Microwave Ovens

Microwave ovens are versatile appliances that can be used not only to reheat food but also expedite cooking time in food preparation. They are safe and convenient because they can heat food without using fire. In recent years, they have been considered more energy-efficient than gas stoves.

How Do Microwave Ovens Work?

Household microwave ovens typically operate at 500-1000W and emit radio-frequency magnetic fields (microwaves) at 2.45GHz (gigahertz). When these microwaves are absorbed by water molecules in the food, they cause the molecules to vibrate. The resulting friction between the molecules generates heat, which cooks the food.

Health Effects of Microwaves Used in Microwave Ovens on Humans

Microwaves in microwave ovens are securely contained inside the microwave oven by a mesh-like structure attached to the door. The design ensures the door is opened, the microwaves stop and not leak out. Consequently, the levels of microwaves around the oven are well below the limits for the general public established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Under normal use, the small amount of microwaves that might leak from the oven is not considered to pose any adverse health effects.

Safety of Food Cooked in Microwave Ovens

The safety of food cooked in microwave ovens is described in the WHO information sheet "Microwave Ovens" as follows.
"When used according to manufacturers' instructions, microwave ovens are safe." "Food cooked in a microwave oven is as safe, and has the same nutrient value, as food cooked in a conventional oven." "To dispel some misconceptions, it is important to realize that food cooked in a microwave oven does not become "radioactive"." "Nor does any microwave energy remain in the cavity or the food after the microwave oven is switched off. In this respect, microwaves act just like light; when the light bulb is turned off, no light remains."

Therefore, food cooked in a microwave oven are not any adverse health effects.

Regulatory

In Japan, the strength of microwaves emitted by microwave ovens is regulated by the Electrical Appliance and Material Safety Act and the Radio Law Enforcement Regulations.

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