Ammonia and Cloth Diapers

>Sooner or later, all of us cloth diapering parents are going to face one of the dreaded beasts that comes hand in hand with diaper cleaning: ammonia. Sometimes it creeps up on us as a faint, unplaceable stink that we can’t quite put our finger on. Other times it burns our nose, makes our eyes water, and nearly knocks us out with its familiar, caustic smell when we open the diaper pail on a hot day. Why do my baby’s diapers smell like ammonia, anyways? you’re probably wondering. You may best remember ammonia from cleaning products or junior high science class. How in the heck did it end up festering away in the bottom of the diaper bin? Well, there’s simple science behind it.


The human body naturally produces ammonia as a byproduct when it breaks down amino acids through a process called deamidation. However, storing up ammonia within our bodies is not a viable solution; ammonia is a toxic base (the opposite of an acid), and if our bodies allowed it to accumulate within us, it would prove to be fatal for us. So, cleverly, our livers convert the ammonia (in combination with carbon dioxide) in our bodies into urea, the chemical compound found in urine. This liquid waste is then excreted and removed efficiently from our bodies. For us adults, this waste is simply flushed away. For our babies, it is stored up in their diapers until wash day, where it can be effectively removed with soap and a proper laundry routine. However, there is a catch to this. Once the urea is out of the body, it begins converting back into ammonia. Normally this may take a couple of days, but the conversion can be accelerated by higher temperatures (like in a warm diaper pail in a hot room) and by anaerobic conditions (where oxygen is low/lacking, like in a lidded pail).

To minimize or prevent ammonia conversion from happening in your diapers and/or pail before wash day, you can do any of the following things to help:

  • rinse all diapers and inserts (or at least the heavily soiled/wet ones) before depositing them in the bin. This will dilute the urea and rinse much of it away
  • store your diaper pail in a darker, cooler place away from direct sun and heat
  • leave the lid open on your diaper pail (contrary to popular belief, this will actually help to REDUCE odors)
  • wash your diapers more frequently, before the urea has the chance to convert into ammonia (wash every 1-2 days)
  • keep your bin/liner washed/wiped down and free of urine residues
  • always run at least one pre-wash (with spin) before you start your normal wash routine–this will help to rinse away lingering urine & particles
  • consider adding vinegar to your pre-wash routine (read more below)


Sometimes, if we let our storage or washing routine get lax for a few days (or, sometimes even despite our best efforts!), ammonia can actually start building up on diapers. Essentially this occurs for one reason only: diapers are/were not getting clean enough at some point in time. Ammonia CAN be tricky to simply wash away once it has set in. Because it is a base, neutralizing it first can help to break down its components into compounds that are easier to wash away with your normal soapy routine. For this reason, doing a pre-rinse/soak in vinegar can be a good way to break down and neutralize ammonia which can then be washed away in hot, soapy water (do not add vinegar to the final rinse as this will not help to remove the ammonia as it is “too late” in the wash cycle). Keep in mind that some diapers (with PUL and/or elastic) can suffer some wear & tear if vinegar is used repeatedly. Avoid adding baking soda (another base) to laundry pails & loads that are ammonia-laden, as it will only exacerbate the problem. Be sure to use an adequate amount of soap, and high levels of hot water to wash and rinse your diapers to completely remove ammonia residue.

If ammonia is not completely removed from diapers, you will quickly know it. Diapers may have a “funky” smell left over out of the wash (or when put on baby or re-wet with water or urine). This smell can range from anything like a “dead animal” smell, a fishy smell, or another strange smell (I’ve often had it smell like a wet paper bag right out of the wash). Any smell whatsoever indicates buildup and needs a quick remedy. Diapers that are reapplied to baby’s bum with ammonia residue on them can cause rash or even burns (as ammonia is an extremely caustic base–think of what bleach can do to bare skin!). Be sure to stay on top of ammonia problems right away. Sniff your diapers right after they come out of the wash. If they have any lingering smell, re-wash them, adding more (hot) water and extra rinses. Prefold and flat diapers can be boiled on the stove from time to time to completely remove all residues (whether from ammonia or detergent build-up). Other stripping methods can also be used (such as using a product like Rockin’ Green’s Funk Rock, a specially designed “ammonia bouncer” that can be used either for stripping or can be sprinkled in your pre-wash as an ammonia deterrent.

The Urea Cycle

6 thoughts on “Ammonia and Cloth Diapers

  1. Pingback: Stripping. | Third Culture Mama

  2. Kate

    I’d love to pin this, but there’s nothing on here that pinterest will recognize to let me pin. Thanks for the great info anyways, very helpful in defeating my ammonia problems!

  3. Brandalynn Ann

    Thank you so much!! I almost threw my cloth diapers away thinking they were no good now, only to see they CAN be salvaged, praise the Lord 🙂 It’s so nice to have reliable information about cloth diapering when I feel like I’m in over my head. Blessings!!


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