Listeria monocytogenes in Ready-to-Eat Foods: Risk Perspectives Across Different Regulatory Systems

Listeria monocytogenes poses a significant challenge in ready-to-eat (RTE) foods due to its persistence in processing environments and severe impact on vulnerable populations. Regulatory approaches differ internationally, reflecting distinct conceptual frameworks and tolerance thresholds. These differences arise from the adoption of zero-tolerance or risk-based regulatory models, which define qualitative or quantitative microbiological limits (absence in 25 g or up to 100 cfu/g) based on a product's growth potential, and vary in the extent of environmental monitoring, sampling plans, and verification intensity across jurisdictions. In 2024, the European Union updated its regulatory framework governing the microbiological criteria for L. monocytogenes. Previous requirements were strengthened, responsibility was extended across the supply chain, and a strategic role was assigned to challenge testing carried out by manufacturers. This review examines how the European Union and the United States apply risk assessment principles, challenge testing, predictive modelling, and environmental monitoring to control L. monocytogenes in RTE foods. By integrating epidemiological trends, regulatory criteria, and experimental evidence, key differences in safety objectives, validation procedures, and risk management strategies are highlighted. This review also identifies gaps and opportunities for harmonisation, providing guidance for improved evidence-based decision-making and regulatory compliance.