Fruit flies, meal moths, cockroaches, mice, rats, snakes, birds, and numerous other vermin and insects are just some of the pest control challenges facing the food industry.

Each creature may pose a serious risk to the safety of the food, either by direct infestation or through indirect contamination. Legislation worldwide requires pests to be excluded from food processing plants. Pest control is also one of the prerequisite programs essential to the development of effective Hazard Analysis Critical Control Points (HACCP) systems. Lack of pest activity in a facility is the key indicator of a successful pest control program, but how is the enviable pest free status achieved?

Professional expertise necessary

Professional expertise from a pest control provider must be sought prior to implementing monitoring points if any pest control program is to be successful. These contractors provide an understanding of the biology and ecology of the available pests, as well as methods of exclusion and eradication, and must be licensed and trained. Where part or all of the pest management is conducted in-house, personnel must be appropriately trained, including those responsible for carrying out inspections, determining and applying suitable treatments, and managing the system.

Rather than resorting to a series of temporary solutions for the pest issues, the providers are often exhorted to device permanent ones. In an ideal situation, they should apply principles of integrated pest management (IPM) that have the least impact on the environment and nontarget organisms. An IPM is the combining of appropriate pest control tactics including sanitation, mechanical, cultural, biological, and chemical control into a single plan to reduce pests and their damage to an acceptable level.  

Sanitation key for pest prevention

Proper sanitation is not only essential for prevention, but also an effective way to control and eliminate infestations. Your sanitation schedule should factor in type of pests, different areas of your site and other factors that make it unique. The removal of food and water sources stresses populations, making traps and baits more effective. Oil residues and greases also render many insecticides ineffective. Other forms of sanitation that help prevent pest spread include using pest-free seeds or transplants and decontaminating equipment, animals, and other possible carriers before allowing them to enter a pest-free area or leave an infested area. It is important to design the plant sanitation program so that all cracks, joints, crevices, and hidden surfaces are cleaned and inspected routinely. If this is not done, then buildup occurs, and pests are attracted.

Mechanical control

Mechanical pest control is the management and control of pests using physical means such as traps (mechanical or non-mechanical), barriers (caulking, strips, seals, foam), and mechanical exclusion (screens, bird wire, strip curtains). It also involves using air currents and manipulation of environmental factors (temperature, humidity). Typical traps are designed to allow the pest to enter and be detained or to feed on a tainted food substance and return to its habitat. The most common mechanical rodent catching traps are the low-profile Tin Cat and Ketchalls. Non-mechanical insect control involves using either Vectors; wall stations that utilize a blue light to attract insects to a glue board or Insectocutors; wall units that utilize a blue light to attract insects and then electrocute them when they come in contact with an electrically charged set of metal rods. Insectocutors should be located in areas where there are no open food products or packaging while Vectors should be located in the more sensitive areas.

Barriers, usually of a pliable material, foam, or strip material, fill door–floor, wall–floor, and other joints. Rubber strips fill other oddly shaped holes and cracks. Canned foam is a unique addition to the pest control applicator’s arsenal. Found at most local hardware stores, canned foam can be sprayed into any opening and, when released from the pressure, expands to many times its initial size, thus filling the hole or crack. Mark Clute, a Food Management Specialist and author of Food Industry Quality Control Systems, advises in his book that this product should not be used as a permanent maintenance tool or as a temporary tool for filling cracks or holes leading to the outside. Plastic strip curtains is another barrier that can be used to create “compartments” within the facility. They help to prevent the unencumbered roaming of pests throughout the facility since they act as semi-permanent doors.

In conjunction with the Ketch-alls located in the interior of the facility, Clute adds that the company must establish an 18-inch barrier between the wall and any racking or other materials. This barrier should be painted white to allow the pest control inspector to see rodent droppings easily. At 18 inches, the barrier is wide enough for inspectors to have easy access for traveling between the traps as well as access to the back of pallets for inspection and inventory purposes. All exterior and interior walls should have this barrier.

Both the contract pest control provider and the company should be involved in determining the location of the rodent traps, bait stations, and insect-attracting units.

In conjunction with the Ketch-alls located in the interior of the facility, the company must establish an 18-inch barrier between the wall and any racking or other materials.

Mark Clute – Food Management Specialist


Cultural control

Cultural controls are generally the cheapest of all control measures because they usually only require modifications to normal production practices. This involves changing the habits or behaviors of employees and visitors. Too often, visitors who come to the plant—whether seasoned food products professionals, first time visitors or, even company employees—have a varying degree of pest control knowledge. This disparity can often lead to routes of pest entry through open doors, dropped food, or poor cleaning practices. One way to prevent this contamination is to institute programs and procedures for visitors and employees to follow that assist in the exclusion of pests and change the cleaning schedules to prevent waste buildups. These procedures should be part of the good manufacturing process (GMP) rules that employees and visitors sign.

Biological control

These methods utilize living organisms or their byproducts to control pests. This includes the use of parasitic wasps for fly control, bacteria-based products for fruit fly control, and pheromone traps for insect collection and identification. These are complicated strategies for control of pests and generally should be left to licensed professionals.

Chemical control

Chemical control is based on substances, i.e., pesticides, that are toxic (poisonous) to the pests involved. The pest control industry’s continued commitment to research and development has spawned a new generation of products that are low dose, highly effective and environmentally safe for use in food processing establishments. However, rarely does any pesticide kill all the target pests. Some pests are even resistant to the pesticides and may pass along these resistance traits to their offspring. This can be caused by repetitive use of the same pesticide in the same place against the same pest. As such, rotating pesticides may help reduce the development of pest resistance.

It is nevertheless important to note that not every pesticide failure is caused by pest resistance. Applying the wrong pesticide, dosage and application method can all lead to failure. Other applications fail because the pesticide was not applied at an appropriate time – the pest may not have been in the area during the application or it may have been in a life cycle stage or location where it was not susceptible to the pesticide. Also reminisce that the pests that are present may be part of a new infestation that developed after the chemical was applied.

Evaluating a pest control provider

Just like any other service, when selecting a pest control provider, one should look for quality and value. Depending on the facility’s size, type of pests, and the knowledge level of the quality control manager, the contract pest control provider should provide any and/or all of the following services: plan development, plan implementation, periodic evaluation, accurate record keeping, and pest elimination. Hiring a contract pest control provider involves requesting proposals from local providers. Before hiring the contract pest control provider, each prospective company should be interviewed and a proposal received that outlines the type of program, its validation procedures and timelines, and initial and ongoing costs associated with the program.

In anticipation of the proposal, Clute recommends an initial meeting to discuss the proposed program and evaluate the facility. This involves inspecting the facility and any specific areas of concern, preparing a basic diagram of the facility for use in preparing the proposal, determining the state of the current pest control program, if any. The provider should also interview the quality control manager to determine the level of involvement the company will have during the development and implementation phase.

The responsibility for the program’s development, implementation, and enforcement rests on the back of both parties. After implementation, the company should conduct weekly or bimonthly inspection while the provider should offer a periodic service, most preferably on a monthly basis.

Program documentation

In spite of proper documentation of pest management programs being a top priority for many food processing facilities, it can inadvertently be neglected during busy, high-stress situations. Being a tool used by auditors to verify pest control claims, the lack thereof can lead to harsh penalties being meted to the facility. A food processing facility’s documentation must show that a pest management program is in place, to intervene and eliminate pest threats and describe the pest issue and what the response was to the issue. It should also document the effectiveness of the response and that the risk to the facility has been mitigated.

All in all, care must be taken never to sacrifice food safety when choosing the proper pest control measures.

This feature appeared in the May/June 2022 issue of Food Safety Africa. You can read the magazine HERE