CLAYTON, Mo. – The first local trial is underway in a lawsuit over the weed killer product Roundup. The lawsuit claims Bayer-owned Monsanto’s popular herbicide causes cancer.

Three plaintiffs in their 60s and 70s claim long-time exposure to Roundup—specifically the chemical glyphosate—gave them lymphoma and that Monsanto neglected to warn the public of its dangers. Monsanto claims Roundup does not cause cancer.

Monsanto developed and patented glyphosate in 1970. It began selling the product in 1974 under the name Roundup.

There remains scientific debate over glyphosate as a cancer-causing agent. The World Health Organization’s International Agency for Research on Cancer (IARC) in 2015 identified glyphosate as a possible carcinogen. However, a WHO and Food and Agriculture Organization of the United Nations (FAO) joint committee on pesticides announced in 2016 that glyphosate did not pose a significant health risk to humans. The Environmental Protection Agency considers glyphosate as noncarcinogenic.

In 2015, the World Health Organization’s International Agency for Research on Cancer (IARC) identified glyphosate, the world’s most commonly used herbicide, as a probable human carcinogen. 12 It quickly became evident that separating science from politics and economic interests would be difficult for glyphosate.

According to Courtroom View Network, Monsanto had attempted to bar digital news media from the courtroom. However, St. Louis County Circuit Judge Brian May denied the company’s request.

The jury trial is expected to last anywhere from four to six weeks.

Attorneys for local firm Carey Danis & Lowe are representing the plaintiffs, along with Texas-based firm Fears Nachawati PLLC.

Monsanto is represented by Husch Blackwell LLP of Kansas City, as well as Covington & Burling LLP’s New York City and Washington D.C. offices, and Proskauer Rose LLP’s Los Angeles office.

Bayer issued a statement late Wednesday morning amid opening statements from the plaintiffs and defendants:

While we have great sympathy for the plaintiffs in this case, the extensive body of scientific research on glyphosate-based herbicides over four decades, as well as the conclusions of leading health regulators worldwide, support the conclusion that Roundup is not responsible for their illnesses.

With the recent trial wins in Clark, Stephens, Shelton, and Johnson and a winning record in this litigation, Bayer is confident in its legal strategy, which the company has laid out in its five-point plan.

Bayer spokesperson

Other Roundup trials are scheduled in the St. Louis area through next year.

Monsanto was founded in St. Louis in 1901 and named for founder John Francis Queeny’s wife’s maiden name. The company initially manufactured food additives before expanding to industrial chemicals. Over the next several decades, Monsanto would produce the insecticide DDT, the infamous herbicide Agent Orange, polychlorinated biphenyl (PCBs), bovine growth hormone, and genetically engineered crop seeds.

Monsanto stopped producing PCBs in 1977 amid concerns of contamination of land and water sources. The company’s Sauget plant along Dead Creek had been the country’s biggest producer of PCBs in the years prior. That plant was eventually designated a Superfund site by the Environmental Protection Agency. Congress banned the production of PCBs in 1979.

In 1984, Monsanto settled a class-action lawsuit by Vietnam veterans for injuries suffered due to Agent Orange exposure.

Monsanto moved its headquarters from Downtown St. Louis to Creve Coeur in 1957 and launched its agricultural division in 1961.

Bayer acquired Monsanto in 2016 for $66 billion.

In June 2020, Bayer agreed to pay $10.9 billion to settle approximately three-quarters of existing Roundup claims against its subsidiary—both filed and unfiled claims—at the time.