Glyphosate and the Many Ramifications of an IARC Classification

May 30, 2017 | Complex Torts & Product Liability

As is frequently the case, a regulatory development or finding will serve as the impetus for activity in the realm of toxic tort. From the plaintiff’s perspective, the underlying science has been given the patina of credibility by the regulatory action; from the defense view, the regulatory action does not elevate the underlying science to the requisite legal standard because the purpose and criteria for the regulatory action are different and less stringent. Nevertheless, spurred by the regulatory action, issue is joined and the debate ensues, sometimes on fronts in addition to a traditional toxic tort lawsuit.

Glyphosate, an active ingredient in herbicide formulations, provides a good example of this scenario. In March 2015, the International Agency for Cancer Research (IARC) classified glyphosate as “probably carcinogenic to humans.” Notably, this classification is contrary to the findings and status of glyphosate determined by the U.S. Environmental Protection Agency (EPA) and the European Chemicals Agency (ECHA), and IARC’s comparable standing as a “regulator” might be questioned, although it is commonly thought of as the world’s preeminent cancer “agency.”

Against this backdrop, and based largely on the IARC finding, glyphosate is now the focus of (1) traditional toxic tort lawsuits, (2) consumer class action claims alleging that a food product is improperly labeled as “natural” because glyphosate was used in the growth of the crops that went into that product, and (3) regulation under California’s Proposition 65.

IARC’s Glyphosate Classification
IARC is an agency of the World Health Organization and follows the general governing rules of the United Nations family. With respect to matters of cancer causation, which would be pertinent to the toxic tort area, IARC describes itself and its mission as follows:

The objective of the IARC is to promote international collaboration in cancer research. The Agency is inter-disciplinary, bringing together skills in epidemiology, laboratory sciences and biostatistics to identify the causes of cancer so that preventive measures may be adopted and the burden of disease and associated suffering reduced. . . .

Emphasis is placed on elucidating the role of environmental and lifestyle risk factors and studying their interplay with genetic background in population-based studies and appropriate experimental models. This emphasis reflects the understanding that most cancers are, directly or indirectly, linked to environmental factors and thus are preventable. The IARC Monographs Programme is a core element of the Agency’s portfolio of activities, with international expert working groups evaluating the evidence of the carcinogenicity of specific exposures. The Agency is also committed to studying approaches for the early detection of cancer and in evaluating prevention strategies.

Int’l Agency for Research on Cancer, IARC’s Mission: Cancer Research for Cancer Prevention. Note, however, that by its own statement, “IARC is not involved directly in implementation of control measures,” i.e., regulation.

IARC’s findings have been criticized because while “[t]he agency says it assesses ‘hazard’—the strength of evidence about whether a substance or activity can cause cancer in any way[—i]t takes no account of typical levels of human exposure or consumption. So it is not measuring ‘risk’ or the likelihood of a person getting cancer from something.” Kate Kelland, “How the World Health Organization’s Cancer Agency Confuses Consumers,” Reuters, Apr. 18, 2016. Such findings would seem incomplete and incapable of addressing the issue of toxic tort causation, which is dependent on exposure and dose.

IARC’s classification of levels of carcinogenicity is likewise criticized for its ambiguity. IARC maintains five categories:
•Group 1: The agent is carcinogenic to humans.
•Group 2A: The agent is probably carcinogenic to humans.
•Group 2B: The agent is possibly carcinogenic to humans.
•Group 3: The agent is not classifiable as to its carcinogenicity to humans.
•Group 4: The agent is probably not carcinogenic to humans.

Most findings of carcinogenicity fall into either Group 2A or Group 2B. Group 2A (probably carcinogenic) is used when there is limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals. In some cases, an agent may be classified in this category when there is inadequate evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals and strong evidence that the carcinogenesis is mediated by a mechanism that also operates in humans. Exceptionally, an agent may be classified in this category solely on the basis of limited evidence of carcinogenicity in humans. An agent may be assigned to this category if it clearly belongs, based on mechanistic considerations, to a class of agents for which one or more members have been classified in Group 1 or Group 2A.

Int’l Agency for Research on Cancer, Preamble to IARC Monographs (2006), at 22.

Group 2B (possibly carcinogenic) is used for agents for which there is limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals. It may also be used when there is inadequate evidence of carcinogenicity in humans but there is sufficient evidence of carcinogenicity in experimental animals. In some instances, an agent for which there is inadequate evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals together with supporting evidence from mechanistic and other relevant data may be placed in this group. An agent may be classified in this category solely on the basis of strong evidence from mechanistic and other relevant data.

Id. at 23.

In March 2015, IARC classified glyphosate as “probably carcinogenetic to humans.” Kathryn Z. Guyton et al., “Carcinogenicity of Tetrachlorvinphos, Parathion, Malathion, Diazinon, and Glyphosate,” 16 Lancet Oncology 490 (May 2015). The full IARC monograph, Some Organophosphate Insecticides and Herbicides, is available online.

Contrary to IARC’s conclusion, neither the EPA nor the ECHA find that glyphosate is hazardous to humans. Nevertheless, the IARC classification has produced a slew of ramifications.

In re Roundup Products Liability Litigation Multidistrict Litigation
Glyphosate is at the center of toxic tort claims as the active ingredient in the Monsanto herbicide product Roundup. In re Roundup Prods. Liab. Litig., MDL No. 2741, No. 16-md-02741-VC (N.D. Cal.); see, e.g., Complaint ¶¶63–69, Giglio v. Monsanto Co., No. 3:15-cv-02279-BTM-WVG (S.D. Cal. filed Oct. 9, 2015) (describing “IARC Classification of Glyphosate” in support of allegations that plaintiff’s non-Hodgkin’s lymphoma was caused by exposure to glyphosate contained in Roundup product). As summarized by District Judge Vince Chhabria, overseeing the multidistrict litigation (MDL) docket, “[t]hroughout this litigation the plaintiffs have trumpeted the conclusion of the International Agency for Research on Cancer (‘IARC’) that glyphosate is a ‘probable carcinogen.’” In re Roundup Prods. Liab. Litig., MDL No. 2741, slip op. at 1 (Mar. 13, 2017).

Indeed, the proceedings currently focus on the relevance of “reports prepared by agencies like the IARC and EPA” to the matter of general causation. In a recent discovery ruling, Judge Chhabria explained:

As a result [of the plaintiffs’ reliance on IARC], Monsanto is conducting third-party discovery in the hope of finding fault with the IARC’s conclusion.

In turn, Monsanto has trumpeted reports generated by the Environmental Protection Agency (“EPA”) concluding that glyphosate is not hazardous. As a result, the plaintiffs are conducting third-party discovery (and have made Freedom of Information Act requests) in the hope of finding fault with the EPA’s reports.

This raises a general question: whether the reports prepared by agencies like the IARC and EPA are relevant to the first phase of this multi-district litigation. In this phase, which is limited to “general causation,” the Court will decide only whether there is sufficient admissible evidence that glyphosate and/or Roundup is capable of causing cancer (specifically, Non- Hodgkin’s Lymphoma) in humans.

Although Monsanto has taken inconsistent positions on this issue, at the most recent hearing it conceded that the IARC and EPA reports are relevant. Any expert testifying about general causation will, for his opinion to be admissible, almost certainly need to account for the conclusions reached by these agencies.

This does not mean, however, that the IARC and EPA reports are central to the general causation question; it means only that they are relevant. The IARC and EPA reports analyze studies that were previously conducted on the carcinogenicity of glyphosate. The experts in this case will need to do the same thing—that is, they will need to analyze the studies themselves and offer opinions about what they show. The opinions of the IARC and EPA about what the studies show, while important, are secondary.

Id. at 1–2.

Note that while an IARC or similar finding might be enough to prompt the filing of a toxic tort claim, sustaining that claim will still require adequate proof of causation from the underlying studies.

Quaker Oats
Another ramification of IARC’s glyphosate finding have been consumer class actions asserting that Quaker Oats misleadingly labeled its products as “100% Natural” when the oats are grown and processed using glyphosate. Plaintiffs allege, for example:

1. Defendant aggressively advertises and promotes its oatmeal products as “100% Natural,” and claims its oats are grown using “eco-friendly” methods that pose “less risk of pollutants and groundwater pollution.” These claims are false, deceptive, and misleading. Quaker Oats are not “100% Natural,” but instead contain the chemical glyphosate, a potent herbicide that last year was declared a probable human carcinogen by the cancer research arm of the World Health Organization. Glyphosate makes its way into Quaker Oats not simply because it is used as an agricultural weed killer, but because it is sprayed on the oats as a drying agent shortly before harvest.

2. There is nothing unlawful about Quaker Oats’ growing and processing methods. What is unlawful is Quaker’s claim that Quaker Oats is something that it is not in order to capitalize on growing consumer demand for healthful, natural products.

* * *
72. In 2015, the International Agency for Research on Cancer (“IARC”), a research arm of the World Health Organization, declared glyphosate a category 2A “probable” human carcinogen. A summary of the study underlying this declaration was published in The Lancet Oncology, Vol. 16, No. 5 (May 2015). . . . The IARC study noted such carcinogenic risk factors as DNA damage to human cells resulting from exposure to glyphosate. See id. Glyphosate has been previously found to be a suspected human endocrine disruptor, with estrogenic effects even at extremely low concentrations See Thongprakaisang, S. et al., “Glyphosate induces human breast cancer cells growth via estrogen receptors,” 59 Food & Chem. Toxicol. 129 (June 2013), abstract available at (last visited April 26, 2016); see also, e.g., Gasnier, C. et al., “Glyphosate-based herbicides are toxic and endocrine disruptors in human cell lines,” 262(3) Toxicology 184 (Aug. 21, 2009), abstract available at (last visited April 26, 2016).

Complaint, Gibson v. Quaker Oats Co., No. 1:16-cv-04853 (N.D. Ill. filed May 2, 2016).

As it is based on a consumer class action theory, the Quaker Oats cases will not necessarily need a determination of the underlying science, as required in the Roundup cases, and the IARC toehold might be enough. Ultimately, the dispute might largely turn on the position taken by another regulator, i.e., what the Food and Drug Administration defines as “natural.”

Monsanto was also recently named in another deceptive advertising action with respect to glyphosate, facing allegations that it misleadingly claims that glyphosate targets an enzyme “found in plants but not in people or pets,” when that enzyme is found in people and pets, giving rise to a health risk associated with exposure. See “Monsanto Sued for Misleading Labeling of Popular Herbicide Roundup,” Beyond Pesticides Daily News Blog, Apr. 10, 2017.

California’s Proposition 65
Last, the IARC finding has resulted in the listing of glyphosate as a substance known to cause cancer under California Prop 65. On September 4, 2015, within months of the IARC classification, the California Office of Environmental Health Hazard Assessment (OEHHA) issued its notice of intent to make such listing; Monsanto thereafter filed a petition for writ of mandate in California Superior Court to enjoin the Prop 65 listing. Monsanto Co. v. Office of Envt’l Health Hazard Assessment, No. 16CECG00183 (Cal. Super. Ct. Fresno Cty.) The Superior Court recently rejected Monsanto’s petition, which Monsanto is seeking to stay pending appeal.

Monsanto complained that “OEHHA effectively elevated the determination of an ad hoc committee of an unelected, foreign body, which answers to no United States official (let alone any California state official), over the conclusions of its own scientific experts,” even though “IARC’s process for classifying chemicals, such as glyphosate, as to their carcinogenicity contains no inherent safeguards against arbitrary action” and “IARC expressly disavows any law- or policy-making role.” Complaint ¶¶8–9, Monsanto Co., No. 16CECG00183. Monsanto thus argued (unsuccessfully, in the trial court) that the glyphosate listing and OEHHA’s practice of automatically listing substances classified by IARC as carcinogenic violated the California and U.S. Constitutions by, among things,

(i) “delegating law-making authority to an unelected, undemocratic, unaccountable, and foreign body without providing intelligible principles or procedural safeguards to define the boundaries of that authority or prevent its arbitrary exercise,” in derogation of the non-delegation doctrine;

(ii) improperly granting law-making powers to a private corporation “by identifying IARC to have the power to identify substances for placement on the Proposition 65 list without any substantive review by OEHHA or any other California governmental entity”; and

(iii) violating the Guarantee Clause that citizens of every state be entitled to a republican form of government in “empowering an unelected, undemocratic, unaccountable, and foreign body to make laws applicable in California.”

Complaint ¶10.

Monsanto is appealing the denial of its petition. The implications for the use and weight of IARC classifications (and perhaps other similar regulatory classifications and measures) in the courtroom and otherwise is a story worth watching.

The classifications rendered by IARC on the carcinogenicity of substances can have a number of ramifications beyond some support for a causation argument in a toxic tort lawsuit. We should watch for trends in IARC classifications providing a basis for consumer class actions, and we await the views of the California appellate courts on the proper role of IARC in the regulatory process.

This article is reprinted with permission from the American Bar Association.
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