Safety when Using the Microwave Oven

When using a microwave oven to cook food, one has to make sure the food is cooked thoroughly to destroy any bacteria that may be present.
You can cook pasta, rice, potatoes, meats, fish, poultry, vegetables, and any pre-cooked meals. Fruits and vegetables are more nutritious because less water is used and the shorter cooking time reduce nutrient depletion.
Food cooked in the microwave has to be laid evenly in a covered dish and added with only a little liquid if needed. The dish is covered loosely with a lid or plastic wrap; so that there is an outlet to let steam escape. The moisture created from the heat will help destroy harmful bacteria and ensure even cooking.
Large cuts of meat are not cooked on high power (100%). They are be cooked on medium power (50%) for longer periods. This allows heat to reach the centre without overcooking the outside.
Food cooked should be about the same size. This helps to distribute the heat more evenly and cook them thoroughly.It is better to cook the meat separately and added to the sauce which have been cooked earlier.
Stir or rotate food midway through microwaving to eliminate cold spots where harmful bacteria can survive, and for more even cooking.
Meats, fish and poultry can be cooked in the microwave, but it is important to check that it has been cooked until the inside is no longer pink or bleeding. Foods keep cooking after the microwave is off, so allow standing time.

Uneven Heating

Unwanted microorganisms may thrive in the food if it is not cooked evenly.
Manufacturers use stirrer fans and turntables and recommend standing times to help alleviate the problem of uneven heating. Many microwavable meal packs carry the instruction to stir the food part way through the cooking process. Items such as lasagne that cannot be stirred should be allowed standing time to allow the whole product to reach a uniform temperature.

It is better to divide large portions into smaller portions for reheating than to heat a large amount for longer.
Care should be taken that frozen food has been completely thawed. Water absorbs microwaves far more easily than ice does; incomplete thawing will result in uneven cooking and the potential survival of undesirable microorganisms in those parts of the food, which have been insufficiently heated.

You have to make sure that frozen food are thoroughly thawed before cooking.You can thaw it fast, though,using the microwave.Microwave ovens' safety feature is that food can be taken from the freezer, thawed quickly, cooked and served without it spending long periods of time in the danger temperature zone between 4°C and 60°C, which provides favourable conditions for dangerous microorganisms to thrive.

Accidents with the Microwave Ovens

Microwave ovens are less likely to cause burns than are conventional ovens.
Burns have occurred from the steam emitted from microwaveable popcorn bags and similar closed packages and from the boiling portions of foods, which heat unevenly. An example of this is a jam-filled donut; the jam centre may exceed the boiling point of water while the donut itself is only warm. Frozen macaroni cheese is another example as the cheese reaches a high temperature more quickly and retains more heat than the macaroni.

When warming up milk,test the temperature before drinking.You would not want your tongue to be scalded with boiling milk.

Always use oven gloves to remove items from the microwave oven to avoid unexpected burns.

Containers and Films for Microwave Cooking

Only utensils designed for the purpose should be used in a microwave oven.

I prefer to use ceramic or porcelain as opposed to plastics because plastics may migrate to the food at high temperatures and may be dangerous to imbibe on a long term basis as it can be carcinogenic.
Only those plastic containers, which have been specifically designed for microwave cooking, should be used, and they should be discarded when the surface shows any signs of breaking down.
When plastic films are used in microwave ovens, it is preferable that they are not in direct contact with the food they cover. Meals to be reheated on a plate may be covered with clean white absorbent kitchen paper to prevent spatter.
Frozen food containers which have been designed to package frozen or chilled foods such as ice cream or margarine, should not be exposed to high temperatures in a microwave oven. The low melt temperatures of these plastics may result in migration of undesirable contaminants into the food or in physical disintegration of the containers themselves.

Container shape may also influence the way a food reacts to reheating. Circular or oval containers help prevent edges of the food burning because energy absorption occurs evenly around the edges. Square containers tend to encourage burning on the edges of a product.