Microbes and food 5. Food poisoners
5.9 How to avoid food poisoning
All food poisoning is preventable. People at all stages in the process from farm to table are responsible for making sure that the food produced is safe to eat and free from contamination by harmful microbes.
Photo of prawn factory
Picture 5.9a Workers at a prawn shelling factory wear gloves to avoid contaminating the prawns.

Farmers and growers must ensure their harvest of fruit, vegetables and crops or fish/meat and milk are produced in good conditions, avoiding contamination by potentially pathogenic microbes.


The manufacturers who process and package food need to make certain that all their staff work to the highest standards of hygiene including personal cleanliness and dress. They follow “good manufacturing practice” (GMP) which lays down rules about how food is handled. Sometimes food and the factory environment are tested for certain types of micro-organisms. A more effective approach is known as HACCP (Hazard Analysis Critical Control Point) where the whole process is analysed carefully and potential danger points are identified. Regular checks of these CCPs allow any problems to be spotted quickly and remedied. The temperature at which foods are transported and stored is closely monitored and all the equipment in a food processing factory is cleaned and maintained to the highest of standards.

Retailers and caterers

Shopkeepers, supermarkets and caterers also play their part in keeping our food safe. The correct storage and hygienic handling of food is very important. Refrigerators and freezers are constantly monitored to make sure that food is kept at the correct temperature: refrigerators below 5oC and freezers below –18oC. Great care is also taken to stop microbes being passed from uncooked foods onto cooked foods that are ready to eat. Knives, cutting boards and separate areas of the kitchen are used to prevent any cross-contamination.

Environmental Health Officers employed by local authorities are responsible for ensuring that food safety laws are being met.



The final link in the chain is the consumer. Proper handling, good personal hygiene and correct cooking will help them avoid becoming the victim of food poisoning. Regular cleaning of utensils and separation of foods in the refrigerator can help to prevent any cross-contamination. Care must also be taken to ensure that foods are stored at the right temperature and cooked thoroughly before they are eaten.

Ten tips for food safety in the home

  1. Take chilled and frozen food home quickly and put it in the ‘fridge or freezer straight away.
  2. Prepare and store raw and cooked foods separately. Raw meats and fish or defrosting food should be covered and stored underneath any cooked food. Any juices from the raw or defrosting food cannot then drip on to cooked foods or foods which are eaten raw such as salads.
  3. Keep the coldest part of your ‘fridge at 0-5oC to restrict the growth of food poisoning bacteria. Check this by using a ‘fridge thermometer.
  4. Check the use–by date. Use food before it reaches the use-by date shown on the pack. After this date you cannot be sure that the food is safe to eat – even if you cook it thoroughly!
  5. Keep pets away from foods, dishes and worktops in the kitchen.
  6. Wash hands thoroughly before preparing food, and after handling raw food, going to the toilet, handling pets and touching the dustbin.
  7. Keep your kitchen clean. Disinfect worktops. Wash cutlery and dishes in hot soapy water. Bleach or change dish cloths regularly.
  8. Use separate chopping boards for raw meat, cooked food and fresh vegetables.
  9. Do not eat food containing uncooked eggs as they may contain Salmonella. Keep eggs in the ‘fridge.
  10. Cook food thoroughly. Follow the instructions on the pack and if you reheat food, make sure it is piping hot throughout.
  11. Keep hot foods hot and cold foods cold. Don’t leave them standing around for a long time so that they reach room temperature.