Green Breakthrough: Save Energy by Washing Diapers in Cold Water

Posted by rebecca

29 Apr

I’d always heard that diapers needed to be washed in the hottest water possible. After two years of washing diapers in hot water, a post on Treehugging Family made me think about whether I could wash diapers in cold. Peggy writes about saving 72 pounds of carbon dioxide in one month just by washing four out of five loads in cold water. Keep that up for an entire year and you’ll save $60-100 on your energy bill.

But doesn’t washing in hot water kill germs and bacteria? Everything I read said no–unless your washer has a built-in heater, the hot water in your machine does not get hot enough to kill anything. Most water heaters are set to 120 degrees. You’d need a temperature of 160 to kill anything and 212 to actually sanitize your laundry. Jennifer (Peggy’s co-blogger on Treehugging Family) pointed out that the dryer does get hot enough to kill bacteria.

Armed with all this information, I figured it was worth a try. I loaded the diapers in the machine and set the knob to “cold.” At the last minute, I almost turned the knob back to hot. After years of believing the hot water I was using was beneficial–no, necessary–to the cloth diapering process, it was hard to make the change, even for investigative purposes. Then, in one of the most daring moves of my cloth-diapering career, I pressed the start button and let the cold water gush into the machine.

Now that you are all on the edges of your seats, I’ll break this amazing news: the diapers came out of the dryer white, clean, and fresh-smelling. Now, if anyone has some scientific evidence in favor of the hot-wash, please post a comment. Until I hear advice to the contrary, I am going to wash diapers in cold water. I just wish I’d had the gumption to take the plunge years ago!

Filed under: Diapers, Eco-friendly Laundry, The Green Household

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52 Responses for "Green Breakthrough: Save Energy by Washing Diapers in Cold Water"

Peggy April 29th, 2008 at 1:00 pm 1
Rebecca, Glad you tried it! This is nice to know.
joy April 29th, 2008 at 8:17 pm 2
This simple switch can save cloth diaper users so much money, not to mention energy, over the course of a few years. We have switched to cold already and our diapers still come out perfectly clean. Let the cold water revolution begin!
Jennifer April 30th, 2008 at 2:44 am 3
Hey, you did it. Very cool. I always thought the hot water washing was a hype after taking all those science classes. You just can’t get washer hot enough to kill germs, so why bother. I’m really glad you ran the experiment. Now we need to write a book
eileen April 30th, 2008 at 4:14 pm 4
So what did our grandmother’s and great grandmother’s do without the benefit of washers and dryers? We know they used cloth diapers because that’s all there was. I’m curious as to how horrible it is to simply not sanitize the diapers? I mean, diaper services need to because you never know who used the diapers last and what deadly viruses they might have been carrying. But in your own home, what are we worried about that soap won’t take care of? Soap kills a lot of the germs doesn’t it? I’m not asking this rhetorically, I really want to know. We are not having our babies eat out of their diapers, they are going back on their bottoms. The same bottom they sit on the sand at the public beach with. Right?
rebecca April 30th, 2008 at 4:35 pm 5
Eileen, I am not sure what our grandmothers did . . . well, I know MY grandmother dried her diapers out the car window (she posted a comment about this on a previous diaper post!). Can anyone chime in with a tale about the cloth-diaper-washing process without a washing machine?

I would venture to say that it is NOT necessary to sanitize cloth diapers at home, and as I pointed out above, using hot water does not sanitize them anyway. If you wanted to sanitize your diapers at home for some reason, you would need a washer with a built-in heater. These washers would have a “sanitary” cycle. Or you could boil your diapers in a cauldron.
Sara May 2nd, 2008 at 11:24 am 6
eileen, I’m almost positive that soap doesn’t actually kill germs it just makes a surface slippery so that they slide off. I’m sure there’s a more scientific way to say that but that’s the idea. I’m all for washing the diapers in all cold water. I’m going to have to try that now. I know that hanging them in the sun gets out the stain but I’m not sure if that kills anything or not, anyone know?
Eileen May 3rd, 2008 at 12:42 am 7
YOu are probably right Sara as I have no basis in fact for any of my comments – the are all just hearsay.=) I think I’ve heard that soap “takes care of” a lot of germs. And I think I heard that in reference to why we don’t need anti-bacterial soap as that is just “overkill”. ha ha ha.

My washer does have a heat setting but I don’t think it’s for sanitizing. I remember the salesman said something about using that setting in the winter, I don’t know! Again, all hearsay.

Okay, I just checked my “complete book of MOthercraft” c. 1952. That book says to wash the diapers in very hot water and put them through 4 rinsings. Not the answer we were looking for, eh? I do think by 1952, washing machines were common and nobody at that point worried about water conservation. I think the conventional wisdom among my mom’s age group and older is that “scalding” will take care of germs. Just really good hot water for dishes, laundry, etc. will matter.

So, next question, we obviously don’t wash our dishes in 220 degree water – can they be done in cold too? To me, the dishes DO need to be sanitized because they are going in our mouths and you might be doing something with raw meat, etc. What’s the best way to sanitize the dishes if you don’t have a washing machine?
sommer May 3rd, 2008 at 3:52 am 8
I’m not a handwasher! BUT we wear our clothes more than once and always use cold water. We also have a HE energy effecient washer. The idea is you don’t have to go extreme (more good karma if you do) but you can make small changes to make a difference. Great post. Informative, well written and researched. You made me think!
rebecca May 3rd, 2008 at 9:21 am 9
I remember looking into the idea of washing dishes in cold water awhile ago and didn’t come to any solid conclusions. Dishwashers DO sanitize dishes because they heat the water to very high temperatures. Handwashing dishes does not sanitize them. However, hot water does a better job at dissolving grease than cold water, so using hot water for dishes does have a purpose.

Any cold-water dish-washers want to assure us that your dishes come out sparkly clean?

Eileen, that is intersting to read the 1952 diaper-washing tips! Machines were certainly less efficient back then. Plus, like you said, people probably didn’t think much about water conservation.
Eileen May 3rd, 2008 at 2:32 pm 10
Well there is the boy scout camping method for washing dishes with the 3 rinse stations and the last or middle will have a capful of bleach in it. I remember from my food service days that a capful of bleach in a bucket of water is enough to sanitize. It seems like that little bit of bleach wouldn’t be so bad right? I mean, our water is already chlorinated. then again, will the bacteria survive on the hard, dry surface of a dish? So many factors! It is so confusing!!!! I wish there was a handbook titled “The Right Way to Live” and all the answers to everything would be laid out for us.
rebecca May 5th, 2008 at 8:56 am 11
Eileen, I would not use bleach to sanitize dishes, since bleach is an environmental toxin. (I know it’s already in our water supply, but I wouldn’t want to add MORE to it.) I would also be more worried about eating bleach than eating whatever germs it was killing off. I personally do not even try to sanitize my dishes. I haven’t had a dishwasher in over fifteen years and I am no worse for the wear. However, if you wanted to remove more germs from your dishes, you could try a hydrogen peroxide or vinegar rinse instead of bleach. I read that a 5% solution of vinegar will kill 99% of bacteria, 82% of mold, and 80% of viruses. Pretty cool!
Erika May 5th, 2008 at 12:55 pm 12
Wow so now I’m wondering why I’ve been using the hot water setting at all- I thought it was making my towels and sheets extra clean- hmmm another way to pad the pocket book – I love it!
Eileen May 6th, 2008 at 12:49 pm 13
OF course, vinegar in the rinse water! I knew that.
Kamber May 6th, 2008 at 7:09 pm 14
Because everyone is already talking about cloth diapers and washing I have a question that maybe some one could help me with. I use AIO (all in one) cloth diapers. I think they are convenient and love them, but I can’t get them to stop smelling. I’ve used bumgenius spray, baking soda, hot water, drying in the dryer, air drying cold water, warm water, well you get the picture. Is there any ideas or advice that anyone could give me to help get the smell out?
rebecca May 6th, 2008 at 7:36 pm 15
Kamber, did you read Joy’s post about diaper-friendly detergents? http://greenbabyguide.com/2008/04/02/finding-diaper-friendly-earth-friendly-detergent/ (I hope that link works.) She explains there how she solved her stinky-diaper problem by switching detergents. If that is not the issue, I am not sure WHAT the problem is. Anyone else?
Sara May 8th, 2008 at 11:28 am 16
just how much vinegar equals 5% solution? I’m not too with it in the math dept. I actually just bought vinegar this week to wash my husband’s undershirts to try and degunk the arm pits. oh wait, i just reread the post and it’s for dishwashing. How much is good in the clothes washer?
Eileen May 8th, 2008 at 9:15 pm 17
Sara, a 5% solution would be 19 parts water to one part vinegar. Since there are 16 tablespoons in a cup, you could do one tablespoon vinegar to one cup water and get pretty close. It’s not rocket science though and nothing will explode if the ratio is off.

For the washer – I just put vinegar in the part where it says to put softener. I would guess a half cup to a cup would do just fine, but that is totally off the cuff and not legit advice that you should follow or trust.=) I love math but I am completely incapable of following a recipe.
Amber May 16th, 2008 at 7:47 am 18
Does anyone know if you can just line dry your diapers after washing them in cold, or should you dry them in the machine to kill the bacteria?
rebecca May 16th, 2008 at 8:51 am 19
Amber, as I mentioned above, the dryer (unlike the washing machine) does actually get hot enough to kill some bacteria. I think that sunlight can also do this. Certainly the greenest way to wash diapers would be to wash in cold and dry in the sun. Maybe someone else can pipe up with a scientific answer to your question!
Robert Dinse May 26th, 2008 at 10:59 pm 20
Actually, soap does kill most but not all germs. For example, staphylococci and typhoid bacilli are highly resistant to many germicides. But not even boiling hot water will kill all germs, in fact not even an autoclave can kill all germs. For example, the prions responsible for madcow disease will survive even autoclave temperatures. But ordinary soap and water will kill most non-resistant bacteria.

Also, UV light is a good germ killer; if you dry your diapers on a clothes line under direct sunlight, that will go a long way towards sterilizing that which survives the wash cycle.
Renee October 25th, 2008 at 12:52 pm 21
I am so glad I found this website. I have found cloth diapering to be one of my ownly sources of confidence during a recent divorce. Now that I am moving back in with mom and dad temporarily, they are trying to switch me to disposables because they believe it would be cheaper not having to use hot water for washing and high setting for drying. I have been contemplating just washing on cold and scalding once in a while. I think I will give it a try and hope that my parents (also environmentally aware) will go for the compromise if I line dry them as well. The only thing I am concerned about as a full-time working mom is the amount of time it will take to line dry my kissaluvs fitteds.??? I only have twelve right now and luckily my sitter uses them. Any tips on time management?
rebecca October 25th, 2008 at 1:56 pm 22
Renee, I have never used Kissaluvs myself, so I am not sure how long they’d take to line dry. One idea is to wash diapers in the evening, hang them to dry for 24 hours, then throw them in the dryer if they aren’t completely dry by then. Once you already own cloth diapers, there’s really almost no way you could spend more with washing/drying than you’d spend on disposables. If you let me know a few things about your diapering, I can probably figure out how much it costs you:

1. What state do you live in?
2. What type of washer do you have? (Front-loader or top-loader?)
3. How often do you do diaper laundry?

For me, washing diapers every four days on cold and drying in the dryer, I’d spend about $55/year laundering cloth diapers.
Tiffanymcoy February 15th, 2009 at 2:03 pm 23
soap will take care of most microbials, and what doesnt get destroyed, get washed away. washing in warm will actually allow more bacteria to grow than hot or cold, so if you wanna wash w/ warm, wash cold first and add vinegar during the warm cycle to help kill any reproducing bacteria.
Joanna February 23rd, 2010 at 1:51 pm 24
I’m so glad to have found this! I am about to have our first baby, and we are going to use cloth diapers. We have an old washer right now that works great for us, but we always wash on cold because the hot setting is broken. My mom always washed clothes on cold, too, so I didn’t think it was a bad thing until I started reading all the diaper instructions about how important it is to wash on hot… Nice to know that I don’t really have to go invest in a new washer, but can just keep using cold water! I think I will use the dryer, though… softer on baby and it’s good to kill any extra germs I can. Thanks!
Pippi March 9th, 2010 at 10:55 am 25
I tried doing my diapers in cold…and my daughter got a terrible diaper rash right afterwards. So I stick to hot
Heather May 17th, 2010 at 1:16 pm 26
So ok…washing diapers in cold is fine since as someone here said, its at home. But what about the transfer of bacteria to other clothes? Towels? Germs and bacteria are far different when they are coming from fecal matter. How can someone really say they aren’t worse for wear? How do they know that last cold didn’t come from their own clothes?
Ginger August 17th, 2010 at 2:10 pm 27
For anyone who happens along this post in the future googling like I did:
The hot wash is to get the soap off most effectively, not to kill anything. The diaper rash after the cold wash was probably do to soap build-up. You can disolve your laundry soap in boiling water and add it in the cold load to combat this. Also, boiling your diapers will strip this build up.
Sunlight kills bacteria and that’s what our predecessors relied on.
Thanks for the post, it got me thinking critically!
rebecca August 17th, 2010 at 3:52 pm 28
Ginger, thanks for the comment! Hot water does indeed help soap dissolve, and it also can help get things cleaner if cold water doesn’t cut it. (We discuss this in more detail in our book, The Eco-nomical Baby Guide.) A lot of people do seem to think that the hot water also kills germs/sterilize/etc. the diapers, which prompted this post.
Sara August 19th, 2010 at 4:47 pm 29
If I choose to wash my diapers in warm or cold and then dry them on a rack inside my house instead of in the sun, will they be unsanitary? If they don’t go in the dryer and don’t get dried in the sun?
Angel October 20th, 2010 at 3:50 am 30
Sara- I want to know the answer to this also! We just got our AIO’s today & want to make sure they get the cleanest possible. That being said, here are our home dynamics. We are missionaries in China and have NO HOT WATER piped to our washer. We also ONLY have a washer. Everything is line dried here. So, the dilemma comes when, in winter, it is so damp out and cool, will it be ok to still line dry them? I’m guessing yes, but that they will just take longer. We are told that the temp here gets only to about 50 degrees at the lowest. I’ve never used cloths, I’m sad to say (we couldn’t cough up the cost right away until being here), so I was doing research on washing CDs in cold water because we CAN’T wash in hot.
rebecca October 20th, 2010 at 8:25 am 31
No, your diapers won’t get sanitized if you wash in cold and then line dry–but the real question is: is that necessary? I would give it a try and see if there are any problems (diaper rash, yeast infections, etc.). If not, great! If so, then try something else. In most countries, people do not tumble dry their clothes, but they use the iron more. Ironing will kill yeast and other various germs, so perhaps that is an option.

The only other problem I anticipate, if you live in a damp and cold climate, is that they simply won’t dry on the line. I can’t line dry laundry during the winter in the Pacific Northwest because clothes will sit on the rack for a week and grow mildew before they dry. If you had pocket diapers (usually made from man-made materials), they might dry out more quickly.
Corin December 5th, 2010 at 7:27 pm 32
i wash in cold for everything, use home made detergent, and i use vinegar in a downy ball for a softener. my thinking is we dont sterilize our underpants, so if the dipes are staying on the family bums, sterilizing isnt important. to put germs in perspective… think about how often you touch shoelaces… and no one washes them. they drag around in animal pee and poo, human spit, and germ infested buildings all day, and i bet you dont wash your hands after every time you tie your shoes. thats way worse than anything my kiddo can produce.

however, i do use a couple hot cycles every 2 or three months to strip my dipes to avoid stinkies.
Tara December 28th, 2010 at 9:45 am 33
I wash my cloth diapers in cold water. I will occasionally throw in some vinegar. I’ve never had a problem with rashes or stinky diapers. I line dry in the sun in summer, and line dry inside in winter. Drying your cloth diapers and wetbags with PUL (the waterproof material) will actually shorten their lifespan, so line drying is better for them.
jayne February 23rd, 2011 at 11:12 pm 34
I also wash my dipes in cold water, and then I dry them on high in the dryer. I’ve been doing this for a total of five years of diapering and I have NEVER had a problem with anyone getting sick. We don’t tend to have stomach-type illnesses and haven’t had any more of them during our diapering years than other times. I think dh and I got sick once five years ago at a time when several of our adult friends were sick. I have gotten the stinkies a couple of times and when that happens I’ve bleached the dipes and used Dawn for one load and done several rinse loads and that’s gotten rid of the smell (this smell I’m talking about is after the child pees in the dipe and it’s stronger than normal — dipes always come out of dryer smelling clean).
Ma Jen March 2nd, 2011 at 8:37 pm 35
There are many places where dishes are washed in cold water (3rd world countries) with bleach added b/c hot water (due to lack of fuel for heating) is not readily available, but commercial bleach is easy to buy. The key is adding a bit of bleach to the water.
Ruth March 3rd, 2011 at 9:47 am 36
In the old days, in Trinidad, they had a special large pot where they boiled the cloth diapers after washing them. After that line drying.
Amanda March 16th, 2011 at 7:57 pm 37
We live in Mexico and do not have hot water to the washer either. However we do have very hard water and I think this has added to our stink issue. I ended up boiling once a month to take the stink out. Expecting new baby any day now and have a nice prefold stash waiting…..praying that we dont get the stink with a new born…not a good thing!
Hopefully the cold water wash with the dryer will help with that.
Amy @ simply necessary April 29th, 2011 at 5:29 am 38
Good post…found by googling b/c I was wondering this same thing. We now live in a rented house where our water doesn’t get as hot as in our previous house and we also have harder water now. I have been dealing w/LOTS more stink issues and leaky diapers. At first I thought it was all hard water issues but after tackling that and still getting no results I started wondering if washing in hot was actually backfiring on me b/c it was never getting hot enough to sanitize but actually getting warm which could be a breeding ground for more germs. Just a thought.
Coral June 20th, 2011 at 9:10 am 39
To the previous poster who lives in China, I live in CT and when the temp reaches about 50 degrees I begin line drying. It does take all day at those temps but it saves my electricity bill. AIO may take up to 24 hours to dry in cooler weather as the pockets, fitteds and prefolds will dry faster.
jenn September 7th, 2011 at 12:24 pm 40
I would like to add my knowledge to this conversation…
(I wash in cold water. fyi)

For washing diapers- (smell problems)
-Vinegar works for sanitisizing. The secret is putting it in your rince cycle. (i put it in my fabric softener compartment)
-I also use Borax as a presoak and a little in the wash. It is also for staining and smells.

To answer the question about vinegar and pit stains. No it wont work. Its not a stain remover. Ive never tried but Ive heard that a few tsp of salt with boiling water (obviously cooled a bit) rub it into the stains with a cloth soaked in solution.

I also have a spray bottle with a few drops of teatree oil. which is cool for killing germs, mold etc.) I spray the pee in the diaper before foring it in the bin. (never add too much though since it is an oil, literally 8 drops for a full bottle)
heather September 13th, 2011 at 8:20 pm 41
We just got a new washing machine which doesn’t have a true hot cycle (it switches between hot and cold and it ends up to be more like a warm cyle). I was ready to sell it and find another machine. So, I found this post in my search for whether 120 degrees was truly necessary. It seems to me that you can wash on cold and treat any problems that arise (stink, build up, rashes, etc.) with a tiny amount of bleach or oxygen bleach every once in awhile and some vinegar in the rinse. After a child is ill, it is probably better to sanitize the diapers with a little bleach or oxygen bleach than to rely on hot water to kill the bacteria. I do agree with the fact that detergent does dissolve much better in warm to hot water. Does washing only in cold require more rinse cylces to get all of the soap out?

I was wondering about prepping new cloth prefolds though. Do those still have to be washed in hot (120 degrees) to strip the cotton oils? Or can you strip the oils with warm water and just do more washes?
rebecca September 14th, 2011 at 10:11 am 42
Heather, is the washing machine broken, or does it just work that way for some reason? I think it should work fine for diaper laundering. My diaper days are long gone, but I feel like I very rarely run the hot wash. I lived in Europe for a few years, and all of the washing machines I used were cold-water only; it seems to be the norm in some parts of the world. As for stripping new prefolds, it seems like washing and drying them a few times should do the trick. If not, you could always take the stack to the Laundromat one time to break them in.
Heather September 18th, 2011 at 2:17 am 43
I’m glad I found this post- I live in a 3rd world country about to have my first baby and don’t have a washing machine with hot water. I considered borrowing the $700 I would need to get one, but if it doesn’t get hot enough to kill the germs, then what is the point? I’ll use cold water and some tea tree oil and dry them in the sun, which does kill germs, at least when you’re at high elevation I know it does! We do wash our dishes in hot water because they get cleaner. Oil and stuff comes off easier. Then we rinse and then rinse again in a tub of water with a capful of bleach. this is because we don’t have bleach in our water but we do have tons of water born diseases and lots of people using the same dishes. Since we started doing this, one kid with a runny nose didn’t mean everyone has a runny nose and one kid with diarrhea didn’t mean eveyone had to get it!
Krista November 12th, 2011 at 10:08 pm 44
Hello, I live in Taiwan and have no hot water piped to my machine. 6 weeks ago, we began washing our cloth diapers. Our baby has had no diaper rash and the diapers seem to come clean, and smell great. Since we can’t always dry outside (pollution) we often bring them inside and put a fan on them. To the lady inquiring about the kissaluvs-they take a while to dry, but I’m in a humid environment and I’d say about 24 hours (with a fan on them) and they are good to go. If we can get them outside in the sun, the drying time is cut down considerably.
I’m all about cold water-it saves energy and seems to me to do a great job of cleaning.
Julie March 5th, 2012 at 11:53 am 45
Rebecca,
I REALLY hope you are still monitoring this post because I am contemplating going the cloth diaper route (with first baby due in July) and want to try the cold-water method.
My question for you is what is your step-by-step washing method? 2 cold washes and 2 rinses?? If so, what do you use in each wash? And if any what do you use in the rinse cycle(s)? Thanks so much!
rebecca March 5th, 2012 at 10:45 pm 46
Julie, I don’t know if you have our book, but in it I describe my system for washing diapers. But also I can just tell you here: I put the diapers in the washing machine with half a scoop (two tablespoons, I think) Biokleen laundry detergent. (I have a front loader). I then wash it on a heavy cycle in cold water. I think I put white vinegar in the little washing machine drawer (?) for a rinse agent. That’s it. No extra rinses or cycles. We go into a lot more detail in our book (The Eco-nomical Baby Guide), but that’s it in a nutshell!
Julie March 6th, 2012 at 1:02 pm 47
Thanks! Just what I was looking for! I think I will check your guide out.
Sasha April 24th, 2012 at 9:11 am 48
We use cold water, vinegar and line dry and baby has no issues. I like the post about washing your hands after tying your shoes! So don’t be afraid! Use cold water and the natural UV of the sun to stay safe and stay real.
Joana A April 29th, 2012 at 5:59 pm 49
i have only been cloth diapering 7 months but this whole time i have washed them in cold water. i havent had any problems yet but i did add a little bit of bleach twice just in case. i did alot of research when i decided i wanted to use cloth diapers but in the end i just did my own thing when it comes to washing. i dry them twice in the dryer though because once doesnt seem like enough to me. since i havent had any problems i will just keep doing the same thing for now
Jen May 7th, 2012 at 7:24 pm 50
I didn’tthinkhot was for sanitizing, more for removing soap and grease (like fat fromEBF baby poop). Most diapers have PUL and aren’t supposed to go in the dryer.
rebecca May 7th, 2012 at 8:06 pm 51
That’s right, Jen. The hot water can help wash diapers better, but they aren’t actually sanitizing. The idea is to try cold and see if your diapers come out just as clean. If not, go back to hot water or longer cycles or whatever it takes–but try the lowest impact method first.

Do most cloth diapers have PUL? Mine were 100% cotton.
HeatherA May 20th, 2012 at 7:21 am 52
I love in the USA. I have a washer that only has a hot/cold cycle for the hottest. It doesn’t even get as hot as I would bathe in. Our DD has had plenty of urine burns to prove it doesn’t work. The hot water is needed to get the soap out> It’s the soap and the agitation that neutralizes the acid and breaks up the filth making it come out of the diapers. Especially when stripping diapers because you use stronger soap, the hot water is essential. Any stink = acid and germs. Our fore-mothers boiled their diapers. For those of you who live where hot water is not available you will have to boil them (but not with PUL in them). For those with cheap washers like mine you can either boil enough water to fill the tub of your washer or take your diapers to a laundry mat. I’m all for natural but I’m not for spreading untruth. You need to make your diaper water hot to get the soap out. You are right with the facts about sanitizing though.