Scientific study investigates in vitro toxicity and composition of chemical mixtures migrating from everyday plastic products made of eight polymer types; demonstrates that thousands of chemicals can leach under realistic use conditions, including compounds toxic in vitro that contribute to human exposure; emphasizes the importance to rethink and redesign plastics to achieve safe materials.
In an article published online on August 17, 2021, in the peer-reviewed journal Environmental Science and Technology, Lisa Zimmermann and co-authors from the Goethe University and the Institute for Social-Ecological Research in Frankfurt am Main, Germany, as well as the Norwegian University of Science and Technology, Trondheim, Norway, reported on the chemicals migrating from 24 consumer plastics and their in vitro toxicity.
In a publication in 2018, the scientists demonstrated that methanolic extracts of plastics contain a wide variety of chemicals and are toxic in vitro (FPF reported). As a follow-up, their current study aimed to find out whether these mixtures also leach under realistic use. To this aim, they performed migration experiments with water according to EU regulation’s experimental standards on plastic food contact materials (FCMs) and analyzed the migrates with four in vitro bioassays and nontarget high-resolution mass spectrometry (UPLC-QTOF-MSE).
The study results showed that all 24 samples induced baseline toxicity, 22 activated an oxidative stress response, 13 contained antiandrogenic compounds, and one sample contained estrogenic compounds. Comparing the eight different polymer types, including petroleum- and bio-based products, demonstrated that chemicals migrating from polyvinyl chloride (PVC) and polyurethane (PUR) articles were highly toxic. However, toxicity levels varied within one polymer type leading the authors to conclude that “the toxicity migrating from plastics is specific to the product rather than the polymer type.” A comparison of the 12 FCMs with the 12 non-FCMs further showed that FCMs, although mores strictly regulated, have a similar potential to induce oxidative stress and baseline toxicity as non-FCMs. According to the article, this “underpins concerns over the adequacy of the traditional approach of assessing the safety of FCMs that prescribes to assess the migration of starting substances.” Moreover, Zimmermann and colleagues compared the effects of migrates to the effects of methanolic extracts analyzed in their previous study. They found that the chemical mixtures migrating into water are generally less toxic than those extractable with methanol. However, some migrate samples induced a greater toxic effect than their corresponding extract.
~sFood Packaging Forum, 18 August 2021