A systematic evidence map, published on May 15, 2023, in the peer-reviewed journal Environment International, evaluates the food safety and risk assessment evidence-base of polyethylene terephthalate (PET) oligomers. The study was led by scientists from the University of Basel, Switzerland, and co-authored by scientists from six further institutions, including the Food Packaging Forum. It makes use of scientific studies included within the database on Migrating and Extractable Food Contact Chemicals (FCCmigex).
Oligomers are small molecules made of just a few repeating polymer units. They can be present in PET food contact materials (FCMs) and can migrate into food and beverages. Currently, there is no clear guidance on how to evaluate their safety. The goal of this study was to identify and organize existing knowledge of hazard and exposure data on 34 PET oligomers. In their systematic literature review, the authors sorted published information into different evidence categories to fully record all hazard and exposure data available. Human, animal, organism (non-animal), ex vivo, in vitro, in silico, migration, hydrolysis, absorption, distribution, metabolism, and extraction/toxicokinetics/pharmacokinetics studies were considered.
For the 34 oligomers investigated, 25 have been measured in extracts from PET food contact materials, and 19 of them have also been found to migrate into food and/or food simulants. For only 13 of the oligomers present in PET food contact materials, in silico toxicological predictions have been published. And only one oligomer has in vitro data available (related to the androgen receptor and cytotoxicity) as well as more general in vivo data on organisms and ecotoxicological endpoints. So far, these very limited safety testing data do not point to major concerns, but they are also severely limited in scope and have not checked for impacts on most health endpoints. Further findings also place into question the conventional assumption that PET oligomers are completely hydrolyzed, which has previously been used as a rationale to only assess the risks of the respective monomers.
Concluding, the systematic evidence map reveals crucial gaps concerning safety data of PET oligomers present in food contact materials, which prevents appropriate risk assessment. The authors emphasize the importance of developing “more systematic and tiered approaches to address the identified research needs and assess the risks of PET oligomers.”
Reference
Schreier, V.N. et al. (2023). “Evaluating the food safety and risk assessment evidence-base of polyethylene terephthalate oligomers: A systematic evidence map.” Environment International. DOI: 10.1016/j.envint.2023.107978
Read more
Food Packaging Forum (May 18, 2022). “FCCmigex Database.”
Schreier, V.N. et al. (2022). “Evaluating the food safety and risk assessment evidence-base of polyethylene terephthalate oligomers: Protocol for a systematic evidence map.“ Environment International. DOI: 10.1016/j.envint.2022.107387
