Microplastics
Microplastics are typically defined as small pieces of solid polymer-containing material, to which additives or other substances may have been added, five millimetres (mm) in size or less. Their release into the environment can be unintentional, for example from the erosion of car tyres or textiles during washing, or intentional such as microbeads added to cosmetic products. The term ‘microplastics’ describes a wide category with large variations in both physical and chemical characteristics as well as sources. Generally, microplastics are categorised as ‘primary’ and ‘secondary’ microplastics. Nanoplastics represent another category of microplastics, with dimensions of one to 1000 nanometres (nm).
What are the sources of microplastics? • Primary microplastics are a category of microplastics that includes microbeads used for cosmetic products (banned in the EU and UK), plastic pellets used to manufacture consumer goods, microfibres shed from washing clothes, as well as particles resulting from tyre erosion, road markings, marine coatings and city dust. It is estimated that close to two thirds of the primary microplastic releases to oceans are from textile laundry and the erosion of tyres.17 • Secondary microplastics are generated through the breakdown and degradation of larger pieces of plastic waste once these have been exposed to the natural environment, for example through UV degradation. It is important to note that this typically occurs with ‘fugitive plastic products’, i.e. those that have escaped the waste stream. Plastic packaging does not appear to be a source for primary microplastics, however fugitive materials may break down in the environment. For more information on this topic, please see the section called 'Marine litter'.
22//3 3
Of primary microplastics released to oceans are from textile laundry and the erosion of tyres. (Estimated)
17. IUCN, Primary Microplastics in the Oceans
PLASTICS EXPLAINED: EXPLORING THE KEY TOPICS
37
