What's actually inside
your baby's diaper.
All of it.

Diapers are one of the few products your baby is in contact with almost continuously from birth. They sit against the genitals and inner thighs - skin that is thin, highly absorptive, and in direct contact with a warm, moist, sealed environment for the entire time the diaper is worn. This matters because skin absorption in that environment is significantly higher than on other parts of the body.

And yet most parents never think about what is in a diaper. The box says "gentle" or "sensitive" or "pure." The baby on the packaging looks happy. It's Pampers. Everyone uses Pampers.

In 2019, a French government agency - ANSES, the national agency for food, environmental and occupational health and safety - published a chemical risk analysis of disposable diapers. What they found was not reassuring.

What the 2019 ANSES study actually found

The ANSES study tested a range of popular disposable diaper brands and found the presence of dioxins, furans, formaldehyde, polycyclic aromatic hydrocarbons (PAHs), and certain fragrances. For several of these - PAHs, dioxins, and dioxin-like PCBs - the detected levels exceeded the agency's health reference values.

The study concluded that the contaminants had entered the diapers through manufacturing processes, the materials used, or the addition of fragrances. ANSES called for restrictions on these substances in infant diapers and recommended that manufacturers improve both transparency and testing.

The ingredients worth knowing about

Dioxins and furans are byproducts of the chlorine bleaching process used to whiten the wood pulp inside diapers. They are classified by the EPA as among the most toxic chemicals known to science and are recognised carcinogens. The good news: most major brands have moved away from elemental chlorine bleaching. The nuance: there are two alternatives - Elemental Chlorine Free (ECF), which uses chlorine dioxide and still produces trace dioxins, and Total Chlorine Free (TCF), which uses no chlorine compounds at all. Most conventional brands use ECF. TCF is safer and is the standard used by most certified organic diaper brands.

Fragrance is listed as a single ingredient but can legally contain hundreds of individual chemical compounds - many of which are never disclosed on the label. Fragrance in diapers frequently contains phthalates, which are used to help the scent last longer. Phthalates are known endocrine disruptors, meaning they interfere with the hormone system. They have been banned from cosmetic products in the EU. The US still permits their use and does not require them to be listed on labels. If a diaper says "fragrance" and does not explicitly state "phthalate-free," it likely contains them.

Superabsorbent polymers (SAP) are the gel-like crystals that give modern diapers their absorbency. Almost every disposable diaper contains them, including most "natural" brands. The SAP itself - sodium polyacrylate - is generally considered safe. The concern is how it is manufactured: depending on the process, it may be contaminated with residual acrylamide and acrylic acid. The Environmental Working Group notes that the National Toxicology Program has classified acrylamide as reasonably anticipated to cause cancer in humans.

Vegetable oil is listed as an ingredient in several Pampers products. It sounds harmless - but "vegetable oil" in a diaper is an unspecified term that does not disclose the actual source. Palm oil is commonly used in diaper manufacturing as a skin conditioning and softening agent. The concern is twofold: palm oil is one of the most common contact allergens in baby skincare, and the term "vegetable oil" on a label tells you nothing about what you are actually applying to your baby's skin 6,000 times. A brand that is genuinely transparent would name the oil.

Formaldehyde can be present in diaper adhesives and materials as a byproduct of manufacturing. The ANSES study identified it as a concern. The 2024 review found formaldehyde poses the highest dermal exposure dose of any chemical detected in diapers.

Lotions are added to many diapers to protect against rash. They sound benign but can contain petrolatum, mineral oils, and synthetic compounds that are not tested for long-term dermal absorption in infants. They also create a barrier that can interfere with rash treatment.

How the most popular US brands compare

The brands below cover the majority of the US diaper market. The information is based on publicly available brand disclosures, third-party testing data, and EWG assessments. Where brands have not disclosed information, that is noted - because non-disclosure is itself a data point.

The pattern in the table is stark. The two brands most parents reach for without thinking - Pampers Swaddlers and Huggies Snug and Dry - contain fragrance, lotion, and undisclosed phthalate status. They are ECF bleached, not TCF. They are also the diapers most likely to be given to your newborn in hospital.

Your diaper ingredient checklist

When choosing a diaper, this is what to look for - and what to put back. Save this to your phone.

A note on "natural" and "organic" marketing

This is where the diaper category gets complicated. Unlike formula, there is no regulated standard for "organic" diapers in the US. Any brand can use the word "natural" without meeting any specific criteria. The words "plant-based," "eco-friendly," and "gentle" are marketing terms with no legal definition in the context of diapers.

What matters is not the marketing claim but the specific disclosures: chlorine bleaching method, fragrance status, phthalate status, and third-party certification. A brand that says "organic bamboo" but does not disclose its bleaching method or phthalate status is less trustworthy than a brand with fewer "natural" claims but full ingredient transparency.