Recycling of Post-Consumer Polystyrene Packaging Waste into New Food Packaging Applications—Part 1: Direct Food Contact

The increase in plastic recycling is an essential pre-requisite for the transition to a circular economy. Polystyrene (PS) is a low diffusive polymer and therefore a promising candidate for recycling back into food contact similar to polyethylene terephthalate (PET). However, such a recycling of PS cups has been not established to date on a commercial scale. Even if recycling back into food contact is desired, the health of the consumer must not be at risk. As a consequence, recycling processes must go through a conservative assessment by relevant authorities. For PS, however, evaluation criteria are not published, which is a drawback for process developers. Within the study, post-consumer PS recyclates were evaluated in a similar way to existing evaluation criteria for PET and HDPE. For the recycling of post-consumer PS back into packages with direct contact with food, there are still some points open which cannot be answered conclusively today. Upon closer inspection, there appears to be enough information available to give a first indication as to whether recycling of post-consumer PS packaging materials back into direct food contact can be considered safe. The knowledge gaps in PS recycling were determined and discussed.