California bill would require diaper makers to disclose chemicals used in products, according to report

A proposed California measure would require companies that make disposable diapers to disclose the toxic chemicals used in the products, potentially exposing what supporters describe as a “mystery cocktail” of ingredients that may include regulated industrial compounds, according to a report by The Guardian.

The reporting says the bill cleared the California Assembly and is expected to be taken up next by the state Senate. The measure would shift diaper ingredient information from private formulation data to public-facing disclosure requirements, creating a compliance obligation for manufacturers and related supply-chain actors.

The Guardian’s account describes diapers as containing, in some cases, multiple categories of chemicals that environmental and health advocates have raised concerns about, including phthalates and other plasticizers; lead and other heavy metals; PFAS and other per- and polyfluoroalkyl substances; quaternary ammonium compounds (quats); arsenic; a range of volatile organic compounds (VOCs); and added fragrances. The report also characterizes the substances as often appearing across different parts of diaper materials, such as absorbent components and coatings.

Under the reported approach, manufacturers would be expected to provide information about what chemicals are present and disclose them in a way that allows regulators and consumers to identify the substances at issue. The practical effect, if enacted, would be to increase documentation and reporting burdens on companies, particularly around formulation management, testing or verification of chemical presence, and recordkeeping for product lines sold in California.

The measure would also raise questions about how disclosures are implemented in a way that fits within California’s broader framework for chemical information laws, including how regulators treat trade secret claims and how firms substantiate ingredient or chemical composition. Those issues can affect implementation timelines and could shape how much detail companies must provide to comply.

The Guardian said the bill is now moving through the state legislative process after Assembly action. As of publication, an official bill record confirming the Assembly vote, the bill number, and the specific disclosure requirements was not included in the material provided for this write-up, so additional legal details cannot be confirmed here.

If the proposal advances in the California Senate, the next step will be a Senate vote and, if approved there and by the governor, implementation rules governing how manufacturers report chemical information, what deadlines apply, and what enforcement mechanisms would be available for noncompliance.