Why is it not safe to put metal vessel in microwave oven?

Cassie and his classmates are doing their school projects in their house. Cassie’s mom decided to cook some food for lunch. She turned on the microwave and put the food for quick and easy cooking.

Microwave is pretty helpful in our kitchen, especially when we are in a rush, and cooking seems to be consuming so much time. With just a microwave, you can reheat food from the fridge, and after a few minutes, you can consume the food as if it’s freshly cooked. Some microwaves are multifunctional, which can be used for either baking, grilling, roasting, blanching, boiling, and steaming food items. (click here for more details)

Thanks to Percy LeBaron Spencer, who had discovered it! Spencer worked on magnetrons — vacuum tubes that produce microwave radiation and are used in radar systems. Until in 1941, he found the potentiality microwave oven to be used in cooking food faster, then he had the patent of his invention in 1945.

How Microwave Ovens Work

One of the most used kitchen appliances, microwave, is a simple device that works incredibly. With just a magnetron hooked up to a high voltage source, you can already have your food ready only a few minutes. The magnetron directs microwaves into the metal box. Inside the microwave, the waves bounce around until they are absorbed via dielectric loss in various molecules, which results in those molecules heating up and cooking your foods. (click here for more details)

Substances such as water, ceramics, and certain polymers, work well inside the microwave and end up efficiently converting microwave energy into heat quite effectively.

If, for instance, Cassie’s mom accidentally put a fork or a knife inside the appliance, it could be not good to the microwave. Why?

Metals are electron-filled that can move freely, which means they are great conductors of electricity. Putting metal or even an aluminum foil inside your microwave will cause free electrons on the metallic surface to move from side to side very rapidly. Therefore it prevents the electric wave from entering the metal, and the waves end up being reflected instead.

Microwaves oven has radio waves set at a frequency of about 2,450 megahertz with a power ranging from 500 to 1100 watts, according to the World Health Organization (WHO). This is why any food put inside will be cooked just a short time because microwaves bombard it on all sides.

Arcing may occur between the metal object and another part of the microwave oven if there is no enough material in the microwave oven to absorb the reflected microwaves. If you are to take a look but not too close at it might cause unexpected harm, tiny bolts of lightning sparks inside. These are electricity bouncing inside that can seriously damage the microwave oven by starting a fire, burning a hole in the microwave oven wall, destroying the magnetron, or damaging sensitive electrical components. (click here for more details)

So make sure not to put metal forks or any metal objects inside the microwave. Consequently, you will either buy a new microwave or, in worst cases, burn your kitchen. Due to the utilization of microwave radiation, the use of microwaves has gotten a bad rap. Nevertheless, the WHO said that the proper use of microwave is safe because it is designed to keep the radiation only within the oven and only present when the oven is switched on, and the door is shut. A very minimal amount of radiation may leak but well below international standards that can be considered harmful.

Additionally, several countries and the international standards have set a product emission limit of 50 watts per square meter with a distance of 5 centimeters from the oven’s external surfaces. Radiation emissions from the microwave are substantially below the limit that even rapidly decreases as you make distance away. If you are 50cm away, you will only expose yourself to about one-hundredth of the microwave exposure of someone 5 cm apart.

One main concern is food quality when cooking with microwaves as it can cause uneven cooking due to extremely high temperatures; thus, caution is needed.

In purchasing and using a new appliance, it is always best to read the manuals and research the dos and don’ts of using to keep away from the dangers.