Understanding Listeria monocytogenes New Criteria for Ready-to-Eat Foods
The Commission Regulation (EC) No 2073/2005 on microbiological criteria for foods includes food safety guidelines for controlling Listeria monocytogenes in three different ready-to-eat food categories, depending on the intended use (e.g. infant foods, special medical purpose foods) and the characteristics of the food.
Regulation Update: New Limits During Shelf-Life
If L. monocytogenes is capable of growing above 100 cfu/g at any point during the product’s shelf life, then you must ensure it is not detectable in 25 g of the product throughout the entire shelf life. The presence of L. monocytogenes up to 100 cfu/g during shelf life is allowed for some food categories with characteristics, defined in the regulation, as not supporting growth for L. monocytogenes. The same is applicable for food categories in which L. monocytogenes may grow, if the manufacturer can demonstrate that growth will not exceed the limit of 100 cfu/g throughout shelf life. This can be proven by performing challenge tests according to ISO 20976-1:2019 and the technical guidance document for EURL Lm Technical Guidance Document, by using predictive models, or be based on physicochemical characteristics and scientific literature.
For food categories other than those intended for infants and for special medical purposes that can support the growth of L. monocytogenes, the applicable criteria is not detected in 25g. Until now, this criteria has been applicable just before the product left the immediate control of the manufacturer (release criteria). However, to better guarantee public health protection from this major foodborne pathogen, considering its high fatality rate, the criteria has been amended and the criteria “not detected in 25g” will applyto the entire shelf-life of the food. (Regulation UE 2024/2895 applicable from July 1, 2026).
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Industry Impact: What This Means for Manufacturers
With the new criteria, impacted manufacturers of readyto-eat foods must reevaluate the risk of L. monocytogenes to guarantee that the criteria is not only met when the product is released to the market but throughout the entire shelf life. Measures to reduce the risk could include shortening the shelf life or reformulating the physicochemical characteristics. However, it is not always possible to take these more drastic measures for a product. Ideally, the reduction of L. monocytogenes in a finish product could be achieved by improving hygienic conditions in production sites and environments.
According to a 2024 EFSA Scientific Opinion article, L. monocytogenes in the meat, fish and seafood, dairy and fruit and vegetable sectors is identified as one of the bacterial food safety hazards most relevant to public health that are associated with persistence in the food and feed processing environment. This means that foods that have caused outbreaks are typically contaminated from the environment during manufacturing, processing, or packing. To this end, sampling the processing areas and equipment for ready-to-eat foods to detect L. monocytogenes is also mandatory according to Reg. 2073/2005 Article 5.
In addition to the stricter limits established for L. monocytogenes, starting August 2026, isolates associated with or suspected to be associated with an outbreak derived from food, animal, feed, and related environmental samples will be collected by the competent authority to perform Whole Genome Sequencing (WGS). The food safety authority can compare the results obtained with human isolates to better facilitate foodborne outbreak investigations and detection of the source, according to Reg UE 2025/179.
Best Practices: Monitoring Strategies and Contamination Control
Reduction of L. monocytogenes risks in ready-to-eat food starts with a robust environmental monitoring sampling plan.
Sampling programs aim to detect persistent strains and implement corrective actions to avoid recurring contamination by the pathogenic bacteria. Ineffective sampling programs could result in false-negative detection of L. monocytogenes, despite it being present on surfaces — overall providing a false sense of security.
The choice of sampling location(s), areas, and times should be risk-based and on a case-by-case basis. However, guidelines have been developed by the EURL Lm and the network of National Reference Laboratories (NRLs) on L. monocytogenes, covering how and when sampling should be performed on surfaces of ready-to-eat food processing areas in conjunction with international standards (e.g. ISO 18593:2018).
Strategies for environmental monitoring and corrective actions should be defined in the case of positive results. Preventive and corrective actions like sanitation programs, analysis of raw materials and other ingredients, hygienic design of facilities and equipment, and process controls are part of good manufacturing practices to be considered for reduction of L. monocytogenes.
Our Innovative Approach to Help You Combat Listeria
Preventing Listeria contamination requires strict hygiene, regular testing, and robust environmental monitoring programs. Our Augmented Diagnostics approach combines cutting-edge microbial testing technologies, such as Microbiology and Molecular Biology with the latest Genomics and Data Science methodologies. This approach is further enhanced by an innovative mindset and the expertise of industry professionals.
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We can partner together to help tackle your most pressing Listeria challenges. From enhancing your Environmental Monitoring program through digitalization, to conducting contaminant testing, investigating incidents, and optimizing your quality control process — our experts help identify the right solutions for your unique production environment.
