Wednesday, January 30, 2019

Contamination Control in Deli Production Facilities

When it comes to sanitizing an entire production area with equipment, machinery, 30-foot ceilings, HVAC ducting, and a myriad of other obstacles, physically spraying chemicals onto everything without missing a spot becomes an impossible task. All antimicrobial agents have a certain concentration and required contact time in order to guarantee kill, and with liquids, it’s hard to assure every single organism has been contacted for the appropriate amount of time. Some liquids can also be harsh on equipment and require a post-decontamination rinse. Mists, fogs, and vapors are composed of large molecules which can stick to surfaces preventing penetration of extremely small openings like scratches. Cracks, pipe and screw threads will not be completely decontaminated. Using gaseous chlorine dioxide or ultraviolet light disinfection, these stresses are all eliminated.

Room Decontamination with Chlorine Dioxide Gas
Chlorine dioxide is a true gas at room temperature, so it will fill its container evenly and completely like oxygen in the air, no matter how small or large a volume is being treated. With a molecule size of 0.124nm, CD gas can get inside machinery or equipment that would be difficult or impossible with liquids or vapors, simply because it is such a small molecule.  Coupled with its gaseous state, this means it will contact every surface, penetrate into every crack, all equipment, ductwork and any other place that might harbor micro-organisms.. Gaseous CD is the only decontaminating fumigant that penetrates water, decontaminating both the water and the surface beneath. Being a completely residue free process enables CD gas to be used safely on food contact surfaces as no additional cleaning needs to be performed. In addition to the production or packaging areas, a “Decon Room” can be created where portable equipment, supplies, tools, etc. can be rolled in and completely decontaminated.

Surface Disinfection with UV-C
Daily sanitization of a workspace is the most effective method to reduce the risk of contamination. Quaternary sanitizers are commonly used in wipe-downs, but most liquids require a longer contact time than a wipe-down can guarantee, meaning dangerous microbes can survive. Ultraviolet light, specifically UV-C, is a particularly useful tool in combating these unexpected surface organisms. UV-C is a chemical-free technology which ensures a complete surface disinfection in mere minutes. It works by emitting light at the 254nm wavelength, which inactivates the DNA of cells, rendering them effectively dead. UV does not cause any kind of harm to surfaces or inorganic materials, meaning equipment is safe all the way through the cycle. UV cycles are quick and inexpensive with cycle ranging between one and ten minutes and costing just pennies to operate. Whether the intent is to disinfect an entire kitchen, specific surfaces, or tools/supplies, UV has the ability to meet your needs.

Case Study: UV-C Treatment of Cutting Boards
The University of Guelph studied the effect that the UV-C has on Salmonella typhimurium inoculated on plastic cutting boards (unscratched and scratched). The surfaces were incubated for 0 hours, 1 hour, and 24 hours at room temperature. After incubation, the cutting boards were then exposed for 1 minute and 5 minutes to UV-C light from our Lantern UV-C device. For Salmonella typhimurium inoculated on unscratched cutting boards, there was a >5-log reduction when exposed to 5 minutes and about 3-log reduction when exposed for 1 minute at all incubation times. For scratched plastic, there was a >5-log reduction at 0 hours and 24-hour incubation time, and a 3-log reduction at 1 hour incubation time. For a 1-minute exposure, there was a 2-log reduction for 0 hours and 1 hour incubation time and a 4-log for a 24 hour incubation time. Current testing is being done using similar parameters for Listeria monocytogenes.

For more information on this utilization of chlorine dioxide gas and ultraviolet light disinfection, read our application note. To learn more about improving food safety and sanitation from a variety of perspectives, check out the 3rd Annual Food Safety & Microbiology Conference February 24-27, 2019 in Atlanta.