If you've used cloth diapers for any length of time, you know they're a sustainable, gentle, and a money-saving solution for your baby and the environment. But if you've ever noticed your cloth diapers smell like ammonia, or worse—started to see small holes or “shedding” fibers—you might be dealing with a hidden culprit: ammonia breakdown. Understanding how ammonia can create damage in cloth diapers is key for preventing ruined cloth diapers and keeping your cloth diaper stash in top shape.

What Is Ammonia and Why Does It Affect Cloth Diapers?

Cloth diapers are exposed to urine every time they're worn. When urine sits in fabrics—even just for a few hours—it starts to break down, and one of the byproducts is ammonia: a colorless, pungent, and highly alkaline compound. The stronger your diapers smell, the more ammonia is present. If you’re hit with an overpowering odor when you open your diaper pail or run your wash, that’s ammonia. 

Ammonia doesn’t just make cloth diapers smell; it can actually break down the plant-based fibers commonly used in inserts like cotton, bamboo viscose, and hemp. This means that, over time, the strength and longevity of your diapers can be compromised.

How Ammonia Breaks Down Diaper Fabrics

Repeated exposure to ammonia weakens the structure of fibers in textiles found in cloth diapers. Ammonia attacks the cellulose in natural fibers—cotton, bamboo viscose, and hemp—which leads to fiber breakdown. This process doesn’t usually affect synthetic fibers, so microfiber boosters and synthetic outer shells are generally resilient.

Here’s what happens over time:

• Shedding: As ammonia degrades the fabric, you may notice increased lint in your dryer or small fiber “pills” on insert surfaces. This shedding is a sign fibers are breaking off and being lost. For fabrics like Bamboo Terry, shedding often causes the bamboo viscose fibers to detach from the polyester mesh, leaving the mesh exposed or "naked."

• Thinning and Holes: The most visible sign of ammonia damage is holes developing in your diaper absorbencies. These often start small but can grow quickly with use and ongoing washing. This is not simple wear and tear: it’s the result of repeated chemical exposure beyond normal laundering. This kind of damage is most common with hemp and cotton based textiles. 

• Reduced Absorbency: As fibers are eroded and shed, fewer remain to absorb moisture. This is why ammonia damaged cloth diapers may suddenly start leaking or feel less “thirsty” than before—a direct result of ammonia breakdown affecting fiber integrity.

Why Does This Happen? The Role of Storage and Washing Routines

Allowing urine to sit in soiled cloth diapers—especially overnight or over several days—promotes ammonia buildup. Warmer environments (like a steamy bathroom or summer heat) cause urea in urine to convert to ammonia even faster. Poor washing habits, such as insufficient rinsing, using too little detergent, or not washing diapers frequently enough, can all contribute to higher ammonia retention.

Learn more about odor and cloth diapers » 

Diapers most vulnerable to ammonia breakdown are:

• Night diapers: These stay wet for longer, picking up more urine and ammonia.

• Day diapers in hot, humid conditions: Ammonia forms more quickly.

• Diapers left in closed wet bags or pails for a long time: Lack of air circulation and delayed washing allow ammonia to accumulate.

Spotting the Early Signs: When Is a Smell More Than a Smell?

Cloth diapers smell “off” for all sorts of reasons, but a sharp, nose-wrinkling ammonia stench—compared to cleaning products, hair dye, or a dirty litter box—should be taken seriously. If you notice:

• Diapers reeking straight out of the wash or when baby urinates

• The “barnyard” odor lingers or returns quickly

• Small holes, thinning, or “fuzzy” spots on inserts

• Increased lint or fibers shed during drying

…then you’re likely dealing with ammonia damage and need to take action.

Why You Want to Avoid Damaged or Ruined Cloth Diapers

Once ammonia causes fiber degradation, the result is truly ruined cloth diapers. Holes and shedding mean your cloth diapers will be less absorbent and won’t provide the absorbency or comfort your baby needs. What’s more, ammonia leftover in fibers can cause skin redness, rash, or even chemical burns on your baby—a risk no parent wants.

Prevention: How to Keep Ammonia Breakdowns at Bay

The good news is, while ammonia formation is natural, you can control its impact. Here are easy steps to prevent ammonia damage and keep your cloth diapers fresh, absorbent, and comfortable:

1. Wash Frequently

Don’t let dirty diapers sit around. Wash every 2–3 days. For heavy night-use or in hot weather, consider washing more often or rinsing  and allowing overnight diapers to air dry immediately after use.

2. Store Dirty Diapers Properly

• Dry pail: Store diapers in a breathable pail or bag; avoid sealing dirty diapers in airtight containers for days at a time before washing. 

• Rinse if Needed: For night diapers, a quick cold rinse and air dsry before storing can reduce urine acidity and ammonia formation.

3. Use Enough Detergent and Adequate Water

Follow your detergent’s recommendations and use the right cycle for heavy-duty cleaning. Under-washing leaves behind residue, but too much detergent can also cause buildup, so find the right balance. 

Learn more about washing cloth diapers »

4. Deep Clean for Ammonia Build-Up

If you spot ammonia issues already, “strip” your cloth diapers with a product like RLR and use a sanitizing cycle or an oxygen bleach/bleach soak (check manufacturer recommendations first for bleach use on diapers).

Learn more about stripping cloth diapers » 

5. Address Wash Routine Issues Early

Hard water? You may need a water softener. Regular strong agitation and hot water help fully remove wastes.

6. Keep Baby Hydrated

Well-hydrated babies produce more dilute urine, which slows ammonia formation.

In Summary

Ammonia breakdown is the invisible enemy of cloth diaper longevity. Left unchecked, it causes shedding, holes, and leads to ruined cloth diapers—directly damaging fibers, reducing absorbency, and harming baby’s skin.

By understanding the causes and prevention methods, you can extend the life of your cloth diapers and avoid that dreaded “cloth diapers smell.” Stay on top of regular, thorough washing, avoid long storage, use enough detergent, and react quickly to any signs of damage or odors.

Preventing ammonia breakdown isn’t just about clean diapers—it’s about protecting your investment, your baby’s comfort, and making cloth diapering a happy, hassle-free experience for years to come.