A scientific study entrusted by Styrenics Circular Solutions (SCS) to the German research institute Fraunhofer IVV has demonstrated that the recycled polystyrene (rPS) used as inner layer of packages intended for the contact with foods is safe, due to the functional barrier offered by virgin polystyrene. A co-extruded ABA structure, where inside and outside they have used virgin polystyrene and in the middle polystyrene obtained through mechanical recycling, suitably contaminated to facilitate the analysis on migration, has been subjected to stress test.
Trials have confirmed the low-diffusion properties of PS, resembling PET ones, which would allow a safe use of the recycled in applications in contact with foods, when used as inner layer. Fraunhofer IVV has carried out tests on various yogurt jars, demonstrating the safety, in an ABA structure, with a maximum 50% content of recycled polystyrene. Results can be extended to all stiff packages made of thermoformed PS.
Currently, manifold recycling technologies are available and they allow a simple recovery of post-consumer polystyrene wastes even for material in contact with food, more and more times.