Biowax particles as alternative to microplastics
Microplastics are, in the truest sense of the word, on everyone’s lips. Abrasion particles in toothpaste are only one example of the most diverse applications of microplastics in the cosmetics industry. However, the material has been criticized for some time now, since it accumulates in the environment and very often absorbs harmful substances that can enter the human body via circuitous routes. According to the IKW, the German Cosmetics, Toiletry, Perfumery and Detergent Association (Industrieverband Körperpflege- und Waschmittel e. V.), the cosmetics industry wants to forego the use of microplastics in the near future. Fraunhofer UMSICHT is creating market-ready alternatives in an innovative process; the researchers from Oberhausen (Germany) are focusing on natural materials.
Small particles of plastic that are between five micrometers and maximally five millimeters in size are called microplastics. We encounter them in our daily life in the most diverse cosmetics products – from shower gel to facial cream to toothpaste. The dangers posed by microplastics have been discussed for some time now: The waste water takes it into the environment, where noxious substances, maybe insecticides like dichlorodiphenyltrichloroethane (DDT) are attaching themselves to the particles. If the microplastics are ingested by shellfish, crabs and other denizens of the oceans, the harmful substances are eaten by the animal and can cause inflammations and diseases. This is how, in the end, the harmful substances make it into our food chain again. Microplastics have already been proven to be in honey, drinking water and beer.
Microplastics in cosmetics – not a necessity at all
Microplastics get into the environment via two ways: For one, larger plastic items, such as bags or bottles break down due to solar rays and mechanical impacts. Those microplastics thus are generated only over time, which is why they are also called »secondary microplastics«. Another source are products that contain microplastics from the very beginning. These are called »primary microplastics«. The most minute plastic particles made of polyethylene (PE) or polypropylene (PP) used for the scrubbing effect in toothpaste, shower gels, etc., are flushed into the oceans via the waste water, since they are very difficult to filter out in waste water treatment plants.
At present, there is very little that can be done against microplastics that are generated when larger pieces of plastics break down. »Microplastics in cosmetics products, however, are not necessary«, says scientist Dr. Sebastian Pörschke, who is doing research at Fraunhofer UMSICHT on the subject of biowax powder and its application potentials. He adds: »Alternative materials could also be used here.« Sand and nutshells, for example, or salts. Sand and nutshells, however, have a very abrasive effect on the processing equipment and wear them down quickly; and salts are water-soluble, which is why they are not suitable for all products.«
Currently, work is being carried out at Fraunhofer UMSICHT on a particularly promising alternative that is based on biowaxes. Bees wax, carnauba wax or candelilla wax are renewable raw materials and are – in contrast to plastics and bioplastics – relatively quickly biodegradable in water. We are consuming such waxes almost daily as part of many foodstuffs, for example as coatings of sweets.
Biowax particles according to customer's request
Using existing process technology, Fraunhofer UMSICHT is able to manufacture both cold-milled biowax powders as well as powders with a high-pressure process. In size and shape, the cold-milled particles correspond to the classic microplastics. We are dealing with cubically broken particle shapes, meaning compact particles with closed surfaces.
The examination of various cosmetic products showed that the microplastics contained therein very often have a particle size of about 100 to 500 micrometers. The high pressure process is also suitable for manufacturing this particle size. The wax is being melted and mixed under high pressures with supercritical carbon dioxide. Fraunhofer UMSICHT uses carbon dioxide that is generated as waste gas during the manufacture of fertilizer. In this manner, instead of getting directly into the atmosphere, the waste gas is being used sensibly once more. Through a nozzle, the mixture is then relaxed to ambient pressure while the wax powder is created – at Fraunhofer UMSICHT up to 300 kg of powder per hour. In contrast to the grinding processes common to date, specially designed particles can be produced in this manner. »Depending on the wishes of the customer, balls, porous particles, microsponges or different fibers are possible, just to name a few examples«, explains Pörschke.
Currently research is being done in Oberhausen on more biowaxes, such as berry wax, rice wax or even sunflower wax. There is consensus that with pulverized biowaxes one can contribute to solving the microplastics problem.
The biowax particles that are manufactured with the high pressure process are not only limited to their abrasive effect, but they can also be equipped with an additional function. Pörschke: »Microsponges, for example, could also serve as transport medium for liquid active ingredients, in addition to their peeling characteristics.« Particles can also be envisioned, in which a liquid or a solid substance is encapsulated that is released targetedly when used.
The discussion around the topic of microplastics and its promising alternatives remains thrilling.