Getting Ahead of the Trend for Silicone-free Cosmetics

Volatile silicones are on the way out of the cosmetics industry. Strict new regulations and increasingly eco-conscious consumers are driving a switch to silicone-free products. Why is this happening now? And what alternatives are there? There are two main driving forces for this trend: changing regulations and shifting consumer preferences.

When it comes to regulations for silicones in cosmetics, we’re mostly talking about three commercial volatile cyclosiloxanes: D4, D5 and D6. They are attracting regulatory attention because they were (in case of D4) or continue to be commonly used ingredients in the beauty industry but do not have a positive ecological profile.

This applies in particular to D4, which belongs to category 1 for chronic aquatic toxicity and has a mandatory classification as category 2, “toxic to reproduction”, indicating that it is harmful to humans. D5 and D6 are likewise persistent, not biodegradable, and ultimately harmful to the environment. Governments worldwide are restricting or sometimes prohibiting the use of these materials in cosmetics.

While it is already forbidden to actively use D4 in cosmetic products according to the EU cosmetics regulation (EU/1223/2009), its presence is still possible as an unintended impurity arising from other raw materials. To cover the unintended presence of this type of substance, they are classified as a Substance of Very High Concern (SVHC) in the European Union, while the presence of D4 and D5 in a concentration equal to or greater than 0.1 percent has been prohibited for rinse-off cosmetics since February 2020. The European Chemicals Agency (ECHA) has now submitted a proposal to extend this restriction to D6, and to also include leave-on applications for all three cyclosiloxanes. When this legislation is approved, manufacturers will have five years to phase out these materials.

Outside the EU, a similar regulatory focus is gathering momentum. As cyclomethicones have been under discussion for several years now, some companies have already excluded those structures from their formulations. Due to the recent regulatory developments, there is now fresh impetus to do so.

By staying ahead of this regulatory trend, companies can tap into perception and high technical performance that are difficult to replicate. We are creating a portfolio of sustainable alternatives, i.e. without use of silicones – and not just the materials that

author: Michal Stepulak, PhD, Senior Technical Manager Personal Care, Head of Reginal Formulation Center, BASF the regulators are focusing on. Our specialists are developing state-of-the-art solutions that make it possible to eliminate all silicones from cosmetics.

Fully replacing silicones puts manufacturers in a strong position, because their formulations are ahead of whatever regulations might be introduced for silicones in cosmetics, anytime and anywhere in the world. Emollients are a great example. These ingredients play a key role in creating cosmetic products that have a pleasant skin feel and gratifying textures. Especially light textures are very popular among consumers. They also provide a protective layer on the skin, keep it moisturized, solubilize lipophilic active ingredients and crystalline UV filters, and help to disperse pigments. We reviewed the use of cyclosiloxanes in various recently launched skin care products and color cos-

metics worldwide. Around 50% of facial foundations and about 20% of make-up removers contained at least one of these silicones – so we have now developed and tested sustainable alternatives for these two categories. For the facial foundation category, BASF experts formulated a tinted day care fluid that replaced a volatile silicone emollient with Cetiol® Ultimate (INCI: Undecane (and) Tridecane). This is an ultra-fast-spreading and 100% plant-based emollient that matches the silicone product’s results when tested in a W/O formulation for mechanical smear resistance, rain resistance, gloss kinetics, blemish coverage and color homogeneity.

Using our sustainable alternative, we created a product with SPF 25 sun protection, a natural look and no color shift over time. It is also easy to distribute, and leaves skin feeling powdery and smooth.

In the second category, our scientists created a biphasic make-up remover. It contains a mixture of three fully plant-based emollients that account for 39% of the overall formulation, replacing a volatile silicone ingredient that accounted for 39% of the previous formulation. The optimal mixture of sustainable emollients was designed using a digital modeling tool that applies artificial intelligence (AI). Tests showed that replacing the volatile silicone with our plant-based alternative mixture had no negative impact on the sensory properties of the make-up remover.

It enabled the formulation of a silicone-free biphasic make up remover that provides excellent performance when removing various decorative cosmetics. It is also tear-free, non-sticky, suitable for cold processing, and contains content that is 98% of natural origin in line with ISO 16128. In fact, our formulation performed even better than the silicone-based product.

Another ingredient that could potentially replace cyclomethicone in cosmetic products is Tridecane (Cetiol iSan). Like the previously described emollient, it is characterised by very high spreadability (2500 mm2/10 min) and similar volatility as cyclomethicone. Sensory tests carried out in a group of trained panellists confirmed convergent properties both, in case of parameters related to the stage of application of the cosmetic on the skin (spreadability, glide, stickiness, waxiness), and in case of parameters related to skin care effects (absorption, waxiness, powdery after absorption). An undoubted advantage of Tridecane is its smell, or rather the practical lack of smell, which means that perfuming formulations containing a high concentration of this emollient (e.g. colour cosmetics) is not a major challenge.

This emollient can also be used as the main ingredient in sunscreen oils containing crystalline UV filters. Unlike cyclic silicones, it does not stimulate recrystallization of the filters over time. Tridecane has also been tested for irritating properties and comedogenicity. In the case of the first parameter, both in vitro tests using the EpiDerm skin model and an in vivo test conducted under dermatological supervision on 30 volunteers were used. The results of both tests confirmed the absence of irritant properties. A separate test, also carried out on volunteers, confirmed the absence of comedogenicity at concentrations of up to 10% in the finished product. This makes Tridecane a good emollient for problematic skin care products (sensitive skin, acne-prone skin). It can also be used in make-up removal products. In a test proving its effectiveness, Tridecane proved to be better than dodecane, which is often used in make-up removal products. We expect regulations covering the use of cyclosiloxanes to be introduced around the globe, and that these materials will eventually be banned worldwide. In Canada, for example, D4 is already in the spotlight due to its environmental toxicity. In light of the new European Chemicals Strategy for Sustainability (CSS), the latest approach within the European Green Deal aiming to ensure a toxic-free environment, we can expect similar restrictions to those placed on cyclosiloxanes to be issued or at least discussed for further substances in the same chemical group.

That’s the future – but we can already achieve it today. Our sustainable alternatives offer companies in this industry a clear path to replace silicones in their formulations now – instead of waiting until they have no choice. However, we’re not just trying to stay one step ahead of regulators.

We see the Clean Beauty trend as a massive opportunity for companies in this industry to future-proof their product range by responding to changing consumer expectations at an early stage. Cosmetics manufacturers that offer silicone-free, safe and biodegradable products now can position themselves as market leaders in the years to come. Our sustainable alternatives to volatile silicones open up attractive potential for our customers. And we are offering solutions that tap into this potential while delivering the performance and feeling that consumers expect.

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