The microplásticos, as it ECHA,are solid plastic particles composed of mixtures of polymers and functional additives, usually smaller than 5 mm in size. This term has been heard in our industry for a few years now, and is now back on everyone's lips due to the European Commission's resolution last September announcing a ban on intentionally added microplastics in cosmetics.
Part of the cosmetics industry had already shown its commitment to the elimination of microplastics in its formulations before this resolution became effective. In addition, raw material manufacturers have been working for some time on new ingredients that perform well with a much lower environmental impact, although we must recognise that this is no easy task.
Last year, a CSIC study published in the journal Scientific Reports on the harmful effect of microplastics on the gut microbiota came to light (can read it here). This study confirmed that the presence of microplastics leads to a reduction in the amount of beneficial bacteria present in the colon. As the authors point out, "the latest estimates indicate that, on average, each person could ingest between 0.1 and 5 grams of microplastics each week through food and drink", so we are not only talking about the environment but also about our health.
But let's focus on cosmetic products and the alternatives that formulators can find to replace microplastics. Let's look at where they are introduced, what functions they serve in cosmetics and what ingredients we could replace them with.
- Exfoliants: Microplastic particles help to remove dead skin cells by physical exfoliation, although the vast majority of cosmetic manufacturers have stopped using them for this function. An alternative is to replace these particles with seeds, peels or fruit pits.
- Viscosifiers: Some ingredients currently used as rheological additives are considered microplastics. The most interesting options to replace them come from biodegradable polymers and biopolymers, although sometimes this substitution involves extra work especially to recover lost sensoriality, as is the case with natural gums.
- Opacifiers: some rinse-off cosmetics have a milky appearance, and microplastics such as Styrene/Acrylates Copolymer are often used to give this creaminess. I talked about this in one of my Formulation Tuesdays, you can remember it here. There are mixtures of surfactants and esters (Sodium Laureth Sulfate + Cocamidopropyl Betaine + Glycol Distearate) or even dispersions of inorganic salts such as zinc oxide that can provide a similar effect, although work is still being done to find more effective options.
- Encapsulants: Manufacturers sometimes encapsulate actives or fragrances with microplastics. There is a need to find options that are less harmful to the environment and highly biodegradable. Alternative products are mainly based on biodegradable polymers and biopolymers.
- Other uses: as fixing agents, dispersants, conditioners, etc. The ingredients to be considered will depend mainly on the cosmetic form and application.
This is just a small sample of the daily work that many formulators have to do to find alternatives to microplastics, which are cross-cutting ingredients that are present in more sectors, for example in detergents or agrochemicals. As you can see, the replacement of microplastics is a major challenge, and it is not only the cosmetics industry that needs to step up to the plate. The countdown has begun.