The end-of-life infrastructure gap: When bio-based packaging fails its environmental promise

Objective: Bio-based packaging made from polylactic acid (PLA) and polyhydroxyalkanoates (PHA) is promoted as a circular alternative to fossil plastics, yet its environmental performance depends on end-of-life (EoL) systems that are often absent where the material is sold. This study examines the gap between promised and achievable EoL outcomes. It explains its persistence through the Promise–Infrastructure Mismatch (PIM) framework, which links material design, collection and sorting, treatment, and governance. Methodology: A three-phase design combined a structured evidence synthesis, a scenario-based life cycle assessment (LCA) of five EoL pathways per polymer for one metric ton of rigid food-service packaging, and an Infrastructure Gap Index (IGI) applied to three stylized waste-system archetypes. Results: Under a market-weighted realistic pathway, roughly one item in nine reached compatible biological treatment. IGI values exceeded 0.80 in every archetype, and collection failures outweighed treatment failures. Industrial composting, the advertised route, offered PLA at most a marginal climate advantage over incineration, whereas landfilled PHA produced the heaviest warming burden of any scenario because of methane release. Production emissions and landfill gas management, not consumer sorting, governed climate outcomes. Value: The study reframes compostability as a conditional, infrastructure-dependent claim and supplies a transferable index for testing it. Implications: Regulators and firms should tie compostable claims to verified local treatment access, modulate extended producer responsibility (EPR) fees by EoL compatibility, and steer PHA toward anaerobic digestion rather than landfill-exposed uses.