PLA breaks down substantially only under industrial composting (around 58 °C), while soil, marine and real-world degradation are much slower, and it can shed secondary micro- and nanoplastics and leach additives before it fully degrades. A 'biodegradable' or 'compostable' label is therefore valid only under specified conditions, and PLA's environmental advantages cannot be assumed.
An open-access 2026 review in npj Materials Sustainability, led from the University of Auckland, tests whether bioplastics really have a lower environmental impact than conventional plastics. It covers degradation and secondary micro- and nanoplastic formation, chemical leaching and disinfection by-product formation, and life-cycle impacts, and reviews EU, US and ISO standards.
