Most of the plastics we currently use in our daily lives are not biodegradable, which means they last over time when unintentionally released into the environment.
These materials are considered microplastics when they are made of petroleum- or bio-based polymers, are solid, are less than 5 mm in size, are not water soluble and have low degradability.
Microplastics are also used widely and directly in products such as cosmetics, plastic paints and abrasive and industrial cleaning products, though such use is not currently standardized.
Legislation designed to regulate microplastics throughout their life cycle in the value chain of plastic materials is therefore being drafted.
As part of the definition of “microplastics”, which include plastics less than 5 mm in size, standard UNE-CEN ISO/TR 21960 further defines microplastics measuring between 1 and 5 mm in size as “large microplastics”, and microplastics under 1 µm as nanoplastics. This wide range of particle sizes creates several limitations on the different analytical identification techniques available when the aim is to analyse individual particles while bearing in mind their size and morphology. The resolution of the techniques themselves sometimes makes it impossible to distinguish particles smaller than a specific size and this can be particularly difficult when working with nanoplastics and microplastics smaller than 5 to 20 µm. In these cases, mass detection and identification techniques are generally used because they make it possible to analyse smaller fractions of particles without obtaining information on each individual particle.
