Sterilizing Sponges

Sponges are often used for the dirtiest jobs in the house. Sterilizing them is the best way to make sure they are free of germs and viruses. This is a guide about sterilizing sponges.

A pile of sponges ready for cleaning.
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Tip: Sterilizing Sponges

I put kitchen sponges in my dishwasher and run the cycle with a cup of bleach. After the dishwasher disinfects of the kitchen sponges, I spray them with a disinfectant spray and place in the microwave for about 50 seconds on high power. After completion of using the sponges to wash the counters, stove and other areas of the kitchen, I once again wash the sponges thoroughly in hot water, spray with a disinfectant spray and place in the microwave for 1 minutes at medium/high power. Make sure that there is no metal elements on the sponges before placing them in the microwave for disinfecting purposes.

I also use the same method for micro-fiber cloths. The sponges and the micro-fiber cloths are laundered in hot water in the washing machine once a week; otherwise, they are washed in the dishwasher with bleach; the bleach also disinfects the dishwasher.

By WandaJo

CommentWas this helpful? Yes

Question: Sterilize Your Sponge in the Microwave

By gayle 22 3

I have seen comments regarding cleaning kitchen sponges in the microwave. How does one go about cleaning sponges with Teflon "scrubbie" on other side of sponge? Can you put that in microwave?

By Gayle from Rochester, NY

AnswerWas this helpful? Yes


Most Recent Answer

thr502777 Flag

May 29, 2010

I have had no problems with sterilizing sponges with a scrub material on one side. I always do it with the sponge side down and the scrubbing material face up, but I don't know if that is necessary.

ReplyWas this helpful? Yes

Tip: Sanitizing Sponges and Dish Cloths

By Cyinda 214 1,287

Whenever you run your dishwasher, tie or clip your dishcloth to the top rack of your dishwasher. It will get clean with your dishes! My mother does this. It saves both time and money on washing.

CommentWas this helpful? Yes

Archive: Sterilize Your Sponge in the Microwave

I understand that sponges can be sanitized in the microwave. How long should it take to sanitize for a 900 watt microwave? Or a 750 watt?

Gran from Lubbock, TX


Tip: Sterilize Your Sponge in the Microwave


After using your kitchen sponge whether to clean up or to do the dishes, wash it well with liquid detergent and then rinse well. Place it in the microwave and zap it for 1 minute. The result is a sterilized sponge which can be used without worrying about harboring germs.

By Joes Girl

RE: Sterilize Your Sponge in the Microwave 04/09/2004
I put my sponges in my dishwasher with a load of dishes and run them through the wash, they are clean and sterilized at the same time. I use the fishnet bags off of onions to put the small sponges in so they don't get thrown to the bottom of the dishwater when they get water works beautifully.
By tigerlil234
RE: Sterilize Your Sponge in the Microwave 06/01/2005
I've tried using the dish washer for sponges, however the bacteria is still present since the sponge will smell after one use. Instead I do as the restaurants do and keep a spray bottle of watered down bleach under my sink. Each night I spray down the sponges and clothes then squeeze them out. They stay odor and germ free for days. The spray bottle is also a good way to keep your counter tops and plastic cutting boards free of bacteria and germs.
By Kim Hibbert
RE: Sterilize Your Sponge in the Microwave 09/17/2005
Bleaching your sponges is self-defeating. Once they've been bleached, they fall apart!
By Laurel

By moderator

RE: Sterilize Your Sponge in the Microwave

I agree that the dishwasher is probably not hot enough to adequately sterilize a sponge--and I worry that it might contaminate some of the dishes. I also microwave my sponges for at least a minute, more often two. (I just make sure not to wring them too thoroughly, so that they have plenty of moisture.) The added bonus of this method, is that all that steam makes it very easy to wipe out the inside of the microwave--gets rid of the splatters effortlessly.

Just be careful when taking the VERY hot sponge out of the microwave--steam burns hurt!

By Jilson

RE: Sterilize Your Sponge in the Microwave

I read in a newspaper or magazine that sponges are too thick and it's a waste of time sterilizing them. The article suggested just using dishcloths and disposable sponges. The article pointed out that sponges trap bits of food, so because you can not obviously get rid of all of these large particles, you can be sure that the invisible germs are also still present. I don't recall where I read this info.

By cookwie

RE: Sterilize Your Sponge in the Microwave

I like to be environmentally friendly. I say ditch ALL your sponges. After one use, they hold bacteria which is next to impossible to get rid of. Imagine dunking your sponge in your bathroom bowl and wiping down your countertops and dining table with it. EEEWW. Buy some tea towels, about two dozen.. Yes, two dozen at least. Keep them in a small basket in a place easily accessable. For every spill, use one. If you wipe down a counter top, stove, table, use yet another... when you wash them, use HOT water. I use hot water for these, sheets and blankets. I buy white (yes, white) I use bleach with the detergent. They come out still white and the few that don't due to whatever reason, I use to wipe up spills on the floor. But sponges are just no good for cleaning. I do not buy them. It took me about two weeks to get used to the tea towels, but now, I could not go back to sponges.

Just one person's opinion.

By KLS8800

RE: Sterilize Your Sponge in the Microwave

I have put the small 3M Scotch scouring pads in a microwave for a minute or two. But regular sponges I would toss. They are inexpensive, less of a problem just to buy new ones.

By Dean

RE: Sterilize Your Sponge in the Microwave

Wash your sponge carefully then rinse.

Microwave the wet sponge on high for 1.5 - 4 minutes depending on the thickness of the sponge and the power of the microwave oven.

If it smells when you take it out, that's because it was pretty bad. Don't give up - you just need to get it thoroughly clean. Do the following:

In a microwave-safe bowl, put 1-2 tablespoons of Oxyclean. Add hot water and stir, then soak the sponge in it for 5 minutes. Be sure the sponge is thoroughly saturated with the solution - I use an old toothbrush or wear rubber gloves while doing this.

Rinse the sponge well and then microwave it again.

This does not cause the sponge to fall apart, it does remove stains and smells and germs. Actually, the Oxyclean gets rid of many germs because the oxidation that's tough on hands and nails is tough on other living tissue like germs. But microwave it too, to kill viruses and tough bacteria spores.

If you do this weekly, you can use sponges a long time, keep costs and landfill waste down and have a healthy clean kitchen.

By checked this out

RE: Sterilize Your Sponge in the Microwave

I tried microwaving my sponge. It has the 3m scotchbrite on one side. It was barely damp. After 5 minutes in the microwave, it caught fire, and I still have not determined the cause...

By Steve

RE: Sterilize Your Sponge in the Microwave

I microwaved my sponge for 6 minutes and it did not catch fire. But before doing that, I wet the sponge first. I have it absorb water first before putting it in the microwave. The article said to do it that way.

By Richard T

RE: Sterilize Your Sponge in the Microwave

In response to the environmentally friendly person - bleach is not exactly friendly to the environment. Do you pour it down the drain after bleaching your tea towels?

You would think the radiation (not the heat) would kill bacteria in the microwaved sponges. and they shouldn't be too thick, because when you microwave something, it cooks from the inside out.

just some thoughts.

By eliz

RE: Sterilize Your Sponge in the Microwave

I just tried it - a yellow 3m with the scrubby green part, like they sell at Costco. 30 seconds in my micro (on high) and there was no smell left, and it was very hot (be careful). I feel good about that. the smell is what drove me crazy. in the winter here, nothing dries, so it's nice to have an option other than using a new sponge every dishwashing.

Hope that helps!

By Dawn

RE: Sterilize Your Sponge in the Microwave

Washington Post article says microwave sponge for 4 to 10 minutes. My sponge blew up and caught on fire and ruined my microwave.

Archive: Sterilize Your Sponge in the Microwave

Sponges and kitchen scrub brushes can be loaded with disease-causing viruses and bacteria. So microwave them, scientists say.

By Designer sheets from Mississippi

Editor's Note: The University of Florida Researchers recommends, making sure the sponge is very wet and microwave it for 2 minutes.


RE: Sterilize Your Sponge in the Microwave

I wonder if toothbrushes can be sterilized this way?

I buy wash cloths on sale when ever I see them and use one after the other all day. Then I wash them. I have light colored cloths, dark colored cloths because I do laundry everyday, either light or darks. (01/31/2007)

By Christine

RE: Sterilize Your Sponge in the Microwave

Be careful!

By Food 411 for One

RE: Sterilize Your Sponge in the Microwave

I have a question about the tea towels suggestion. Actually, it's a stupid question, but I'm not sure of the answer, so I guess not so stupid, huh? Anyway, tea towels, kitchen towels, same thing? Probably, right? Also, getting them at 99 cent stores, better than say at Wal-Mart or Target? Kitchen towels I found at Wal-Mart are less than $3.00, but still, getting a dozen of them?


By Trish M.

RE: Sterilize Your Sponge in the Microwave

I also read this in the newspaper, and decided it was a quick solution.
I use the kind that has a scrubber on one side, so I try to get my money's worth. Well, I didn't think about rinsing the sponge first.
After 2 minutes in the microwave, I had enough soap suds to do a sink full of dishes!! Make sure you rinse out your sponge first! (02/01/2007)

By hugmehugs

RE: Sterilize Your Sponge in the Microwave

I just read this on the web:

How To Successfully Sanitize Your Sponges

Zapping your sponges in the microwave for two minutes will wipe out bacteria, a recent study says - but the GH Research Institute advises: Don't do it! "Microwaves vary greatly based on size and wattage," says GHRI Kitchen Appliances Director, Sharon Franke. "So if you have a less powerful model than the one used in the study, it may not be able to kill bacteria in two minutes." And if your model is more powerful, your sponge could dry out, harden, get destroyed - or even cause a fire. The safest way to sanitize: Soak sponges in a solution of three tablespoons bleach to one quart water for five minutes. Rinse, wring out, and let dry.

So I guess it's back to good ol' dependable bleach for me!


By hugmehugs

Relax, People

Funny, people have been using sponges for years and years without getting sick. Do you know anyone who's gotten sick from a sponge? This paranoia about bacteria is sick. The world is fully of bacteria and we coexist safely with it most of the time; as long as you take reasonable care handling and preparing your food, you are fine. If I wring out my sponges well and let them dry (note that letting something dry also tends to kill bacteria, just not instantly, and maybe not 100%) they don't get stinky. No problem. (02/14/2007)

By Funny

RE: Sterilize Your Sponge in the Microwave

I really am amazed to see the first posting by "Funny" that indicates a lack of proof that kitchen sponges harbor germs. A collection of various rooms throughout houses across America have shown consistently that surprisingly enough the bathroom is cleanest room and the kitchen is the dirtiest. This is due to the disinfectants being used in the bathroom diligently and not the kitchen - the sponge being the worst by far. I personally pop it in the micro for 4 minutes frequently and also have a spray bottle of diluted peroxide handy for misting the counter after wiping. I've heard the 70% of presumed stomach flus are acutally a case of food poisoning. (02/24/2007)

By Diane and JT

RE: Sterilize Your Sponge in the Microwave

Also, for those who don't have a special preference of sponge style, you can head down to your local dollar store and buy a bunch for very cheap and make them disposable. (02/24/2007)

By Diane and JT

RE: Sterilize Your Sponge in the Microwave

DON'T DO IT and walk away. Our microwave ignited the sponge when my wife walked away after setting the timer. The microwave is toast now, but at least the house still stands and no one got hurt.

Save yourself the worry and place them in the dishwasher to clean them. I don't know if it's as effective, but it won't catch fire. (02/28/2007)

By Greg

RE: Sterilize Your Sponge in the Microwave

Well Greg, she didn't do it wet, did she? This is the same mistake made over and over and over by people who don't read fully. MICROWAVE ONLY WHEN WET! (03/02/2007)


RE: Sterilize Your Sponge in the Microwave

"you can head down to your local dollar store and buy a bunch for very cheap and make them disposable." Just what our world needs, more stuff in our landfills! (03/31/2007)

By John

RE: Sterilize Your Sponge in the Microwave

Just yesterday I decided to microwave my sponge to try and rid it of that horrible stench it develops over time. I tried 30 seconds, then 30 more, and then 30 more, keeping it moist.

VOILA! I thought I was a genius. Now I do this search and it's old news.

Anyway, my house is now one step closer to that sterile state we Americans try so hard to achieve and yet, in doing, only set ourselves up for more resistant bacteria which will inevitably smell worse and be harder to eradicate.


By Mark

RE: Sterilize Your Sponge in the Microwave

OR, you can put it in the dishwasher each time you do the dishes. But the most important thing is to keep your sponge as clean as possible. Who wants to think they are cleaning, when they are really actually spreading germs instead!

REMEMBER - If your sponge stinks, It's REALLY spreading germs! & if it doesn't smell, it probably still is! Disinfect your sponge or dishrag at least several times a week.

If you use a sponge wipe up your cutting board after cutting chicken, fish or meat. You should bleach it, then secondly, wash it in the dishwasher or microwave it, or just throw it out! It's amazing how many people don't realize the germs sponges AND DISHRAGS are harboring!

If you use dishrags instead of sponges: Wash them in the washing machine in hot soapy water and be sure to add bleach!

My daughter keeps 3 kitchen sponges, one for dishes, one for the countertops, & the kitchen table and one for wiping up spills on the floor. Buying 3 different colors helps! (04/10/2007)

By Cyinda

RE: Sterilize Your Sponge in the Microwave

You can also soak sponges in a diluted bleach mixture for at least an hour. I put a tablespoon of bleach, a little dish soap, and a quart of hot water, and use any deep plastic container, and weigh down the sponge(s) with a small plate. It works really well! (06/23/2007)

By opal beach

RE: Sterilize Your Sponge in the Microwave

I saw a commercial on TV about sterilizing sponges. The lady said to put it in the microwave for 5 minutes, and by the way, the sponge looked wet. So, I got mine wet, set it in the microwave for 5 minutes, well, DON'T DO THAT. Although mine had a scrubby on the other side of the sponge, well, when the timer went off, my eyes had been burning, and I know why. The sponge was all burnt like a piece of burnt toast and the house full of smoke. (10/14/2007)

By RoxAnn

RE: Sterilize Your Sponge in the Microwave

The microwave thing works well in a jiffy if your wife is yelling at you to do the dishes, I have found. (10/17/2007)

By sean

RE: Sterilize Your Sponge in the Microwave

In a new, but not mid-powered microwave, I nuked my sponge for a minute and it did the trick. No more stinky sponge. The sponge does have to be wet. Because microwave power varies between different models, do it 30 seconds at a time for no more than 2 minutes, making sure to the sponge stays wet and is not burning. Be careful because that sponge can get HOT. I also use an "oxygenated" detergent, such as palmolive oxy plus, in order to help keep those scents away.

By geniusiknowit

RE: Sterilize Your Sponge in the Microwave

Yeah, I just did this and caused a fire (12/12/2007)

Editor's Note: Be sure to microwave it for 2 minutes or less at a time and stand by to prevent a fire.

RE: Sterilize Your Sponge in the Microwave

But does it really work?

Agricultural Research Service (ARS) scientists in Beltsville, Md., tested several methods for reducing risks from harmful microbes hiding in reused sponges. They soaked sponges for 48 hours in a solution made from ground beef and lab growth medium to attain a high level of microbes to simulate a very dirty sponge. Then they treated each sponge in one of five ways: soaked for three minutes in a 10 percent bleach solution, soaked in lemon juice for one minute, soaked in deionized water for one minute, heated in a microwave for one minute, run through a dishwasher cycle (including the drying cycle).

The conclusion: Microwaving sponges killed 99.99999 percent of bacteria. Dishwashing (with drying cycle) killed 99.9998 percent of bacteria. The other methods killed between 37 and 87 percent of bacteria, still leaving enough bacteria to potentially cause disease. As for yeasts and molds, the sponges treated in the microwave oven or dishwasher were found to harbor less than 1 percent (0.00001 percent), while between 6.7 and 63 percent of yeasts and molds survived on sponges soaked in bleach, lemon juice and deionized water.

The University of Florida did a similar study and also found microwaving to be the most effective way to sterilize a sponge. The researchers soaked sponges and scrubbing pads in raw wastewater containing fecal bacteria, viruses, protozoan parasites and bacterial spores. They used an off-the-shelf microwave oven to zap the sponges and scrub pads for varying lengths of time, wringing them out and determining the microbial load of the water for each test. They compared their findings with water from control sponges and pads not placed in the microwave. The results were unambiguous: Two minutes of microwaving on full power mode killed or inactivated more than 99 percent of all the living pathogens in the sponges and pads. Their conclusion, "What we found is that we could knock out most bacteria in two minutes in the microwave. People often put their sponges and scrubbers in the dishwasher, but if they really want to decontaminate them and not just clean them, they should use the microwave". The researchers said the heat, rather than the microwave radiation, likely is what proves fatal to the pathogens. Because the microwave works by exciting water molecules, it is better to microwave wet rather than dry sponges or scrub pads.

If two minutes in the microwave will kill that gawdawful crud, you don't need to do it for longer!

By Doug

RE: Sterilize Your Sponge in the Microwave

I microwaved my sponge and it loosened the grease splatters in the microwave, so they easily wiped away. (03/12/2008)

By Kitchen Cleaner

RE: Sterilize Your Sponge in the Microwave

So if nuking a sponge kills germs, what does it kill in your food? Soak the sponge and dish rag in an old plastic container (ex. margarine) with hot water, bleach and some soap after dishes. Air dry. I've never had a stinky sponge or dish rag, I can't imagine. I'm not good with smells or germs, so I think I'd die!! I have family members who have allergies/sensitivity to germs and after doing this with my sponge/rags, they noticed the difference right away.

By Friendly kitchen wiz

nipple sterilizing

How long to sterilize bottle nipples in the microwave

By jessica

RE: Sterilize Your Sponge in the Microwave

About disinfecting with bleach. One tablespoon of bleach in a gallon of water is all you need to kill germs. Using pure bleach will definitely disintegrate your sponge. (04/19/2008)

By GrMaLinda

RE: Sterilize Your Sponge in the Microwave

This worked great!! I wish I had known about this a long time ago. I ran the sponge under water and then placed it in a shallow bowl WITHOUT wringing it out AT ALL. I have an 1150 watt microwave, so I only put it in for 1 minute and 45 seconds. When I pulled it out, the bowl and sponge were hot, but quickly cooled. I ran the sponge under water and wringed it out. The nasty smell was gone! I don't see how this could cause a fire if you keep the time down and make sure you soak the sponge and don't wring it out before microwaving it. (06/02/2008)

By Kristina

RE: Sterilize Your Sponge in the Microwave

Don't put a sponge in the microwave DRY! Its common sense to have it soak in water first and not to wring it out. Sort of how Electricity needs water as a conductor, almost the same concept. Microwaves can Kill pretty much everything with some lubrication. Just like it kills all nutrients in Vegetables when microwaving them. All Protein & Vitamins in meats. The most harm it will do to your sponge is cause a few tiny splits. I recommend doing it twice for 2 minutes wringing it out after each time and re-soaking it for better results. (07/07/2008)

By Paul

Archive: Sterilize Your Sponge in the Microwave

Cleaning kitchen sponges? Soak the sponge in water and microwave for a couple of minutes. The heat will kill any bacteria. Use a tong to remove sponge. It will be VERY HOT.

Source: I just thought of this myself, as the microwave gets very hot.

By Robin from Gothenburg, Sweden

Editor's Note: The University of Florida researchers recommend making sure the sponge is very wet and microwave it for 2 minutes. Never walk away from the microwave during this time, just in case of a fire.


RE: Sterilize Your Sponge in the Microwave

I dump mine in with my regular wash. I figure if it gets the clothes clean it will do the sponges too. (07/21/2008)

By SunshineRose

RE: Sterilize Your Sponge in the Microwave

Microwaves operate by causing water, fat, salt, and sugar molecules to vibrate and cause heat. They penetrate from 3/4 to 1-1/2 inches into any item/food placed in the microwave oven. Microwaves are essentially radio waves, (radar, etc.), not nuclear radiation.

The heat of microwaving a wet sponge will surround all bacteria in the sponge, killing it. Bacteria cannot live without food and moisture, and must be in an environment from 40 degrees to 140 degrees F to grow successfully (human bodies are right in the middle of that range). Getting rid of a growth medium (food), drying the bacteria (salt, alcohol, etc.) or raising the temperature above 140 degrees will kill the bacteria. (11/25/2008)

By jstiles

RE: Sterilize Your Sponge in the Microwave

Germs/bacteria are killed at temperatures of over 140 degrees. So yeah the dishwasher or a bowl of boiled water will do the same as a microwave, and save electricity and your microwave. Sometimes lo-tech is better and cheaper than high-tech.

Same thing with toothbrushes, plain boiling water in a glass or cup sterilizes it. Swish it around before you take it out to shake off debris. Whenever you' re sick, you should sterilize your toothbrush every time you use it. Otherwise you're reintroducing the germs from the toothbrush every time you use it. (03/01/2009)

By jojo

Archive: Sterilizing Sponges

Love sponges in the kitchen but not the spread of household germs? Keep your sponges neat and clean simply! Each morning, rinse your sponge with a little soap. Leaving it wet, microwave it for three minutes. Be careful as it will be steamy!


RE: Sterilizing Sponges

I just tried this tip and the sponge almost caught on fire. I don't think I would leave it in for three minutes. (05/23/2007)

By I don't think I would try it

RE: Sterilizing Sponges

Sponge size and microwave power would effect the amount of time to sterilize a sponge. What is and ordinary size of a kitchen sponge? I have not found any reference other than ordinary kitchen sponge as to size or the microwave wattage when on high.


By Hanksberg

Home and Garden Cleaning Cleaning ToolsSeptember 12, 2011
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