In response to regulatory demands for sustainable practices, there has been a significant increase in the use of recycled materials in food packaging, particularly when incorporated behind functional barriers. This study, conducted as part of the “ABA Modeling” project, evaluates the migration of contaminants from the non-decontaminated, recycled polyethylene terephthalate (rPET) B-layer, which is sandwiched between two virgin A-layers in three-layer trays. The study aims to assess the long-term implications for food safety within the context of the European and French circular economy frameworks. Using a migration modeling approach based on “worst-case” scenarios for ten contaminants – similar to methodologies employed for decontaminated direct food contact PET – the levels of chemical residues are analyzed and compared. Findings highlight the significant impact of the co-extrusion process on the suitability of rPET for food contact. Additionally, the study discusses the risks and challenges for the recycling sector, particularly in managing chemical contamination during mechanical recycling. Recommendations are provided to improve industrial practices, emphasizing the importance of ongoing monitoring to ensure the long-term sustainability of these recycling practices.