Micro- and Nanoplastics Derived from Food-Grade Plastic Products: A Critical Review of Release Behavior, Mechanisms, and Detection Techniques

The release of micro- and nanoplastics (MNPs) from food-grade plastic products is an increasing concern in food contact exposure. Using a structured evidence matrix, this review critically evaluates current evidence on particle release, differences among polymers and product types, combined stressors, source attribution, and potential health effects. By integrating polymer properties, product design, and conditions of use, it summarizes product-specific release characteristics and the mechanisms governing MNP formation and detachment. An analytical decision framework is also proposed to guide method selection according to sample matrix, target particle size, and analytical objective, thereby linking sample pretreatment, particle enrichment, counting, and polymer identification. Current evidence indicates that MNP release depends strongly on product type and use scenario but remains insufficient to support robust ranking of polymers or products. Future studies should prioritize component-level source attribution under realistic use conditions, controlled assessment of combined stressors, and multimethod validation to improve data comparability and the reliability of exposure assessment.