Recently I've gotten worried about overuse of cleaning rags / sponges / scouring pads / scrubbers in my kitchen (let's call them "scrubbers" for short), and whether I should perhaps replace them more often than I do. Then I got to thinking - maybe I could just sterilize them thoroughly to increase their longevity?

My questions are:

  • Is this known to be effective?
  • Are there health risks to this procedure (e.g. material detaching from the sponge/scrubber and going into my food)?
  • How long and with what amount of power should I nuke my scrubber?
  • Is there there some preparation work I need to do?
  • This should be asked in the context of our Skeptics site (assuming it hasn't already) where they investigate the truth or effectiveness of notable claims. Exploring whether these techniques work or disproving them is not within the topic for this site -- lifehacks.meta.stackexchange.com/a/1296/80. Sorry about the confusion. Aug 19, 2017 at 19:29
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    @RobertCartaino: The skeptics site is not a place to discuss how to best apply what seems to be a sound method. I would claim that using your microwave for sterilization is a hack indeed: It's an "uncommon solutions to a common problem" and an "unusual way of using an everyday object to make life easier".
    – einpoklum
    Aug 19, 2017 at 20:40
  • I agree that the 'microwave for sterilization is a hack indeed'; a novel alternative to pouring boiling water over your cleaning rags as my great grandmother and following generations used to do. However you provided the hack in the question and asked if (and how) it is going to work, what is an approach that has been decided by votes not to work for this site. If you don't agree with this policy, follow the link to meta provided by @RobertCartaino read the question and answers and cast your own votes.
    – Flint
    Sep 21, 2017 at 22:44

1 Answer 1


This article:

Researchers: Microwave oven can sterilize sponges, scrub pads

Suggests the following:

  • Before doing this, make sure the scrubber has no metal content
  • Douse your scrubber fully in water <- really?
  • 2 min suffice for 99% of bacteria/pathogens <- but at what power?
  • 4 min are required for rare super-resistant spores <- but at what power?
  • If you cook and use your scrubber every day, sterilize it every other day

but I would very much like to hear other people's experience and suggestions. Also, the article did not say what power output setting should be used.

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    Careful. Microwaves (reportedly) can sterilize items by heating them, not through the process of irradiation. Irradiating is where ionizing radiation is used to denature any bacteria and other pathogens. Microwaves to not emit any ionizing radiation, so calling any items you place in there "irradiated" is simply not correct. Aug 19, 2017 at 19:33
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    @RobertCartaino: Edited to avoid the argument, but you're wrong, in these sense that "irradiating" = "exposing to radiation", and A microwave oven is a kitchen appliance that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range.
    – einpoklum
    Aug 19, 2017 at 20:38
  • I'm curious about the size of sponges they used: when i microwave my sponge in a bowl of water for 1 minute it reaches boiling temperature, thus effectively killing off most lifeforms within.
    – Ivana
    Sep 7, 2017 at 17:54
  • @Ivana: Some micro-organisms are resistant to short exposures to heat.
    – einpoklum
    Sep 7, 2017 at 18:50
  • FWIW, I have read in various generic sources that when otherwise not stated, 1000 watts is assumed for MW oven power.
    – Stan
    Sep 18, 2017 at 6:39

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