Can an open microwave door leak a dangerous amount of radiation?

October 15, 2006 7:25 PM

My roommates have a really annoying habit of leaving the microwave door ajar after they're done using it. In other words, the microwave beeps, they take their food out, and then leave the door hanging. Am I being exposed to unsafe levels of radiation?
posted by invisible ink to health & fitness (34 comments total)

No. Opening the door shuts off the magnetron.
posted by phrontist at 7:28 PM on October 15, 2006

You're not being exposed to any. "Microwave radiation" is the same type of radiation as light or radio waves, just at different wavelengths, and it stops producing them immediately.
posted by DoctorFedora at 7:28 PM on October 15, 2006

No, the microwave is not emitting any radiation at all when it is not powered-on.
posted by TheNewWazoo at 7:28 PM on October 15, 2006

No.

First off, the microwave isn't on. Second off, if you were getting any radiation from it, your skin would feel uncomfortably warm (that's how less-than-lethal microwave weapons work). Third, no. Your skin is enough of a resistor to remove any real danger, unless your hands are metal forks. If they are, you have bigger problems, Tetsuo Iron Man.
posted by klangklangston at 7:29 PM on October 15, 2006 [6 favorites]

It's off, so it can't be emitting any of that radiation.

And on a semi-sequitor; if microwaves were giving off deadly lukhemia-causing radiation, would the little plastic door be able to stop it from getting to you?
posted by KingoftheWhales at 7:30 PM on October 15, 2006 [1 favorite]

From the FDA:

Although FDA believes the standard assures that microwave ovens do not present any radiation hazard, the Agency continues to reassess its adequacy as new information becomes available.

The link then explains that high levels of microwave radiation could burn you, but low levels (like a standard microwave oven) will not do anything bad.

Oh, and tell your roommate to close the door. How hard is that? If it annoys you, leave the fridge open for them to complain. They'll get the point.
posted by daninnj at 7:30 PM on October 15, 2006 [1 favorite]

Short answer: no.

Long answer: There are no radioactive isotopes in your microwave. As soon as the microwave stops, the microwave ceases to make microwave radiation. Let's suppose your microwave is maybe 20 cm across, and it takes, oh, ten improbable bounces from one wall to another to absorb all of the microwaves (I'm being generous). That'd be two-thirds of a nanosecond after it beeps before all of the microwave radiation is absorbed.
posted by adipocere at 7:31 PM on October 15, 2006

That having been said- if there's a light on in your microwave, the bulb will burn out sooner. Plus, there's a larger chance of the door getting broken when someone walks into it.

No dangerous radiation, but there ARE good reasons to close the microwave door.
posted by JMOZ at 7:34 PM on October 15, 2006

And on a semi-sequitor; if microwaves were giving off deadly lukhemia-causing radiation, would the little plastic door be able to stop it from getting to you?

Um, microwave doors actually do keep the microwave radiation inside the microwave. Because the holes are smaller then the wavelength of the microwave, the energy cannot escape.
posted by delmoi at 7:36 PM on October 15, 2006

Okay, you're all best answers, and I'm obviously the paranoid type. Thanks everyone!:-)
posted by invisible ink at 7:38 PM on October 15, 2006

they might be leaving the door open to "air out" the smells of food just cooked within it.

I usually leave the microwave door open overnight after popping some corn for dinner.

having said this, there is no reason why your room mates could not return to the microwave 10 minutes later to close the microwave door - while the microwave turntable is being washed in the dishwasher.
posted by seawallrunner at 7:38 PM on October 15, 2006

Everybody's right, but complain anyway 'cause you're right, it's annoying as hell. I bet they leave soda bottles in the fridge with only a drop or two in the bottom, too.
posted by Opposite George at 7:47 PM on October 15, 2006

"would the little plastic door be able to stop it from getting to you?"

there's a metal plate in the plastic door, with holes that are "smaller then the wavelength of the microwave
"
posted by fake at 7:48 PM on October 15, 2006 [1 favorite]

I'm glad to hear that radiation doesn't get leaked.

I leave my microwave door open to air out the steam after heating things. I usually close it not too long afterwards, though.
posted by cadge at 7:56 PM on October 15, 2006

Guilty. I do this too to not trap the smells in it. Or the humidity. I also usually close it later.

Of course, I keep the microwave so high up there's no way anyone can run into it. :) (It's on top of the fridge. Hey, that's as much room as I've got.)
posted by smallerdemon at 8:10 PM on October 15, 2006

"If it annoys you, leave the fridge open for them to complain."

Except that leaving the fridge open uses up ridiculous amounts of electricity as the fridge attempts to cool down the entire house, and causes lots of food to spoil. Whereas leaving the microwave open... well... it might blow out a $1 light bulb a bit sooner?
posted by CrayDrygu at 8:16 PM on October 15, 2006

Well, of course I'm not talking about having it open all night or anything. Open it in front of them. They would probably close it quickly.
posted by daninnj at 8:42 PM on October 15, 2006

Also: If you leave an oven door open, eventually its weight can bend the hinges so that it doesn't close properly. If your microwave door is lateral, obviously the forces apply differently — but still, its hinges aren't designed to support the weight for prolonged periods.
posted by cribcage at 9:07 PM on October 15, 2006

Also: If you leave an oven door open, eventually its weight can bend the hinges so that it doesn't close properly. If your microwave door is lateral, obviously the forces apply differently — but still, its hinges aren't designed to support the weight for prolonged periods.

That's nonsense. Or by eventually you mean 47,000 years.
posted by oxford blue at 9:22 PM on October 15, 2006

In the case of my last oven, "eventually" ran about 46,997 short of 47,000.
posted by cribcage at 9:26 PM on October 15, 2006 [1 favorite]

If you don't like the food odours in your microwave, get a little glass bowl and fill it halfway with water, then add a tablespoon or so of lemon juice. Nuke for 1-2 minutes on high (until it starts boiling for a few seconds). This knocks out most odours and dampens the oven walls, making a quick wipe with a clean sponge easier.
posted by maudlin at 9:45 PM on October 15, 2006 [3 favorites]

It may be worth mentioning here that when we speak of "nuking" something in a microwave oven, that's purely a colloquialism--it's not scientifically accurate. Your microwave isn't radioactive, whether on or off (well, no more radioactive than anything else in your kitchen, what with very very low but non-zero levels of background radioactivity), and it doesn't make anything radioactive. That may be the source of some confusion.
posted by DevilsAdvocate at 11:10 PM on October 15, 2006

Yep, I know it's a colloquialism -- that I've picked up from my engineer husband. *g*

(Anyone else here old enough to remember when The Price is Right called them "radar ranges"?)
posted by maudlin at 11:46 PM on October 15, 2006

RadaRange was a particular brand, IIRC, not a generic name for them. I believe they were the microwave ovens made by Amana.
posted by litlnemo at 1:20 AM on October 16, 2006

Derail: If the microwave door does not let microwaves out, then why are they dangerous to people with pacemakers?
posted by iurodivii at 5:36 AM on October 16, 2006

They're not, really.

http://www.straightdope.com/columns/020802.html
posted by Optimus Chyme at 6:03 AM on October 16, 2006

invisible ink: Where is your microwave located? Ours hangs from cabinet over the stove, and if we leave the door open we bang our heads on it. It hurts! It's a more direct hazard than the microwaves themselves.
posted by Robert Angelo at 6:58 AM on October 16, 2006

a second suggestion for airing out the smells from a well-used microwave - set a small ramiken of baking soda in the microwave when not in use. I keep mine on top of the microwave and when I'm doing heating something up, pop it back in. Just like keeping an open box of baking soda in the fridge to absorb odors.
posted by crepeMyrtle at 7:53 AM on October 16, 2006

I'm going to vote No to the passive agressive suggestions for how you can make your roommates realize this is a problem. I've had roommates do this and it is infuriating if they've never even brought it up with you before.

Just talk to them about it, figure out why they leave it open and what the solution is.
posted by utsutsu at 8:35 AM on October 16, 2006

RadaRange was a particular brand, IIRC, not a generic name for them

It was, for a while, a "generic" name in the same way that people say "I need to go xerox this" when they mean "I need to photocopy this".

The "radar" part stems from the fact that microwave cookery was basically invented by Percy Spencer, who used a radar magnetron at Raytheon to cook popcorn (Ref). Marketing guys, being the imitative folks they are, latched on to the futuristic sounding word for the first commercial model, the 1947 Radarange by Amana.
posted by aramaic at 8:56 AM on October 16, 2006

It's probably that I'm too young to be familiar with that generic usage. As a kid in the 70s, when I heard Radarange, it was always on game shows where they were giving one away as a prize, so it was always "An Amana Radarange!" I never knew a single person who actually owned a microwave until the early 80s, and by then we were all calling them microwave ovens.
posted by litlnemo at 2:02 PM on October 16, 2006

Do people still call them microwave ovens? Or just microwaves?
posted by oxford blue at 4:18 PM on October 16, 2006

Oxford: scientists and engineers who work with microwaves (and other nearby wavelengths of electromagnetic radiation) often call them microwave ovens, but as a group, we tend towards precision in our speech to an often irritatin degree.
posted by JMOZ at 4:23 PM on October 16, 2006

This *just* showed up on Consumer Reports: are microwaves dangerous?
posted by IndigoRain at 7:39 PM on October 16, 2006