Trading Standards Institute Advice

Pest control in a food business: rodents

This leaflet is for all food businesses involved in catering, selling food, and producing and preparing food, whether you work from business premises or from home .

The rodent problem
Rats and mice can be a serious health risk and can also do serious damage to your business premises and equipment. They can do this by gnawing through wood, plastic and power cables, which helps them to keep their teeth short - this can lead to an electrical failure, costly repair bills and a possible increased risk of fire.

Rat urine may contaminate food and food packaging, and can cause leptospirosis (also known as Weil's disease). This can cause a range of illnesses including mild flu, jaundice, kidney failure, and even death.

Rats and mice carry fleas, mites and ticks as well as bacteria and viruses that can kill, including Salmonella, E. coli, Cryptosporidium, and bacteria that can cause tuberculosis. 

Your staff and customers may have an allergic reaction if rodents are nearby or in your building.

Rats and mice
There are two types of rat in the UK: the brown rat and the black rat.

The adult brown rat (also known as the common rat) weighs up to 500g and has brown fur on its back and grey fur underneath, and its tail is shorter than its head and body. 

The black rat (also known as the ship rat). The black rat (which may be brown) is less-often seen, weighs up to 300g and has hairless ears and a tail that is longer than its head and body put together.

The house mouse is the most common type of mouse found in the UK. It weighs up to 50g and usually has brown or grey fur on its back and light grey fur underneath. Its tail is the same length as its head and body but is thinner than the tail of a young rat. 

The field mouse is often found on agricultural land and fields but may easily get into buildings and food premises.

Signs of Infestation
Rodents leave an ammonia smell in enclosed areas. Mice leave small, dark droppings. Rat droppings are also dark but are 10 to 14mm in length and are tapered. 

You may hear scratching noises as rodents, especially mice, move around behind wall cladding in ceiling voids and under floorboards. Outside, you may hear rats or see them moving around and digging burrows, especially in compost heaps or under sheds and decking.

Access
Rats could get into your building from a sewer through a broken drain. A young rat can get through a hole which is smaller than 1cm. A mouse only needs a space as wide as a pencil to get into your building. Rodents make their nests in warm, hidden places and these nests will often contain young rats or mice.

Controlling pests
It is cheaper and more successful for you to prevent pests getting into your premises rather than waiting for pests to get into your building before you deal with them. You need to think about how to stop rodents being attracted to your business and building.

Waste
Rodents are attracted to open bins so you should make sure there aren't any outside your building.

If possible, you should put your waste bins away from your building. You should always have enough room to store all your waste under a closed fitted lid.

Rats and mice can easily get into a bin bag, so you should never leave bags to the side, behind, or in front of a waste bin.

You shouldn't store any waste inside your building and you should put any bins outside as soon as possible.

Building maintenance
Rats and mice prefer undisturbed areas and need food, warmth, and nesting material. 

Mice can get enough water from the food they eat but rats need access to a water supply. You need to make sure that you fix any dripping taps.

You should keep any unused equipment and materials, including stored wood, metal, masonry and garden waste, away from your building so there are no areas pests might find attractive. You will also be able to clean the area easier if you do this.

You should keep the parts of your building you don't use as clear and empty as possible and inspect them regularly.

Rats or mice can get into your building at any level, through a broken drain, an open door or window, and through gaps in the eaves of the roof. You should make sure any repairs that are needed are carried out immediately .

You should check areas such as under-stairs cupboards, holes in ceilings and behind wall cladding regularly.

You should fit a brush or rubber strip to cover any gaps at the bottom of doors, and seal gaps where pipes or cables pass through walls or suspended ceilings with a strong material that rats cannot gnaw through.

Cleaning
You should keep your food premises clean and tidy.

If you have a well designed cleaning schedule that is properly carried out, this will make sure that your equipment, walls, floors, doors, windows and ceilings are kept clean, both inside and outside. You should move fridges, freezers and ovens so you can clean underneath and behind them. 

If you have a 'clean as you go' policy this will ensure you clean any spilled food waste or liquid straightaway.

Staff awareness
If any of your staff see a rat or mouse, droppings, or greasy smear marks along the bottom of walls, shelves or other surfaces, they should report it to you immediately.

Packets of food and packaging materials may get gnawed or damaged by rodents. Any signs of damage to the structure of the premises should also be reported.

If there are rodents
If you find a problem, you should contact a pest-control contractor straightaway so they can deal with it.

You should stop preparing food until:

  • the problem has been dealt with
  • all food that may have been contaminated has been got rid of
  • all equipment, food storage, preparation and service areas have been effectively cleaned and disinfected

Pest controllers and contractors
As the operator of the business you are responsible for dealing with any problem and you must check your building regularly for pests. Arranging a pest control contract is always a good idea. (The business operator is often the business owner.)

Pest-control contractors can offer the following services:

  • specialise in protecting food premises
  • service contracts for flying-insect killers, known as insectocutors
  • an emergency call-out service 

Whatever services you need you should look for a company who is registered with a body such as the British Pest Control Association or other trade association.

A good pest-control provider will give you advice about potential problems, carry out work and monitor and report results. 

Pest control is not just about putting poisons down but, if you need to do that, you should leave handling poisons to the professionals. Most baits from domestic retailers are not suitable for food businesses and, poorly handled, could cause food contamination.

More information
You will find further guidance in our other leaflets on this website. Information can also be found on the Food Standards Agency website.

Alternatively, contact your local environmental health service for advice.

Please note
This leaflet is not an authoritative interpretation of the law and is intended only for guidance.  

© 2017 itsa Ltd.