# California diaper ingredient disclosure legislation

> Live situation record from CLSTR: https://clstr.news/situations/california-diaper-ingredient-disclosure-legislation
> Updated: 2026-08-28T08:00:00.000Z. Sources: 6. Developments: 2.

The California Assembly passed AB 1901, a bill designed to require manufacturers of disposable diapers to disclose all intentionally added ingredients. Proponents, including the Environmental Working Group and actress Hilary Swank, argued that the measure is necessary to prevent the use of vague terms like ‘fragrance’ which can hide compounds such as phthalates, PFAS, and lead. Supporters noted that infants are particularly vulnerable to these substances due to thinner skin.

Following the Assembly's action, the California State Senate also passed the bill. Once signed into law by Governor Gavin Newsom, the legislation will require companies to make ingredient lists and their specific functions available on a public webpage by 2028, with mandatory inclusion on product packaging by January 1, 2029. The bill follows similar transparency mandates established in New York and Illinois.

## Claims

- The California State Senate passed a bill to regulate potential toxins in diapers. (corroborated by 3 sources)
- Assembly Bill 1901 requires manufacturers to disclose all ingredients in disposable diapers sold in California. (corroborated by 3 sources)
- Manufacturers must disclose the reason each ingredient is included in the product. (corroborated by 3 sources)
- Ingredient information must be available online by the end of 2028 and on package labels by January 2029. (corroborated by 3 sources)
- Certain diaper ingredients have been linked to hormone disruption, nervous system effects, and skin reactions. (corroborated by 3 sources)
- There is currently no federal law requiring diaper manufacturers to disclose product ingredients. (corroborated by 3 sources)

## Timeline

### 2026-08-28: California passes bill to mandate ingredient disclosure in disposable diapers

California's State Senate passed Assembly Bill 1901, requiring diaper manufacturers to disclose all ingredients and their purposes to address concerns over potential toxins and chemical absorption in infants.

6 sources. https://clstr.news/cluster/california-passes-bill-to-mandate-ingredient-disclosure-in-disposable-diapers

### 2026-08-14: California Assembly passes bill requiring diaper ingredient disclosure

California's Assembly passed AB 1901, a bill requiring diaper manufacturers to disclose all intentionally added ingredients to protect infants from exposure to toxic chemicals.

2 sources. https://clstr.news/cluster/california-assembly-passes-bill-requiring-diaper-ingredient-disclosure

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Cite as: California diaper ingredient disclosure legislation. CLSTR, https://clstr.news/situations/california-diaper-ingredient-disclosure-legislation