Cross Contamination

Bacteria and viruses are hitchhikers and they need help to get from one place to another. Most of the time we provide the help when we are careless and allow cross contamination to happen. The end result can be food poisoning.

What is cross contamination?

Cross contamination occurs when bacteria and viruses are transferred from a contaminated surface to one which is not contaminated. The bacteria and viruses can come from people, work surfaces or equipment, and other foods. For example, it can happen when bacteria from the surface of raw meat, poultry and raw vegetables with visible dirt (such as unwashed potatoes), are transferred onto ready to eat food, such as green salads, rice or pasta salads, cooked meats or poultry and even 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 obvious culprits in transferring bacteria from raw to ready to eat food, but direct contact with raw foods, dirty chopping boards, knives and other cooking implements can also spread the contamination. Chopping boards, plates and knives that have been in contact with raw food need to be carefully washed with warm water and detergent, then rinsed and thoroughly dried before being used for ready to eat foods.

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

Raw foods should always be treated as though they were contaminated.

How should raw and ready to eat food be stored?

Raw food, such as meat, poultry or seafood, should be stored in a rigid container or at the bottom of the fridge to prevent it coming into contact with ready to eat food or allowing meat juices to drip onto 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 survive in the scratches.

When should I wash my hands?

Always wash and dry your hands:

• Before touching or eating food
• After touching raw meat, seafood, 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. 

And for safety's sake remember the 6 key tips:

• Keep hot food above 60°C
• Keep cold food refrigerated or below 5°C
• Cook food properly
• Separate raw and cooked foods
• Keep kitchen and utensils clean
• Wash hands with soap and dry thoroughly.