5 Ways to Manage Biofilm in Food Processing Environments

Biofilm is a persistent threat in food processing environments. It is the root cause of 60% of foodborne disease outbreaks. Managing biofilm is a key part of any good food safety plan. Fully removing biofilm from surfaces—not just killing the organisms within the biofilm—is the best way food processing facilities can reduce the risk of resistant pathogen spread and cross-contamination that can lead to product recalls.

A variety of factors make biofilm difficult to manage, but most are related to the construction and population of the biofilm EPS matrix. Most microorganisms produce this house-like structure, which does an excellent job protecting organisms from extreme environmental threats like chemical attack and even extreme temperatures. The following are five key ways to manage biofilm in your processing environment.

1. Hand scrubbing with soap

Sometimes the oldest trick in the book is still the best. Using a good multi-soil soap/detergent will help break down some of the structure, and the mechanical action of scrubbing or turbulent flow can help loosen or remove the biofilm from the surface. With rinsing, the biofilm and organisms within the biofilm are no longer attached to the surface and ideally leave the system.

Seems simple, right? However, there are two major issues with hand scrubbing—labor input and efficacy. Hand scrubbing requires a high degree of manual effort. Combined with other factors, such as lack of sanitary design, it can quickly become impossible to scrub every surface in a facility. Without the necessary mechanical action, biofilms can be left to thrive on machinery, surfaces and parts. When it comes to efficacy, many cleaners are not registered kill agents: they have no kill claims and typically have very limited ability to kill microorganisms. This means without the proper mechanical action to remove the biofilm, the organisms can be left relatively unaffected.

2. High Heat

While biofilm provides insulation and can protect organisms from some extreme temperatures, there are limits to how much the structure, and especially the organisms, can tolerate. Studies have found that sustained temperatures above 265°F for 10 minutes (most standard autoclaving recommendations suggest at least 20 minutes) kills all the biofilm bacteria reliably. (Williams, p 1545) This temperature is obviously high enough that it can be incompatible with some materials and equipment, particularly sensors and electronics. High heat can also pose a safety risk to employees. In addition, this may not do enough to remove the structure fully, which can shorten the recontamination timeline.

3. Chemical Oxidation

Treatment with an oxidizing sanitizer or disinfectant chemistry can be effective on biofilm, but there can be a few issues with using oxidizing chemistry. Broadly speaking, oxidizers fall into one of two categories for how they interact with biofilm:

  1. EPS-Reactive Oxidizers:  These are chemistries like chlorine bleach, iodine and ozone. These chemicals are typically so reactive that they will interact with almost any other material: bacteria, biofilm or even the surface under and around the biofilm. They also lack penetration ability, so they need to “chew through” all the layers of a biofilm to ensure all pathogens are contacted and killed. Reactivity, coupled with potential equipment damage, makes these chemicals a poor first choice for dealing with biofilm.
  2. EPS-Penetrating Oxidizers: These are chemistries such as PAA and chlorine dioxide. These chemistries will pass through the EPS layers into the interior of the structure to kill pathogens within the biofilm. However, they do not have the ability to remove a biofilm from a surface.

4. EPA-registered Biofilm Agents

Luckily, oxidation is not the only mechanism to target biofilm. Sterilex’s PerQuat® technology has EPA approval to not only kill biofilm organisms but also remove biofilm from a surface. The combination of an oxidizer (hydrogen peroxide) and a phase transfer catalyst (quaternary ammonium) allows our patented combination chemistry to penetrate the outer layers of biofilm before releasing the peroxide to work from the inside out on the biofilm and organisms within it. This synergistic approach kills pathogens within the biofilm and removes biofilm from the surface without the need for mechanical action.

5. Maintenance and Prevention

While not a step for directly dealing with biofilm, the maintenance program is a key part of any biofilm management program. Microorganisms in biofilm grow exponentially and can repopulate in as quickly as a few hours if the biofilm is not completely removed from a surface. The best way to fight biofilm is prevent it from ever forming in the first place. Hand scrubbing is incorporated in most sanitation programs, but chemical biofilm removal should be included in all programs to completely protect all of the food processing environment from biofilm.

By following these steps, any food processing plant can keep their processing lines and areas free from biofilm and reduce the risk of product contamination by foodborne pathogens and other harmful organisms.

Williams, D. L., Taylor, N. B., Epperson, R. T., & Rothberg, D. L. (2017). Flash autoclave settings may influence eradication but not presence of well-established biofilms on orthopaedic implant material. Journal of Orthopaedic Research®, 36(5), 1543-1550. doi:10.1002/jor.23764