Cockroach Control in Food Processing Areas

Quality Assurance photo illustration


The pest control industry is fairly successful at controlling cockroaches. But the tools that make managing infestations easier in some areas — gel baits, sprays or anything that leaves residual traces — present a challenge for food processing or food packaging areas, where traditional pest control approaches are highly restricted by regulations. Combined with the fact that such areas are often large and complex, as well as often being humid, wet or dusty (baking or pet food facilities), it’s easy to feel overwhelmed when a cockroach infestation appears.

Food processing areas typically have a lot of specialized equipment designed for the food product being manufactured. Equipment ranges from vats, cookers and ovens, to sifters and conveyors, not to mention the varying arrays of pipes and conduits found in these spaces. Floors may be concrete or tiled and walls are commonly hollow block or may be protected by tile or steel sheeting. Moisture is usually present and cleaning is often done using water hoses.

The constant moisture and food availability makes food processing a perfect environment for cockroach populations of varying sizes. Differing levels of building maintenance also contributes to the difficulty in controlling cockroaches.

Although German cockroaches are the usual target pest in food processing, American and oriental cockroaches can also be serious pests, particularly in older buildings. German cockroaches are usually carried in via incoming supplies, but larger cockroach species may be inhabiting drain lines leading to infested sanitary sewers on the property or, in rare cases, beneath slab floors where soil has subsided from the bottom of the slab. Here are a few ways to help control the pests.

Written Pest Management Plan. Treatments for cockroaches in production and processing areas in a food manufacturing facility should be restricted to the procedures and details in the written pest management plan for the facility. Meat packing and poultry facilities supervised by the Department of Agriculture may have additional restrictions as to which products and procedures may be allowed in the facility based on the decisions of the inspector-in-charge.

If the facility has a third-party auditing agency, its particular treatment guidelines will need to be incorporated into the overall plan. Alternative treatments to deal with a specific infestation where the approved written procedures are not successful should be submitted in writing and approved by facility management.

Treatment Restrictions. Application of residual insecticides in food processing areas are restricted to cracks and voids only. Sealing of cracks following treatment may be required in the written pest management plan. Exposed surfaces and equipment will typically be cleaned following a pest control service, so any spot treatments even allowed by label directions will be removed. The amount of heat and moisture present have an effect on the residual life of insecticide treatments, making them less effective.

Service Timing. Since your processing area cannot be in operation during a pest control service, look to schedule treatments on weeknights or during the weekend. Also, try scheduling more comprehensive services during periods of shutdown, such as when heavy maintenance is being done.

Don’t be afraid to put in a call for emergency service if pest activity peaks, but be prepared to shut down that portion of your facility.

At any rate, make sure service times and frequency are detailed in the written pest management plan.

What You Need To Know About That Cockroach Infestation

Bayer’s Alex Ko fills us in on a common cockroach species and how to manage them.
By Jason Brill

Understanding your foe is half the battle. For example, German cockroaches — one of the most common species found in food manufacturing facilities and food storage warehouses — are travelers, according to entomologist Alex Ko, a product development manager at Bayer. “They have quite an impressive range,” Ko said. “[In one study], researchers placed food around an Olympic-sized swimming pool and wanted to know whether or not cockroaches released in the middle would be willing to visit all the food at all of the edges of the swimming pool. And they did.”

Ko says German cockroaches represent a significant challenge for a number of reasons. First, their reproductive potential. Given the right environmental conditions, populations can grow exponentially once they become established in food processing facilities. Second, they’re “incredibly adaptable” creatures capable of developing insecticide resistance within just a few generations. Third, their small size provides access to cracks and crevices and complex food processing equipment, making them difficult to control. “They’re just very impressive creatures,” he says.

Ko filled us in on more info we should know about the pestiferous little invaders.

Q. What’s the biggest mistake that someone can make when trying to control German cockroaches?

A. Because the population tends to grow exponentially, you really have to take care of the problem as soon as you encounter it. If you allow the population to grow too large, it becomes very difficult and very expensive to manage. Once you have some indication, some piece of evidence that you’ve got a German cockroach infestation, your best bet is what I call the kitchen sink approach, which is throw everything at them. So, you’re employing spray insecticides, cockroach baits, [and] sticky traps that monitor cockroaches.

Q. How can sticky traps help monitor the infestation?

A. These monitoring devices are immensely helpful if you know how to read them. For instance, if you have a sticky trap and you are collecting a lot of adult males, [they] tend to forage pretty long distances. So, you know that maybe you’re a little farther away from the main source of the population. But if you look at your sticky trap and you’re collecting small nymphs, these are the developing stages, or adult females, then you know that you’re getting close because these cockroach stages don’t typically forage that far [from their harborage sites]. The adult males tend to have a tapered abdomen. Whereas the adult female’s abdomen tends to be more rounded.

Inspection and Evaluation. If your food processing area is on the larger side or portioned into separate rooms, keep an eye out for pockets of cockroaches that may be scattered around the area. While the larger area makes them more time-consuming to find, interviewing employees to have them point out where cockroaches have been seen is helpful in targeting inspections.

Keep track of where cockroaches have regularly been an issue and be prepared to open up equipment to allow for more careful inspection of areas where cockroaches may be hidden.

If you’re seeing continued, regular activity, analyze the area to determine if any underlying factor (i.e., cockroaches being brought on incoming supplies) is occurring, active harborages are being overlooked (i.e., high above floor level, wall voids) or a deeply hidden pocket of cockroaches may be present (i.e., under a slab or double walls in an older facility).

Use pyrethrins-based aerosols to chase hidden cockroaches into the open, then follow with a pest control vacuum to remove as many as possible as they are discovered and flushed from harborages. Physical removal provides immediate population reduction and results.

Meanwhile, sites where many cockroaches are found should be investigated more thoroughly. And if you’re still seeing increased activity, use the flushing and vacuuming process once or twice a week to ensure the infestation is eliminated more quickly.

Residual Treatments. Remember, best practice is keeping applications restricted to crack, crevice and void treatments only. After application of residual products, treated cracks are typically required to be sealed.

Voids in walls may harbor cockroaches and require treatment using a residual dust product. Installation of plastic wall tubes with caps that allow sealing of the opening can be used when future re-treatments of voids is expected or desired.

Baits labeled for food processing areas may also be used but applied only into cracks and voids, following label directions.

Persistence and Focused Treatments. No easy answers exist for dealing with cockroaches in food processing facilities — just persistence in examining all potential harborages and then focusing treatments on the sites with activity. Whether you’re calling in pest professionals or not, you need to be methodical, starting at one corner and working around and behind all equipment and wall areas. Even the smallest crack may harbor a handful of cockroaches, so when a pocket of them is found, every crack needs examination. Follow-up services may need to be done within a day or two, or weekly, depending on the sensitivity of the situation and/or the numbers of cockroaches found.

The author is owner of Stoy Pest Consulting and one of the country’s leading urban entomologists and an author of several books.

Practical Examples

Each situation and facility is different and may require a specialized approach based on the needs of the facility and the findings of the service, but the following real-world examples from Stoy Pest Consulting’s Stoy A. Hedges involve solving infestations of cockroaches in food-handling environments.

Case No. 1: An infestation of German cockroaches in one Florida facility was traced to expansion joints near equipment where cockroaches were seen by facility employees. The pest professional had repeatedly flushed and inspected the equipment without finding cockroaches. My inspection was focused on looking at areas he was overlooking, which led me to flush expansion joints in the floor and thus discover cockroaches. These joints in the slab were treated with a residual insecticide and then immediately closed off with a sealant by the facility maintenance department.

Case No. 2: German cockroaches were being seen in a spice storeroom adjacent to the main processing area of a bakery in Indiana. All cracks and voids had been repeatedly flushed and treated by the pest professional without success in stopping cockroach sightings. My inspection revealed a number of boxes of spices with live cockroaches. These boxes were taken to an outside area where the cockroaches were removed and killed.

Due to these boxes having had cockroaches living within them, the facility considered the food product to be potentially adulterated and made the decision to dispose of the spices rather than use them. I recommended that the facility examine all boxes coming from the supplier upon arrival for cockroaches. If those incoming boxes were found to have cockroaches, then the facility would need to work with the supplier to resolve the issue.

Case No. 3: Sightings of German cockroaches in the office of a small Department of Agriculture-certified meat facility in Tennessee was traced to clipboards hanging on one wall of the office. Some of these clipboards were seldom handled or accessed by employees, and it was in such clipboards that cockroaches were found hiding within the papers.

Case No. 4: A large, multi-story brewing facility in Texas was experiencing American cockroaches on the top floors of the building. Repeated inspections and treatments on these floors revealed a few cockroaches on each service call, but they continued to be found on every subsequent visit.

Upon arrival, I decided that something was clearly being overlooked. Since it was the top floors that were involved, an inspection of the flat roof area above the top floor was warranted. Dozens of cockroaches were flushed from beneath roof flashing and from under and around air conditioning units and other equipment and drains on the roof.

Residual treatments were applied under flashing and to cracks around equipment. Cockroaches chased from harborages were removed by vacuuming. Granular cockroach bait was applied in rodent bait stations spaced at intervals around the roof near where activity was found.

Case No. 5: A chronic oriental cockroach problem was plaguing a dairy processing facility in Illinois. Repeated efforts by various pest control companies had failed to discover the source of the cockroaches. I was asked to look at the situation, and because it was a very old building, I suspected a sub-slab infestation of cockroaches might be involved. With the area of the facility where cockroaches were active shut down for maintenance, a hammer drill was used to drill holes in several locations along expansion joints in the slab floor.

A wire was lowered into the holes to check for soil subsiding from the bottom of the slab, thus revealing a couple of areas with a void underneath the floor. An aerosol generating machine (Actisol) was used to inject an ultra-low volume pyrethrins product under the slab through the drill holes. In a few of these areas, oriental cockroaches started emerging from expansion joints and other cracks in the floor (i.e., around pipes). A compressed air duster was used to apply a residual dust labeled for food processing areas though drill holes where the soil had subsided from the slab creating voids. Rubber drill hole plugs (used for termite treatment) were placed in all holes and then sealed. The facility was advised to have all expansion joints in the area and cracks around pipes entering the floor sealed with a suitable sealant.

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