California Prop 65 and the Rise of Consumer Fraud Suits: How to Respond

Recently, a number of the outbound-facing companies we deal with have received California Proposition 65 sixty-day notices of violation. Some are existing clients; others came to us after receiving a notice.

These notices are creating real risk for operations and for Amazon platform activity.

Receiving a sixty-day notice does not mean a court has found a violation. But it is also not an ordinary demand letter that can be handed to a business team for a simple reply. A company needs to determine quickly: what product the other side purchased, what substance the laboratory detected, whether the test result can be compared against the relevant standard, and whether the company in fact bears a warning obligation.

The substances at issue are not limited to PFAS. PFAS is a collective term for per- and polyfluoroalkyl substances; because they break down slowly in the environment, media commonly call them "forever chemicals." It is not a single compound but a broad class of nearly 15,000 substances whose uses, risks, and regulatory status differ.

DEHP — di(2-ethylhexyl) phthalate — also appears frequently in consumer product testing and Prop 65 notices. Cosmetics, outdoor goods, plastics, food-contact materials, and other everyday consumer products may all fall within the testing scope.

California also offers a parallel route to recovery.

A plaintiff need not sue directly under Prop 65. It may instead frame "the product contains a chemical and this was not disclosed to consumers" as consumer fraud and bring a consumer class action. Common causes of action include California's Consumers Legal Remedies Act (CLRA), the Unfair Competition Law (UCL), fraudulent concealment, and breach of warranty.

The two categories rest on different legal bases, but both return to the same concrete questions: what substance is actually in the product? At what level? How much exposure does a consumer receive? Can the tested sample represent the product at issue? Does the company bear a warning or disclosure obligation?

The matter below is one in which the author served as lead defense counsel during prior practice. It was not brought under Prop 65, but it presented the same core questions Prop 65 cases present: the specific chemical, the exposure level, and the disclosure obligation. It also illustrates that a company facing a Prop 65 notice or a consumer fraud class action should not simply respond defensively. Examining the testing evidence early, and raising targeted affirmative challenges at the motion stage, is what creates the opportunity to contain a case at a stage where cost and risk remain manageable.

The Plaintiffs Alleged the Product Contained 160 ppb of PFAS

The case was filed in 2024 in the U.S. District Court for the Northern District of California.

The defendant was our client, a company selling consumer products in the United States. Two California consumers brought a class action, represented by a U.S. firm with a long record in consumer class litigation.

The plaintiffs defined a nationwide purchaser class and a California subclass, asserted federal jurisdiction under the Class Action Fairness Act, and alleged more than $5 million in controversy.

They pleaded four causes of action: violation of the CLRA, violation of the UCL, fraudulent concealment, and breach of the implied warranty of merchantability under U.C.C. § 2-314.

All four rested on the same factual allegation: that the liquid in the product contained PFAS and that the company had not disclosed this to consumers.

The complaint alleged that plaintiffs' counsel had commissioned laboratory testing of the product and obtained a result of "160 ppb of PFAS." Plaintiffs further alleged that this "exceeded the EPA's daily oral exposure limit by 320 times." To convey that 160 ppb was high, the complaint also cited a kale study, noting that researchers had been alarmed to find 0.25 ppb of PFAS in kale.

The complaint cited White House statements, EPA documents, media reports, and more than twenty footnotes. Numbers, multiples, and government documents assembled together make it easy to arrive directly at a conclusion of "serious exceedance."

We did not stop at that conclusion. We pulled the materials plaintiffs cited and checked them one by one.

What Exactly Is 160 ppb?

The first question was what the laboratory had actually detected.

PFAS comprises nearly 15,000 compounds whose chemical structures, uses, and toxicological profiles differ. Some are strictly regulated; others are FDA-approved for specific food-contact applications.

"PFAS detected" is therefore only the starting point of an inquiry. To go further and allege an undisclosed health risk, a plaintiff must at least identify what was detected.

The complaint did not state which PFAS the 160 ppb corresponded to, nor the relationship between the tested sample and the products the two plaintiffs purchased.

Specific test methods, sample chain of custody, and laboratory workpapers can be developed in discovery. But at the pleading stage, a plaintiff must allege enough facts for a court to assess reasonably whether the substance the result concerns carries the risk alleged, and why that result is representative of what these plaintiffs bought.

This is not to say the laboratory detected no PFAS. The point is that "160 ppb PFAS" in a complaint does not permit any assessment of which substance, or group of substances, the figure describes.

Where Did "320 Times" Come From?

The second question was whether 160 ppb could be compared directly against the EPA figure.

The EPA document plaintiffs cited provides an oral reference dose (RfD), expressed in milligrams per kilogram of body weight per day. It measures a daily intake dose scaled to body weight.

160 ppb measures a static concentration of a substance in a product.

One is a dose; the other is a concentration. They cannot simply be divided.

Deriving a daily human exposure dose from a static concentration in a product requires, at minimum, an exposure assessment: frequency of use, quantity per contact, route of exposure, and absorption rate.

Plaintiffs supplied none of that data, and offered no conversion model.

Our position was therefore not that "160 ppb is certainly safe." It was a more basic question: absent an exposure assessment, how does one get from a static concentration in a product to "exceeds the EPA daily oral exposure limit by 320 times"?

Continued review showed that the unit mismatch was not the only problem.

The EPA oral reference dose plaintiffs cited applies only to perfluoropropanoic acid — PFPrA, a single compound. But the complaint did not allege that PFPrA had been detected in the product.

The second benchmark plaintiffs used was a kale PFAS study. Checking the compounds that study listed, we found PFPrA was not among them.

So the first benchmark concerned PFPrA and the second concerned a different group of PFAS — not the same substance. Yet both were used to compare against the same "160 ppb."

More fundamentally, the complaint never stated what the 160 ppb itself represented: one particular PFAS, the sum of several target PFAS, or some other measure.

With no specific compound matched, no unit conversion, and no exposure pathway established, "320 times" lacked the necessary intermediate reasoning.

The Northern District of California had addressed a similar problem in Bullard v. Costco Wholesale Corp., where the court observed that "PFAS" is not a magic word that automatically opens the doors of federal court.

We placed that line at the opening of our motion to dismiss.

What This Case Suggests for Prop 65 and Consumer Fraud Litigation

The complaint did allege that the product bore no PFAS warning.

The two plaintiffs alleged they saw no warning that the product contained PFAS before purchase, and the complaint alleged the defendant had not disclosed PFAS on the packaging, website, or marketing materials.

But this was not a Prop 65 case.

Plaintiffs asserted no Prop 65 claim and served no Prop 65 sixty-day notice. Their pre-suit notice was a CLRA letter under Cal. Civ. Code § 1782(a). The causes of action ultimately pleaded were CLRA, UCL, fraudulent concealment, and breach of implied warranty.

Prop 65 turns on listed chemicals, exposure levels, and warning obligations. Consumer fraud litigation may contend that, even absent a direct Prop 65 violation, a company's failure to disclose that a product contains a substance affected consumers' purchasing decisions.

Different routes — but overlapping evidence.

At the time we filed our motion, the PFAS listed under California's Prop 65 list relevant to this dispute included PFOA, PFOS, and PFNA. Plaintiffs did not allege that the laboratory had detected any of them, nor did they state which other PFAS had been detected.

That does not by itself establish that all of plaintiffs' claims necessarily fail. But it makes one question unavoidable: if the specific compound is never identified, on what basis is a disclosure obligation to be assessed, and on what basis is a consumer's exposure to be found substantially risky?

The case shows that California chemical claims are no longer confined to the traditional Prop 65 sixty-day notice. The same test result may be deployed along different legal routes. A company should not ask only "is this a Prop 65 case?" but also "what substance, what exposure, and what harm is the other side actually alleging?"

We Filed Three Motions

In May 2024, plaintiffs sent their first CLRA pre-suit letter. Suit was filed in October 2024, with an amended complaint in November.

On April 3, 2025, we filed a motion to dismiss. On April 15, we filed a motion to strike and a motion for clarification. All three were set for the same hearing date.

The first was the motion to dismiss.

There, we focused on "exceeds the EPA limit by 320 times." 160 ppb is a static concentration of a substance in a product; the EPA oral reference dose is expressed in milligrams per kilogram of body weight per day. Without frequency of use, quantity of contact, and absorption, the two cannot be compared.

What to Do on Receiving a Sixty-Day Notice

First, identify the route. Determine whether the claim is brought under Prop 65 or as consumer fraud; the elements and the evidence differ.

Second, identify the substance. Is the compound alleged PFOA, PFOS, PFNA — or simply "PFAS"? Did the laboratory test for a specific compound, a sum of target analytes, or a surrogate measure?

Third, check the sample. Does the product tested correspond to what the company actually sells? Do model, lot, and supplier match?

Fourth, check units and exposure. A concentration in a product is not a consumer's actual daily exposure dose. Before any comparison, confirm the units are consistent and that a sound exposure analysis connects them.

Fifth, build the company's own testing file. PFAS, DEHP, other phthalates, heavy metals, and category-specific listed substances should be tested in light of materials, formulation, and supply chain. Reports must correspond to specific products, lots, and suppliers — not a single generic report with no traceability.

Sixth, revisit the Prop 65 warning. Assess whether and how to warn in light of the specific listed substances, exposure levels, sales channels, and current warning formats. A warning label is not a universal answer to be applied indiscriminately.

Defending also does not mean going to trial. Many of the decisive points in consumer class actions occur at the motion stage and before discovery. What a company actually needs is an early assessment of what the other side's evidence can and cannot establish, and then a decision whether to respond, remediate, negotiate, or defend.

Facing a Prop 65 sixty-day notice, or a complaint reciting "160 ppb," "320 times," and "forever chemicals," a company need neither pretend there is no risk nor accept the other side's conclusions at the outset.

Ask first: what was tested, are the units comparable, does the exposure meet the legal threshold, and where does the warning obligation come from?

Those questions often determine what a case is actually worth.

The author served as lead defense counsel in this matter during prior practice. This article is based on public court records and does not constitute legal advice.

This article addresses general legal questions only and does not constitute legal advice on any specific matter. Outcomes depend on the specific facts, evidence, applicable law, and the court's discretion.