# Does a microwave oven kill germs?

**URL:** <https://boards.straightdope.com/t/does-a-microwave-oven-kill-germs/83039>\
**Category:** Factual Questions\
**Created:** [September 21, 2001, 4:35pm UTC](https://boards.straightdope.com/t/does-a-microwave-oven-kill-germs/83039 "2001-09-21T16:35:06Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![SticksDweller](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@SticksDweller](https://boards.straightdope.com/u/SticksDweller)\
**Post date:** [September 21, 2001, 4:35pm UTC](https://boards.straightdope.com/t/does-a-microwave-oven-kill-germs/83039/1 "2001-09-21T16:35:06Z")

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Other than by heat that is. Does exposure to microwave radiation kill germs directly?

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**Author:** ![SticksDweller](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@SticksDweller](https://boards.straightdope.com/u/SticksDweller)\
**Post date:** [September 21, 2001, 4:46pm UTC](https://boards.straightdope.com/t/does-a-microwave-oven-kill-germs/83039/2 "2001-09-21T16:46:07Z")

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harmful bacteria, the same sort of bugs that would would be the reason for boiling water and cooking meat

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**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\
**Post date:** [September 21, 2001, 5:19pm UTC](https://boards.straightdope.com/t/does-a-microwave-oven-kill-germs/83039/3 "2001-09-21T17:19:40Z")

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Exposure to microwave radiation causes heat, which is what kills the germs. Microwave radiation is just radio waves on a particular wavelength that causes some substances, most notably water, to heat up. It’s effects are much different than other kinds of radiation (e.g., gamma rays, UV, x-rays) that do their damage in other ways.

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**Author:** ![armedmonkey](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@armedmonkey](https://boards.straightdope.com/u/armedmonkey)\
**Post date:** [September 21, 2001, 5:25pm UTC](https://boards.straightdope.com/t/does-a-microwave-oven-kill-germs/83039/4 "2001-09-21T17:25:59Z")

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Yes, but it **is** through heat. Let me explain. Microwaves are radio waves with a very high frequency. Because of their particular frequency, microwaves are absorbed by water and various carbon molecules. When the molecules absorb the microwave energy, it is converted to heat. This heat is what causes food to cook and bacteria to be killed. Microwaves cook stuff on a molecular level from the inside out. Since bacteria are made of water and organics, they’ll cook right along with everything else.

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**Author:** ![armedmonkey](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@armedmonkey](https://boards.straightdope.com/u/armedmonkey)\
**Post date:** [September 21, 2001, 5:27pm UTC](https://boards.straightdope.com/t/does-a-microwave-oven-kill-germs/83039/5 "2001-09-21T17:27:39Z")

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sorry about the simulpost **jseigle**

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**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\
**Post date:** [September 21, 2001, 6:08pm UTC](https://boards.straightdope.com/t/does-a-microwave-oven-kill-germs/83039/6 "2001-09-21T18:08:45Z")

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So in general, microwaves will kill harmful bacteria if the food is thoroughly cooked. However, most microwave ovens have dead spots which don’t necessarily get as hot as the rest of the oven. This is lessened somewhat by using a turntable, some more by stopping halfway through and stirring it up.

I’d still never use one to cook raw meat, though.