Rodents, insects and birds are commonly considered food pests. The food industry has a legal duty to keep their premises free of these pests, principally because they carry bacteria that can contaminate food.
It is vital for all food businesses to take steps to prevent pest problems. It is also just as important to have monitoring procedures in place detailing what to do if pests do gain access to the premises.
Windows are one of the most common ways that pests, particularly insects, can gain access to food.
The regulations state that:
Waste and refuse
Food businesses must make adequate provisions for the removal and storage of food waste and other refuse. In particular refuse stores must guard against access by pests and contamination of non-waste food. Storing refuse in a cupboard area sealed against pest access can do this.
Catering businesses should not accept raw materials and ingredients if they are known or suspected to be contaminated with parasites, bacteria or foreign substances which would make the food unfit for human consumption. In order to comply with this provision, food businesses are encouraged to make routine checks on deliveries of food.
Types of pests
Rats and mice are the most common form of rodent. They carry bacteria and will readily feed on food intended for human consumption.
The house mouse is the most common rodent pest in Britain. The main problem is the frequency with which it breeds. Providing a food source is available, the female mouse will produce litters of up to sixteen young every three weeks.
Mortality rates run high but there is still the potential for premises to get a serious infestation of mice in a matter of weeks.
Incoming goods and delivery vehicles need to be constantly inspected as mice can often be found to have made nests in the packaging. Rodents can squeeze into gaps as small as 1cm so any gaps in the outer walls of the property can let them in. It is essential, therefore, that all food businesses have high standards of maintenance to prevent the entry of rodents, and also to restrict their movements within the building by protecting pipes and wall cavities.
An infestation of rodents can be tackled using various treatments such as traps and poisons. However, treatments should only be carried out by trained pest control technicians due to the high level of volatility and danger involved.
The importance of prevention rather than cure cannot be overemphasised. Simple measures like preventing the accumulation of waste, sealing gaps in the outer fabric of the building, installing wire meshes over openings and sealing gaps under doors will be the most effective at preventing rodents getting in.
Flies and wasps
A variety of insects are considered to be food pests, but flies are the worst. They carry bacteria and contaminate food by landing on food and food surfaces and transferring bacteria from their legs and body.
Flies live, eat and breed on faeces. Drains, gulleys and refuse areas need to be regularly cleaned with high pressure hoses. Insect screens over windows and doors can be highly effective as can ultraviolet electrocution units which lure the flying insects towards a high voltage electric grid, but care must be taken to ensure that their eggs and dead bodies do not fall onto any food.
Wasps are a nuisance as they can worry employees as well as carry bacteria. If a wasp nest is located, the local environmental health department should be notified and they will send out a professional exterminator. A single nest can house up to 30,000 wasps.
Cockroaches also carry a variety of bacteria and easily contaminate food with their faeces and dead bodies. Food businesses often use sticky traps to detect early signs of infestation.
Cockroaches are nocturnal insects, preferring dark and warm crevices. The traps should be left overnight in places where cockroaches may walk over the surface. They have voracious appetites and will be attracted to any organic material. They carry not only bacteria, but also viruses, protozoa and fungi and have been implicated in a wide range of diseases that can be transmitted to man.
The problem is that as cockroaches can squeeze through the smallest of gaps, it can be immensely difficult to protect against entry by these pests. They are very difficult to eradicate and professional treatment will almost certainly be required.
Birds do not necessarily carry pathogens, but they can carry salmonella and camplyobactera. Birds have excellent memory capabilities and once they have located a useful food source, will return frequently and may even seek nesting nearby.
Food businesses should ensure that they take extensive precautions to prevent entry by birds as it is expensive and difficult to remove them once they are inside the building. Exceptional cleanliness and hygiene will ensure that premises are not attractive to them in the first place.