Assessing the Role of Compostable Plastics in Circular Economy Transition

The increasing environmental impact of conventional petroleum-based or nondegradable plastics has prompted the development of compostable alternatives that can be safely degraded within managed organic waste management systems. Compostable plastics, a type of biodegradable plastic, are specifically designed to degrade under aerobic conditions without producing toxic residues or degrading compost quality. This review provides a comprehensive overview of compostable plastics, focusing on international standards, degradation mechanisms, compatibility with composting systems, and recently developed materials. Key compostability criteria such as biodegradability, degradability, nontoxicity, and neutral impact on compost quality are discussed in the context of certification schemes such as EN 13 432, ASTM D6400, and ISO 17 088. Notable studies on representative compostable plastics, including polylactic acid (PLA), polyhydroxyalkanoates (PHA), polybutylene succinate (PBS), starch-based plastics, and polybutylene adipate terephthalate (PBAT), are also reviewed.