Paper-based packaging is widely promoted as a sustainable alternative to plastic; however, functional coatings can reduce fibre integrity and lead to burden shifting in industrial recycling systems. This review examines how these effects undermine the environmental benefits expected from fibre-based packaging and weaken progress towards high-quality circularity, as required by current EU sustainability policy. By comparing leading assessment schemes (PTS, CEPI, 4evergreen) with industrial evidence, we identify a systemic gap: laboratory-focused recyclability tests often overlook fibre-quality degradation and the resulting limitations for circular material loops. To close this gap, we propose a sustainability-oriented extension module based on three measurable ISO-anchored indicators—fibre length, fines fraction and WRV—that prevent “recyclable-only-on-paper” claims and support genuinely sustainable recycling performance. Case studies demonstrate how high laboratory yields can mask low industrial recyclability and thus hinder circular economy objectives. This study contributes to sustainability science by operationalising recyclability in a manner consistent with EU circularity goals and by providing a transparent method to protect fibre value in multiple loop cycles.
Dubowik et al. (Thu,) studied this question.