Last year Synvina, the joint venture of Avantium and BASF, received interim approval from the European PET bottle platform (EPBP) for the market introduction of PEF up to 2 % of the total European PET consumption. The actual recyclability of a PEF end-product, as any product, will however depend on how it is designed and where it is launched, influencing what type of collection and sorting infrastructure is present and if this can divert the products components to recycled material streams. Why then, did the EPBP already grant an interim approval? One of the reasons was that Synvina already at an early stage gathered and shared a significant amount of data that demonstrated that PEF is not only sortable, but that low levels of PEF are compatible with PET. Although not unique, this is a rare feature for plastics while the more common incompatibility has caused issues for some bioplastics in the past. In this article we take a deeper look into the nature of this compatibility and how it can put PEF in a unique position for a circular bottle economy