Microplastics have caused a massive problem in the ocean and it is a major environmental concern. Cosmetic products often contain microplastics made of polyethylene (PE) and polypropylene (PP), particularly in dental and skincare products, due to their abrasive nature and ability to assist in cleaning. Since they possess a better chemical stability, they are used as stabilizers and fillers. Nevertheless, their non-biodegradable nature becomes a serious limitation. The microplastic particles due to their small size are easily absorbed by sea-living organisms and thereby enters our food chain. As the use of microplastic particles or microbeads has to be phased out by the end of 2020 (deadline set by Cosmetics Europe), many companies are seeking for suitable alternatives.
Researchers at the Fraunhofer Institute for Microstructure of Materials and Systems IMWS have developed and tested biodegradable cellulose particles as an alternative for microplastic particles that could meet the requirements of abrasive particles in dental care products as well as provide better cleaning performance in skincare products (Fig. 1(a)). When tested, the biodegradable cellulose particles incorporated toothpaste exhibited a low abrasion and efficient cleaning. The biodegradable cellulose particles present in the toothpaste are found to be effective in mechanical removal of bacterial plaque, tooth discoloration and food residues, with no damage to the tooth enamel (Figs. 1(b-d)). The cellulose particles are highly comparable to the microplastic particles, in terms of effectiveness of plaque removal and cleaning.
Fig. 1 (a) SEM image of the cellulose particles prepared from beech wood; (b-d) Photographic images of tooth enamel samples: (b) in their initial state; (c) after discoloration; and (d) after cleaning using toothpaste containing cellulose particles (Source: Fraunhofer IMWS)
Currently, the researchers are aiming at a cost-effective and large scale production of biodegradable cellulose particles from beech wood, oats, wheat and maize. The easy biodegradability and low production cost are the major advantages in using cellulose particles in place of microplastic particles. Designing the cellulose particles with a suitable size, shape, hardness and surface profile to meet the requirements of the product is the main challenge ahead. The researchers are optimistic that these cellulose particles could also find application in cosmetic products such as mascara, powder and lipstick.
T.S.N. Sankara Narayanan
Recent Advancements in Science 