11 ms·

Microwave ovens and their hazards

82 points by trifit 5y ago

smegsicle 5y ago
is this anti-science, since microwaves are non-ionizing therefore cannot cause cancer or any other ill effect at low doses?
- tlavoie 5y ago
  From, well, reading the article, I'd say no.
  - BizarroLand 5y ago
    Yeah, this article is more for people who had a random thought about the dangers of microwaves and wanted to see if there was any truth to it. It should put you at ease to know that as long as you don't microwave yourself there isn't much to worry about.
- somebodynew 5y ago
  The article seems to be focused on the potential risk of interfering with medical devices using the same frequencies for communication. The more obvious danger of a microwave oven is that you must not stick your hand inside a microwave with a defective door sensor while it is running as it will cause heating in the same way that it can boil a cup of water. I will note, however, that the statement "microwaves are non-ionizing" does not automatically imply the common follow-up that "the absorption of microwaves cannot have any chemical effect other than indirectly through heating". This is evident, for example, in that proteins in the human eye undergo a chemical change in response to absorbing non-ionizing red light. Whether there is such a thing as a non-thermally microwave-driven chemical reaction is an open question in chemistry [1]. I feel the need to clarify as an addendum that nothing in this post suggests any danger associated with the use of low power microwave radiation from consumer wireless communication electronics. [1] https://en.wikipedia.org/wiki/Non-thermal_microwave_effect https://en.wikipedia.org/wiki/Non-thermal_microwave_effect
- moltke 5y ago
  Careful observation and investigation is never "anti-science" by definition.
- j15t 5y ago
  Non-ionizing radiation is certainly able to have effects on biological systems, and there is no reason to believe that effects are strictly neutral or positive. Calling these facts 'anti-science' is blatantly asinine.
  - mjbeswick 5y ago
    Cooking food by frying or grilling is probably much more of a health risk, not accounting for food being heated in plastic packaging.
52-6F-62 5y ago
Yes we need documentation like this. When I was younger I worked in a warehouse. In that warehouse we had a break room. In that break room we had a microwave that was not in good working order. The mechanism that would stop the machine from emitting microwaves when the door was opened had failed, and instead of fully disabling the machine out of safety it would allow it to continue to run with the door wide open. One day a coworker had been heating up some food and wanted to check on it, so he opened the door while it was running and stuck his head inside. Right inside. I had to holler at him to stop and pull his head out. Of course he was in no immediate danger, but I'm sure rotating all those water molecules in your brain can't do much good... those things do bake potatoes after all.
- somebodynew 5y ago
  The biggest danger is generally to your eyes because they contain significant water content but lack the circulatory cooling found in other parts of the body due to the need to be transparent. Looking into a running microwave with the door open can pose a cataract risk. https://www.fda.gov/radiation-emitting-products/resources-you-radiation-emitting-products/microwave-oven-radiation#Microwave_Ovens_and_Health https://www.fda.gov/radiation-emitting-products/resources-yo...
  - bell-cot 5y ago
    Oh, yes. Think of what happens to the clear "white" of an egg (proteins + water) when you heat it up. Which clear parts of your eyeballs (also proteins + water) would you be okay with that happening to?
  - causality0 5y ago
    Interesting. I wonder if looking too closely into a fire carries the same risk.
    - somebodynew 5y ago
      Infrared eye protection is important for glassblowers looking at molten glass [1]. Back of the envelope math suggests that an occupation that required staring at an intense fire for long periods of time would violate the same workplace safety thresholds, but I have not been able to locate any studies that specifically investigated looking at fire. There are a surprising number of different jobs that involve staring at incandescence from molten glass or metal, but I think the most interesting is an operator of a disappearing-filament pyrometer [2]. [1] https://www.sciencedirect.com/science/article/abs/pii/S0275540896000877 https://www.sciencedirect.com/science/article/abs/pii/S02755... [2] https://en.wikipedia.org/wiki/Disappearing-filament_pyrometer https://en.wikipedia.org/wiki/Disappearing-filament_pyromete...
account-5 5y ago
I remember when I was younger looking into a microwave that was on, after the door had been smashed (don't ask). I remember my vision going all wavey, proper freaked me out. From this article it sounds like the water in my eyes was being rotated, which is kinda freaking me out again.
- jcl 5y ago
  Wow... that's scary. But I think that when the article talks about water being "rotated", it's talking about individual water atoms, whose rotation would be too small to see. I imagine that the waviness would actually be due to the change in refraction due to the microwave's uneven heating -- like the waviness seen in the air just above a hot road, or the faint ripples seen at the bottom of a pot of cold water, when you start to heat it on a stove.
macintux 5y ago
When I was in my teens, we took a class trip to a nuclear reactor being built (never completed) in southern Indiana. I’ve long regretted I didn’t have a camera with me to capture the large sign on one gate that read (paraphrased): “Danger: Microwaves on premises” I wasn’t sure (still am not) whether they were referring to something industrial, but the thought that household microwave ovens at a nuclear power plant were sufficiently hazardous to require warning signs like that amused me.
- dijonman2 5y ago
  The sign was most likely for pacemaker patients.
  - ortusdux 5y ago
    Are modern ones still susceptible?
    - Nextgrid 5y ago
      Aren't they encased in some bio-compatible metal, essentially making them a faraday cage that should be immune even to direct exposure?
    - joezydeco 5y ago
      I was always under the impression that microwaves posed a hazard to pacemakers because of the magnetic fields involved, not the RF emissions themselves. Pacemakers use magnetic switches inside the sealed device for programming and/or battery shutoff. Lots of things involve pacemaker warnings, including iPhones with MagSafe charging ports in the case.
- mark-r 5y ago
  I believe they use microwaves for inspecting the welds on pipes and such.
  - 52-6F-62 5y ago
nimbius 5y ago
a major hazard missing from the article: high voltage transformers and capacitors inside can easily generate and store north of two-thousand volts. metal scrappers should take care to de-energize the circuit before diving in.
- someguydave 5y ago
  Yeah that plus they often contain beryllium oxide which is dangerous to inhale as a dust.
  - duskwuff 5y ago
    My understanding is that this risk is overstated. BeO dust can be dangerous, but new microwaves no longer use it as an insulator, and the amount of dust which is likely to be produced by breaking the insulator in older microwaves (rather than deliberately grinding it to a powder) is minimal.
    - agumonkey 5y ago
      I had the shameful experience of breaking one of this rings. I got so scared from hearing about BeO that I mailed a bunch of safety hazard chemists and doctors. Most of them told me BeO is not used anymore in most kitchen appliances MWO and that it's most probably AlO which is enough to dissipate consumer devices' power. BeO was used in high wattage or military devices. After digging magnetrons manufacturer data sheets I found mentions of AlO and Chromium but no BeO.
    - someguydave 5y ago
      Could be. In my estimation - for the vast majority of even technical people it is probably best to dispose of a nonfunctional microwave rather than attempt a repair.
- agumonkey 5y ago
  Caps shock can happen so easily. Lots of tutorials online on how to make a discharge rod. I still have a dozen to make a 10kV ladder one day.
walterbell 5y ago
Consumer microwaves use the same frequency as WiFi (~2.4Ghz) and leakage can be measured with EMF meters. We need an open-source database with test measurements of microwave ovens: - new devices (does max leakage vary by country?) - annual measurements of door seal decay
- syntheticnature 5y ago
  Worth noting that most microwave ovens are made by two companies (only one, in the US), other than some high-end models. See https://twitter.com/wirecutter/status/1263549250719416321?lang=en https://twitter.com/wirecutter/status/1263549250719416321?la...
  - bri3d 5y ago
    Panasonic microwaves besides the very cheapest ones are unique to Panasonic and much better than the Midea models. I no longer own a microwave (due to kitchen space, not ideological opposition) but when I did, the Panasonic microwave I owned was noticeably better in every way than any microwave I had owned prior (which it turned out were all probably Mideas).
  - aetherspawn 5y ago
    Imagine being able to get a product reliable at that scale.
  - alliao 5y ago
    huh it used to be Sharp that made most of these OEM/ODM microwaves
- mutagen 5y ago
  I have a 5 year old microwave purchased from a retailer with a reasonable expectation of quality (Costco) with no visible issues with the door seal that significantly interferes with 2.4 Ghz WiFi. I'm sure my neighbors don't enjoy the occasional internet issues that must result.
  - 5y ago
naoqj 5y ago
DantesKite 5y ago
I find dishwashers to be surprising dangerous. They can catch on fire from the heating element and their failure rate is astonishingly high.
- buescher 5y ago
  I’ve met folks who’ve worked in that industry that won’t leave one running unattended.
  - londons_explore 5y ago
    The manual to my fridge says to never leave it running unattended...
    - effingwewt 5y ago
      This is actually because the compressor can fail, generating heat and so possibly catching fire. Wires can also melt. I've seen far more than my share of appliances-turned-bonfires. Shorted wires, terminals, animal fur. Magnetrons and capacitors running amok. Those are especially fun when the microwave is mounted into wooden cabinets. Dryer belt pulleys freezing up causing friction rubber fires. The dangers abound, they just are never thought of until it happens. Now you have the extra fun of ICUs being on backorder 6+months (9/10 failures on all new models are ICU/touchscreen board failures). I'd really hate to be an appliance technician right now.
      - BizarroLand 5y ago
        I think there is irony in having an appliance that you cannot safely take your eyes off of.
- choward 5y ago
  Interesting. What's the actual root cause of that?
  - 5y ago
oceanghost 5y ago
I know this is tangential-- but does anyone know what the normal failure modes of microwaves are like? 20 years ago I microwaved some leftover macaroni and cheese from just a few seconds-- and it came out absolutely charred. I was confused but then noticed the microwave making an awful sound--a low rumble--it wasn't supposed to be on at all. Then the sparks started, then the smoke. Unfortunately the plug for it was behind a refrigerator so I ran to the electrical panel to turn the house power off. I figure some mosfet or something that controlled power must have failed closed or something. It most likely would have burned the house down if I hadn't happened to be right there.
323 5y ago
Getting burned when taking the food out is a far bigger risk.
tejohnso 5y ago
Sabine Hossenfelder has a great explanation of 5G controversy[1] that is somewhat relevant. Explains why it is probably not dangerous, but also indicates why some additional study is warranted. [1]: https://www.youtube.com/watch?v=FBsP-bmDLOo https://www.youtube.com/watch?v=FBsP-bmDLOo
exogen 5y ago
What's the latest science on microwaving plastic containers? Many now say "microwave safe" on them... did something change, like the research or the plastics used? Many of my friends still refuse to do it, but I'm not sure if that's still well-founded. My thought process is: well, the lawyers let 'em explicitly print "safe" on there... so they must be pretty damn sure.
- wyldfire 5y ago
  The safety they're referring to is whether the container will melt. But plastic leaching into foods is still a problem as far as I know. So I use glass containers for leftovers that I take to work, for example.
- tejohnso 5y ago
  I don't think they have to be pretty damn sure that they're safe. They only need to be pretty damn sure that they can't be proven to be liable for damage in a court of law.
- m463 5y ago
  I think the distinction people need to make is between heating in plastic and cooking.
toothpicked 5y ago
UHF microwave gun: https://www.youtube.com/watch?v=FIU8WZR9DNA https://www.youtube.com/watch?v=FIU8WZR9DNA
macromaniac 5y ago
Supposedly you can test for this using a wifi device since the frequencies are similar so I threw this together https://ismymicrowaveleaking.isotropic.us https://ismymicrowaveleaking.isotropic.us if anyone wants to try it. No clue how accurate it is, seems to work for my sample size of 2 microwaves. Phone had to be on 2.4ghz wifi or the signal was unaffected.
forgotmypw17 5y ago
>this would pose no known health risks Feels like I've seen these words so many times before...
poisonarena 5y ago
my gf's mom here in Colombia wont allow microwaves in the house since 'they make you sick'. she also believes having hair wet for too long will make you sick
pomian 5y ago
There was an HN post a year or so back about the microwave oven used in the lunch room, of a SETI facility, or other radio astronomy setup, that befuddled everyone by interfering with the received signals. No one could detect the source, which occurred at certain 'periodic' times of the day. Until it was tied in with coffee breaks and lunch time. I found this with a quick search: https://www.theguardian.com/science/2015/may/05/microwave-oven-caused-mystery-signal-plaguing-radio-telescope-for-17-years https://www.theguardian.com/science/2015/may/05/microwave-ov...

82 points by trifit 5y ago

is this anti-science, since microwaves are non-ionizing therefore cannot cause cancer or any other ill effect at low doses?

tlavoie 5y ago
From, well, reading the article, I'd say no.
- BizarroLand 5y ago
  Yeah, this article is more for people who had a random thought about the dangers of microwaves and wanted to see if there was any truth to it. It should put you at ease to know that as long as you don't microwave yourself there isn't much to worry about.
somebodynew 5y ago
The article seems to be focused on the potential risk of interfering with medical devices using the same frequencies for communication. The more obvious danger of a microwave oven is that you must not stick your hand inside a microwave with a defective door sensor while it is running as it will cause heating in the same way that it can boil a cup of water. I will note, however, that the statement "microwaves are non-ionizing" does not automatically imply the common follow-up that "the absorption of microwaves cannot have any chemical effect other than indirectly through heating". This is evident, for example, in that proteins in the human eye undergo a chemical change in response to absorbing non-ionizing red light. Whether there is such a thing as a non-thermally microwave-driven chemical reaction is an open question in chemistry [1]. I feel the need to clarify as an addendum that nothing in this post suggests any danger associated with the use of low power microwave radiation from consumer wireless communication electronics. [1] https://en.wikipedia.org/wiki/Non-thermal_microwave_effect https://en.wikipedia.org/wiki/Non-thermal_microwave_effect
moltke 5y ago
Careful observation and investigation is never "anti-science" by definition.
j15t 5y ago
Non-ionizing radiation is certainly able to have effects on biological systems, and there is no reason to believe that effects are strictly neutral or positive. Calling these facts 'anti-science' is blatantly asinine.
- mjbeswick 5y ago
  Cooking food by frying or grilling is probably much more of a health risk, not accounting for food being heated in plastic packaging.

52-6F-62 5y ago

Yes we need documentation like this. When I was younger I worked in a warehouse. In that warehouse we had a break room. In that break room we had a microwave that was not in good working order. The mechanism that would stop the machine from emitting microwaves when the door was opened had failed, and instead of fully disabling the machine out of safety it would allow it to continue to run with the door wide open. One day a coworker had been heating up some food and wanted to check on it, so he opened the door while it was running and stuck his head inside. Right inside. I had to holler at him to stop and pull his head out. Of course he was in no immediate danger, but I'm sure rotating all those water molecules in your brain can't do much good... those things do bake potatoes after all.

somebodynew 5y ago
The biggest danger is generally to your eyes because they contain significant water content but lack the circulatory cooling found in other parts of the body due to the need to be transparent. Looking into a running microwave with the door open can pose a cataract risk. https://www.fda.gov/radiation-emitting-products/resources-you-radiation-emitting-products/microwave-oven-radiation#Microwave_Ovens_and_Health https://www.fda.gov/radiation-emitting-products/resources-yo...
- bell-cot 5y ago
  Oh, yes. Think of what happens to the clear "white" of an egg (proteins + water) when you heat it up. Which clear parts of your eyeballs (also proteins + water) would you be okay with that happening to?
- causality0 5y ago
  Interesting. I wonder if looking too closely into a fire carries the same risk.
  - somebodynew 5y ago
    Infrared eye protection is important for glassblowers looking at molten glass [1]. Back of the envelope math suggests that an occupation that required staring at an intense fire for long periods of time would violate the same workplace safety thresholds, but I have not been able to locate any studies that specifically investigated looking at fire. There are a surprising number of different jobs that involve staring at incandescence from molten glass or metal, but I think the most interesting is an operator of a disappearing-filament pyrometer [2]. [1] https://www.sciencedirect.com/science/article/abs/pii/S0275540896000877 https://www.sciencedirect.com/science/article/abs/pii/S02755... [2] https://en.wikipedia.org/wiki/Disappearing-filament_pyrometer https://en.wikipedia.org/wiki/Disappearing-filament_pyromete...

account-5 5y ago

I remember when I was younger looking into a microwave that was on, after the door had been smashed (don't ask). I remember my vision going all wavey, proper freaked me out. From this article it sounds like the water in my eyes was being rotated, which is kinda freaking me out again.

jcl 5y ago
Wow... that's scary. But I think that when the article talks about water being "rotated", it's talking about individual water atoms, whose rotation would be too small to see. I imagine that the waviness would actually be due to the change in refraction due to the microwave's uneven heating -- like the waviness seen in the air just above a hot road, or the faint ripples seen at the bottom of a pot of cold water, when you start to heat it on a stove.

macintux 5y ago

When I was in my teens, we took a class trip to a nuclear reactor being built (never completed) in southern Indiana. I’ve long regretted I didn’t have a camera with me to capture the large sign on one gate that read (paraphrased): “Danger: Microwaves on premises” I wasn’t sure (still am not) whether they were referring to something industrial, but the thought that household microwave ovens at a nuclear power plant were sufficiently hazardous to require warning signs like that amused me.

dijonman2 5y ago
The sign was most likely for pacemaker patients.
- ortusdux 5y ago
  Are modern ones still susceptible?
  - Nextgrid 5y ago
    Aren't they encased in some bio-compatible metal, essentially making them a faraday cage that should be immune even to direct exposure?
  - joezydeco 5y ago
    I was always under the impression that microwaves posed a hazard to pacemakers because of the magnetic fields involved, not the RF emissions themselves. Pacemakers use magnetic switches inside the sealed device for programming and/or battery shutoff. Lots of things involve pacemaker warnings, including iPhones with MagSafe charging ports in the case.
mark-r 5y ago
I believe they use microwaves for inspecting the welds on pipes and such.
- 52-6F-62 5y ago

nimbius 5y ago

a major hazard missing from the article: high voltage transformers and capacitors inside can easily generate and store north of two-thousand volts. metal scrappers should take care to de-energize the circuit before diving in.

someguydave 5y ago
Yeah that plus they often contain beryllium oxide which is dangerous to inhale as a dust.
- duskwuff 5y ago
  My understanding is that this risk is overstated. BeO dust can be dangerous, but new microwaves no longer use it as an insulator, and the amount of dust which is likely to be produced by breaking the insulator in older microwaves (rather than deliberately grinding it to a powder) is minimal.
  - agumonkey 5y ago
    I had the shameful experience of breaking one of this rings. I got so scared from hearing about BeO that I mailed a bunch of safety hazard chemists and doctors. Most of them told me BeO is not used anymore in most kitchen appliances MWO and that it's most probably AlO which is enough to dissipate consumer devices' power. BeO was used in high wattage or military devices. After digging magnetrons manufacturer data sheets I found mentions of AlO and Chromium but no BeO.
  - someguydave 5y ago
    Could be. In my estimation - for the vast majority of even technical people it is probably best to dispose of a nonfunctional microwave rather than attempt a repair.
agumonkey 5y ago
Caps shock can happen so easily. Lots of tutorials online on how to make a discharge rod. I still have a dozen to make a 10kV ladder one day.

walterbell 5y ago

Consumer microwaves use the same frequency as WiFi (~2.4Ghz) and leakage can be measured with EMF meters. We need an open-source database with test measurements of microwave ovens: - new devices (does max leakage vary by country?) - annual measurements of door seal decay

syntheticnature 5y ago
Worth noting that most microwave ovens are made by two companies (only one, in the US), other than some high-end models. See https://twitter.com/wirecutter/status/1263549250719416321?lang=en https://twitter.com/wirecutter/status/1263549250719416321?la...
- bri3d 5y ago
  Panasonic microwaves besides the very cheapest ones are unique to Panasonic and much better than the Midea models. I no longer own a microwave (due to kitchen space, not ideological opposition) but when I did, the Panasonic microwave I owned was noticeably better in every way than any microwave I had owned prior (which it turned out were all probably Mideas).
- aetherspawn 5y ago
  Imagine being able to get a product reliable at that scale.
- alliao 5y ago
  huh it used to be Sharp that made most of these OEM/ODM microwaves
mutagen 5y ago
I have a 5 year old microwave purchased from a retailer with a reasonable expectation of quality (Costco) with no visible issues with the door seal that significantly interferes with 2.4 Ghz WiFi. I'm sure my neighbors don't enjoy the occasional internet issues that must result.
- 5y ago

naoqj 5y ago

DantesKite 5y ago

I find dishwashers to be surprising dangerous. They can catch on fire from the heating element and their failure rate is astonishingly high.

buescher 5y ago
I’ve met folks who’ve worked in that industry that won’t leave one running unattended.
- londons_explore 5y ago
  The manual to my fridge says to never leave it running unattended...
  - effingwewt 5y ago
    This is actually because the compressor can fail, generating heat and so possibly catching fire. Wires can also melt. I've seen far more than my share of appliances-turned-bonfires. Shorted wires, terminals, animal fur. Magnetrons and capacitors running amok. Those are especially fun when the microwave is mounted into wooden cabinets. Dryer belt pulleys freezing up causing friction rubber fires. The dangers abound, they just are never thought of until it happens. Now you have the extra fun of ICUs being on backorder 6+months (9/10 failures on all new models are ICU/touchscreen board failures). I'd really hate to be an appliance technician right now.
    - BizarroLand 5y ago
      I think there is irony in having an appliance that you cannot safely take your eyes off of.
choward 5y ago
Interesting. What's the actual root cause of that?
- 5y ago

oceanghost 5y ago

I know this is tangential-- but does anyone know what the normal failure modes of microwaves are like? 20 years ago I microwaved some leftover macaroni and cheese from just a few seconds-- and it came out absolutely charred. I was confused but then noticed the microwave making an awful sound--a low rumble--it wasn't supposed to be on at all. Then the sparks started, then the smoke. Unfortunately the plug for it was behind a refrigerator so I ran to the electrical panel to turn the house power off. I figure some mosfet or something that controlled power must have failed closed or something. It most likely would have burned the house down if I hadn't happened to be right there.

323 5y ago

Getting burned when taking the food out is a far bigger risk.

tejohnso 5y ago

Sabine Hossenfelder has a great explanation of 5G controversy[1] that is somewhat relevant. Explains why it is probably not dangerous, but also indicates why some additional study is warranted. [1]: https://www.youtube.com/watch?v=FBsP-bmDLOo https://www.youtube.com/watch?v=FBsP-bmDLOo

exogen 5y ago

What's the latest science on microwaving plastic containers? Many now say "microwave safe" on them... did something change, like the research or the plastics used? Many of my friends still refuse to do it, but I'm not sure if that's still well-founded. My thought process is: well, the lawyers let 'em explicitly print "safe" on there... so they must be pretty damn sure.

wyldfire 5y ago
The safety they're referring to is whether the container will melt. But plastic leaching into foods is still a problem as far as I know. So I use glass containers for leftovers that I take to work, for example.
tejohnso 5y ago
I don't think they have to be pretty damn sure that they're safe. They only need to be pretty damn sure that they can't be proven to be liable for damage in a court of law.
m463 5y ago
I think the distinction people need to make is between heating in plastic and cooking.

toothpicked 5y ago

UHF microwave gun: https://www.youtube.com/watch?v=FIU8WZR9DNA https://www.youtube.com/watch?v=FIU8WZR9DNA

macromaniac 5y ago

Supposedly you can test for this using a wifi device since the frequencies are similar so I threw this together https://ismymicrowaveleaking.isotropic.us https://ismymicrowaveleaking.isotropic.us if anyone wants to try it. No clue how accurate it is, seems to work for my sample size of 2 microwaves. Phone had to be on 2.4ghz wifi or the signal was unaffected.

forgotmypw17 5y ago

>this would pose no known health risks Feels like I've seen these words so many times before...

poisonarena 5y ago

my gf's mom here in Colombia wont allow microwaves in the house since 'they make you sick'. she also believes having hair wet for too long will make you sick

pomian 5y ago

There was an HN post a year or so back about the microwave oven used in the lunch room, of a SETI facility, or other radio astronomy setup, that befuddled everyone by interfering with the received signals. No one could detect the source, which occurred at certain 'periodic' times of the day. Until it was tied in with coffee breaks and lunch time. I found this with a quick search: https://www.theguardian.com/science/2015/may/05/microwave-oven-caused-mystery-signal-plaguing-radio-telescope-for-17-years https://www.theguardian.com/science/2015/may/05/microwave-ov...