Storage-driven migration of plastic additives from packaging to fish: influencing factors and human exposure assessment

Plasticizers are widely used in food packaging materials, but their potential migration into food remains largely unknown and of growing concern for human health. This study aimed to evaluate the migration of four classes of compounds, phthalate esters acids (PAEs), non-phthalate plasticizers (NPPs), organophosphate esters (OPEs), and bisphenols (BPs), from common packaging materials into fresh fish (salmon, tuna and hake) under realistic household storage conditions (2 °C for 48 h, and −18 °C for 30 days). After examining the packaging materials, three representative types were selected for migration experiments. Plastic additives were detected in fish after storage, demonstrating that migration occurs under both refrigerated and frozen conditions. Migration rates varied widely ('0.01–100%) and were strongly influenced by storage temperature and time, fish lipid and water content, packaging materials, and physico-chemical properties of the compounds. Lipid content played a key role in the migration of hydrophobic compounds such as di(2-ethylhexyl) adipate (DEHA), while water content influenced the migration of bisphenols. Dihexyl phthalate (DHexP) showed significant migration rates in frozen samples compared to refrigerated ones. The maximum concentrations detected in each class were 243 ng/g wet weight (ww) for PAEs, 358 ng/g ww for NPPs, and 54.0 ng/g ww for BPs, while OPEs were generally below the LOQ. Estimated daily intake (EDI) and hazard index (HI) calculations for adults, children, and infants indicated that packaged fish may contribute to dietary exposure to plastic additives, with worst-case HI values reaching 3.17*102, mainly due to the presence of bisphenol A (BPA). These findings demonstrate how common storage practices can promote migration of plastic additives, potentially increasing human health risks through dietary exposure.