Safety concerns of recycling postconsumer polyolefins for food contact uses: Regarding (semi-)volatile migrants untargetedly screened

Plastic recycling is one of the important ways to mitigate plastic pollution. However, chemicals present in recycled plastics is one of the key qualities affecting their potential uses and deserves more attention. 475 migrants coming from 15 postconsumer recycled polyolefins were identified by direct immersion-solid-phase micro-extraction gas chromatography mass spectrometry (DI-SPME-GC-MS) and atmospheric pressure-gas chromatography-quadrupole-time of flight-mass spectrometry (APGC-QTOF-MS). About 60 % of them might not be of human risk because they were food additives/components or they are saturated hydrocarbons, fatty acyls, or prenol lipids. Most of them had molecular weight (MW) between 150 and 210 Da, though, high concern substances with high MW (e.g. octocrylene) implied that high MW surrogates are required to study the efficiency of recycling processes for polyolefins. The mean predicted octanol/water partition coefficient (XLogP) was about 6.5 and 3.5 for 95 % ethanol and 3 % acetic acid food simulants, respectively. Octocrylene, 1-tetradecene, 1-dodecene, dodecyl acrylate, 2,4-di-tert-butylphenol, 1,4-benzenedicarboxylic acid, diethyl ester, benzenamine, 2,4-dichloro-, and diethyl phthalate were of high concern depending on the potential food contact use of the materials. The results presented are informative and can be of great help for recyclers and law makers to recycle polyolefins for safe food contact use.

Automated summary

The study found that most of the compounds identified through chemical testing may not pose a risk to human health, with a majority being food additives or components that do not harm the human body; some high molecular weight substances require further study. The results are informative for recyclers and policymakers in recycling polyolefins for safe food contact materials.