EURL Lm Technical Guidance Document on challenge tests and durability studies for assessing shelf-life of ready-to-eat foods related to Listeria monocytogenes

Contact person: eurl-listeria@anses.fr

This document is the fourth version of the European Union Reference Laboratory for Listeria monocytogenes (EURL Lm) Technical Guidance Document (TGD) on challenge tests and durability studies for assessing shelf-life of ready-to-eat foods for Listeria monocytogenes. It replaces the third version of 6 June 2014 – Amendment 1 of 21 February 2019. The fourth version of the TGD was prepared by EURL Lm together with a working group of six NRLs Lm and was approved by the Standing Committee on Plants, Animals, Food and Feed on 1 July 2021.

The first version of this TGD (2008) was prepared at the request of the Directorate General Health & Consumers (DG SANCO) of the European Commission (EC) in response to the needs expressed by EU Member States to have a document providing both detailed and practical information on how to conduct shelf-life studies on Listeria monocytogenes (Lm) in ready-to-eat (RTE) foods to ensure compliance to the microbiological criteria set out in Article 3(2) of Regulation (EC) No 2073/2005.

The purpose of this revision is to ensure consistency between the EURL Lm TGD and the standard EN ISO 20976-1 on "Requirements and guidelines for conducting challenge tests of food and feed products - Part 1: challenge tests to study the growth potential, lag time and maximum growth rate" published in 2019.

The EURL Lm TGD should be read in conjunction with EN ISO 20976-1 and be considered a supplementary document to the standard. This document remains complementary to the DG SANTE document, entitled “Guidance document on Listeria monocytogenes monitoring shelf-life studies for ready-to-eat foods, under Regulation (EC) No. 2073/2005 of 15 November 2005 on microbiological criteria for foodstuffs”.

An amendment to this fourth version has been prepared by the EURL Lm and published in February 2026.

The purpose of this amendment is to update the reference to the new version of the DG SANTE Guidance document, published in December 2025. In addition, the Annex on the recommended EURL Lm set of strains has been deleted and replaced by a reference to the appropriate dedicated report on this topic. The formula in section 6.2.2.7 has been corrected. Identified typographical mistakes have been fixed or clarified.