Bill would require manufacturers to publish ingredient lists by 2028
California Assembly Member Marc Berman authored the bill, which the Assembly passed 68-1. The legislation is supported by a coalition of at least 150 public health and environmental groups.
“Parents deserve better than a guessing game, especially when it comes to a product that will be touching their babies’ skin for every minute of every day for the first two or three years of their lives,” Berman said.
Under the bill, manufacturers would be required by 2028 to publish a list of all intentionally added ingredients in their diapers on a publicly accessible website, along with each ingredient’s specific function. By January 1, 2029, that information would also have to appear on diaper packaging.
The chemicals commonly found in disposable diapers include phthalates, lead, PFAS, quats, arsenic, and a range of volatile organic compounds (VOCs), along with fragrance ingredients that can include any of 1,200 compounds thought to be hazardous to human health. The risk to infants is acute because diapers press against a baby’s skin almost continuously for several years, and babies’ skin is thinner than adult skin and is more prone to absorbing substances. Phthalates can disrupt the endocrine system, potentially interfering with hormones essential for brain and reproductive development.
Researchers and advocates have documented the presence of these chemicals in commercial products. Testing commissioned by Mamavation, a public health advocacy site, found PFAS in a range of popular diaper brands. French regulators detected widespread use of chemicals including formaldehyde, pesticides, and dioxins in diapers. Other peer-reviewed research has identified numerous VOCs in disposable hygiene products and diapers.
A small 2025 study in China checked diapers and urine samples from 66 babies for several phthalates and found correlation for some of the compounds. The study also found markers of DNA damage in the urine, and the researchers estimated that absorption of the phthalates likely accounted for major portions of the phthalate levels measured. The study does not establish that wearing diapers causes DNA damage or other disease, but points to a risk. Research on how steady exposure to these chemicals affects babies remains limited.
California is the only state besides New York that currently requires any disclosure of diaper ingredients. New York requires some labeling, but the California bill goes further.
The Center for Baby and Adult Hygiene Products, a trade group representing many top manufacturers, has defended the industry. “Diapers are designed and manufactured to meet strict safety standards, and decades of real-world use support their safety for infants and children,” the group said.
Advocates say that industry has at times argued that diaper ingredients are protected by confidential business information laws and that those laws do not cover diaper ingredients.
“California parents shouldn’t need a chemistry degree to buy a diaper,” said Susan Little of the Environmental Working Group, which helped develop the legislation. “They deserve to know exactly what is touching their child’s skin.”
The bill’s sponsors stopped short of including a ban on any specific chemicals, in part because industry pressure would likely defeat any such measure. Governor Gavin Newsom, who has indicated he is running for the Democratic nomination for president, has a history of vetoing strong chemical legislation that faced industry or donor opposition.
Advocates argue that transparency requirements alone could shift the market. “Transparency laws can move the marketplace,” said Oriene Shin, safety advocacy manager with the nonprofit Consumer Reports, which has performed testing that identified toxic chemicals in diapers. “When a customer can compare ingredients, manufacturers have an incentive to follow what the consumer wants, instead of deciding what to do based on internal analyses.”
Other states often follow California’s lead on environmental and consumer-protection laws, and similar past laws on toxic chemicals have spread beyond the state. The bill’s advocates say the disclosure requirement could create market pressure for manufacturers to reformulate products and could boost nontoxic brands.
Parents seeking to reduce their infants’ exposure can take practical steps, advocates say. Choosing fragrance-free diapers reduces one common source of undisclosed chemicals. Cloth diapers are typically a better option, though they are not always chemical-free — dyes, detergents, and waterproofing agents can still include toxic compounds. The Environmental Working Group’s safe diaper guide evaluates diaper ingredients, and the nonprofit also provides recommendations for products that meet its standards, though companies pay for the EWG-certified label. Mamavation maintains a list of which diapers it tested do or do not contain PFAS.
Parents should be skeptical of claims like “natural,” “plant-based,” and “eco-friendly,” which have no legal definition and do not necessarily mean the diapers are nontoxic, advocates say. Parents can also contact diaper manufacturers directly and ask whether they use PFAS, phthalates, heavy metals, or other substances.