From plastic waste to biodegradable solutions: environmental assessment and future directions in sustainable packaging

Plastic packaging plays a fundamental role in modern society but also represents a major source of environmental pollution due to its persistence, widespread accumulation, and limited recycling efficiency. These challenges have accelerated the development of biodegradable packaging materials as potential alternatives to conventional plastics. This review critically evaluates the environmental performance of the principal biodegradable packaging materials, including polylactic acid (PLA), polyhydroxyalkanoates (PHAs), starch-based polymers, and cellulose-based materials, from a systems-oriented perspective. Unlike previous reviews that primarily focus on material properties or biodegradation, this review integrates material functionality, biodegradation behavior, environmental fate, wastewater treatment compatibility, resource recovery, and life-cycle considerations within a unified environmental assessment framework. Particular emphasis is placed on the interactions between biodegradable packaging, functional additives, microbial communities, and biological treatment systems, highlighting their implications for sludge treatment, methane production, and circular economy strategies. The review demonstrates that the environmental performance of biodegradable packaging depends not only on polymer chemistry but also on degradation conditions, waste-management infrastructure, wastewater treatment capacity, and regional implementation. It further identifies key knowledge gaps related to standardized environmental assessment, additive behavior, wastewater treatment processes, and real-world degradation, and outlines future research priorities for developing biodegradable packaging systems that provide measurable environmental benefits throughout their entire life cycle.