Silicone oils or also synthetic oils are based on half-organic polymers and copolymers with silicon-oxygen units and organic side chains. They are relatively insensitive to oxidation, heat and other influences. Next to the use as grease in industry, it is also found in body care products or special industrial uses (e.g. for taking away foam).

Silicones are environmental and skin burdens. Therefore, they are not to be used as well as the 25 further cosmetic ingredients in combination with dimethicone, from dimethicone copololyol to dimethicone/sodium PG propyldimethicone thiosulphate copolymer. They are used as oil replacements, moisture providers, defoamers and are used for hair rinses. This also applies to compounds with dimethiconol which are also made from a silicone basis.

The chemists set no limits on the use of silicones. It can build almost unlimited in many chains; it can be used wholly as needed as emulsifiers, for manufacturing and employment. Silicone oils are, for example, soft and are easily applied to the skin. Whether a silicone ingredient has skin-care characteristics or not depends on the quality of the synthesis. Mineral oils are clearly favored for skin care aspects. Silicone oils as well as silicone waxes have however a decisive disadvantage: They are extremely pollutive, because they are not biologically degradable. Therefore their usage should remain within limits.

Silicones are surface active, show good spraying capability, remain stable over a high temperature range, chemically stabile, with outstanding skin tolerance. Their films are breathable, i.e. they do not hinder skin breathing and water evaporation.

Thin liquid, easy to distribute on the skin, lipid which leaves a smooth and silky feeling on the skin. Very well tolerated by the skin. Well dissolved in alcohol. In emulsions, silicone oil distributes well and prevents foaming when put on the skin.

Silicone oil. Anti-foaming agent, emollient. Not recommendable. Persistent.

Hazardous chemicals found in cosmetic products ECHA/NR/24/28 Helsinki, October 30, 2024 - A pilot project by ECHA's Enforcement Forum has found that 6% of cosmetic products checked contained hazardous substances banned under the POPs and REACH Regulations. National enforcement authorities in 13 European Economic Area (EEA) countries screened almost 4,500 cosmetic products for the presence of perfluorooctanoic acid (PFOA), long-chain perfluorocarboxylic acids (PFCAs) and related substances, and cyclic siloxanes D4 and D5, mainly based on the list of ingredients. The authorities found that 285 of the cosmetics inspected contained hazardous chemicals whose use in these products is banned. The substances found were: Perfluorononyl dimethicone Perfluorooctylethyl triethoxysilane Perfluornonylethyl-carboxydecyl-PEG-10-dimethicone; and Cyclopentasiloxane (D5), cyclomethicone (a mixture of D4, D5 and D6), cyclotetrasiloxane (D4). These substances are not permitted in cosmetics as they have been identified as persistent organic pollutants (POP) or (very) persistent, (very) bioaccumulative and toxic substances (PBT/vPvB), which have a negative impact on human health and the environment. Their use is banned under the Stockholm Convention on POPs or restricted under the REACH Regulation. Based on national experience, perfluorononyl dimethicone was mainly found in eyeliners and lip liners in the form of pencils or crayons. D4 and D5 were found in hair conditioners and hair masks. Perfluorononyldimethicone, for example, is degraded to PFOA and long-chain perfluorocarboxylic acids. PFOA and siloxanes, D4 and D5, degrade slowly in the environment and accumulate in humans and other living organisms. PFOA is not only persistent in the environment, but is also toxic to reproduction and is suspected of causing cancer. D4 is also suspected of impairing fertility. Measures taken by the authorities The controls were mainly carried out by checking the list of ingredients - measures that can also be easily applied by consumers. Consumers should be aware that the banned substances were found in different types of cosmetic products, from different suppliers and in all price ranges. Enforcement authorities have taken action to remove the non-compliant products from the market. In most cases, the first step was to issue written guidance to suppliers on how to comply with the legislation. At the time of writing, investigations were still ongoing in around half of the cases. Background ECHA is responsible for the REACH and POP regulations, which also apply to cosmetic mixtures. This pilot project focused on the enforcement of PFCAs and related substances, PFOA and D4/D5 in cosmetics. The project contributes to the harmonized enforcement of integrated control of chemicals in cosmetics under the POP and REACH regulations. The inspections of this pilot enforcement project were carried out between November 2023 and April 2024 in 13 EEA countries.