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Guarding Against Pathogens During Production
May 16th 2022

Guarding Against Pathogens During Production


By David Rosenblatt, D.V.M.


A few years back, I was called in to consult on a Salmonella contamination issue at a food ingredient plant. Thankfully, the pathogen contamination was detected by the customer upon routine testing, and no affected products had been released to the market. Sadly, this isn’t always the case.

When I arrived on location, met a very confused and frustrated team of highly capable and dedicated managers who were facing the worst crisis in their company’s history. Their frustration only worsened when, following a few days of intense investigation, they learned that if they’d done a more methodological risk assessment of environmental pathogens, the incident could have been prevented.

My hope is that readers of this blog might consider rethinking their pathogen prevention methodologies, and contribute to a safer food supply chain for humans and animals everywhere.

When I first became involved in food safety, back in the early 1990s, we saw a lot of food safety incidents associated with process failure, e.g., poor pasteurization, acidification, sterilization etc. As HACCP became more and more popular and its effective implementation more widespread towards the new millennium, these cases tapered off and have virtually disappeared. This is because our pathogen reduction process steps are currently under control at our CCPs.

This fortunate trend is, however, concurrent with a rise in incidents associated with pathogens entering our food supply during production. Generally, our success in mitigating environmental pathogen risk is seriously lagging behind our success of eliminating pathogens by controlled processes.

This includes pathogens being introduced by employees, pests, packaging materials, leaky roofs, dirty equipment and more.

For years CCPs were revered, while GMPs were relatively neglected. In 2005 the writers of ISO 22000 rose up to the challenge and introduced PRPs as the new GMPs and the oPRPs as critical control measures to be managed parallel to the good old CCPs, thus enabling us to effectively implement risk-based thinking not only for process risks, but for environmental risks as well.

In 2011 FSMA embraced this novel approach and introduced Preventive Controls, which include the traditional CCPs in a broader framework of food safety preventive measures, including sanitation practices, allergen control practices and supply chain practices, all of which are at least as important as the CCPs and identified using a risk-based approach.

A Strategic Approach

In our company, we approach the threat of pathogenic bacteria entering our food supply with a military state of mind. The pathogens are the invisible enemy, ever striving to wreak havoc, if given the opportunity. It is our duty to develop a strategy, that not only includes effectively killing pathogens, but also preventing them from gaining access to our food and feed.

As with any strategy, it must be implemented tactically. We call our tactical measure for preventing infiltration “CREEP”: Comprehensive Risk Evaluation of Environmental Pathogens.

CREEP focuses on those zones where ready to eat products are exposed to the environment. The process should be carried out as follows:

Mapping: Using a map of the establishment, identify the physical zone where ready to eat food is exposed. That will be your Safe Zone, and it is your responsibility to ensure that the enemy is excluded from this zone.

Border identification: Physically identify all border crossings into the Safe Zone. This includes doors, windows, drains, air vents, access points to water (including fire extinguishing water), gas, steam, etc. If there are any redundant border crossings that can be safely eliminated, get rid of them.

Border patrol: At this point in the evaluation process, we list all potential opportunities for pathogens to cross the border into our Safe Zone. Consider foot traffic, forklift traffic, equipment traffic, waste and waste water, packaging materials, roof leaks, etc. Remember, the World outside of the Safe Zone is contaminated with Listeria monocytogenes, Salmonella, Clostridium perfringens and botulinum, and more. The enemy is lurking everywhere, patiently waiting for an opportunity to infiltrate our food. There is no point in trying to fight this enemy outside of the Safe Zones. They are on our shoes, and our clothes, on our hands, on the dust coating palletized raw and packaging materials and present on all unprocessed goods from vegetable and animal origin.

Of course, many of our PRPs are aimed at minimizing the numbers of pathogens outside of the Safe Zone: employee health policies, supplier approval and ingredient acceptance policies, pest control, good housekeeping and sanitation and more and more. As effective as these may be in supporting our effort, the basic assumption is that the key to managing this threat is managing the access points into the Safe Zone.

Based on the CREEP, which must be risk based, we construct our control measures:

  • Personal hygiene practices – clothes, hair covering, hand washing and sanitizing, shoe management…
  • Forklift entry policies
  • Packaging material stripping and introduction practices
  • Practices for transferring finished goods out of the Safe Zone
  • Water management
  • Liquid and solid waste management
  • Airflow and air quality management
  • Dust control
  • Roof and overhead fixtures maintenance
  • Etc.

Reconnaissance: As in any conflict situation, solid and reliable intelligence is crucial. Remember, these bugs that can destroy lives and your organization are invisible to the naked eye, which is why we must utilize state of the art technology to monitor and identify enemy activity. This is where a robust and risk based environmental sampling plan comes into play. When planning our sampling tactics we must determine methods, locations, frequencies, target organisms, action levels, and more.

Affirmative action: The final tactic included in the overall strategy is taking action to actively kill microorganisms that may have infiltrated our Safe Zone despite all of our abovementioned efforts. A strong and validated sanitation program to be implemented in the Safe Zone for food contact equipment and surfaces and for non-food contact elements is critical. This complements PRPs enforced while working in the Safe Zone, specifically employee behavior (glove practices, prevention of contact with the floor, prohibition of unhygienic practices, etc.).


Following my investigation, we came to the conclusion that the Salmonella had infiltrated the company’s Safe Zone and contaminated the product through a breach in security at a forklift access point. The management team was dumbfounded. They had the feeling that the threat was overwhelming, and that there are infinite contamination possibilities. They feared that in the future, their efforts might again prove to be futile. That fear is unjustified. The most important thing to remember when managing food safety is that nobody is expected to do “everything possible” to protect public health. There is always an additional something we could be doing. The goal is to do “everything necessary”. There will always be a gap between what is necessary and what is possible. This gap is determined by you, with the help of trustworthy professional consultants, and must be based on a thorough risk assessment.

Mérieux NutriSciences offers expert consulting and testing services to help you guard your products from pathogens during production. Our consultants can guide you through the tedious CREEP process and help you manage your Safe Zone and choose the most effective environmental monitoring and sanitation programs.

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