Purpose: The purpose of the decontamination was to kill the L. monocytogenes that put a halt on production. Listeria is a somewhat common, and very serious problem within cold food processing areas. The facility chose to decontaminate the processing areas with chlorine dioxide gas, a proven sterilant capable of killing L. monocytogenes.
Methods: The chlorine dioxide gas decontamination took place over the course of two days. The first day consisted of the setup of all equipment, and the sealing of all doors and penetrations into the space. Injection lines were brought to various places throughout the facility as were concentration monitoring lines to measure the amount of chlorine dioxide gas in various locations. The second day consisted of the decontamination itself, as well as the removal of all equipment.
Results: The decontamination proved to be a success. Concentration monitoring data showed that all locations within the facility were exposed to the proper dosage required to exhibit a 6-log, sterilization level kill (99.9999% reduction) of all microorganisms including spores. Biological indicators (or spore strips) were placed throughout the facility to prove efficacy as well, with each of those confirming that a sterilization level kill took place. Finally, swab testing confirmed that the production area no longer contained L. monocytogenes as well.
Significance: Aside from the significance given to this issue from the media, and a significant hit to a company’s financials, listeria contamination of cold food processing areas is of major concern to the industry. A method and process to eliminate it is of great significance to those working in those facilities, as listeriosis is a major health issue for consumers if contamination occurs.