citrate, trioctyldodecyl citrate, triisostearyl citrate, isodecyl citrate, stearyl citrate, dilauryl citrate and ethyl citrate.
Safety Information
U.S. CIR
The safety of citric acid and its salts and esters was assessed by the Cosmetic Ingredient ReviewThe 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 in 2014. Given that the FDA determined citric acid, calcium citrate, potassium citrate, sodium citrate and triethyl citrate as 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. for use in food, in addition to the fact that citric acid is essential for the production of energy in cells in both plants and animals, the CIR Expert Panel focused on the potential for citric acid and its salts and esters to cause adverse effects when placed on the skin.
CIR reviewed scientific literature and data which indicated that at concentrations used in cosmetics and personal care products, citric acid and its salts and esters were not eye irritants, nor did they cause skin irritation or allergic skin reactions. Thus, CIR concluded that the available scientific data showed that citric acid, its salts, and esters were safe under current conditions of use in cosmetics and personal care products.
The CIR Expert Panel did note that although citric acid could be considered an alpha-hydroxy acid, it is also a beta-hydroxy acid making it distinct from the other alpha-hydroxy acids previously reviewed by the CIR Expert Panel (for example lactic acid and glycolic acid). The CIR Expert Panel concluded that the concern about increased sun sensitivity resulting from the use of alpha-hydroxy acid containing products was not relevant to products containing citric acid and its salts and esters because of the difference in chemical structure
FDA
Citric acid, calcium citrate, potassium citrate, sodium citrate and triethyl citrate are on the FDA’s list of direct food substances affirmed as Generally Recognized as Safe (GRAS ). FDA permits tributyl citrate and triethyl citrate to be used as indirect food additives in some food packaging materials.
Learn more about FDA Code of Federal Regulations for Citric Acid and its Calcium, Potassium and Sodium Salts, and Tributyl and Triethyl Citrates:
· Substances for Use as Components of Coatings: Sec. 175.300 Resinous and polymeric coatings
· Specific Prior-Sanctioned Food Ingredients Sec. 181.27 Plasticizers
· Substances for Use Only as Components of Adhesives Sec. 175.105 Adhesives
European Union (EU)
All of the ingredients reviewed by the CIR are listed in the European Union inventory of cosmetic ingredients and 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..
The safety of citric acid and its calcium, potassium and sodium salts has been assessed by the Joint FAO/WHO Expert Committee on Food Additives. The most recent review concluded that these additives ‘do not constitute a significant toxicological hazard’ and it was therefore not necessary to set an Acceptable Daily Intake limit. As such, the amount in food is limited only by the amount needed to achieve the technical function within the product.
Resources
Find out more about FDA food additives regulation
· Food Ingredients and Packaging
· Substances Generally Recognized As Safe (GRAS
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