Oct. 10, 2011
by Kimberlie Clyma
Pests are unavoidable in food processing facilities, but proper monitoring, sanitation and control techniques can help stop pests from causing contamination and possible disease. An effective pest-control program begins with an understanding of potential pests, their feeding habits, where and how they live and various safe and effective methods of controlling and eliminating them. If a pest-control specialist is not hired to control pests in the food plant, then a specific employee should be trained and held responsible for pest-control management.
The most common pests in food processing facilities are cockroaches, insects- including flies, ants and beetles- rodents and birds.
Roaches are the most common pests in food processing plants and foodservice facilities around the world. Controlling them is extremely important because they can transmit diseases and foodborne pathogens such as Salmonella, Staphylococcus aureus, Vibrio cholerae, and others. The three most-common species in the US are the German cockroach, Oriental cockroach and American cockroach.
Cockroaches can be found in any location where food is being processed, stored, prepared or served. They tend to hide in dark, warm, hard-to-clean areas. They are a year-round pest, so control should be an ongoing process.
Roaches can be controlled by eliminating cardboard boxes where they often live; filling and sealing structural cracks and crevices; maintaining sealed, smooth surfaces throughout the plant; and by using pesticides approved for use in food plants.
Flies are the most common insect in foodservice and food processing facilities, especially the house fly and fruit fly. It’s been estimated that a single fly carries more than 3.5 million bacteria. Other insect pests include ants, beetles, moths, silverfish and firebrats.
To control both house and fruit flies, remove and eliminate breeding areas; control garbage storage (outdoor garbage storage should be as far away from entryways as possible); and use electrocution traps. Ants, beetles and moths can survive on very small amounts of food, so good housekeeping and proper storage of food and supplies are essential to help avoid these pests.
Pesticides can be effective in helping to eliminate insects, but they can also be limiting in food plants. Some methods of pesticide application include crack and crevice treatment, aerosol or fumigant application of nonresidual insecticides and baits (insect attracting systems combined with an insecticide).
If there is a particular infestation of a particular insect, a systematic inspection and surveillance of the pests should be established. Monitoring needs to be done to ensure that the pest control method being used is actually effective.
Rodents, such as rats and mice, are difficult to control because they have highly developed senses of hearing, touch and smell. But it is crucial to eliminate any infestation of these pests because they not only carry disease but can also cause economic loss by contaminating and consuming food.
Because rats and mice are nocturnal, the presence of an infestation isn’t always immediately detected. Looking for fecal droppings is one of the best methods of detecting their presence. Plant workers should also be on the lookout for tracks, signs of gnawing, urine stains and the sounds of scratching or scurrying.
The most effective method of rodent control is proper sanitation. Eliminating entrances to shelter and removing debris that can nourish these pests will make survival difficult and will force them to migrate to a new location. The best way to rodent proof an establishment is by eliminating any possible entrances. Vents, drains and windows should be covered with screens; masonry around buildings should be repaired; and fan openings and other potential entrances should be blocked.
Another method of control is through the elimination of rodent shelters. Crowded storage rooms can provide sheltered areas for rodents to build nests and reproduce. And areas where garbage and refuse are located can also be homes to rodents. The proper storage of food in tightly sealed containers, as well as immediate and thorough cleaning of any spills, will help eliminate food sources for rodents.
The most effective methods of eliminating rodents, aside from sanitation techniques and eliminating points of entry, include poisoning, gassing, trapping and the use of ultrasonic devices.
Birds, such as pigeons, sparrows and starlings, can present problems in food facilities. Bird droppings can carry diseases, and the birds themselves can carry insects or microorganisms than can cause disease. Proper management and sanitation can greatly reduce a bird population – if food sources are eliminated and entry points reduced, the bird infestation can easily be controlled. In addition, traps, electric wires and netting can also be used to help reduce a bird infestation.
If pesticides are necessary to control or eliminate pests in a food facility, the following precautions should be taken:
• Insecticides should not be used in a food plant during the hours of operation.
• Precautions should be taken to ensure against splattering or drift of the insecticide out of the treatment area.
• Pesticide containers should be properly identified and labeled.
• Instructions should be followed when using pesticides. An insecticide for one pest may not eliminate others.
• Use the weakest concentration possible to destroy the pest.
• Oil-based and water-based sprays should be used in appropriate locations. Oil and water could cause damage to equipment.
• Protective clothing should always be worn during application and hands should always be washed after. And, prolonged exposure to the chemicals should be avoided.
• If accidental poisoning occurs, a physician should be called immediately.
Chemical pesticides should not be considered a substitution for proper and effective sanitation – thorough sanitary practices are more economical and effective than pesticides. Pesticides will help eliminate pests temporarily, but if unsanitary conditions remain in the facility, they will return.