A US jury has awarded $US80 million ($A112.2 million) to a man who claimed his use of Bayer AG's glyphosate-based weed killer Roundup caused his cancer, in the latest legal setback for the company facing thousands of similar lawsuits.
The jury in San Francisco federal court said the company was liable for plaintiff Edwin Hardeman's non-Hodgkin's lymphoma.
It awarded $US5 million in compensatory damages and $US75 million in punitive damages to Hardeman after finding that Roundup was defectively designed, that Monsanto failed to warn of the herbicide's cancer risk and that the company acted negligently.
Bayer bought Roundup maker Monsanto last year for $US63 billion.
The company in a statement on Wednesday said it was disappointed with the jury's decision and that it would appeal the verdict.
"This verdict does not change the weight of over four decades of extensive science and the conclusions of regulators worldwide that support the safety of our glyphosate-based herbicides and that they are not carcinogenic," Bayer said.
The company added that the verdict in Hardeman's case had no impact on future cases and trials, "as each one has its own factual and legal circumstances."
The trial is only the second of more than 11,200 Roundup lawsuits set to go to trial in the United States. Previous litigation setbacks and a prior jury verdict against the company have sent Bayer shares plunging.
The verdict comes after the same jury on March 19 found Roundup to have been a "substantial factor" in causing Hardeman's cancer, allowing the trial to proceed to a second phase to determine liability and damages. Bayer shares fell more than 12 per cent after last week's jury finding.
In the trial's second phase, Hardeman's lawyers were able to present previously excluded internal documents allegedly showing the company's efforts to influence scientists and regulators about the widely used product's safety.
"As demonstrated throughout trial, since Roundup's inception over 40 years ago, Monsanto refuses to act responsibly," Hardeman's lawyers said in a statement, adding that the company instead focused on "manipulating public opinion and undermining anyone who raises genuine and legitimate concerns about Roundup."
After the verdict, Hardeman told reporters he was "overwhelmed."
"It hasn't sunk in yet," he said.
Hardeman's case was considered a bellwether trial to help determine the range of damages and define settlement options for the more than 760 other federal cases pending in the same court before US District Judge Vince Chhabria.
The US Environmental Protection Agency, the European Chemicals Agency and other regulators have found that glyphosate is not likely carcinogenic to humans.
The World Health Organisation's cancer arm in 2015 reached a different conclusion, classifying glyphosate as "probably carcinogenic to humans."
Australian Associated Press
