The Microbead-Free Waters Act of 2015 banned the use of plastic microbeads in toothpastes and other personal care products in the United States. These tiny, non-biodegradable items are still used throughout the rest of the world, though. The Fraunhofer Institute for Microstructure of Materials and Systems IMWS is now developing materials based on cellulose that can replace plastic microbeads without negatively impacting the environment.
Microbeads are smaller than 5 mm and made of materials like polyethylene and polypropylene. They lack color, smell, and taste, so they’re used as abrasives in personal care products and as stabilizers and fillers. But because they are so small, sewage treatment plants can’t remove them from wastewater, and they eventually are absorbed by living organisms and enter the food chain.
Working with government and industrial partners, the Fraunhofer IMWS researchers have successfully developed and tested alternative biodegradable particles from beech wood, oats, wheat, and maize that meet the requirements for abrasiveness and cleaning performance in dental and skincare products—specifically, alternatives for body peelings and toothpastes.
The challenge was in designing the cellulose particles so their size, shape, hardness, and surface structure led to the desired product properties. Cellulose made of beach wood was specifically modified, and the optimization process was accompanied by microstructure analysis at Fraunhofer IMWS.
“After two years of research work with the project partners, we have achieved very good results. A test toothpaste with the optimized beech wood cellulose particles is characterized by a low abrasion effect, but nevertheless good cleaning performance,” said Dr. Sandra Sarembe, project coordinator at Fraunhofer IMWS.
The biodegradable particles in toothpaste are used for the mechanical removal of bacterial plaque, tooth discoloration, and food residues, but they may not damage tooth enamel.
“In the material characterization of several cellulose types, we have consistently collected positive data. This also applies to the use of these substances in wash peelings and other skin cosmetics,” said Sarembe.
The researchers scientifically confirmed that cellulose particles have comparable effects in cosmetic products as a substitute for polyethylene. The particles also are biodegradable in water and can be produced at low cost. Cellulose particles can be used as filler in aluminum-free deodorants as well.
“The use of cellulose as bio-based fillers could also be possible in other fields of application such as medical products. In addition, different cellulose types can be mixed, which promises a wide range of applications,” said Dr. Andreas Kiesow, project manager at Fraunhofer IMWS. “Therefore, the particles have a high potential for new product developments and attractive marketing opportunities for sustainable or even vegan products.”