Dynamic Risk Profiling of Polylactic Acid-Based Food Packaging: From Migration-Derived Toxicity Biomarkers to Green...

Polylactic acid (PLA) has emerged as a pivotal biodegradable alternative to petroleum-based plastics, playing a critical role in mitigating global plastic pollution. However, its overarching "green" reputation often obscures latent food safety concerns. Under complex thermal and humid storage conditions, PLA packaging is highly susceptible to in-situ degradation, precipitating the release of microplastics (MPs) and low-molecular-weight migrants-such as oligomers and functional additives-directly into food matrices. This review critically assesses these often-overlooked ingestion risks and their chronic health implications. By systematically linking PLA synthesis pathways and microstructural degradation mechanisms to dynamic migration behaviors, we delineate the specific toxicological pathways activated by these migrants. Although synthesized primarily via ring-opening polymerization to ensure stability, PLA undergoes hydrolysis in food-contact environments. Emerging toxicological evidence robustly correlates these migratory degradation intermediates with severe physiological disruptions, including intestinal barrier dysfunction, systemic oxidative stress, and immune dysregulation. Consequently, current regulatory frameworks-which predominantly focus on macroscopic material disintegration-are insufficient to address the complex biochemical toxicity of intermediate degradation products. To bridge this gap, this review evaluates sustainable risk mitigation strategies, advocating for the establishment of strict, specific migration limits (SMLs). Ultimately, we emphasize the urgent necessity for a paradigm shift toward active "Safety-by-Design" frameworks, ensuring that the ecological benefits of biodegradable packaging are not achieved at the expense of human dietary health.