Recently, I had the opportunity to sit down with Cliff Coles, president for over 20 years of Clifford M. Coles Food Safety Consulting, Inc., to discuss the topic of what makes an effective environmental program. Here’s how the conversation went:
Richard Stier: Should every company put together a hygiene monitoring program? Why or why not?
Cliff Coles: A hygiene monitoring program should reflect the risk assessment on the product being made. Certainly, a ready-to-eat product such as a salad or a cold-cut sandwich should and would have a more in-depth significance, whereas a beverage facility producing shelf-stable juices would be concerned with economic spoilage organisms, such as yeast, molds, and perhaps Lactobacillus or Alicyclobacillus. Whatever the case, it becomes the report card that justifies the efforts and dollars being spent by a company to remain in the marketplace. With respect to food safety, keep in mind that regulatory officials do not need to prove that a product is contaminated. They simply need to show that the product is being manufactured in an environment whereby it may become contaminated. This is a big difference, and if a company fails to monitor and control the environment, it could fail the test.
RS: Do you have a preference for the type of tests used?
CC: A company needs to decide how it will set up an environmental swab program. Will the program include Zone 1 swabs (direct food contact surfaces) or Zone 2, Zone 3, and Zone 4 only? Those who choose to include Zone 1 areas may opt for testing for “indicator” organisms, such as coliforms, as their choice over the other options. Several companies have chosen non-specific genetic testing (performance testing) to gauge the effectiveness of the sanitation on Zone 1 and Zone 2 environmental areas.
The options for monitoring an environment are plentiful, each has its own pros and cons, and each can be used to support the other. While plate counts and other counting methods require incubation time and can be cumbersome, counts can be used to determine levels of a specific organism and identify indicator organisms. Adenosine triphosphate (ATP) is a longstanding technique that is sometimes misunderstood. ATP results do not equate to the microbial load on a surface being sampled but do reflect the presence of organic material that can be the source of bacterial contamination, or at least be a food source for bacteria. A word of caution however: If the sanitation chemicals contain phosphates (the “p” being “phosphate” in ATP) and the chemicals are not sufficiently rinsed off of equipment surfaces, then the ATP swab results will naturally be consistently over the action limits that a company has deemed as acceptable.
Allergen swabbing is not a measure of microbial sanitation, but again, if the cleaning for microbial contamination is insufficient it’s pretty much a guarantee that the allergen proteins, if present, will remain. Environmental monitoring has to include the presence of allergens within the facility if allergenic ingredients are used. If gluten is the allergen of concern for example, the monitoring program needs to include ancillary areas of the production zones like walls, overhead structures, air ducts and air filters, and other product contact surfaces on adjacent equipment and in Zones 1 and Zone 2.
RS: If a company gets positives in its hygiene monitoring, what do you suggest as a corrective action?
CC: How a company reacts to a positive should be dictated by where the positive is found. Unless the company is doing ATP swabs, non-specific genetic performance testing, indicator organism swabs, or protein swabs on Zone 1 sites, finding a positive swab implicates finished products, while a Zone 2 or Zone 3 positive may not have a direct impact on the finished product. A Zone 1 positive for a pathogen should at a minimum indicate that the finished products manufactured since the last break-and-clean should be placed on hold.
This also assumes that the company has a hold-and-release program in place. The dilemma some industries face (produce for example), is the shelf life of the product dictates that almost immediately after packaging the product is into distribution—often before results are available. The response to that situation is the company should have a well-founded, extensive sanitation program, environmental monitoring program (EMP), and one heck of a WIP testing program with rapid methods that are: 1) reliable, 2) recognized reliable and applicable to your matrix, and 3) being used effectively to provide the warnings before the product gets out of the control of the company.
FDA has always taken the following approach: You cannot test enough samples to prove the product is not contaminated or test your way out of a problem. This is basically why most companies do not test for the pathogen but rather test for an indicator that does not incriminate the product. Keep in mind that by not testing Zone 1 sites, it doesn’t mean the product does not represent a potential health hazard in the marketplace. Should that product be associated with an illness outbreak, there are severe consequences to:
- Failing to keep the product safe;
- Having a paper trail that indicates you knew, or should have known, there were potential issues associated with the finished product based on the Zone 1 swab result, or lack thereof; and
- Testing the product, finding nothing in the few samples you tested, and assuming that the rest of the “untested” production was acceptable.
Finding a positive environmental swab result, regardless of the Zone, still requires the offending area be cleaned and that subsequent swabs are negative. I will also add that if the remedial actions and result aren’t documented, then you didn’t do them.
The Food Safety Modernization Act (FSMA) has expanded the swab zone to be a 12-inch-by-12-inch area. The increase in size represents an increased potential of finding a positive, and that is exactly the point of any well-designed environmental program. John Butts, PhD, one of the foremost authorities on Listeria and environmental sampling, preaches the Seek and Destroy mission, which is the fundamental foundation of every environmental swab program. Seek out the niche places that harbor the offending microorganisms and adjust the sanitation programs and environmental surveillance to destroy that harborage. FDA expects:
- A positive environmental swab to be attacked and eliminated;
- Negative results for a minimum of three consecutive swabs be conducted on separate dates;
- That the once-positive site be monitored and continually swabbed for at least six months; and
- Documentation, documentation, documentation!
Positive environmental swab results are telling you something, and you need to listen. A positive result in a drain that is cross connected to other drains tells you all the drains are potentially positive, and cleaning that one single positive in no way ensures you’ve eliminated the source of the problem. Establish the fact that you have a drain cleaning program and use things like quaternary-containing socks or appropriate biocides throughout the production day to minimize the chances that aerosolization of the drain water is not allowing pathogens to become airborne. Having a intermittently positive drain may also indicate that your cast iron drain pipe is harboring a biofilm and continuing to put chlorine and other harsh chemicals down the drain in an attempt to eliminate the problem is actually making it worse.
The corrective action to consider is to isolate the entire drain area with floor-to-ceiling polyethylene and sandblast the corrosion off the inside of the drain. Once the drain is again smooth, a metal epoxy coat should be applied to the inside of the drain to prevent further rust development and/or pitting. Consider inserting a cleanable, stainless steel insert that extends significantly down into the drains.
Many companies will expand the swab site following a positive environmental sample. This vectoring-out concept will keep reaching further away from the initial positive until the positive detections are no longer found. In many cases, this can be several feet to several yards from that original finding, but this is the definition of Seek and Destroy.
One effective tool in eliminating pathogens is the use of silver ion-containing compounds. I find PURE Bioscience is helpful in eliminating Listeria and Salmonella from environmental niches.
RS: Should companies routinely do air testing of any sort? Do you have suggestions for the best means to do so?
CC: Air testing should be an integral part of an effective environmental program. All air sampling programs should include a sample of the environmental air outside the facility as a baseline. Granted, it will vary day to day and season to season, but when it is done in conjunction with the samples being taken in the production area, it will give a perspective as to how effective the air filtration system is.
Similar to the swab results, air sampling is telling you something. If you investigate, you might find the excessive counts in the facility in comparison to outside air indicate that the PM for changing filters is not occurring at the frequency the plan requires. Maybe there is a tear in the filters or there are no filters; I encountered both situations during plant visits to determine the high rate of mold contamination of finished products. The air sample program also indicated that access doors directly across from the filling lines were left open far too long or too often, and the dust and debris from a neighboring non-food manufacturer were infiltrating into the food plant’s production areas.
The very best method for air sampling is to purchase equipment that actually pulls definable volumes of air into the unit and impinges the targeted microorganisms onto differential growth media. The results can be expressed as count per “X” liters of air or converted to counts per cubic foot.
Many companies continue to rely on air exposure plates. While it can be a reasonable indicator of air quality, realize the downside to the method is that results are obtained only when a random spore or microbe happens to settle on the open plate of growth media. Not very scientific, but if the plates are exposed in areas of high pedestrian or vehicular traffic, or directly under an air exhaust vent, the data can still be valuable and indicative of a need to initiate corrective actions.
RS: What steps should companies take to develop an EMP? Should they do it in-house or go outside?
CC: The steps companies need to take before designing the EMP start with a comprehensive risk assessment of the process, the raw materials being used, the product being manufactured, and an assessment as to whether the “category” of the product has been recalled or implicated in a foodborne outbreak. The entire management team needs to be on board with the program, the implications, the responsibilities of each department, and the fact that FSMA requires the environment be monitored. This is not just another “Oh there goes QC again!” program. A proactive environmental program requires every level of management from the very top down to be engaged in the goals and execution of a sound EMP. It is also not a bad time to engage the corporate or outside legal counsel with the intent of the program and how Zone 1 swabs are handled or not conducted at all.
Does the process have a kill step? Should it and could it have a kill step? Does it have something that could be or should be a kill step? Blanching might be considered a reduction step or in some corners a kill step. If you are applying a heat step to the product and the product still contains pathogens, there’s a problem. You have re-contaminated the product through the environment, unclean equipment, handling practices, or whatever. If the product is manufactured under conditions whereby it may become contaminated, FDA and other regulatory agencies will hold you accountable.
Getting a qualified consultant in to provide onsite assistance in evaluating the program and suggesting improvements or even deletions to a program can be a valuable tool. It has always been my opinion that the program belongs to the company and the company must be responsible for executing the EMP. It is not something to pass off to a third party. It is imperative the company understands and completely owns the program.
Stier, industry editor for Food Quality & Safety, is a consulting food scientist with international experience in HACCP, plant sanitation, quality systems, process optimization, GMP compliance, and food microbiology. Reach him at firstname.lastname@example.org.