Scientists at the Norwegian University of Science and Technology have studied the endocrine- and metabolism-disrupting properties of common food-contact plastics. They shared their findings in ‘Plastic Food Packaging from Five Countries Contains Endocrine- and Metabolism-Disrupting Chemicals’, published today in the journal Environmental Science & Technology.
The researchers purchased 36 plastic food-contact articles made of HDPE, LDPE, PET, PP, PS, PU, and PV from domestic retailers in five countries (US, UK, South Korea, Germany, and Norway). The samples consisted of single-use packaging (cups, films, trays, etc.) and food-contact articles for repeated use (food containers, hydration bladders, etc.).
They analysed the chemicals present in the packaging using nontarget high-resolution mass spectrometry and reporter-gene assays for four nuclear receptors that represent key components of the endocrine and metabolic system. The first technology is used to distinguish between compounds with the same nominal mass, determine elemental compositions, and identify unknowns. Reporter gene assays, on the other hand, are typically used to measure the regulatory ability of an unknown DNA-sequence.
The team found that chemicals disrupt the endocrine and metabolic systems are prevalent in plastic packaging. They detected up to 9936 chemical features in a single product and found that each product had a rather unique chemical fingerprint.
The chemicals present in food packaging made of PVC, PU, and LDPE induced most effects, whereas the extracts of HDPE, PET, and PP were less active.
“Nonetheless, we cannot conclude that a particular polymer type is free of toxic chemicals as methanolic extracts of samples of each polymer activated most receptors,” the authors wrote. “This research highlights the importance of analysing the toxicity of whole chemical mixtures of finished plastic products because it covers all extractable chemicals, including unknowns.”
The researchers used techniques to reduce the chemical complexity of chemicals in plastic products and found that samples with fewer chemical features induce less toxicity.
“Moving forward, it is essential to consider chemical simplicity as a guiding principle in plastic design and production,” they urged. “This is supported by our findings according to which chemically less complex plastic products induced lower toxicity. By the use of fewer and better-characterized chemicals, the safety of plastic products can be significantly improved,” the scientists concluded.