Environmentally friendly microplastic alternatives in cosmetics items

In the laboratory, toothpastes containing biodegradable particles were tested for their cleaning effect.
© Fraunhofer IMWS

Interview with Dr. -Ing. Sarembe, scientist at Fraunhofer Institute for Microstructure of Active Agents and Systems IMWS in Halle (Saale).

KosLigCel is a research project in the framework of the top cluster BioEconomy for the researching of cheap manufacturing of biodegradable cellulose particles made of beechwood, oats, wheat and corn. These fulfil the same requirements for abrasiveness and cleaning performance in dental and skincare products as conventional microplastics, but are considerably more environmentally friendly.

Microplastics are now even used in our mouths. So why is microplastic so dangerous for our environment?

Microplastics are plastic particles that perform useful functions in many products, such as in creams, shower gels and nappies. Two characteristics make them a problem for the environment: First, the particles are very small (between a few micrometres and 5 millimetres), i.e. if they are used as part of a shower gel and get into the sewerage, they cannot be filtered out by common treatment plants like other pollutants. They go further into the water cycle, can be absorbed there by different organisms and thus get into the food chain. In the worst case, we than have a fish on our plate that contains plastic from our shower gel. The second problem is the great durability of the particles: The natural decomposition takes place very slowly, this can last more than 100 years. After all, materials such as polyethylene have been specifically developed for a long service life. This is a desirable characteristic for pipes, bottles or gears made of plastic. It becomes a problem when microplastic particles get into the water cycle. This is why, together with our industrial partners, in the project “KosLigCel”, we developed natural cellulose particles that can replace microplastics and are biodegradable.

What products use microplastic where you would not expect to find it?

In the public debate at the moment, people often talk about peelings, toothpastes, deodorants and many other cosmetic products. It has to be said, however, that many manufacturers now no longer use microplastics in these products or are at least intensively searching for environmentally friendlier solutions. According to a current study, cosmetic products account for 4.1 percent of the annual quantity of microplastic put in the seas in Europe. That is still several thousand tons per year. A much greater role, however, is played by the pollution of bodies of water with microplastic from tyre abrasion or from items of clothing that get into the environment when they are washed. Not least of all, there is not just primary microplastic, which is deliberately manufactured as such, but also microplastic particles that occur when plastic waste gradually disintegrates in the environment.

What can your “biological granules” do better? And what are perhaps their disadvantages?

We have concentrated on skincare products and toothpaste. In these, microplastic particles are used as “gentle abrasives”, contributing to the products’ cleaning performance. Together with partners, we have proven that a similar cleaning performance can be achieved if one uses particles made from cellulose, which are biodegradable. Another advantage is that cellulose particles – unlike plastic – also absorb water and oil. This is a promising characteristic for moisturising creams.

In what areas can the natural particles be used?

We can see possible applications for the cellulose particles developed by us and our partners in skin cosmetic products like creams and peelings, but also in decorative cosmetics, such as for mascara, powders and lipstick. Use in medical products is also conceivable. Microplastic particles are also often used as stabilisers and filling materials, such as in deodorants, because of their chemical resistance and colourlessness, odourlessness and tastelessness. Our biodegradable replacement materials are also suitable for this.

Why are there still no widely-used alternatives to microplastics?

There are functioning replacement materials that are environmentally friendly. We have proved that in our project, among other things. Of course, it takes time until such alternatives have been developed and sufficiently tested. In addition to this, the manufacturers have to switch their production and the new materials also have to be competitive in price. But a lot of things have been set in motion – politicians are also upping the pace, because, in view of the increasingly clear findings about environmental pollution, bans on microplastics are anticipated in many places or have even already been enacted.

What are the biggest problems and challenges in this research project?

This can be illustrated very well using the example of the toothpaste developed in our project with cellulose particles: First of all, we had to identify a suitable base material and chose cellulose, which is obtained from beechwood, oats, wheat and corn. Then it was a matter of manufacturing the cellulose particles in such a way that their size, shape, hardness and even surface structure are exactly right for the desired cleaning properties. The cellulose particles have to remove plaque, tooth discolouration and food residues, but must not damage dental enamel. We have repeatedly examined the structure of the particles with high-resolution microscopes, measured the cleaning performance with other test methods, and gradually optimised the manufacturing process. Of course, we also have to bear in mind that the particles are harmless to health, and that the manufacturing has a moderate cost ratio.

What partners are you cooperating with?

Our partners in the project “KosLigCel” were CFF GmbH from Gehren in Thuringia, which was above all responsible for the manufacturing of particles, and Skinomics GmbH from Halle (Saale), who have primarily taken over the manufacturing and dermatological testing of the products.

Which natural materials are particularly suitable? What have the best results been achieved with?

We have tested several cellulose types on the basis of beechwood, oats, wheat and corn as replacements for microplastic particles. All of these have proven to be suitable. Tests are also being carried out at other research institutes using biowax, salt and olive pits. In our project, we have created the basis for also being able to test such alternatives and others, with detailed materials research, and thus test their suitability.

Are there already concrete examples of market-ready applications?

The particles developed in our project are already on the market and are distributed by CFF GmbH.

What do you think the future might hold? Will microplastics soon disappear completely from products?

A comprehensive replacement of microplastic in cosmetics products by biodegradable materials is feasible, in the next five to ten years. Niche products such as vegan cosmetics will be the first to make the change, then the mass market will follow. Consumer demand and policy guidelines are both pointing in this direction, both have recognised the problem and are looking for alternatives. As I mentioned, though, use in cosmetics products only accounts for a small proportion of the complete environmental pollution from microplastics. More research is necessary for other fields of applications, like textiles and colours, or for the problem of tyre abrasion. This will definitely take longer than five to ten years. Also, no solution has yet been found for the problem of secondary microplastic. Overall, however, one can recognise a trend towards producing plastics in a more environmentally friendly way, based on renewable raw materials. A great deal is happening in the research on this and we are also collaborating on it intensively at the Fraunhofer IMWS in Saxony-Anhalt.

Contact person for the research project:
Dr. -Ing. Sandra Sarembe
Characterization of medical and cosmetic care products at Fraunhofer IMWS
+49 345 5589-256
sandra.sarembe@imws.fraunhofer.de

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