Originally, food business operators (FBOs) were only required to ensure that L. monocytogenes is undetectable in 25 grams (g) of RTE foods before the food left the immediate control of the manufacturing facility, in cases where the producer is unable to demonstrate that the level of L. monocytogenes will not exceed the limit of 100 colony forming units (CFU)/g throughout the shelf life of the foods concerned. Now, this responsibility is expanded to all situations where RTE foods that may support the growth of L. monocytogenes beyond 100 CFU/g are placed on the market throughout their shelf life.

The recently published revised guidance document provides new information to FBOs about the evaluation of whether a RTE supports the growth of L. monocytogenes, and if the new criteria apply to their situation. It also provides guidance on shelf-life studies to demonstrate their foods comply with the criteria, including the selection, execution, validation, verification, and documentation of such studies. Information about environmental monitoring and food product testing are also included.

The document may also assist competent authorities when performing official controls and third parties in the development of shelf-life studies.