Linoleic Acid

What Is It?

Linoleic Acid is a straight chain unsaturated fatty acidA natural organic compound that consists of a carboxyl group (oxygen, carbon and hydrogen) attached to a chain of carbon atoms with their associated hydrogen atoms. The chain of carbon atoms may be connected with single bonds, making a ‘saturated’ fat; or it may contain some double bonds, making an ‘unsaturated’ fat. The number of carbon and hydrogen atoms in the chain is what determines the qualities of that particular fatty acid. Animal and vegetable fats are made up of various combinations of fatty acids (in sets of three) connected to a glycerol molecule, making them triglycerides.. It is a colorless oil that is prepared from edible fats and oils. Dilinoleic Acid and Trilinoleic Acid consist of two and three units of Linoleic Acid linked together, respectively. In cosmetics and personal care products, these ingredients are used in the formulation of many types of products including bath products, body and hand preparations, cleansing products, eye makeup, makeup, nail care products, skin care preparations and hair care products.

Why Is It Used?

The following functions have been reported for Linoleic Acid, Dilinoleic Acid and Trilinoleic Acid.

Hair conditioning agentIngredients that enhance the appearance and feel of hair, by increasing hair body, suppleness, or sheen, or by improving the texture of hair that has been damaged physically or by chemical treatment.: Linoleic Acid
Skin conditioning agent – miscellaneous: Linoleic Acid
Skin conditioning agent – occlusive: Dilinoleic Acid, Trilinoleic Acid
SurfactantAn ingredient that helps two substances that normally do not mix to become dissolved or dispersed in one another. Also called a surface active agent. – cleansing agent: Linoleic Acid
Viscosity increasing agent – nonaqueous: Trilinoleic Acid

Scientific Facts

Linoleic Acid is abundant in many vegetable oils including safflower and sunflower seed oils. It is considered an essential fatty acid as it must be supplied by the diet. Dimerization of Linoleic Acid results in Dilinoleic Acid, also called dimer acid. Trimerization of Linoleic Acid results in Trilinoleic Acid, also called trimer acid.

Safety Information

The Food and Drug Administration (FDA) includes Linoleic Acid on its list of direct food substances affirmed as 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.). The FDA permits dimers, for example Dilinoleic Acid, and trimers, for example Trilinoleic Acid, of fatty acids to be used as indirect food additives as defoaming agents in the manufacture of paper and paperboard.

FDA: Link to Code of Federal Regulations for Linoleic acid and dimers and trimers of fatty acids:

The Joint FAO/WHO Expert Committee on Food Additives (JECFA) reviewed the safety of a mixture of Linoleic Acid and linolenic acid when used as a flavoring agentIngredients that impart a flavor or a taste to a product. in food. They concluded that there was no safety concern at current levels of intake.

Link to the JECFA Summary:
http://www.inchem.org/documents/jecfa/jeceval/jec_1285.htm

Linoleic Acid, Dilinoleic Acid and Trilinoleic Acid 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…

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/