A federal US judge on Tuesday allowed hundreds of lawsuits alleging that Monsanto Co's glyphosate-containing weed-killer Roundup causes cancer to proceed to trial, finding that there was sufficient evidence for a jury to hear the cases.
The decision by U.S. District Judge Vince Chhabria in San Francisco followed years of litigation and weeks of hearings about the controversial science surrounding the safety of the chemical glyphosate, the key ingredient in Monsanto's top-selling weed-killer.
The agrochemical company Monsanto is facing a lawsuit accusing them of having a weed-killing product which causes cancer.
Many government regulators say there is no link between cancer and glyphosate, the AP reported.
George Lombardi, an attorney for Monsanto, said there is overwhelming evidence that Roundup and similar products do not cause cancer.
The company had told Chhabria in March that none of the plaintiffs' specialists fulfilled scientific or legal requirements for admissibility and urged the judge to dismiss the cases.
"When you look at the body of epidemiological literature on this topic, there's no evidence of a positive association between glyphosate and National Hockey League risk", she said of non-Hodgkin's lymphoma.
But serious doubts remain as the World Health Organization in 2015 classified glyphosate as "probably carcinogenic to humans".
But the judge also said some of the expert opinions presented so far in the case are "shaky".
Roundup, made by U.S. giant Monsanto, is sprayed on gardens and parks and is used by farmers producing food crops.
Dewayne Johnson's lawsuit is the first case to go to trial among hundreds of lawsuits saying Roundup caused non-Hodgkin's lymphoma. Homeowners use it on their lawns and gardens.
There was "at least a strong argument that the only reasonable conclusion one could draw right now is that we don't yet know" whether the herbicide is causing non-Hodgkin's lymphoma, he said.
There are hundreds of lawsuits in state and federal courts, and Chhabria is handling more than 400 of them.
The U.S. Environmental Protection Agency last September concluded glyphosate is likely not carcinogenic to humans. The agency noted that scientific studies from other countries concluded the same.