People have always been dubious about the safety of microwave ovens. I came across a microwave that kept whirring and spinning even with the door wide open – it simply wouldn’t turn off. The microwave was promptly kicked to the curb, but I started to wonder: should I be concerned for my safety?
Common knowledge would have you believe you should always be concerned for your safety around even working microwave ovens. Many still stray from them today, fearful that microwave ovens are leaching radiation into us and our food. The radiation cooking technology has incited fear in the masses, ever since its adoption in the 1970s, but it’s largely a myth stemming from a misunderstanding of the science of microwave rays.
I’m probably fine, according to Robert Dellavalle, the principal engineer for cooking appliances with UL Solutions. He’s been testing the safety of appliances with UL for 40 years. Even with a seriously malfunctioning microwave oven, there’s minimal risk of any human injury.
“If your microwave is operating with the door open, that’s definitely an unsafe condition,” said Dellavalle. “However, as you step away from the microwave oven, those radiation levels decrease exponentially.”
There’s been significant work done over the years to make sure that microwaves don’t travel much further than your dinner plate, according to Dellavalle. However, open or closed, he says you should always just be a few feet away from an operating microwave as a safety precaution. In an extreme but unlikely scenario, he says the microwave radiation could affect your eyes. It’s similar to how the sun’s ultraviolet rays can impair your vision, but microwaves are just lower on the electromagnetic spectrum.
“You would not get cooked,” Dellavalle said regarding if you were exposed to low doses of microwaves. “But it does have an effect.”
Dellavalle also notes that people have misconceptions about the radiation involved in microwaves. Microwaves have lower energy than more harmful, “ionized” radiation such as gamma rays or X-rays, according to the CDC. Microwaves are even below ultraviolet and visible light on the energy spectrum. It’s unclear if the cancer risks of microwaves are truly zero, but microwaves are typically not associated with the cancer risks of high energy wavelengths.
In working microwave ovens, however, there are several fail safes to ensure microwaves don’t travel into your kitchen, according to Dellavalle. The glass door is equipped with a metal mesh screen that blocks microwaves. Dellavalle also notes there are several interlocks in the door of your oven, that will shut off the machine’s magnetron as soon as it’s opened.
But as evidenced by the aforementioned microwave oven, these interlocks can break down over time. While microwave ovens are rigorously tested, radiation leaks can happen as the machine gets older. Even then, the amount of radiation leaking into your kitchen is likely well below what’s considered dangerous for humans, according to Dellavalle.
“You’re usually doing something else anyways, it’s an unattended appliance,” Dellavalle said. “If you’re a couple of feet from the oven, it’s usually safe.”
Origins of the myth
Microwaves have incited fear and conspiracy since their very inception. Appliance manufacturer Whirlpool says the technology really took off in the 1970s, and ever since, people have been terrified about what a microwave could do to you.
In 1978, residents of Westchester, New York started a movement called “Citizens Against the Microwave Tower,” according to The New York Times archive. The movement opposed a new telephone tower in the area and was partially led by Paul Brodeur, author of The Zapping of America. His book alleged the Defense Department and microwave equipment manufacturers have conspired to conceal the dangers of microwave radiation, according to The Times.
The movement was part of a broader, national fear around microwave technology that occurred right as the ovens were taking off. Even then, experts were working on radiation leakage. In 1971, new standards took effect to ensure that microwave ovens went through rigorous testing, according to The Times archive. Their radiation leakage could not exceed 5 milliwatts, far lower than what’s considered dangerous to humans.
That 5 milliwatt standard still exists today, but many independent safety testers of microwave ovens, such as UL Solutions, test to ensure leakage of popular microwave ovens doesn’t exceed 1 milliwatt. The technology has become increasingly safe, but the fears from the 1970s persist today.
Why it’s pervasive
Despite the safety measures that have been put in place, concerns around the safety of microwaves continue today. The reason for this is that microwaves feel more unnatural than any other cooking instrument in our kitchen. Our ancestors never used microwaves, so they’re an easy scapegoat for many of our modern problems.
There’s more evidence around other concerns with microwaves. You probably shouldn’t microwave in plastic, according to Wired, which notes that nanoplastics can leach into your food when microwaved.
Microwaves also get grouped in with fears around other types of radiation. There’s abundantly more evidence that ultraviolet rays, gamma rays, and X-rays are harmful to you, so people throw microwaves into that group just in case. But there’s no clear evidence to say so.
It’s not ridiculous to be cautious, but you probably don’t need to be so worried about microwaves. The fear stems from a long-held conspiracy theory around microwaves, while the technology has gotten significantly safer over the last 50 years. If your microwave is still running with the door open, you should probably toss it. Otherwise, just stand a few feet back and you’ll be fine.
A version of this article originally appeared on Gizmodo.