Extracted from Law360
There's more to the bisphenol family of chemicals than the well-known bisphenol A, or BPA, and bisphenol S, or BPS. And a new California initiative seeks to classify all p,p'-bisphenol chemicals as causing reproductive toxicity under Proposition 65.
With the new move by California's Office of Environmental Health Hazard Assessment, or OEHHA, companies that have switched out BPA or BPS for structurally similar p,p'-bisphenols may need to reevaluate.
Bisphenol chemicals are found in many consumer products, from food packaging to medical devices. An expanded classification will create new opportunities for private enforcers to challenge a wider array of products.
On Oct. 21, OEHHA announced that it has selected the p,p'-bisphenol class of chemicals for review by its Developmental and Reproductive Toxicant Identification Committee, or DARTIC, part of the agency's Science Advisory Board.
DARTIC's review will consider the possible listing of the chemicals under Proposition 65 as causing reproductive toxicity.
OEHHA has requested information from the public to inform the potential listing. This is a significant development for companies that may have replaced BPA and BPS in their products with other p,p'-bisphenol alternatives.
A potential listing of the entire class of p,p'-bisphenol chemicals could require new Proposition 65 warnings for a vast range of consumer and industrial products.
This is particularly concerning since private enforcers have served over 900 notices of violation for BPS this year alone — representing over 20% of all notices of violation served in 2025. Listing a larger class of chemicals has the potential to open the floodgates to new litigation.
As a result, companies may want to consider proactively reviewing their supply chains to look for products that contain any p,p'-bisphenol chemicals, not just BPA or BPS.
Proposition 65
California's Proposition 65, formally known as the Safe Drinking Water and Toxic Enforcement Act, requires businesses to provide warnings before exposing individuals to chemicals known to the state of California to cause cancer, birth defects or reproductive harm.
Proposition 65, enacted in 1986, requires OEHHA to annually update and publish a list of these chemicals. The list has grown to include approximately 900 chemicals since it was first published in 1987.
DARTIC serves as the state's qualified experts on reproductive toxicants, and renders an opinion about whether a chemical has been clearly shown to cause reproductive toxicity. The chemicals identified by the DARTIC are added to the Proposition 65 list.
Proposition 65 imposes civil penalties of up to $2,500 per violation. The statute also provides that any company that "threatens to violate" the warning requirement may be "enjoined in any court of competent jurisdiction."
The California attorney general, any district attorney and certain city attorneys are authorized to enforce Proposition 65. Any individual may also bring a private enforcement action, but must first serve a 60-day notice of violation on the alleged violator before proceeding to file a lawsuit.
These private enforcers take home 25% of all civil penalties imposed as a bounty for their efforts, and their attorneys routinely recover their fees.
These so-called bounty hunter lawsuits often result in settlements, which include civil penalties, attorney fees and injunctive relief — such as displaying Proposition 65-compliant warnings or agreeing to reformulate a product.
OEHHA's Information Request
According to OEHHA's October announcement, DARTIC will review p,p'-bisphenols, as well as ethers and esters of p,p'-bisphenols. In addition to BPA and BPS, this category of chemicals includes bisphenol AF, bisphenol AP, bisphenol B and bisphenol Z.
These chemicals may be found in:
- Liners, lacquers, and adhesives for food and beverage cans to prevent corrosion;
- Food containers, takeout containers and other food packaging;
- Dishes, baby bottles and water bottles;
- Laminate and industrial flooring;
- Hard plastic parts used in various items, such as household appliances, cars, airplanes and other vehicles;
- Medical devices and dental sealants; and
- Building materials like sealants, adhesives and grout.
Some p,p'-bisphenol chemicals have been found as contaminants in food products like yellow mustard, meat products, dairy products, vegetables, cereals and canned foods.
OEHHA is requesting information from the public to support its assessment of evidence of the potential reproductive effect of these chemicals, including:
- Animal studies examining reproductive toxicity, i.e., evidence of developmental and male and female reproductive toxicity;
- Epidemiological studies in humans;
- Studies related to mechanisms of reproductive or developmental toxicity; and
- Other pertinent studies on pharmacokinetics and effects on biochemical and physiological processes, including findings in humans.
The public comment period ends on Dec. 1.
Implications for Industry
P,p'-bisphenols are a large class of chemicals. The European Chemicals Agency previously assessed 148 bisphenols as a group and found that 34 bisphenols may need to be restricted under the European Union's Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals, because they may interfere with hormonal systems and affect reproduction.
The potential listing of all or part of the class of p,p'-bisphenol chemicals poses a significant compliance challenge — particularly for companies that have relied on switching from BPA or BPS to other compounds to maintain compliance with Proposition 65.
Two types of p,p'-bisphenol chemicals — BPA and BPS — are already listed as reproductive toxicants under Proposition 65. Many companies responded to these listings by substituting BPA or BPS with other structurally similar p,p'-bisphenol chemicals, sometimes marketing their products as "BPA-free" or "BPS-free."
If OEHHA lists additional p,p'-bisphenol chemicals under Proposition 65, this may result in a regrettable substitution problem. A product containing one of these chemicals would be subject to the warning requirement if the exposure exceeds the relevant maximum allowable dose level, or if a risk assessment cannot demonstrate an exposure at a level that meets regulatory requirements.
A broad listing will also create new opportunities for private enforcers to challenge a wide array of products across multiple industries.
So far, notices of violation for BPS have focused on thermal receipt paper products. In addition to thermal receipt paper, notices of violation for BPA have focused on apparel, food and beverage products, and phone cases.
Given the recent listing of BPS, as well as the possibility that OEHHA may list all or part of the class of p,p'-bisphenol chemicals, some companies may want to consider moving beyond chemical-by-chemical risk management.
They may also consider mapping out their supply chain to proactively identify products that may contain any p,p'-bisphenol chemical, not just BPA or BPS.
Companies and trade groups may also consider submitting comments to OEHHA when studies demonstrate certain p,p'-bisphenol chemicals do not present evidence of reproductive toxicity to humans. This evidence could help narrow the scope of any potential listing.