In an article published on December 9, 2024, in the journal Environmental Science: Advances, Kara B. Loudon and co-authors from the University of Manitoba, Winnipeg, Canada, analyzed polycyclic aromatic hydrocarbons (PAHs) migrating from single-use polypropylene (PP), polyethylene (PE), polycarbonate (PC) and polyethylene terephthalate glycol (PETG) plastics into olive oil.
For their experiments, the scientists used food grade plastic sheets cut into 3.1 x 3.1 cm squares and performed migration experiments into extra virgin olive oil. They simulated refrigeration (20 °C, up to 10 days) and microwaving (125 °C for 20 min). Upon sample processing, they subjected the samples to high-resolution gas chromatography-tandem mass spectrometry (HRGC-MS/MS) for the targeted analysis of 36 alkylated polycyclic aromatic hydrocarbons (PAHs) and 16 unsubstituted PAHs.
Loudon and co-authors reported that a variety of PAHs migrated from the assessed food-grade plastics, with greater amounts of alkylated PAHs migrating compared to their non-alkylated analogs. Temperature strongly influenced migration with a negligible migration of PAHs from plastic to oil at 20 °C. Generally, migration was highest from PE followed by PETG while it was lowest from PC. For instance, all alkylated compounds studied were detected to migrate from PE at some point until day 10 at 20 °C, with the greatest share (30%) migrating at day 4.
To better understand potential human exposure, the researchers calculated the estimated daily intake of PAHs. For PE, the most significant contributor, they estimated 1794.4 ± 163.5 and 169.4 ± 23.5 ng/person/day at 20 °C and 120 °C, respectively. Loudon and co-authors assessed the cancer risk from PAH exposure by assuming most detected PAHs are 1/1000 as toxic as benzo[a]pyrene. They concluded that the specific PAHs migrating from the studied plastics pose negligible cancer risks, equating to less than one additional case per million people over a lifetime. However, they noted variability in PAH distribution across plastic samples and highlighted that prior studies have shown that dietary PAH exposure presents a potential cancer risk.
According to the authors, their study is the first comprehensive one to measure and demonstrate the migration of a broader range of PAHs from plastics into foods.
Reference
Loudon, K.B. (2024). “Estimating dietary exposure to polycyclic aromatic compounds from food grade plastics.” Environmental Science: Advances. DOI: 10.1039/d4va00195h
