The Supreme Court is set to hear arguments on Monday in a case that could lead to the dismissal of tens of thousands of lawsuits against Bayer, the pharmaceutical and biotech giant, that claim the weedkiller Roundup caused non-Hodgkin lymphoma.

Developed by Monsanto in the 1970s, Roundup is one of the best-selling weedkillers in the world, but it has been dogged by controversy over its effects on human health. The company, which was acquired by the German conglomerate Bayer in 2018, has faced thousands of lawsuits, amounting to one of the largest waves of such litigation in U.S. history.

Evidence in lab animals, and more limited evidence in humans, has indicated a link between Roundup’s active ingredient, glyphosate, and cancer. The World Health Organization’s International Agency for Research on Cancer in 2015 classified glyphosate as “probably carcinogenic to humans.”

The Environmental Protection Agency considers the herbicide to be safe. The E.P.A. is responsible for pesticide labeling nationwide, and Bayer argues that the federal agency’s decision overrides state-level legal claims, effectively insulating it from lawsuits. The federal government faces an Oct. 1 deadline to re-examine the effects of glyphosate.