There's something missing from HealthyBaby diapers, and that's intentional.

When we set out to make the safest disposable diaper, we purposely avoided unnecessary chemicals and chemicals of concern. That meant leaving out the wetness indicator found in most diaper brands.

We get A LOT of questions about this feature, or lack thereof. Wetness indicators are so common that many parents assume they must be safe. Unfortunately, the diaper industry is alarmingly under-regulated.

Keep reading for an inside look at wetness indicators: what they're made of, how they work, and why HealthyBaby opted to put safety first and leave them out.

Why were diaper wetness indicators invented?

Kimberly-Clark introduced the first diaper wetness indicator in 1978. Instead of the chemical strip that’s common now, a larger design on the outside of the Kleenex Super Dry diaper brightened and faded as the diaper core absorbed liquid. The goal was to make it easy to see that a baby’s diaper was wet without physically touching the diaper or baby.

Over the years, the wetness indicator became a standard feature in conventional disposable diapers in America. In Europe, however, many premium diaper brands still don’t use wetness indicators, due to safety and health concerns.

You might also like: Why Safe Diapers Matter More Than Ever

What are diaper wetness indicators made of?

Diaper wetness indicators are made of pH-neutral or pH-sensitive chemical dyes, most commonly bromophenol blue (BPB) and bromothymol blue (BTB), combined with acid buffers, plus a carrier matrix that holds the dyes and indicator in place on the diaper.

Historically, diaper brands haven’t disclosed the chemicals in wetness indicators. That’s starting to change, due to diaper ingredient transparency laws.

You might also like: What Parents Should Know About Diaper Ingredient Transparency Laws

How do diaper wetness indicators work?

Wetness indicators contain pH-sensitive chemical dyes that change color when exposed to liquid. In most disposable diaper brands, a yellow line becomes blue or green.

Exposure to any liquid, not just urine, will change the color of a wetness indicator. Even the slightest dribble of liquid. In some cases, heavy sweat and high humidity can trigger a wetness indicator. So it’s not always a reliable sign that your little one’s diaper needs to be changed.

What makes diaper wetness indicators potentially harmful?

Diaper wetness indicators are made with chemicals that can range from mildly irritating to toxic. These chemicals are put in a product worn nearly 24/7 by babies—the youngest, most sensitive group of all.

Chemical dyes

The most common chemical dyes in wetness indicators, bromophenol blue (BPB) and bromothymol blue (BTB), are mild to moderate irritants that can cause redness and stinging when in contact with skin and eyes, ingested, or inhaled. In sensitive individuals, long-term exposure has been linked to dermatitis and conjunctivitis. These potentially harmful chemical dyes are used in the wetness indicators in Huggies and Honest diapers, among others.

Many diaper companies now use other chemical dyes, like bromocresol green (BCG) and crystal violet lactone (CVL), in wetness indicators. These chemicals also carry potential health risks.

Bromocresol green (BCG) is considered a low-hazard chemical and can cause mild irritation to skin, eyes, and respiratory and digestive tracts upon contact, dust inhalation, or ingestion. This potentially harmful dye is found in Kudos diapers.

Crystal violet lactone (CVL) has been recognized as a hazardous endocrine disruptor and potential carcinogen that can be absorbed through skin. Exposure has been linked to a range of health concerns, including allergic contact dermatitis, severe eye irritation, and long-term hormonal and reproductive harm. This concerning chemical dye is found in Coterie and Pampers diapers.

Carrier matrix

Chemicals are also found in the carrier matrix that holds the chemical dyes and indicator in place on the diaper. Often, the carrier matrix includes quaternary ammonium compounds (quats) and halogenated organic compounds. Both quats and halogenated organic compounds have been associated with several health concerns, including reproductive and developmental issues, skin and eye damage, and asthma.

The carrier matrix of wetness indicators may also contain petroleum-derived and ethoxylated compounds, which are often contaminated with polycyclic aromatic hydrocarbons (PAHs) and 1,4-dioxane.

Polycyclic aromatic hydrocarbons (PAHs) are chemical compounds found naturally in crude oil and coal deposits and formed by incomplete burning of organic matter during fires or through industrial emissions. PAHs can bind to human DNA and cause genetic mutations and serious long-term health issues.

1,4-dioxane is a synthetic liquid chemical classified as a likely human carcinogen by the U.S. Environmental Protection Agency. It's used mainly as an industrial solvent and can be found in some shampoos and body washes as a foaming agent. Short-term contact can lead to skin, eye, and lung irritation. Long-term exposure has been linked to liver and kidney cancer.

You might also like: What You Should Know About "The Fearsome 14"

Shouldn't wetness indicators be safe, since they're inside the diaper?

Wetness indicators are inserted between a diaper's absorbent core and topsheet, the inner layer in contact with your baby's skin. Ideally, a disposable diaper will always stay intact. But diapers can tear or burst, if they're too small or saturated.

No diaper brand wants to directly expose your baby's sensitive skin and developing body to the chemicals in a wetness indicator, but it could happen. That's a safety risk HealthyBaby isn't willing to take.

What makes HealthyBaby diapers effective without a wetness indicator?

One of the first things parents notice about HealthyBaby diapers is that they’re shockingly absorbent for such a slim-fitting, non-bulky diaper. This is by design.

When liquid hits the topsheet, Magical Air Channels® quickly and evenly distribute moisture across Our Diaper. This prevents the diaper from bunching up with liquid, which can cause sagging, tears, or bursting in other diaper brands. Liquid travels to the diaper core, where superabsorbent polymer (SAP) absorbs the liquid and turns it into gel.

Will HealthyBaby diapers ever have a wetness indicator?

At HealthyBaby, our priority is making the safest, most effective products with fewer ingredients and materials. We’ll never compromise children’s health to make our products more convenient or competitive.

That said, we understand that some parents use wetness indicators to track their baby’s hydration. We’re committed to helping parents make the safest, most intentional choices for their families.

If we ever find a truly safe way to add a wetness indicator to Our Diapers, we might! And if we do, it will be thoroughly tested, with all ingredients and materials disclosed on diaper packaging.

References

Environmental Working Group.EWG's Healthy Living: Guide to Safer Diapers. Retrieved 8/26/26.

U.S. Environmental Protection Agency. (2024.)EPA Finalizes Solvent 1,4-Dioxane TSCA Risk Evaluation. Retrieved 8/18/26.

Mallah, M., Changxing, L., Mallah, M., Noreen, S., Liu, Y., Saeed, M., Xi, H., Ahmed, B., Feng, F., Mirjat, A., Wang, W., Jabar, A., Naveed, M., Li, J., and Zhang, Q. Polycyclic aromatic hydrocarbon and its effects on human health: An overview.(2022.) Chemosphere. Retrieved 8/19/26.

Wang, C., Gui, W., Zhang, K., Cao, L., An, R., Zhou, J., Li, M., Chen, X., Wang, H., Dai, J., and Zhao, Y. Typical Thermochromic Dye Crystal Violet Lactone Acts as an Endocrine Disruptor: Nontargeted Screening, Prioritization, and In Vivo Experimental Verification. (2025.) Ecotoxicology and Public Health. Retrieved 8/18/26.