Peer-reviewed studies have detected phthalates and trace volatile compounds in diapers, but detection is not the same as proof of harm. Here is what the evidence shows, what manufacturers say, and what parents can do now.
Published: 1:18 p.m. EDT
The most unsettling thing inside a baby’s diaper may not be what the baby put there. It may be what a parent cannot see on the package.
A modern disposable diaper is a layered product made from plastic films and fibers, cellulose or wood pulp, superabsorbent polymers, elastics, adhesives, inks and, in some products, wetness indicators, lotions or fragrance. That engineering keeps babies dry and has helped reduce moisture-related skin problems. It also creates many possible routes for intentionally added chemicals, manufacturing residues and contaminants to enter a product worn against warm, sometimes irritated skin for hours at a time.
That does not mean every diaper is poisonous. It does mean the public conversation has moved beyond vague claims about “clean” or “natural” products. Researchers have now measured volatile organic compounds, or VOCs, in U.S. diapers. A 2025 study found phthalates in diapers used by a small group of infants in China and reported correlations with chemicals measured in their urine. Independent consumer testing has found indications of organic fluorine in some disposable and reusable diapers, a screening signal that can be consistent with PFAS.
Now lawmakers are responding. On August 27, California legislators gave final approval to Assembly Bill 1901, a measure that would require diaper manufacturers to disclose intentionally added ingredients. The bill passed the state Senate without opposition and cleared its final Assembly vote 71 to 1. As of this article’s publication, the state’s official legislative record lists it as passed and in the engrossing and enrolling process. It has not yet become law and still requires action by Gov. Gavin Newsom.
The result is a story more complicated than a frightening social media post. Chemicals have been detected. Important questions remain. The best available studies do not prove that ordinary diaper use causes cancer, infertility, DNA damage or another disease. What they do show is a serious information gap around an essential product that an average child may use roughly 7,000 times before toilet training.
First, what does “toxin” actually mean here?
The word “toxin” is commonly used for any substance people fear, although toxicologists use it more narrowly for poisons produced by living organisms. For diapers, “chemical of concern” or “potentially hazardous chemical” is usually more accurate.
Three ideas matter when interpreting any test result:
Hazard describes whether a substance is capable of causing harm.
Exposure describes how much reaches a person, by what route and for how long.
Risk describes the likelihood of harm under the actual conditions of exposure.
A laboratory can detect a hazardous chemical at a level too low to create a meaningful health risk. The reverse is also possible when a chemical can migrate from a product at a high enough dose, especially through damaged skin or with repeated use. A responsible conclusion therefore requires more than a chemical name. It requires concentration, migration, absorption and real-world use data.
That distinction is central to the diaper debate. The Center for Baby and Adult Hygiene Products, an industry trade group, has said that diapers are manufactured to meet safety standards and undergo assessments by scientists, medical professionals and toxicologists. In a statement reported by the Los Angeles Times, the group said, “Diapers are designed and manufactured to meet strict safety standards.” The industry also argues, correctly, that merely detecting a chemical does not establish danger.
The unanswered question is whether families receive enough product-specific information to evaluate that assurance.
What U.S. researchers found in disposable diapers
One of the most useful studies for American families was published in Environmental Science & Technology. Researchers selected 31 disposable hygiene products sold in the United States and analyzed them for 98 target VOCs. The sample included baby diapers, baby wipes and adult diapers.
VOCs can come from fragrance, adhesives, binders and moisture barriers. Some may also be unintended residues or manufacturing byproducts. The researchers detected VOCs in all 31 products, including benzene and 1,4-dioxane in some baby diapers. Those names are alarming because of their hazard classifications, but the measured levels and modeled risks supply essential context.
The study found that the tested baby diapers had modeled cancer risks below a conservative benchmark of one additional case per million people exposed. The authors described the cancer risk from VOCs in the baby products as negligible under their assumptions. Most baby diapers also had noncancer hazard ratios below one, though one diaper exceeded the reference level because of n-heptane, a solvent-related compound that can irritate sensitive tissue.
In plain language, the study did not find evidence that the sampled diapers presented a meaningful cancer risk from the VOCs measured. It did find undesirable chemicals, product-to-product differences and one result that warranted closer attention for potential irritation. The researchers recommended eliminating toxic constituents and creating uniform testing and disclosure rules.
The limits are just as important. Researchers did not test multiple production lots, the baby-diaper subgroup was small, extraction conditions may not perfectly match use on a baby, and the analysis did not capture every possible chemical or the combined effect of mixtures. A single result cannot tell a parent what is in every package of the same brand today.
The 2025 phthalate study raises a different concern
A second study, published in the journal Toxics in March 2025, examined phthalate exposure more directly. Researchers recruited 66 infants in Guangzhou, China and collected a disposable diaper and urine sample from each child. They measured six phthalates in the diapers and nine phthalate metabolites in urine.
The researchers reported a statistically significant correlation between di-n-butyl phthalate, or DnBP, in diapers and its metabolite in urine. They also found that several urinary phthalate metabolites were positively associated with 8-hydroxydeoxyguanosine, a biomarker of oxidative DNA damage. Their model estimated that skin absorption from diapers accounted for varying portions of total exposure to four phthalates, from 7.76 percent for DEHP to 44.9 percent for DEP.
Those findings justify follow-up research, especially because diapers create prolonged skin contact. They do not prove that diapers caused the oxidative marker, that the marker led to disease or that the findings apply to diapers currently sold in the United States. The study was observational, involved only 66 infants in one city and could not fully separate exposure from diapers from phthalates encountered in food, dust, packaging, personal-care products or other sources.
The correct reading is neither “nothing to see here” nor “diapers damage babies’ DNA.” It is that a plausible route of exposure has been identified and deserves larger, product-specific studies with repeated sampling and health follow-up.
What about PFAS in disposable and cloth diapers?
PFAS claims require another layer of caution. A recently refreshed Mamavation diaper guide reports that an outside laboratory screened a wide range of disposable and cloth products for total fluorine, then calculated organic fluorine when the total result reached at least 10 parts per million. The testing identified organic fluorine in parts of several products, which the publisher treated as an indication of possible PFAS.
The fine print matters. Most samples were purchased from February through August 2023. Total organic fluorine is a useful screening tool, but it does not identify a specific PFAS compound, explain why fluorine is present or measure what could migrate into a baby. The testing often examined limited samples. In one case, the first Babyganics diaper sample had detectable organic fluorine on the outside, while a second product from the same lot was nondetect. That difference underscores why repeat testing is essential.
The findings should prompt manufacturers to disclose whether PFAS are intentionally used and to publish compound-specific testing. They should not be treated as proof that every current package of a named brand contains PFAS or that a baby absorbed a harmful dose.
Cloth diapers are not automatically chemical-free. Waterproof covers may use polyurethane laminates or other synthetic materials, colored fabrics can contain dyes, and detergent or fragrance residue can irritate skin. A simpler reusable system made with an uncolored absorbent fabric can reduce some added features, but its safety still depends on the cover, washing routine, fit and how often it is changed.
The regulatory gap California is trying to close
The U.S. Consumer Product Safety Commission considers a diaper a children’s product because a child has direct contact with it. The CPSC’s rules impose requirements that apply to children’s products, including limits for lead in accessible components. Yet there is no nationwide rule requiring a complete diaper ingredient list.
Federal phthalate limits also illustrate how product categories can leave gaps. The CPSC’s phthalate rule applies to children’s toys and a defined group of child-care articles used for sleep, feeding, sucking or teething. That language does not clearly encompass a diaper simply because it is a children’s product.
New York moved first. A law signed in December 2024 made the state the first to require diaper ingredient labeling, and packages sold there were required to carry ingredient lists within a year. The New York Assembly’s announcement says ingredients must be listed conspicuously and in order of predominance.
California’s AB 1901 would go further in the detail required online. The final bill text calls for each intentionally added ingredient’s chemical or raw-material name, Chemical Abstracts Service number and function. Earlier news coverage cited a 2028 online deadline, but the Senate-amended current text moved the main dates. If signed in its present form, product-specific online disclosure and package requirements for diapers manufactured or distributed in California would begin January 1, 2029. Diapers sold in the state would have to comply by July 1, 2029.
The measure would not ban phthalates, PFAS, VOCs or fragrance. It would require disclosure of intentionally added ingredients. That is progress, but it also creates a blind spot: an unintended contaminant, processing byproduct or trace residue may not qualify as intentionally added and may never appear on the label.
That is why disclosure and independent testing are complementary, not interchangeable.
What parents can do without panicking or overspending
Parents should not interpret this reporting as a direction to throw away an unopened supply of diapers that is working well. The available evidence does not show that ordinary use of all disposable diapers harms babies. A measured approach can reduce unnecessary ingredients while still prioritizing dryness, fit and affordability.
Choose fragrance-free when possible. Fragrance adds no absorbency and can introduce more ingredients. The American Academy of Pediatrics recommends fragrance-free products for babies with diaper irritation.
Look for a real ingredient list. A front label that says “natural,” “plant-based,” “clean,” “organic” or “hypoallergenic” does not disclose every material and does not guarantee low chemical emissions. Check the package and the manufacturer’s product-specific website. New York-compliant packages may offer more detail.
Ask precise questions. Contact the manufacturer and ask whether the product contains intentionally added PFAS, phthalates, fragrance, lotion, latex or antimicrobial treatments. Ask whether the company tests finished diapers for VOCs and heavy metals, whether results are available by lot, and which bleaching process is used for the pulp. A yes-or-no answer is more useful than a general promise of purity.
Reduce optional features if a baby reacts. A plain, fragrance-free diaper without lotion or printed areas near the skin may be easier to troubleshoot. A wetness indicator is convenient, but caregivers who do not need it can ask whether a version without one is available.
Do not sacrifice dryness. Highly absorbent diapers help keep urine away from skin. A poorly fitting or less absorbent product that stays wet may create a more immediate and proven irritation problem than a theoretical reduction in chemical exposure.
Change one variable at a time. If a rash appears after switching diapers or wipes, return to the prior product or try a fragrance-free alternative for about two weeks. Changing diapers, wipes, detergent and cream all at once makes the trigger difficult to identify.
Report a suspected product problem. Save the package, lot number, receipt and photographs. Contact the manufacturer and file a report through SaferProducts.gov if a diaper appears to cause an injury or contains a foreign material.
Most diaper rashes are not evidence of toxic exposure
At least half of babies develop diaper rash at some point, according to the American Academy of Pediatrics. The most common type is irritant dermatitis caused by prolonged contact with urine and stool, moisture and friction. Yeast and bacterial infections can also occur. Allergy to dyes, elastics, fragrances or preservatives is possible, but it is less common.
The AAP’s pediatric dermatology guidance recommends frequent changes, gentle cleansing with water or alcohol-free and fragrance-free wipes, time for the skin to air-dry, and a thick barrier of zinc oxide or petrolatum. A looser fit can reduce rubbing.
Call a pediatrician if a rash worsens or does not improve after two to three days of home treatment, or if it includes blisters, peeling, pus, oozing or crusted sores. Medical advice is also warranted for severe pain, a rash that appears during antibiotic treatment, or any rash accompanied by fever.
Medical note: This article provides general information and is not a diagnosis or substitute for care from a qualified pediatric professional.