Skip to main content
English Cymraeg

Why avoiding cross-contamination is important

Cross-contamination occurs when bacteria is transferred between different foods, from food to surfaces, and from surfaces to food.

Last updated: 15 March 2024
See all updates
Last updated: 15 March 2024
See all updates

It’s important to be aware of cross-contamination when preparing and storing food.

You can avoid food poisoning and keep yourself and others in your household safe by:

  • preparing food hygienically
  • not washing raw meat, fish and poultry
  • washing fruit and vegetables
  • storing food properly
  • cleaning recyclable plastics carefully
  • using shopping bags safely
  • cleaning any reusable containers properly

Preparing food hygienically 

You should always wash your hands with soap and warm water before preparing, cooking, or eating food. It's also important to make sure any surfaces you are using for food preparation are clean and clear.

If possible use different chopping boards and utensils for:

  • raw meat, fish or poultry
  • fruits and vegetables
  • ready-to-eat foods like salads and cheese

If this is not possible then prepare vegetables and fruit first followed by raw meat, fish or poultry last, washing with soap after use. Always use a clean chopping board to prepare ready-to-eat or cooked foods. And clean as you go - if you spill some food or juices from food, clear it up straight away and clean the surface thoroughly.  

Don’t wash raw meat, fish or poultry

Washing meat, fish and poultry doesn’t get rid of harmful bacteria - only thorough cooking will. In fact, washing meat can splash harmful bacteria onto hands, work surfaces, ready-to-eat foods and cooking equipment. These bacteria could then cause food poisoning.

Always wash hands after handling raw meat, fish and poultry and take care when washing plastic food trays, see our advice below.

Washing fruit and vegetables

It is good practice to wash fruit and veg before use. This is to make sure they are clean and harmful bacteria can be removed from the outside.

Tips for handling raw fruit and vegetables:

  • always wash hands thoroughly before and after handling raw food, including vegetables and fruit
  • keep unwashed raw fruit and vegetables separate from ready-to-eat food during storage and preparation
  • where possible use a separate chopping board, knives and utensils for raw and cooked food
  • if this is not possible prepare vegetables/fruit first and raw meat, fish and poultry last, washing with soap after use
  • check the label - unless packaging around vegetables, fruit or salads says ‘ready-to-eat’ you must wash, peel or cook them before eating

For more information on how to clean fruit and veg see our cleaning pages.

Store food properly

Not all food needs to be refrigerated (check any food labels for guidance) but it all needs to be stored safely. Here are out tips:

  • your fridge should be between 0 and 5°C
  • cover raw food, including meat, and keep it separate from ready-to-eat food in the fridge, for advice on where to store food in the fridge see our chilling page
  • try to keep food in sealed bags or containers - this helps to keep them fresh and stops anything falling into the food by accident
  • don't store food or drinks near cleaning products or other chemicals
  • don’t store food in containers that have been used for other purposes other than food
  • only reuse plastic water bottles if they’re not damaged and you can clean them
  • avoid storing food on the floor, because this can encourage mice, ants, and other pests
  • keep storage areas dry and not too warm
  • remember that some types of food might need to be kept in the fridge once you’ve opened them – follow any storage instructions on the label

Recyclable plastics - advice when washing plastic food trays

Effective cleaning removes bacteria from recyclable plastic trays and containers. This helps to stop harmful bacteria from spreading onto food, surfaces, and equipment through cross-contamination. We advise that you:

  • wash trays/containers with hot soapy water
  • take care to avoid drips and splashes when washing and clean as you go
  • if possible, use a sink away from food preparation areas to reduce the risk of cross contamination 
  • if access to a separate sink away from food preparation areas is not possible ensure effective cleaning is carried out to prevent cross contamination
  • drying recycled plastics naturally helps to prevent bacteria being spread back onto items via a tea towel or cloth  

Regularly washing hands will also prevent the spread of any potential contamination.  

Using shopping bags safely 

When using reusable bags, always pack raw foods in separate bags from other foods.

Try and keep one or two bags specifically for raw foods only and don’t use the same bags again for ready-to-eat foods. Even if a carrier bag looks clean, if it’s been used for raw meat, there may be bacteria present which could transfer to fresh produce or ready-to-eat foods. You could even label or colour code your bags to show what you intend to use them for.

As well as keeping raw food away from other foods it's important to pack cleaning products and other household items separately from food too.

Always check your bags for spillages, for example raw meat juices or soil, after every use. If there has been spillage, soiling or damage, plastic-based re-usable bags or single-use plastic carrier bags should ideally be disposed of or recycled. Fabric bags can be washed on a hot wash.

Reusable containers

You can re-use your plastic tubs and containers to transport and store food such as meat, deli products, loose fresh produce, and dry ingredients like pulses. This is a great way to care for the environment, but be mindful to reuse containers in a safe way by following the below advice:

  • after use wash thoroughly in warm soapy water and dry thoroughly or use a dishwasher
  • have separate and clearly labelled containers for raw meat, fresh produce and ready to eat foods
  • containers should have a sealable lid for raw foods to avoid leakage and spread of bacteria
FSA Explains


Cross-contamination is what happens when bacteria or other microorganisms are unintentionally transferred from one object to another. The most common example is the transfer of bacteria between raw and cooked food.

This is thought to be the cause of most foodborne infections. For example, when you’re preparing raw chicken, bacteria can spread to your chopping board, knife and hands and could cause food poisoning if you aren’t careful.

Cross-contamination can also happen when bacteria is transferred in ways that are less obvious. For example, via reusable shopping bags, or in the drips and splashes produced if meat is washed which can contaminate other surfaces.