Microplastics are an emerging concern, not only because of their harmful effects on human and animal health, but also due to increasingly stringent legislation targeting microplastics originating from human activities.
Microplastics are defined as discrete, solid, non-degradable, and water-insoluble (≤ 2 g/L) particles that are partially or entirely composed of synthetic polymers or chemically modified natural polymers. As the term suggests, microplastics are small: their width (W) is limited to a maximum of 5 mm. Based on their shape, microplastics are further categorized into particles—where the length (L) is less than or equal to 5 mm and the aspect ratio (L/W) is ≤ 3—and fibers, where the length can be up to 15 mm and the aspect ratio (L/W) is ≥ 3.
A closely related concept is synthetic polymer microparticles (SPM), which can be considered a primary source of microplastics. When SPM enter the environment, their degradation leads to the formation of microplastics. The definition of SPM is broad and includes chemically modified natural polymers, such as modified starch, meaning that materials not traditionally perceived as plastics may still fall within this category.
Current legislation primarily addresses microplastics in drinking water and emissions from industrial sites that intentionally incorporate SPM into their processes or products. Due to the broad definition of SPM, some industries may be unaware that the polymers they use are classified as SPM. Importantly, regulatory development at the EU level is ongoing. It is highly likely that future legislation will introduce stricter limits on microplastic emissions as well as the use of raw materials containing SPM or microplastics. This is particularly relevant for operations utilizing recycled fiber, which typically contains residual plastics.
Until recently, state-of-the-art microplastic analysis has been challenged by samples with high fiber content, such as bio-based end products. However, KCL has now overcome this limitation by developing a protocol that effectively removes the interference caused by cellulose, hemicellulose, and lignin. This advancement enables reliable quantification of microplastics in high-fiber samples.
To learn more, join us on June 11th, 20026 for the KCL BIOHUB webinar focused on recycling, including a discussion on microplastics. KCL BIOHUB webinar
More information:
Anu Kettunen
(firstname.lastname@kcl.fi)