STEARIC ACID

Name / description

Stearic Acid; Octadecanoic Acid

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Function(s) of this ingredient in cosmetic products

CLEANSING

Cleans skin, hair or teeth

EMULSION STABILISING

Supports emulsion formation and improves product stability

FRAGRANCE

Enhances the smell of a product and / or perfumes the skin

REFATTING

Brings lipids back to the hair or to the upper layers of the skin

SURFACTANT - CLEANSING

Surface-active agent to clean skin, hair and / or teeth

SURFACTANT - EMULSIFYING

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

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Origin

animal/synthetic/plant

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Occurrence in cosmetics

In many emulsions and products for skin and hair cleansing

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Occurrence in other products

Starting material for the production of different surfactants and additives in the automobile and pharmaceutical industry; also in foodstuffs (additive E 570)

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Background information on use in cosmetics

Stearic acid is a saturated carboxylic and / or fatty acid. Its salts and esters are called stearates. Stearic acid can be obtained by saponification from vegetable and animal oils and fats. The fat is cooked together with caustic soda and hydrolysed (separated) into glycerine and the sodium salts of the fatty acids (soap). These fatty acid salts are transferred with mineral acid back into the free fatty acids. Since fats contain in most cases a mixture of different glycerine esters from various fatty acids, the saponification products must be separated by a complex distillation or continue to be used as a mixture. Fragrances or mixtures of fragrances are often referred to in the cosmetics area as "perfuming agents" or "perfume oils" or "parfum oils". On the cosmetic products they are declared with the INCI name "PARFUM". These are undiluted individual substances or their mixtures which originate from natural raw materials or can be produced (semi-) synthetically. They are starting materials for the production of perfume, eau de parfum, eau de toilette, eau de cologne and other perfumed cosmetic products. The average content of fragrances amounts in perfume to 15-30 %, in eau de parfum to 10-14 %, in eau de toilette to 6-9 %, in eau de cologne to 3-5 % as well as in skin creams, shampoos, hair and deodorant sprays to approximately 0.2-1 % and approximately 1-3 in deodorant sticks. The perfume oils include essential oils, resinoids and absolutes. The sources are, amongst others, flowers, leaves and stems, fruits and fruit peels or roots of plants; woods, grasses or herbs, needles, resins and balsams. Moreover, only compounds isolated from natural products such as aldehydes, ketones, esters, alcohols etc. are used (geraniol, citronellal, citral, eugenol, menthol) as well as semi-synthetic (citronellol, geranyl acetate, jonone) and synthetic scents (eg phenylethyl alcohol and linalool) are used. Scents of animal origin such as musk and ambra are only rarely used. Surfactants are so-called detergent substances and have a major significance in cosmetics for the cleansing of the skin and hair. Surfactants are substances which, based on their molecular structure, are able to reduce the surface tension of a liquid. In this way it is possible that two actually not mixable substances, such as oil and water, can be finely mixed. Because of their properties, surfactants have manifold uses in cosmetics: they can cleanse, produce foam and act as emulsifiers and mix substances with one another. In shampoos, shower gels and soaps, surfactants are, for instance, used to wash fat and soil particles with water off from the body. Surfactants are also used in toothpaste. Here they promote during tooth cleaning the rapid and full dissolution and distribution of the paste in the mouth. The surfactants used in cosmetic products are primarily produced synthetically on the basis of vegetable raw materials. Surfactants are often used in combination to equally meet all desired requirements – like dissolution of soil and formation of foam in combination with a good skin tolerance – in the best possible manner. Through a skilled combination of a surfactant – viewed on its own – with unfavourable skin tolerance but a very good soil removal property with a very mild, skin protecting surfactant altogether a product with good cleansing properties and the same good skin tolerances is obtained. 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.

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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.