PEG-18 CASTOR OIL DIOLEATE

Substance information

"PEG" refers to a PEG-(polyethylene glycol-) derivative. The number behind "PEG-" (or the first number behind "PEG/...-") refers to the average number of molecular units -CH2-CH2-O-. Ingredient on the basis of castor oil (ricinus communis seed oil). Dioleates are di-esters of oleic acid (cis-9-octadecenoic acid).

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Function(s) of this ingredient in cosmetic products

SURFACTANT - EMULSIFYING

Allows the formation of finely dispersed mixtures of oil and water (emulsions)

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Origin

synthetic plant/synthetic

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Occurrence in cosmetics

Face toners, aftershaves and hair tonics, as solvent and solubiliser for active ingredients, perfume oils and colourants, humectants, basis for creams, as consistency enhancer, binding agent, softening agent and fixative

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Background information on use in cosmetics

Emulsifiers are often used in cosmetics as excipients. They allow actually unmixable components like oil and water to be brought in a permanently stable emulsion. In this way both aqueous and oily care and active ingredients can be used in one and the same product in cosmetics. Emulsifiers are able to do that since their molecules consist of a lipophilic and a hydrophilic part. In this way they can reduce the interfacial tension which actually exists between two incompatible substances like fat and water. Emulsifiers are, more particularly, used for creams, lotions and cleansing agents. At present emulsifiers are, however, more than only excipients which keep an emulsion stable. Fatty acid esters on the basis of sugar, lecithin or glycerin monodistearate contribute, for instance, to improving the moisture balance of the skin and are, therefore, also considered as cosmetic active ingredients. Solid PEG serve as consistency enhancers in lipsticks and creams as well as humectants. They are well tolerated by the skin and are not microbiologically sensitive, so that in general it is not necessary to add any preservatives. Polyethylene glycols (INCI: PEG-...) are poly condensation products of ethylene glycol, or polymerisation products of ethylene oxide. The number added to the name refers to the mean number of ethylene oxide units in the substance. The consistency of the PEG derivatives is increasingly solid with a growing degree of polymerisation. PEGs with a mean molar mass of up to 600 g/mol are liquid, up to 1,000 g/mol wax-like and from 4,000 g/mol solid wax-like substances. By mixing solid and liquid components, products of a creamy consistency are obtained which are used as water-free and water rinse-off bases. With growing molar mass water solubility and hygroscopicity (ability to absorb moisture) of the polyethylene glycols decrease. Polyethylene glycols and their derivates are preferentially used in cosmetic products since they have a broad spectrum of viscosity and solubility properties and have a very good skin tolerance. As water soluble, non-greasy substances polyethylene glycols are suitable for many cosmetic purposes. The liquid PEGs serve, eg, as glycerol substitute in facial, shaving and hair lotions, as solubilisers and solvents. Castor oil (INCI: RICINUS COMMUNIS SEED OIL) is obtained from the seeds of the miracle tree. Castor oil is characterised by a very high content of a special fatty acid: ricinoleic acid, a C18 fatty acid which has at C12 a hydroxyl group and at C-9 a double bond. The oil is in many cases processed further semi-synthetically to solubilizers, surfactants, emulsifiers and consistency enhancers.

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Information on safe use

Claudia Fruijtier-Pölloth: Safety assessment on polyethylene glycols (PEGs) and their derivatives as used in cosmetic products. In: "Toxicology" (2005), No. 214, P. 1-38. Publisher: Elsevier Ireland Ltd.

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Belongs to the following substance groups

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Regulating cosmetics

Cosmetics Ingredients are subject to regulation. Please note, different regulations may apply to cosmetic ingredients outside the EU.