Pest control – in the food industry
A written pest control programme in all meat and poultry processing facilities, regardless of size, is an essential precondition for food safety.
We all know that pests cannot be present in the food-processing environment and that, to prevent infestation, the food processor must create a proactive programme for stopping pests from posing a threat to the safety and quality of a food item. Yet many processors do not establish a methodical, written pest control programme, as they do not see its validity.
So why should a sanitation programme be in wrting? A written account defines the procedures and responsibilities of a site’s pest control programme, which include planning, implementation and monitoring of the efficiency of the programme by carrying out regular reviews of collected pest data. Moreover, all food safety programmes (HACCP, recall, sanitation, pest) must have validation documentation that certifies that the food safety procedures in place are effective.
An effective written pest control programme can be developed in-house provided the food processor understands the habits and habitats of pests, and how to control them. We will address this issue later in the article. For now, let’s take a look at the points that must be included in a written pest programme.
- Pest control procedures record the detailed activities performed to control each type of pest as well as frequency of action.
- Recordkeeping entails the documentation of each performed activity. These accurate, up-to-date records must include inspection for evidence of pests in each plant area.
- Responsible individuals: The person(s) who are in charge of performing pest control procedures and the supervisor responsible for signing off on recordkeeping must be mentioned.
- Deviation: A deviation has occurred when an allowable limit has been exceeded. For example, intermittently finding a cockroach under a dustbin may be tolerable, but finding many cockroaches would constitute a deviation.
- Corrective measures are written action steps in the plan that will be performed if there is a deviation from the pest control programme.
- Verification and validation include written scientific evidence that the procedures are successful at controlling pests. Verification is also documentation stating visual inspection for evidence of pests.
A pest control programme should start by determining which activities will best control each pest most effectively.
- Inspection (monitoring): Thorough inspection of the entire plant by a pest management specialist to identify pest problem areas and provide a written analysis is highly recommended.
- Physical control: A standard of cleanliness, including regular deep cleaning of premises, must be maintained. In addition, plant layout should take into account restriction of pests from entering the plant and moving from place to place within, i.e. no entrances from outside directly into the processing area and well-positioned doors with adequate seals.
- Mechanical control: These are non-chemical means preventing pest infestations and include sticky and electronic traps.
- Chemical control: Pesticides should be used when necessary and be applied by only trained personnel. Application of controlled pesticides requires certification, and in this instance it may be practical to hire a professional exterminator.
Many small processors acquire the services of private exterminators who provide all the necessary procedures, monitoring and documentation. A pest control contractor must provide records and reports to the processor verifying that the pest control programme employed is efficient. The verification records should include proof of contractor training and certification to apply pesticides in a food-manufacturing environment, and evidence that the pesticides are approved for such use.
Verification is typically done through visual inspection for pests and/or evidence of pests such as cockroaches, flying insects and rodents in the plant or product.
Cockroaches have been shown to transmit diseases including pathogenic food-borne bacteria in the insect’s gut and on its exterior surface. While each species has specific habitat preferences, any species can be found in a food plant building.
Cockroaches will reveal themselves by scurrying into hiding when the lights in a darkened production or storage area are turned on, but they may also be found by inspecting inside electrical boxes, receptacles and control panels, or by looking behind objects and in floor drains. Another common method of driving them out in the open is the usage of flushing gases, which are so highly repellent that a single squirt into a crack or crevice can cause roaches to come pouring out.
Dry powders and dusts, such as boric acid and insecticide powders, take advantage of cockroaches’ habit of preening themselves, but while these, sprays, aerosols and glue traps are good elimination devices, control of cockroaches starts with removal of harbourage.
Incoming packaging, ingredients etc must be inspected and rejected when infested, and all of the locations that can harbour the insects or their eggs must be sealed: structural cracks, electrical boxes, control panels, and openings around conduits and pipes where they pass through walls and ceilings. In fact, a smooth surface must exist throughout the plant in production and non-production areas.
The movement of flies from faecal matter or decaying material to fresh food products, processing equipment and other surfaces provides many opportunities to transmit disease-causing bacteria. A single housefly has been estimated to carry up to 3.6 million bacteria.
Flies must be excluded entirely from entering the food processing facility by air curtains or screens and / or doors that close automatically. The removal and elimination of breeding sites is a key to controlling flies, which need the availability of garbage to survive. Waste disposal areas must therefore be properly maintained and refuse must be located away from doors and removed frequently.
Insecticidal sprays or fogs and electrocution traps are effective in reducing flying insects, but the drawback of the latter is that they literally cause insects to explode, throwing matter into the air. These particles can drift down some distance from the trap, so it is best to place electrocution traps well away from food-handling areas. Sticky strips are a safer alternative in these areas. Dead flies should be removed daily from strips, which should be replaced at least once a week.
Rodents not only carry and transmit disease, but can cause significant economic losses by consuming food, damaging food containers and plant wiring, and contaminating food with droppings. Both rats and mice are primarily nocturnal, but they leave behind several signs of infestation apart from visual sightings. These include droppings, scurrying noises, gnawing, urine stains, tracks in areas coated with talc, chalk or flour, and smudge marks. (Rodents emit oily lipid material from their fur and leave greasy smudges at entry points and frequent travel paths.)
Coating areas around suspected entry points and travel ways with powders can detect footprints and tail marks to identify locations for bait station or trap placement. Tracking powders, placed along rodent travel ways or in burrows, are designed to kill rodents when they groom themselves.
In areas away from food production, traps are a safe and effective method of eradication, but rodents, especially rats, can become trap shy. Glue traps can also be effective, and they may trap cockroaches as well. All traps should be inspected daily. When bait stations are used, they should be inspected once each week.
Again, elimination of harbourage is the most effective way to control rodents, starting with food and water. This includes effective drainage of water, removing all clutter from food and storage areas to eradicate hiding places, and maintaining an open, spotless perimeter around the processing plant to discourage activity.
A mouse can squeeze through the tiniest of holes and, as rats, are adept climbers, which means openings should be located and closed at all levels in the facility. Fill all structural cracks and screening fan and vent openings, and install drain covers.
Roof rodents are especially difficult to control since they typically nest in overhead areas. Solid and liquid baits should be placed in attics or above drop ceilings, and block baits or traps should be attached to rafters, trusses and ledges in open overhead spaces.
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