Bayer shares tumble after second court rules its Roundup weedkiller caused cancer

Glyphosate was a significant factor in causing a man’s tumour, a US jury found, in only the second of more than 11,000 lawsuits Bayer faces over the widely used chemical

Bayer has now lost both of the Roundup lawsuits it has faced so far and has some 11,200 more to come in the US alone (AP)

Shares in Bayer plunged 10 per cent on Wednesday, wiping more than €7bn (£6bn) off the German chemical giant’s valuation after a second court ruled that its Roundup weedkiller caused cancer.

Glyphosate, which Bayer markets as Roundup, is the world’s most widely used herbicide and an important source of revenue for the company.

A jury in San Francisco said that the chemical was a significant factor in causing Edwin Hardeman’s cancer, potentially opening up Bayer to billions of dollars of damages from thousands of similar cases.

Bayer has now lost both of the Roundup lawsuits it has faced so far and has some 11,200 more to come in the US alone. Another California man was awarded $289m in August after a jury found Roundup caused his cancer, though the award was later reduced to $78m.

The company said it was disappointed with the jury’s decision in the latest case and denies allegations that glyphosate or Roundup cause cancer. But the decision is a major blow for Bayer, which only acquired Monsanto, the maker of Roundup, last year in a $63bn deal.

“We are confident the evidence in phase two will show that Monsanto’s conduct has been appropriate and the company should not be liable for Mr Hardeman’s cancer,” the company said.

Monsanto’s Roundup is no longer a patent-protected and many other glyphosate-based weedkillers are now available.

A study published last month found traces of glyphosate in the majority of wine and beer. Researchers tested five wines and 15 beers from the US, Asia and Europe for traces of pesticide glyphosate.

In 2015, the World Health Organisation’s International Agency categorised glyphosate as “probably carcinogenic to humans”, leading the state of California to add it to its list of chemicals that can cause cancer, which makes companies responsible for providing warnings to potential consumers.

Last year, investigations by The Independent and Greenpeace revealed that Monsanto was behind a campaign designed to defend the controversial weedkiller.

The Freedom to Farm campaign – active across Europe’s “eight most important countries” – has marketed itself as a grassroots-led effort by farmers in defence of glyphosate.

But it is administered by Red Flag, a Dublin-based PR and lobbying firm, with the assistance of Lincoln Strategy, a US outfit with close links to Donald Trump’s election campaign.