Is it dangerous to stand in front of a microwave, or just a myth?

As a child, I was fascinated by the microwave, a seemingly magical device, and I frequently stood directly in front of it to watch the food inside spin and cook. But adults would always pull me back with the admonishment, “Standing in front of a microwave is dangerous. You’re going to get cancer.”

Despite rationally knowing that every household wouldn’t have a microwave if it caused cancer, I’ve remained cautious as an adult. With that old adage in my subconscious that microwaves are dangerous and tied to cancer, I still won’t stand directly in front of one.

To once and for all figure out if microwaves pose any health dangers to the point where standing in front of one is ill-advised, I reached out to oncologists, doctors who specialize in diagnosing and treating cancer. 

Can microwaves cause cancer?

A microwave oven operates by activating a magnetron, a high-powered vacuum tube that converts electrical and magnetic currents into microwaves (electromagnetic radiation) with a wavelength of about 12 centimeters. These wavelengths are absorbed by water molecules, increasing their molecular activity and heating them up.

Since our food has a high water content, it cooks when microwaves reflect off the interior of the microwave and heat its water molecules.

“Microwave radiation is at a very different end of the electromagnetic spectrum from ultraviolet radiation, X-ray radiation and gamma radiation,” Dr. Adeel Khan, an academic hematologist/oncologist and epidemiologist in Dallas, Texas, told CNET. “Biologically, microwave rays are considered non-ionizing and thus not particularly mutagenic [genetic mutation-causing] or carcinogenic [cancer-causing].”

The National Cancer Institute reports that most types of non-ionizing radiation haven’t been found to cause cancer. 

Plus, your microwave’s door, lined mesh window and sides should all prevent significant microwave leakage. 

“Over the years, there have been numerous epidemiologic studies looking at relationships between microwave oven use and cancer and these, by and large, do not support a causal link,” said Khan.

Are microwaves safe for pregnant people?

You may have also heard the rumor that pregnant people shouldn’t stand in front of microwaves, or should avoid them entirely, but that’s also a myth. 

Microwaves are safe for those who are pregnant, “and the fetus is further protected by the uterine environment,” Khan said.

Damaged microwaves can leak

Whether a microwave can negatively affect our health in other ways depends on its emission strength, our distance from it and the exposure time, since microwaves can also heat water molecules in the body’s tissues. Yet, the device’s energy is too low for us to actually feel the heat.

“It is generally safe, not perfectly safe,” Dr. Gary Deng, integrative oncologist, program director of integrative oncology at UCI Health and associate director of the UCI Chao Family Comprehensive Cancer Center, told CNET. “Microwaves can leak out of the oven.”

The US Food and Drug Administration (FDA) states that while high levels of microwave exposure can cause burns or cataracts, clouding of the eye, less is known about what occurs at low levels of exposure. However, FDA regulations limit the amount of microwave rays that can leak from a microwave, and this limit is far below the level known to harm people.

On top of that, an FDA standard requires that all microwaves have two different interlock systems that stop the device from producing microwaves the moment the door is opened. 

As long as your microwave is in good working order, it should not leak microwave energy. 

A faulty microwave door, on the other hand, could cause extensive leakage of microwave rays, which could be thermally damaging. If you think your microwave is leaking or notice its door doesn’t look quite right, the FDA recommends contacting your microwave’s manufacturer. 

Just to be safe, don’t stand directly in front of your microwave

To minimize potential harm, we shouldn’t stand directly up against a microwave when it’s on. “If you stand one foot away from it, your exposure drops to 1% compared to when you stand one inch from it,” Deng explained.

Manufacturers and safety experts recommend standing at least one to three feet away from your microwave, out of an abundance of caution, according to Khan.

Other microwave health risks to consider

You’ll also want to be careful about scalding and burns from hot liquids and foods, as well as from steam released when opening bags or covered containers. To avoid this, make sure you follow the heating instructions provided by your microwave and food manufacturers. You could also handle anything that comes out of the microwave with oven mitts and ensure your containers and bags are vented. 

“A more recent concern and one worth highlighting is that microwaving food in non-microwave-safe plastic containers can cause leaching of microplastics into the food,” said Khan. That’s why you should opt for microwave-safe glass or ceramic dishes instead. 

Microwave safety tips

To ensure you’re using your microwave correctly and safely, Khan provided the following tips:

• Use safe containers: Avoid metal, foil or anything with a metallic trim, as these can start a fire. 
• Don’t use cheap takeout containers: They’re often not microwave-safe, since they can warp or leach chemicals into your food. 
• Vent food properly: This will allow steam to escape and prevent burns. 
• Watch for superheater liquids: When a liquid is heated above its boiling point in a smooth container, it becomes unstable. Then, when it’s moved, an object like a spoon is placed in it or a substance like instant coffee is added, the water can boil quickly and even seem to explode out of its container, potentially causing serious burns. To avoid this, make sure you follow the recommended heating times or add substances like instant coffee before heating. Also, don’t open items too close to your face.
• Make sure the microwave door works properly: This will ensure microwave radiation isn’t leaking out. 
• Never run the microwave empty: Microwaving with nothing inside (no food or liquid) can damage the microwave’s magnetron, since there’s nothing to absorb the energy, causing it to bounce back and damage the magnetron itself.

The bottom line

Both Khan and Deng agree that as long as a microwave isn’t broken or tampered with, it’s safe for normal daily use — and it can’t cause cancer. Still, you shouldn’t stand directly up against it. Take a few steps back until you’re one to three feet away.