What are 4 practices that should be followed when preparing foods to prevent contamination?

Harmful bacteria are killed by cooking and reheating food at the right temperature for the correct length of time. Always follow the cooking instructions on the label and check the food is steaming hot in the middle.

Cooking meat and poultry

Chicken, duck, pork and offal

Chicken, duck, pork and offal should always be cooked through until the core temperature reaches 75°C, there is no pink meat and the juices run clear. This will kill any harmful bacteria.

These type of meats should never be eaten pink or rare.

Beef and lamb

Beef and lamb steaks and whole joints (not rolled joints) can be served rare as long as the outside has been properly cooked (sealed), to kill any bacteria present on the surface.

Always cook burgers and sausages made from these meats all the way through. This will kill harmful bacteria - including E. coli O157 - that might have been present on the surface of the meat and then mixed through after mincing.

If possible, use a thermometer to ensure that the internal temperature reaches 75°C and make sure there's no pink in the middle and the juices run clear.

How to tell when meat is cooked

If you have a food thermometer, the internal temperature should reach 75°C.

If you don't have a food thermometer, the meat:

shouldn't be pink in the middle
juices should run clear
should be steaming hot throughout

To check whole birds, pierce the thickest part of the leg. For thicker joints, pierce the centre.

Cooking fish, shellfish and crustacea

Although most fish and some shellfish (oysters) can be eaten raw, cooking will kill any bacteria present. If you choose to eat raw fish, make sure that it's been frozen first as the cold temperature will kill any parasites present.

Raw shellfish should always be cooked alive but never cook any shellfish if the shell doesn't close.

How to tell if fish, shellfish and crustacea are cooked

Fish, shellfish and crustacea are cooked if:

fish flesh will turn opaque (loses its transparency) and flake easily with a fork - cook fish until it reaches 62°C with a food thermometer or fish flesh
shrimp and lobster flesh will turn opaque
scallops will become firm and turn opaque
mussel, whelk and oyster shells will open - never eat shellfish if the shell remains closed after cooking

Cooking on a barbecue

Undercooked foods and cross-contamination are the greatest risks when using a barbeque. Cooking food in the oven before finishing on the barbecue is a great way to ensure food is cooked all the way through.

To ensure food is safe to eat:

defrost meat thoroughly before cooking - ideally in your fridge
keep meat and ready to eat foods - such as salad and bread - separate
regularly turn and move around to cook evenly
use separate utensils for raw and cooked meats
don't use a sauce or marinade for cooked food that has had raw meat in it

You'll know when your barbeque is at the right temperature for cooking when the coals are glowing red and have a powdery grey surface. Never cook food over flames as the outside will burn, but the inside will be raw and unsafe to eat.

Reheating cooked food

When reheating food make sure that it's steaming hot and heated all the way through to 75°C.

Use chilled food within 2 days of cooking. If the food has been cooked, frozen and then defrosted, reheat within 24 hours.

You should only ever reheat food once. The more times you cool and reheat food, the higher the risk of food poisoning.

Cross-contamination is the physical movement or transfer of harmful bacteria from one person, object or place to another. Preventing cross-contamination is a key factor in preventing foodborne illness.

Minnesota Department of Health Consumer Fact Sheet
Revised April, 2007

On this page:
When shopping
When refrigerating food
When preparing food
When serving food
More about cross contamination

When shopping:

Separate raw meat, poultry, and seafood from other foods in your grocery-shopping cart.
Place these foods in plastic bags to prevent their juices from dripping onto other foods.
It is also best to separate these foods from other foods at check out and in your grocery bags.

When refrigerating food:

Place raw meat, poultry, and seafood in containers or sealed plastic bags to prevent their juices from dripping onto other foods. Raw juices often contain harmful bacteria.
Store eggs in their original carton and refrigerate as soon as possible.

When preparing food:

Keep it clean:

Wash hands and surfaces often. Harmful bacteria can spread throughout the kitchen and get onto cutting boards, utensils, and counter tops. To prevent this:
Wash hands with soap and hot water before and after handling food, and after using the bathroom, changing diapers; or handling pets.
Use hot, soapy water and paper towels or clean cloths to wipe up kitchen surfaces or spills. Wash cloths often in the hot cycle of your washing machine.
Wash cutting boards, dishes, and counter tops with hot, soapy water after preparing each food item and before you go on to the next item.

Cutting boards:

Always use a clean cutting board.
If possible, use one cutting board for fresh produce and a separate one for raw meat, poultry, and seafood.
Once cutting boards become excessively worn or develop hard-to-clean grooves, you should replace them.

Marinating food:

Always marinate food in the refrigerator, not on the counter.
Sauce that is used to marinate raw meat, poultry, or seafood should not be used on cooked foods, unless it is boiled just before using.

Fruits and vegetables:

Rinse fresh fruits and vegetables in running tap water to remove visible dirt and grime.
Remove and discard the outermost leaves of a head of lettuce or cabbage.
Because bacteria can grow well on the cut surface of fruit or vegetables, be careful not to contaminate these foods while slicing them up on the cutting board, and avoid leaving cut produce at room temperature for many hours.

When serving food:

Always use a clean plate.
Never place cooked food back on the same plate or cutting board that previously held raw food.

More about cross contamination

Last Updated: 10/20/2022

Cook food properly – to at least 75 °C or hotter.
Use a thermometer to check the temperature of cooked foods.
If you use a microwave, check that the food is cooked evenly throughout.
Cook foods made from eggs thoroughly.
Cool and store cooked food as soon as possible.
Reheat food until steaming hot.

The way we cook our food is as important as the way we prepare and store it. Inadequate cooking is a common cause of food poisoning. Cross-contamination from raw to cooked foods, such as from hands, chopping boards or utensils, can also cause food poisoning. Most foods, especially meat, poultry, fish and eggs, should be cooked thoroughly to kill most types of food poisoning bacteria.

In general, food should be cooked to a temperature of at least 75 °C or hotter. When food is cooked, it should be eaten promptly, kept hotter than 60 °C, or cooled, covered and stored in the fridge or freezer.

Watch this video about cooking food safely.

People at risk from food poisoning

Some people are more at risk from food poisoning than others. Vulnerable groups include:

pregnant women
young children
the elderly
anyone with a chronic illness.

Special care should be taken when preparing, cooking, serving and storing food for these groups.

Safety when cooking high-risk foods

Food poisoning bacteria grow more easily on some foods than others. High-risk foods include:

raw and cooked meat - such as chicken and minced meat, and foods containing them, such as casseroles, curries and lasagne
dairy products - such as custard and dairy based desserts like custard tarts and cheesecake
eggs and egg products - such as mousse
small goods - such as ham and salami
seafood - such as seafood salad, patties, fish balls, stews containing seafood and fish stock
cooked rice and pasta
prepared salads - such as coleslaws, pasta salads and rice salads
prepared fruit salads
ready-to-eat foods - such as sandwiches, rolls, and pizza that contain any of the food above.

High-risk foods and the temperature danger zone

Take care with high-risk foods. You should remember to:

Keep high-risk foods out of the temperature danger zone of between 5 °C and 60 °C.
If high-risk foods have been left in the temperature danger zone for up to 2 hours the food should be reheated, refrigerated or consumed.
If high-risk foods have been left in the temperature danger zone for longer than 2 hours, but less than 4 hours, they should be consumed immediately.
Throw out any high-risk foods that have been left in the temperature danger zone for more than 4 hours.

Cook all food to a temperature of 75 °C

How you cook food is very important. Different foods need a different approach:

Aim for an internal temperature of 75 °C or hotter when you cook food. Heating foods to this temperature kills most food poisoning bacteria. Use a thermometer to check the internal temperature of foods during the cooking process.
Cook mince, sausages, whole chickens or stuffed meats right through to the centre. You should not be able to see any pink meat and the juices should be clear.
Generally you can cook steak, chops and whole cuts of red meat to your preference as food poisoning bacteria are mostly on the surface. However, if you are at a greater risk of the more serious effects of toxoplasmosis (for example, you are pregnant or immunocompromised) you should ensure your meat is cooked thoroughly to reduce that risk.
Cook fish until it flakes easily with a fork.
Cook foods made from eggs such as omelettes and baked egg custards thoroughly.

Food safety with raw eggs

Take extra care when preparing foods that contain raw egg, such as homemade mayonnaise, sauces, such as hollandaise, and desserts, such as tiramisu and mousse. Bacteria present on eggshells and inside the egg can contaminate these types of food and cause food poisoning.

Avoid giving food containing raw eggs to pregnant women, young children, elderly people and anyone with a chronic illness.

Food safety and microwave cooking

Microwaves are a quick and convenient way to cook food. However, if they are not used correctly, they can cook food unevenly. This may leave food partially cooked or not reaching a uniform temperature of 75 °C. When you cook food in the microwave:

Cut food into evenly sized pieces if possible or put larger or thicker items towards the outside edge of the dish.
Cover the food with a microwave-safe lid or microwave plastic wrap. This will trap the steam and promote more even cooking.
Rotate and stir food during cooking.
Wait until the standing time is over before you check that the cooking is complete. Food continues to cook even after the microwave is turned off.

Cooling and storing food

If you need to store food for later use, wait until the steam stops rising, cover the food and put it in the fridge. This helps keep the food out of the temperature danger zone as fast as possible. Large portions of food cool faster when you put them into shallow trays or divide them into smaller portions. If you need to keep food warm, keep it hotter than 60 °C and out of the temperature danger zone. Under ideal conditions, cooked food can be stored in the fridge for a few days. If you want to keep cooked food longer, freeze the food immediately after cooling in the fridge.

Always store cooked food separately from raw food, especially raw meats, poultry and fish. Keep raw meats and poultry at the bottom of the fridge to avoid raw juices dripping onto other food. Ensure that all food is covered or sealed.

Reheat food to steaming hot

Reheat food until it is steaming hot - above 75 °C or, preferably, boiling. Food should steam throughout, not just on the edges. Take care when reheating food in a microwave oven. Follow the same actions as when cooking with a microwave to ensure all the food is heated to above 75 °C.

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