Managing Listeria by Cleaning and Disinfection: Experiences from Food Processing Industries and from Manufacturers of Cleaning and Disinfection Agents

Effective cleaning and disinfection (C&D) are crucial to control Listeria monocytogenes in the food processing environments (FPE). There is a lack of studies examining the effect of C&D agents and practices in the FPE. The aim of the present study was to collect practical experiences from food processing facilities and compare them with the guidelines for control of L. monocytogenes. The experiences of 130 food processors from 15 countries were collected by a web-based survey, and 12 manufacturers of C&D agents from six countries were interviewed. Most of the food processors (64%) reported detection of Listeria spp. in their FPE at least once in the last five years, with 13% reporting repeated detection in the same sampling location for a period of over three months. Alkaline cleaning agents (72%) and disinfectants based on peracetic acid (48%) or quaternary ammonium compounds (QAC; 36%) were the most used products. Large variations were found in the composition of C&D agents, both regarding additives and the concentrations of biocidal agents. For drains and floors, changing C&D practices (frequency, concentration, exposure time) was reported to eliminate reoccurring L. monocytogenes by 12 out of 27 respondents. For equipment, upgrading or replacing parts was reported successful by 6 out of 20 respondents. No association was found between the active ingredient in C&D agents used and the elimination of Listeria spp.. Industry guidelines should be kept updated to support hygiene best practice and stricter requirements for environmentally friendly and low-toxicity C&D agents.