Analyses of Food-Consumption Data and Migration for the Safety Evaluation of Recycled Polystyrene Intended for Food-Packaging Applications

The recycling of post-consumer plastics for food-contact applications is subject to stringent regulatory requirements, particularly with regard to the removal of potentially harmful non-intentionally added substances (NIAS). While polyethylene terephthalate (PET) recy-cling processes are already approved by the European Food Safety Authority (EFSA), there is a lack of guidance for other polymers like polystyrene (PS). This study aims to provide a scientific basis for assessing the decontamination efficiency required for recycled post-consumer PS in food-contact applications. As one of the first studies to propose a framework for PS decontamination assessment based on EFSA food-consumption data and conservative diffusion modeling, it contributes to filling this regulatory gap. First, Eu-ropean food-consumption data were analyzed to identify critical scenarios of the age-group-dependent intake of PS-packaged food. Based on this, a conservative migration model was applied using a one-dimensional diffusion simulation to determine the maxi-mum allowable initial concentrations of NIAS in PS. The calculated values were then compared with published reference contamination levels to calculate the required cleaning efficiency. The combination of food-consumption values and the migration process showed that trays for fruits and vegetables are the most critical food-contact application for post-consumer PS recycling. The most stringent assumptions resulted in necessary de-contamination efficiencies ranging from 92% for the smallest molecule, toluene (92.14 g/mol), to 42% for the largest molecule, methyl stearate (298.50 g/mol). The results provide a methodological basis for regulatory assessments and offer practical guidance for de-signing safe recycling processes, thereby supporting the circular use of PS in food pack-aging and building the basis for future regulatory assessments of other polymers, in line with the European Union Plastics Strategy and circular economy objectives.