In an article published on June 25, 2021, in the peer-reviewed journal Food and Chemical Toxicology Journal of Food Science, Choonshik Shin and colleagues from the Ministry of Food and Drug Safety, Cheongju, Republic of Korea reported on the overall and specific migration of chemicals from food contact plastics.
The scientists analyzed 344 samples collected from online or local markets in South Korea. The food contact materials (FCMs) were made of of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), poly(1,4-cyclohexylenedimethyl) terephthalate (PCT), polylactide (PLA), polybutylene terephthalate (PBT), and cross-linked polyester products. Migration experiments were performed using 4% acetic acid, water, and n-heptane as food simulants at 70 or 100 °C for 30 min (exception for n-heptane: 25 °C, 1 h).
The average overall migration of all seven FCMs complied with the current regulatory limit of 30 mg/L for plastic FCMs in South Korea. The authors also measured the specific migration of four substances, terephthalic acid (CAS 100-21-0), acetaldehyde (CAS 75-07-0), 1,4-butanediol (CAS 110-63-4), and lead (CAS 7439-92-19) and calculated the estimated daily intake using the standard methods applied by the Ministry of Food and Drug Safety in Korea (MFDS) and the US Food and Drug Administration (FDA). Subsequently, they compared the estimated daily intake with “health-based guidance values, such as tolerable daily intake” to allow for drawing conclusions on the materials’ safety. Based on their assessment of specific migration from all analyzed FCMs, they considered the dietary exposure to the four substances to be safe. This safety was confirmed when applying either the MFDS or the FDA method to calculate the estimated daily intake. Shin and co-authors concluded that according to “current exposure assessment, it could be considered that the studied food contact plastic materials are properly controlled by the regulatory authorities.”
In their study, Shin et al. draw their conclusion based on the traditional risk assessment approach, which focuses on separately considering the migration of and exposure to individual, known substances. According to current scientific understanding, this approach does not consider other toxicological aspects and may lead to misleading conclusions of a product’s safety. For instance, such approaches based on assessing single chemicals neglect mixture effects although FCMs are known to contain complex mixtures (FPF reported here and here) of both known and unknown compounds (FPF dossier) and may rely on often outdated toxicity threshold values.
Shin et al. (2021). “Migration of substances from food contact plastic materials into foodstuff and their implications for human exposure.” Food and Chemical Toxicology (published online June 25, 2021).