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7 things you should never heat in the microwave

News Desk

The Jakarta Post

-  /  Sun, June 9, 2019  /  07:03 pm
7 things you should never heat in the microwave

Hands closing microwave oven door and preparing food at home (Shutterstock/Andrey_Popov)

Food, liquids and containers: There are quite a few things that have no place in the microwave. According to the FDA, manufacturers are not obliged to test their products for microwave suitability, which is why a “microwave safe” label is not really convincing.

To avoid a fire or reactions of harmful chemicals, do not heat these seven things in the microwave, as compiled by Reader's Digest.

Hard boiled eggs

Even though the internet might say otherwise, you should never boil eggs in a microwave. As the heat creates steam inside the egg which can ́t escape, it will eventually explode.

To avoid burned fingers and cleaning up the mess, better cook eggs on the stove or in a special egg boiler.


When we spontaneously decide to have meat for lunch, some of us may try to defrost it in the microwave. While the thin edge will cook early, the thicker middle might still be frozen, which is why it is better to defrost meat overnight in the fridge.

Additionally, a microwave that doesn't rotate leads to an uneven distribution of heat, which attracts bacteria.

Breast milk

Heating breast milk in the microwave is not recommended at all, as it warms unevenly and could create hot spots that can scald the baby. Also, some of the immune-boosting proteins could be destroyed.

To preserve the nutrients, better place the bottle of breast milk in a mug full of warm water. Once it reaches room temperature, the breast milk is safe to use.

Plastic containers

Even though we shouldn ́t, everyone does it from time to time: Placing plastic containers in a microwave.

Heated plastic can release estrogen-like chemicals like BPA, strictly speaking, 95 percent of 450 tested plastic products showed this effect, according to a study published in Environmental Health Perspectives. Washing the containers, baby bottles or zipper-top bags in the dishwasher or soaking it in water had the same outcome. Therefore, better warm up your meal on a normal plate.

Certain plates

Speaking of plates, in case you have any metallic-trimmed ones, do not put them in the microwave. Even a minuscule metallic trimming can cause harm, according to the USDA.

To be on the safe side, get a plain glass plate for microwave use only.

Read also: Microwave ovens are cooking the environment: study

Cups of water

Boiling a cup of water in the microwave may seem harmless, but it turns out to be a really bad idea. Heating plain water in a ceramic cup or a glass for too long keeps bubbles from building. As a consequence, the liquid can ́t cool down, becomes superheated and erupts boiling water when the glass is moved.

The best way to boil water is on the stove or in an electric kettle.


Interestingly, heating nothing in the microwave can be as harmful as heating one of the things mentioned above.

If the machine is running without any food or liquid inside, the magnetron responsible for the microwave function would end up absorbing the waves. As a result, the microwave can break or catch fire. Hence, before pressing “start” always make sure you put something inside. (sop/kes)