Unveiling incidental contamination of recycled PET for food contact: Safety insights and ongoing challenges

Mechanical recycling of polyethylene terephthalate (PET) for food contact materials (FCMs) is increasingly important in the context of circular economy goals. However, incidental contamination, arising from previous misuse, environmental exposure, or processing, could potentially pose safety concerns. Understanding the occurrence and behaviour of such contaminants is essential for reliable risk assessment and regulatory compliance. This systematic literature review (SLR) evaluates the current knowledge on incidental contamination in recycled PET intended for food contact. A broad screening of intentionally added substances (IAS), non-intentionally added substances (NIAS), and inorganic elements was conducted. Reported concentration ranges and associated analytical methodologies were catalogued to assess contamination prevalence and potential migration risks to food. In addition, meta-data analysis was used to identify common limitations across studies, such as sample sizes, PET origin reporting, and methodological standardization. It was identified that while many common contaminants, both organic and inorganic, were consistently detected, quantitative data were often limited or highly variable. Sorting and washing steps during recycling were frequently implicated as vectors for cross-contamination. The main limitations and critical data gaps were identified on the exact sources, uses, recycling technologies, and analytical practices, underlying the importance of standardization for reliable assessment, while enhancing consistency and reliability of FCM recycling. Addressing these data gaps through more comprehensive studies will be essential for deepening our understanding of rPET contamination sources and for supporting further developments. • Systematic review to screen PET potential contaminants (type, levels). • Identified contaminants were below EFSA's safety threshold (3 mg/kg). • PET source details often inadequately reported. • Sorting and washing is a critical parameter. • Standardized analytical methods for FCMs are lacking.