This methodological review addressed persistent challenges in micro- and nanoplastic research — particularly in hazard identification and exposure assessment — and proposed practical solutions to improve reliability and reproducibility. The authors emphasized the need for standardized protocols that account for the complex mixture nature of MNPs including polymer, additives, and adsorbed chemicals.
The potential human health and environmental risks of micro- and nanoplastics (MNPs) have received increasing scientific attention in recent years. However, methodological challenges, particularly in hazard identification and exposure assessment, continue to hinder reliable risk characterization of MNPs. Taking into account the often complex composition of MNPs as a mixture of polymer, additives, and possible chemical and biological contaminants, comprehensive and robust assessments based on reproducible and harmonized protocols are needed before evidence-based regulatory decisions can be made. Furthermore, given the increasing amounts of plastics in various applications, it is already necessary to develop risk-mitigating strategies aimed at minimizing potential adverse effects on ecosystems and human health. To address 1) the need for better networking of research and standardization across the entire analytical workflow and 2) the requirements for risk-minimizing design and labeling of plastics, an expert workshop was held in the course of a Horizon 2020 research and innovation project, PlasticsFatE. The results of the event contain concrete recommendations, such as 1) a graduated approach to methodological unification with harmonization in particle and hazard analysis and standardization in monitoring, 2) a risk-minimizing design of plastics, and 3) the obligation to label toxic substances.