Silicones are a family of high-performance specialty ingredients, widely used across many industries. Since the 1950s, they have been used in several segments of the cosmetics industry for their safety and their ability to enhance skin and hair. They can today be found in categories such as hair care products, makeup, and skincare and sun protection products.
In recent years, the press and social media have pointed the finger at silicones, sometimes without any real scientific basis.
As a result, some consumers have lost interest in cosmetic products containing silicones. In the United Kingdom, for example, 40% of women in 2021 said they expected makeup brands to exclude silicones from their products (Mintel). This has led formulators and cosmetics industry professionals to turn to alternative solutions. But is this the right approach?
This article aims to provide a comprehensive and science-based perspective on silicones in cosmetics, from the types of silicones found in formulations to the advantages they offer.
What are the different types of silicones and their benefits in cosmetics?
Silicones used in cosmetics come in a variety of structures and properties. Dimethicone, phenyl trimethicone and cyclopentasiloxane are among the most commonly found.
They are generally used as emollients, film-forming agents and sensory agents, and allow, among other things, the formulation of long-lasting products. In cosmetics, they bring numerous benefits to formulations, such as a soft and silky feel, moisturization and thermal protection for hair care products.
The safety of silicones is well established and they are approved by the FDA and the European Pharmacopoeia for certain pharmaceutical applications. So where does this reputation regarding skin and hair care come from?
Contrary to popular belief, most silicones are non-comedogenic and do not clog pores. They are inert, high-performing ingredients that offer many advantages, including moisturizing and repairing properties.
Why are they also used in hair care products? They make hair shinier, easier to style, and can protect it from heat damage caused by styling tools. Furthermore, although they deposit on the hair, there is no build-up effect. This deposit depends on the quantity and type of product used and can be easily removed with a clarifying shampoo.
Are silicones bad for the environment?
Contrary to what one might think, silicones are not petrochemical derivatives derived from oil, but are obtained from silica, which is an abundant element found in quartz or sand.
Silicones are not biodegradable, but they are nonetheless degradable and therefore have no major impact on the environment.
What does this mean? Biodegradability tests were developed for carbon-based materials. Silicones, however, have a completely different chemistry, as they are composed of a siloxane chain, which excludes them from biodegradability criteria. Regardless of the chemical reactions involved, silicones are always ultimately broken down into carbon dioxide, water or silica. They do not accumulate in the environment at concentrations considered harmful and are retained by wastewater treatment plants.
How are silicones compatible with "clean beauty"?
Although there is no clear definition of what is called "clean beauty," it is at least certain that it focuses on the use of ingredients that are safe, effective, sustainable and that make the best use of both science and nature.
Silicones are versatile and when used in cosmetic products, even at low percentages, they offer unique performance that is difficult to match. They can thus help find the balance between naturalness and sensoriality.
Furthermore, they can align with eco-design principles by providing alternatives to disposable cosmetic products. Reusable silicone patches, for example, have been developed to replace single-use masks.