Ammonia- Causes, Treatment, and Prevention.

Prevent and treat ammonia in cloth diapers


is the most feared word in the cloth diaper community.  It is the scourge of the earth, a menace to society, some even call it a “beast” because it is so hard to get rid of.

Ammonia is unmistakable, and if you aren’t sure if you have build-up in your diapers all you need to do is take a whiff of a wet diaper.  If a diaper that has been urinated in smells strongly, and singes your nose hairs, it is ammonia.  Ammonia is used in cleaning products like window cleaner  (and can be purchased in pure form) so you have that smell to compare it to.

There are acceptable amounts of ammonia and if your diapers only smell strongly after a few days in your wetbag or pail then this is quite normal, though you may want to increase the frequency of your washing to prevent a problem.  When the smell is acrid and “knock you over” strong this should be addressed as soon as possible.

Other than just an offensive odor, ammonia can cause topical rashes that often present as flat and red, though in severe cases they can leave open sores. Ammonia “burn” is the worst presentation of the rash and is a chemical burn on the skin that is very painful.

I am not a chemist or a laundry scientist and I won’t start spouting off a lot of chemical explanations of why and how ammonia builds up in cloth diapers.  There are many resources for that, including this one from Rockin’ Green.

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advertisement from 1929

Ammonia in diapers is a problem that is as old as cloth diapers themselves.  Instances referring to the “ammoniacal diaper” go back to the early 1900’s in newspaper advice columns, baby care handbooks, and advertisements.  There was even a study done on why and how ammonia builds up in cloth diapers done in the 1920’s.  Many products were designed to wash the ammonia from the diaper, and some ads for washing machines even claimed to prevent ammonia build-up!  This problem has been around so long and yet no one has created a magical cure, which goes along with my stance that there is not a single method for washing diapers that works for everyone.

For those of you with younger infants you may not experience this issue.  This is for several reasons

  • Younger babies are changed more frequently.
  • Younger babies are on pure breastmilk or formula
  • Younger babies have less concentrated urine due to their diets of pure liquids and they drink often.

The older the baby, the more ammonia… One you begin introducing solid foods and your baby starts sleeping for longer stretches at night you may notice the increasing odor of ammonia creeping in.  The diapers used overnight are the biggest offenders, and babies who sleep all night are usually not changed so by the morning the diaper can reek of the scent!

All diapers are not created equal

Now that you understand why ammonia builds up (concentrated urine, longer times before changing, varied diets and older babies/toddlers) you should also know that all diapers are not created equal in how they wash.  This can greatly affect your chances of success and your method of attacking the ammonia.

Microfiber is the cheapest absorbent material and therefore a popular one for cloth diapers.  Pocket diapers often come with microfiber inserts and some All-in-Ones or All-in-Two’s use this material as well.  Very few fitteds use them but a couple come to mind.  The thicker the microfiber the harder it is to get clean.  Microfiber strands, when looked at under a microscope, will explain why they hold onto the ammonia so effectively.  The same design that makes them so absorbent is their weakness.  Avoiding diapers with super thick layers of microfiber, or microfiber that is sandwiched under a stay dry synthetic layer and sewn down is good advice when you consider what a pain the ass butt it is to wash the ammonia out.  The highest amount of agitation is needed.

That being said, the thicker the layers of any diaper and the inability to wash and clean them throughly, the more likely you are to have odor/ammonia build up.  If you are up for the challenge (and the immense rewards) you can opt to use flat cloth diapers.  These are one layer and fold to various diaper shapes or rectangular diaper inserts.  Being made from natural materials, and a single layer, means the chances of ammonia build-up are practically impossible with an effective wash routine.


Natural fibers (cotton, bamboo, hemp) have smoother strands, making the ammonia build-up less likely.  I’m not saying diapers with natural fibers won’t experience ammonia, but if they do, ridding it will be easier than microfiber diapers. If at all possible, using natural fibers at night is a wise choice for many reasons.

Treatment This becomes a touchy subject because some treatments that I may suggest, and that are often effective, may void the manufacturer’s warranty on your diapers.  Please be aware of this fact and check the warranty (if you still have one) before trying any of these methods.  Also know that I cannot be responsible for the results of your efforts and this is strictly advice.  

Oh I wish, I wish I could solve all of your problems with ammonia.  I myself have never truly been able to cure it, though many times I was able to keep it at bay.  I can offer tips that are based on my experiences, the experiences of others, and other literature.

Chlorine Bleach is effective against ammonia.  Some brands, like bumGenius, suggest using bleach regularly.  1/4 cup added to the wash once a month.  In my experience, bleach can work, especially when nothing else will.  If you use microfiber diapers you may want to use it monthly to prevent ammonia.  If you are treating diapers with severe build-up strip them first, then bleach and wash again.

Stripping your diapers with many hot washes (no detergent) and using a laundry additive designed for removal of ammonia like Funk Rock is another option.  Usually you will need to let the diapers soak in the Funk Rock for several hours or overnight, then do many hot washes with no detergent.  Soaking will allow the Funk Rock to penetrate into the thicker diapers.

RLR is another laundry additive used for stripping.  If you suspect the ammonia is trapped thanks to other build-ups in your diapers (minerals from hard water or laundry soaps) the RLR soak will remove the build-up. (You can find RLR at many cloth diaper retailers including DDL affiliate Kelly’s Closet)

Eco Nuts makes something called “Ammonia Bouncer” that I’m just giving a try.  It does remove ammonia from the test swatches immediately (when I first saw it at an expo, a swatch was soaked in pure ammonia and the product was added to the soak and the odor was gone!) but will it work on diapers?  I hope so.

Switching detergents can help too.  As much as I hate to say it, one of the ways we got rid of ammonia odor after moving states and changing water types was switching to Tide Original.  Sometimes that switch is all it takes, and then I switched back to a more natural detergent after the ammonia was gone.  Using the Tide on occasion worked best for us.  I wouldn’t use it full-time since in previous years that led to repelling issues.


If you know your baby is prone to ammoniacal diapers you can try a few things to prevent the build up.

Pre-rinse the wet diapers (or just overnight diapers if you know that is the main issue) with the diaper sprayer or in the sink and put them in the pail after a squeeze.  Rinsing the urine away before letting it sit until wash day can prevent more ammonia from occurring.

Make sure your baby is well hydrated!  Let them drink plenty of water.  The less concentrated the urine, the less ammonia will be present.

Be sure the diapers are well rinsed after washing.  Removing any alkali already present or bacteria will reduce the chance of ammonia building in the diapers.

Very hot washes will kill ammonia and bacteria (unless there is already build-up).  You may consider temporarily raising the temperature on your hot water heater to 135 or above for washing the diapers.

Spraying the wet diaper inserts with a solution called “Bac-Out” before placing in the pail/wet bag has been testified to work by several friends.  Bac-Out contains an enzyme and could potentially irritate the baby’s skin.  Bac-out is often found in natural food stores or on


Ammonia is a bitch (we are all adults here…).  I understand why many cloth diapering parents take breaks when this problem arises, or quit altogether.  There is almost a science to washing cloth diapers and finding the right method can be downright impossible.

That being said, you have invested a lot of money into your cloth diapers!  Taking steps to get rid of the problem, even if you take a break while doing so, will ensure you continue cloth diapering for many months or years to come.

Have you had an ammonia problem and been successful at getting rid of it?  Please share in the comments and include your type of washer and water if you can! Disclosure: I am not a scientist.  Please use this post as a guide, not a guarantee, and take any advice at your own risk.  


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  • I recommend anyone with this ammonia problem to get themselves and their children’s genes mapped at 23andme dot com. There is a gene mutation called a CBS mutation that makes it so a person’s body cannot break down sulfur and phosphorus adequately. This makes the person more likely to have acidic urine that can eat into the skin and is more likely to develop ammonia. To decrease this type of urine, breast feeding is best and avoid soy products and any beans or legumes or any other food high in phosphorus. Also, diets high in sugar will produce urine that is more caustic on the skin.

  • LO

    What about boiling the inserts only? Will that help brake up the amonnia and get rid of deturgent residue?

  • LO

    Or what can I do for tpu backed soakers? I use arm and hammer free. It worked for my first child and I didn’t have to strip the diapers. I also have hard water and no water softener. I have tryed sunning the diapers and I have dryed them in the dryer on low. Still a big issue. Help …

  • NurseKC

    For those suggesting regular laundry detergent. What would you suggest for a baby with eczema that flares up with ann amount of scents and dyes or possible something else? I can’t even use regular detergent on clothes for my whole family, so I don’t see it being okay for my babies cloth diapers. Also the ammonia only seems to be an issues in synthetic fabric diapers and not cotton/bamboo.

    • Alicia Anderson

      I’d use whatever detergent you’re using already, as long as it isn’t some sort of “free and clear”.

  • Charlene Sneed

    I used to do a cold rinse then a hot wash with tide power and an extra rinse. I never had a problem. Then sadly I switched to a detergent that I thought was specifically for cloth diapers (a very popular brand I might add) now my daughter’s diapers smell so strongly of ammonia, after a few hours in the diaper pail, it burns your nostrils. Do I have to do something special to get the smell out or will going back to my old routine help?

  • Tante Pollewop

    I switched to using flat cloth diapers to manage my urinary incontinence with some years ago, precisely because I was fed up with the ammonia problem of all-in-one or other shaped reusable diapers.
    I found that these still need to be washed on 140 degrees every other time to keep the ammonia deamon at bay.

    I also found a quite simple trick to quickly eliminate ammonia. To dig up some chemistry from school: ammonia is a base. You can neutralise a base with an acid. Vinegar might work, but that doesn’t smell very nice either. So I tried it with the limescale remover I use to clean the bath (etcetera) with: the active ingredient is usually formic acid, which is quite safe like vinegar but smells not anywhere near as strong.

    And that works. I always put he diapers in the bath tub, give them a few sprays of limescale remover, rinse with water and any ammonia smell disappears like magic. Not all brands seem to work equally well though. I’ve used it for over two years and it does not damage the diapers at all.

    I should put a bit more effort in figuring out how to remove ammonia smell from the plastic pants as well – unfortunately, the vinyl seems to absorb some of the ammonia smell and it does not disappear immediately after applying the limescale removed, like with the diaper. Maybe the plastic needs to be soaked for a bit longer.

    I hope someone can use this!

    All the best,

  • Eri

    I did an rlr treatment and I’m still having ammonia problems! Even in my new diapers 🙁 but not rashes on my baby?
    I guess I have to use chlorine, hoping this finally helps me.