Controlling Cross Contamination: Optimal Use of Doorway Sanitizers

In January, FDA published the first of the Food Safety Modernization Act (FSMA) proposed rules, including those on Preventive Controls (FSMA Section 103) and Standards for Produce Safety (Section 105). Both are expected to significantly impact the industry and elicit a great deal of feedback during the comment periods. In this issue’s Legislative Update (pg. 12), Dr. David Acheson, formerly of the FDA, discusses the two proposed rules in detail, and provides an overview of the key points of the rules, which is included on page 14.

Preventive food safety is, in fact, a core focus of FSMA, with verification and documentation as key components. Throughout the year, we will continue to bring you related news, updates, analyses, and expert recommendations on the rules as they roll out. Additionally, as in the following articles and those throughout the issue, we will continue to feature general ideas for preventive food safety that you can apply in your facility today.

In these articles, the preventive focus is on sanitation management and controlling cross contamination in areas that may not always be top of mind.

Many studies have demonstrated that surfaces in food manufacturing facilities, especially floor areas, can harbor and transmit bacteria and increase the risk of cross contamination. Footwear may act as a vehicle for the transfer of pathogens within production areas. Often food processors institute restricted traffic controls to prevent cross contamination within manufacturing facilities. Sanitizing applications, such as dry-powdered sanitizer and foam-sprayed sanitizing systems are commonly used, footwear-decontamination methods in the industry. These methods provide the advantage of sanitizing other vectors at the same time, such as pallet jacks, forklifts, and carts.

To reduce or eliminate the introduction of pathogens into food manufacturing areas from soiled footwear, forklift wheels, and other equipment, both dry-powdered sanitizers and automated foam-sprayed sanitizing systems are frequently used within the wet-cleaned food processing facilities such as meat and poultry and dairy.

When used appropriately, dry- powdered sanitizer can be very effective against pathogens that are present in the food processing environment. A study conducted by Ceylan (2011) has shown that dry-powdered quaternary (Quat) and hydrogen peroxide (H₂O₂) were not effective against Listeria monocytogenes on clean and/or soiled dry surfaces of floor tiles. However, Quat and H₂O₂ were found to be greatly influenced by moisture levels and required moisture to become effective against L. monocytogenes.

This application is often misused in dry food processing plants, or in locations where there is limited water or moisture available to activate the dry-powdered sanitizer.

Considerations that should be reviewed when using these sanitizers are:

1. Is the application of a dry-powdered sanitizer appropriate for the facility? For example, dry food processing versus wet-cleaned food processing plants.
2. Is the dry-powdered sanitizer appropriately applied to obtain its efficacy in order to eliminate or control the potential pathogens that are present in the environment?
   For example, the dry-powder sanitizer may not be effective in an area where moisture is not available; or, if the leg of packaging equipment has harbored pathogens over time and it is not meant to be wet cleaned, the application of a dry-powdered sanitizer may not be sufficient to eliminate or control the pathogens.
   
    

Automated Foam Spray. The automated foam-sprayed sanitizing system constantly applies a fresh layer of rich foam sanitizer to the floor on a timely or preprogrammed basis. Therefore, it creates an effective barrier to bacteria, while the automatic recycling function ensures the sanitizing foam blanket is reapplied before it has been completely dissipated by traffic movement. Although doorway foam sanitizing systems can be highly effective, it is important to assess that the application is used properly and accordingly so that the system is effective at all times.

Following are a few items to consider when performing an assessment on an automated foam-sprayed sanitizing system:

1. Is the type of chemical appropriate for the facility? For example, alternative chemical(s) may be used to prevent the build-up of pathogen resistance.
2. Is the frequency of foam delivery sufficient to maintain an appropriate level of foam sanitizer on the floor? For example, heavy traffic area(s) should maintain a higher frequency of re-applying sanitizer.
3. Does the foam sanitizer spray the proper distance to cover the entire doorway; and is it delivered evenly so that all traffic is exposed to the appropriate concentration of sanitizer? For example, all wheels of a forklift should be in contact with the applied-foam sanitizer when travelling through. If the width of a doorway is not covered entirely with foam sanitizer, then a second sprayer may be needed.
4. Is the door foam sanitizing system installed in an appropriate location? For example, is it installed too near a drain, so that the foam sanitizer flows into the drain instead of staying in the doorway, thus is being wasted?
5. Is foam sanitizer spraying onto a pool of water? For example, concentration of the foam sanitizer will be diluted if water pools in the area, thus it becomes less effective against bacteria.

Conclusion. It is recommended that an assessment be made in order to understand what would be the most suitable sanitizer to be used in heavy traffic areas, such as a doorway within the food manufacturing facility, to control the activities of pathogens and prevent cross-contamination. Dry-powdered sanitizer, as mentioned above, should be applied in an area where there is water or moisture which allows activation to take place and increase its efficacy against pathogens. The automated foam-sprayed sanitizing system, on the other hand, is considered highly effective, when used sufficiently, to prevent cross-contamination from contaminated footwear and/or equipment. Ultimately, an assessment checklist will be helpful to the food processor when selecting a doorway sanitizer and utilizing the sanitizer optimally to reduce the introduction of pathogens into food manufacturing areas.

Reference: Erdogan Ceylan. Validation of Quaternary Ammonia and Hydrogen Peroxide Powder for Control of Listeria monocytogenes in Ready-to-Eat Meat and Poultry Plants. AMIF Report (2011).