Cooking Safely in the Microwave Oven

Microwave ovens can play an important role at mealtime, but special care must be taken when cooking or reheating meat, poultry, fish, and eggs to make sure they are prepared safely. Microwave ovens can cook unevenly and leave "cold spots," where harmful bacteria can survive. For this reason, it is important to use the following safe microwaving tips to prevent foodborne illness.

Microwave Oven Cooking

Arrange food items evenly in a covered dish and add some liquid if needed. Cover the dish with a lid or plastic wrap; loosen or vent the lid or wrap to let steam escape. The moist heat that is created will help destroy harmful bacteria and ensure uniform cooking. Cooking bags also provide safe, even cooking.
Do not cook large cuts of meat on high power (100%). Large cuts of meat should be cooked on medium power (50%) for longer periods. This allows heat to reach the center without overcooking outer areas.
Stir or rotate food midway through the microwaving time to eliminate cold spots where harmful bacteria can survive, and for more even cooking.
When partially cooking food in the microwave oven to finish cooking on the grill or in a conventional oven, it is important to transfer the microwaved food to the other heat source immediately. Never partially cook food and store it for later use.
Use a food thermometer or the oven’s temperature probe to verify the food has reached a safe temperature. Place the thermometer in the thickest area of the meat or poultry—not near fat or bone—and in the innermost part of the thigh of whole poultry. Cooking times may vary because ovens vary in power and efficiency. Check in several places to be sure red meat is 160 °F, whole poultry is 180 °F, and egg casseroles are 160 °F. Fish should flake with a fork. Always allow standing time, which completes the cooking, before checking the internal temperature with a food thermometer.
Cooking whole, stuffed poultry in a microwave oven is not recommended. The stuffing might not reach the temperature needed to destroy harmful bacteria.

Microwave Defrosting

Remove food from packaging before defrosting. Do not use foam trays and plastic wraps because they are not heat stable at high temperatures. Melting or warping may cause harmful chemicals to migrate into food.
Cook meat, poultry, egg casseroles, and fish immediately after defrosting in the microwave oven because some areas of the frozen food may begin to cook during the defrosting time. Do not hold partially cooked food to use later.

Reheating in the Microwave Oven

Cover foods with a lid or a microwave-safe plastic wrap to hold in moisture and provide safe, even heating.
Heat ready-to-eat foods such as hot dogs, luncheon meats, fully cooked ham, and leftovers until steaming hot.
After reheating foods in the microwave oven, allow standing time. Then, use a clean food thermometer to check that food has reached 165 °F.

Containers and Wraps

Only use cookware that is specially manufactured for use in the microwave oven. Glass, ceramic containers, and all plastics should be labeled for microwave oven use.
Plastic storage containers such as margarine tubs, take-out containers, whipped topping bowls, and other one-time use containers should not be used in microwave ovens. These containers can warp or melt, possibly causing harmful chemicals to migrate into the food.
Microwave plastic wraps, wax paper, cooking bags, parchment paper, and white microwave-safe paper towels should be safe to use. Do not let plastic wrap touch foods during microwaving.
Never use thin plastic storage bags, brown paper or plastic grocery bags, newspapers, or aluminum foil in the microwave oven.

For further information, contact:

Meat and Poultry Hotline:
1 (800) 535-4555 (Toll-free Nationwide)
(202) 720-3333 (Washington, DC area)
1-800-256-7072 (TTY)

Source: http://www.fsis.usda.gov/

* Distributed May 2002 for use in September 2002 as part of the International Food Safety Council's National Food Safety Education Month.