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COMMENTARY: California OEHHA and EPA's Prop. 65/FIFRA Skirmish—The Latest in a 30 Year Dispute over Pesticide Labeling

The Recent Skirmish: EPA’s Dear Registrant Letter and OEHHA’s Response

On August 7, 2019, EPA fired a shot across the bow of the California agency responsible for Proposition 65,[1] OEHHA,[2] by issuing a letter[3] to a glyphosate registrant notifying it that use of the Prop 65 “safe harbor” cancer warning on glyphosate product labels would be “false and misleading”—and therefore subject to enforcement—under the federal pesticide law, FIFRA.[4] EPA’s “Dear Registrant letter” is a rebuttal to OEHHA’s Prop 65 listing of glyphosate as a carcinogen. It is a statement of disagreement—according to EPA, glyphosate is not a carcinogen, and to act as if it is a carcinogen would be false and misleading.   OEHHA mounted a precarious response to EPA’s Dear Registrant letter by pointing to the Constitutionality of California’s Prop 65 listing procedures and the alleged scientific legitimacy of the IARC[5] report[6] underpinning the listing.

EPA’s Dear Registrant letter is more of a capital-“S” Statement and less of a practical enforcement warning—and may actually be beneficial to glyphosate registrants—because (1) there are a couple reasons to think that EPA will not enforce against glyphosate registrants; and (2) the letter may lend glyphosate registrants credibility in glyphosate lawsuits brought by private individual plaintiffs, which have recently yielded huge dollar figure verdicts.

Many commentators have cast the Dear Registrant letter as part of the larger California-versus-Trump EPA battle, and that would seem to be true. In the EPA press release published in tandem with the Dear Registrant letter,[7] EPA Administrator Andrew Wheeler stated that EPA “will not allow California’s flawed program to dictate federal policy.” OEHHA contradicted this point directly in its August 12 response to the Dear Registrant letter:[8] “California law does not dictate federal policy.” But this recent fracas is also the latest in an unresolved pesticide-specific California-versus-EPA conflict that began with the passage of Prop 65 in 1986.

The Dear Registrant Letter is More a Denouncement of the Prop 65 Glyphosate Listing and Less a Practical Warning

The Dear Registrant letter serves less as a warning to glyphosate registrants and more as a position statement (disclaimer: this is not legal advice). Yes, EPA rattles the FIFRA-violation sabre in the letter, but there are two reasons to think that EPA may not pursue enforcement against glyphosate registrants.  First, registrants with Prop 65 warnings on their labels received EPA approval of those label statements and can wield that approval as a defense to enforcement.  Second, although EPA’s letter requests that registrants submit amended labeling to EPA to remove the Prop 65 warning within 90 days, there may not be an “or else” at the end of the request. EPA could initiate mandatory registration cancelation proceedings if registrants don’t comply, but it has been loath to do so in the past. Mandatory cancellation proceedings give registrants the opportunity to seek a hearing, which can be an onerous and lengthy process, not to mention that the registrant(s) can continue selling the registered product at issue during the cancellation process (also, a fun fact: EPA has only initiated a handful of mandatory cancellation proceedings ever). 

To induce a registrant to change its label, EPA’s common practice is to wait until a registrant applies for an amendment to the registration, and then dangle that approval as leverage to induce the registrant to agree to the change EPA wants. (Even if the registrant’s requested amendment is unrelated to EPA’s desired change.)   

At any rate, glyphosate registrants intending to comply with Prop 65 can omit the Prop 65 warning from product labels and labeling without risk of government or bounty-hunter enforcement until the resolution of Nat’l Ass’n of Wheat Growers, et al. v. Zeise, per a preliminary injunction ordered by the U.S. District Court for the Eastern District of California in February 2018.[9]

The Dear Registrant letter will instead benefit glyphosate registrants in the current barrage of lawsuits brought against them by private individual plaintiffs. For the uninitiated, California juries in glyphosate lawsuits have awarded plaintiffs who alleged that glyphosate gave them cancer verdicts of $2 billion, $289 million, and $80 million in the last year. And there’s no reason to think the tide of glyphosate lawsuits will recede any time soon. As a result, the Dear Registrant letter may have been warmly received by glyphosate registrants because they can hold it up in a California courtroom and say “look! EPA agrees with us! It’s not a carcinogen! Don’t award this private plaintiff an 8-to-10 figure dollar amount!”

The Parts OEHHA Neglected to Mention in Its Response to EPA

In the Dear Registrant letter, EPA lists the numerous regulatory bodies that have found glyphosate “not likely to be carcinogenic to humans” or similar. As EPA points out, there are many more credible, international regulatory and scientific bodies that have found glyphosate safe than the one that has found glyphosate “probably carcinogenic to humans,” the International Agency for Research on Cancer (IARC).  EPA also points out that, after IARC classified glyphosate probably carcinogenic, EPA convened a panel of scientists to perform an independent evaluation of glyphosate data. The panel found glyphosate “not likely to be carcinogenic to humans.”

In its response, OEHHA defends its Prop 65 glyphosate listing by giving a few sentences about IARC’s glyphosate classification, stating that a California Court unanimously upheld the listing, and by listing the organizations from which the IARC panel members hailed, as if to say that the IARC decision reflects the findings of all those organizations.

OEHHA failed to disclose a few key points in its response that undermine its position (we’ll save the best for last). First, glyphosate was listed on the Prop 65 cancer-causing chemicals list[10] as a result of an automatic trigger in California statutory law to list it because IARC classified it as “probably carcinogenic to humans.”[11] OEHHA was required to list glyphosate on the Prop 65 list and did not have to make any scientific findings or verify IARC’s findings for the listing to occur. In fact, when OEHHA proposed to list glyphosate, it stated “[u]nder this listing mechanism, OEHHA cannot consider scientific arguments concerning the weight or quality of the evidence considered by IARC when it identified these chemicals and will not respond to such comments if they are submitted.”[12] OEHHA has not considered, and is not permitted by law to consider, the scientific veracity of the Prop 65 glyphosate listing.

Second, OEHHA’s case reference to Monsanto v. OEHHA, 22 Cal.App.5th 534 (2018), is equally flimsy support for its allegedly science-based position. In Monsanto v. OEHHA, the Court simply answers the question of whether the automatic statutory IARC listing trigger is Constitutional under the California and United States Constitutions. The Court held that the triggering mechanism is Constitutional, not that IARC’s conclusions have any scientific validity. As an aside, this seems a potentially dangerous holding (where IARC goes, California goes). Also, this case is interesting in part because it mentions that all 17 other reviews of the same data IARC looked at have resulted in the conclusion that glyphosate is not carcinogenic.

Third and finally, OEHHA neglected to mention that it conducted its own scientific assessments of glyphosate in 1997 and 2007 and found glyphosate non-carcinogenic.  Specifically, in its 2007 report, OEHHA stated “[b]ased on the weight of the evidence, glyphosate is judged unlikely to pose a cancer hazard to humans.”[13] In its 1997 report, OEHHA stated “glyphosate is a Group E carcinogen (evidence of no carcinogenic effects).”[14]

Since IARC classified glyphosate as a probable carcinogen, OEHHA has jumped through hoops—press release after lawsuit after lawsuit—to defend glyphosate’s mandatory Prop 65 cancer listing, with which its own scientists and nearly all of the international scientific community have disagreed. EPA has now called out OEHHA’s insubstantial (or in Mr. Wheeler’s words, “flawed”) basis for the listing and puts its weight behind its position by declaring all Prop 65 glyphosate warnings a violation of FIFRA.

For questions or assistance with pesticide-related issues, please contact Mike Novak (, 202.434.4485).

[1] Cal. Health & Safety Code § 25249.5 et seq. (“Prop 65”).

[2] The California Office of Environmental Health Hazard Assessment (“OEHHA”).

[3] Letter from Michael L. Goodis, Director, Registration Division, Office of Pesticide Programs, EPA, to Glyphosate Registrant (unidentified) (Aug. 7 2019).

[4] The Federal Insecticide, Fungicide, and Rodenticide Act (“FIFRA”), 7 U.S.C. § 136 et seq.

[5] International Agency for Research on Cancer (“IARC”).

[6] OEHHA, Some Organophosphate Insecticides and Herbicides, Monograph 112, (Jan. 2017).

[7] EPA, EPA Takes Action to Provide Accurate Risk Information to Consumers, Stop False Labeling on Products (Aug. 8, 2019).

[8] OEHHA, OEHHA Statement Regarding US EPA’s Press Release and Registrant Letter on Glyphosate (Aug. 12, 2019).

[10] OEHHA, Chemicals Known to the State to Cause Cancer or Reproductive Toxicity (June 28, 2019).

[11] Cal. Labor Code § 6382(b)(1).

[12] OEHHA, Notice of Intent to List: Tetrachlorvinphos, Parathion, Malathion, Glyphosate (Sept. 4, 2015).

[13] OEHHA, Public Health Goal for Chemicals in Drinking Water: Glyphosate, at 1 (June 2007).

[14] OEHHA, Public Health Goal for Glyphosate in Drinking Water, at 10 (Dec. 1997).