Food Safety

What is cross contamination?

Cross contamination is one of the causes of food poisoning. It can happen when bacteria from the surface of raw meat, poultry and raw vegetables with visible dirt (such as unwashed potatoes) gets transferred onto ready to eat food, such as green salads, rice or pasta salads, bread or fruit. The bacteria on the raw food are killed when the food is cooked, but the ready to eat food gets eaten without further cooking — bacteria and all.

How are the bacteria transferred?

Hands are among the culprits in transferring bacteria from raw to ready to eat food, but chopping boards, knives and other cooking implements can also spread the contamination. Cooking utensils and chopping boards need to be carefully washed with warm water and detergent, and after washing, need to be thoroughly dried to further reduce their ability to transfer bacteria and prevent their growth.

Incorrectly storing raw food in the fridge by allowing it to come into direct contact with ready to eat foods, or allowing meat juices to drip onto cooked foods, fruit and other ready to eat food, are also causes of cross contamination.

When should I wash my hands?

Always wash and dry your hands:

  • before touching or eating food;
  • after touching raw meat, fish, chicken or unwashed vegetables;
  • after using the toilet;
  • after blowing your nose;
  • after touching a pet.

How should I wash my hands?

Wet hands, rub together well to build up a good lather with soap — don’t forget the back of the hands, between the fingers and under nails. Rinse well in warm water and dry thoroughly on a clean towel.

How should raw and ready to eat food be stored?

Raw food, such as meat, poultry or fish should be stored at the bottom of the fridge or in a container to prevent meat and juices dripping onto other food. Make sure that it can not directly touch other food.

Ready to eat food should be stored covered in the fridge to further reduce the risks.

What kind of chopping board is best to avoid cross contamination?

In the home it really doesn’t matter whether you have wooden, plastic or glass chopping boards so long as they are kept really clean and in good condition. The porous nature of wood makes it advisable to use plastic or glass chopping boards for raw meat, poultry and seafood. It may be easiest to have two boards — one for raw food and one for ready to eat food. All chopping boards should be scrubbed with hot water and detergent after preparing raw foods. Plastic chopping boards are good as they can be washed at high temperatures in the dishwasher. However, any board should be replaced when its surface becomes scratched because bacteria can hide in the scratches.