Microplastic particles and infusion therapy — Evidence, implications, and unanswered questions

• Infusion therapy identified as significant, overlooked microplastic exposure route • Review emphasizes clinical relevance of particle properties beyond size • Addresses limitations of current test methods and regulatory standards for microplastics • Proposes functional classification of particles based on size for clinical relevance • Calls for standardized, multi-method approach for microplastic detection and risk assessment The growing accumulation of plastic waste, including microscopic particles in the environment, is an alarming development. It has long been recognised that these particles can enter the human body. Recent studies focus on environmental sources of these particles. This article highlights a less frequently discussed, but significant, route of exposure: the infusion of particles via medical devices and pharmaceutical containers. One possible reason for this is the assumption that infusion devices are inherently safe due to strict regulations and rigorous testing. Nonetheless, advances in clinical research and the development of specialised test methods have yet to be fully integrated into current industry standards. This paper reviews the current understanding of microscopic plastic particles, with emphasis on their interaction with the human body, applied test methods and limitations. It further contrasts these insights with existing regulations. Finally, it identifies key areas for future interdisciplinary research in biomedicine, engineering, and public health.