In recent years, there are ways too many myths saying that silicones are harmful. Thus in this post, I would like to put some information together to help you clear out what silicones are and what makes them have bad reputation.
What are silicones?
Silicones are groups of synthetic molecules based on a backbone of repeating silicon and oxygen (silicon dioxide or silica) and hydrocarbon groups attached to them. Silicone used in cosmetics is synthetic polymers that can be found on the labels by these endings: –cone, -conol, -siloxane.
Silicones are everywhere in beauty products. Some examples are dimethicone, cyclomethicone, polysilicone, cyclopentasiloxane. There are good reasons that silicones are so popular. Silicones have low surface tension thus having a good spreadability. Powdered pigments treated by silicone such as ZnO, TiO2…spread well in products.
Silicones deliver greater emollient values than other cosmetic ingredients. In skincare and haircare, silicones retain moisture but do not clog pores, provide slip and shine to your hairs, and enhance penetration of active ingredients.
Many silicones are not water-soluble, thus they can form a film layer on the applied surface, which are commonly used in waterproofed products.
Thanks to these properties, silicones are often the best choice in formulating products.
Types of silicones in cosmetics:
–Volatile silicone fluids: easily evaporate off the hair or skin.
Groups of cyclomethicone:
- Cyclotetrasiloxane: Also called D4, usually found in haircare (leave-on products: styling or heat protection products). It provides a silky feel and slips for the hairs but does not build up (because it evaporates quickly).
- Cyclopentasiloxane: it sometimes appears on the labels as D5. It is used in cosmetics to form a protective barrier on the skin and hair, which is found in hair spray, sunscreen, foundation… Research shows that cyclopentasiloxane is not absorbed into the skin high enough to cause any harm to our bodies.
–Silicone liquids (non-volatile)
- Dimethicone: works in skincare products as an emollient that improves the softness of the skin, and optimizes the absorption of actives ingredients. Dimethicone is also used as a water-resistant ingredient in sunscreen and lotion.
–Amodimethicone blends:
Micro-emulsions of silicones have silky look which is added to hair care products (shampoo…) for conditioning benefits.
–Silicone gums or Dimethiconol: antifoaming agent, anti-static agent, and skin-conditioning agent.
–Silicone- acrylate copolymer: water-resistant, film-forming agent.
Why does silicone have such bad reputation?
Safety concerns: Silicone is safe to use as existing concentrations in cosmetics. There is no research showing that silicone can do harm to our health. The only concern that makes silicone “evils” is the environmental hazards, which are still not necessarily that bad according to some blow-up information. Silicone is a synthetic polymer and not biodegradable, but it has high durability and can be recycled properly multiple times.
Silicones used in rinsed-off products can stay in the drain, pollute the environment, and accumulate in aquatic animals. However, there is no evidence proving this information.
Silicones are assumed to clog pores on the skin and cause irritation. Indeed, silicones are resistant to oxidation and enhance the spreading of ingredients, thus this misinformation makes people avoid silicones at all costs.
In short, the benefits of silicones in skincare and haircare are obvious, thus choosing products containing silicones or avoiding them depends on consumers’ skin/hair types and their preferences.
Reference:
Barel, A., Paye, M., Maibach, H., Handbook of Cosmetic Science and Technology 2001, p.390- 395.
Chemistscorner.com
