It has been a busy month in the courtroom for tort lawyers. Two judicial rulings handed significant victories to plaintiffs against Bayer (the manufacturer of Roundup®) despite a consistent body of scientific evidence demonstrating the product’s main ingredient, glyphosate, is safe for human use.

Glyphosate is a widely used herbicide found in hundreds of products for sale across the United States. It is one of the most thoroughly researched herbicides in the world, with more than 800 studies conducted in the last 40 years.

The Environmental Protection Agency (EPA) has repeatedly reaffirmed glyphosate does not pose human health risks when used as instructed on the label. Further, the agency will not approve product warning labels that claim glyphosate causes cancer since it would be “irresponsible to require labels on products that are inaccurate when EPA knows the product does not pose a cancer risk.”

Even after the Biden EPA recently asked a federal court for a chance to review possible ecological effects of glyphosate, the agency emphasized it stands by its position that glyphosate does not pose major risks to human health and is not interested in revisiting that part of its analysis.

The EPA is joined by the U.S. Agricultural Health Study, European Food Safety Authority, Health Canada’s Pest Management Regulatory Agency, New Zealand’s Environmental Protection Authority, Japan’s Food Safety Commission, and the European Chemicals Agency, who have all concluded glyphosate is “unlikely to cause cancer in humans.”

Despite overwhelming scientific evidence that glyphosate does not increase risk of cancer, this month the 9th U.S. Circuit Court of Appeals in San Francisco upheld a $25 million verdict against Bayer that ruled Roundup® caused a case of non-Hodgkin’s lymphoma in a California resident.

A federal judge also rejected a proposal by Bayer to create a $2 billion fund to finance settlements for users of Roundup® who are not currently sick, in addition to providing free medical exams for users, while limiting punitive damages.

The judges in these two cases were relying on a single 2015 International Agency for Research on Cancer (IARC) review that concluded glyphosate is “probably carcinogenic to humans.” It was later discovered one of the epidemiologists leading the review had withheld knowledge of critical unpublished research finding no evidence of a link between glyphosate and cancer.

The ability of judges—many of whom have little scientific training—to pick and choose which evidence will be admitted in their courtrooms is one of the most intractable problems at the intersection of science, justice, and the economy. This issue was explored in a recent white paper published by R Street Institute.

The probability that exposure to a substance causes an adverse health outcome should be determined by the best possible scientific evidence, which is not necessarily the objective of the mass tort industry. Often, companies will pay billions of dollars in settlements—most of which goes into the pockets of the attorneys—to escape the incalculable costs of endless litigation and reputational damage. As a result, we have years of litigation alleging an association between glyphosate and cancer, despite substantial scientific evidence to disprove such allegations.

When bad things happen, it’s a very human feeling to want to know what caused it. People want simple and quick answers that place blame on someone or something. The trial bar fuels this urge by facilitating mass tort cases based on panic and greed, rather than sound science. The inability of judges to recognize and separate the best possible scientific evidence from the noise only exacerbates the problem.

The Center has awarded a research grant to SciPinion to complete a systematic analysis of the methodologies and results of the research studies most frequently cited in the risk assessment, public policymaking, and judicial decisions on the toxicity and carcinogenicity of glyphosate on humans.

It is our hope this analysis will help judges better determine the credibility of data presented to the court and provide clarity on what is known—and not known—surrounding glyphosate and human health. With this knowledge, judges can become better “consumers of the science” and resolve complex cases surrounding glyphosate based on the best available scientific evidence.