CANBERRA - An Australian judge will rule on Thursday on whether Bayer's Roundup weedkiller can cause a type of blood cancer, a closely watched decision that follows some jury verdicts in similar U.S. cases that have found for the plaintiffs.

On Thursday, Justice Michael Lee of Australia's Federal Court will only rule on whether Roundup can cause non-Hodgkins lymphoma and not on whether subsidiaries of Bayer were negligent regarding the risks its products posed and should pay damages.

The hearing, which will take place in Sydney, is due to start at 3:15 p.m. (0515 GMT).

The German pharmaceutical and chemicals company has maintained that Roundup, a glyphosate-based herbicide, is safe. It says it "fully stands behind its glyphosate-based products, which have been used around the world for almost 50 years."

The Australian class action against Bayer subsidiaries unites more than 1,000 claimants and is one of some 40 cases filed outside the United States, all in either Canada or Australia.

The lead claimant is 41-year-old Kelvin McNickle, who says he used Roundup to spray weeds for over two decades on his family's property and while working for a vegetation management company. He developed non-Hodgkins lymphoma aged 35.

In the United States, Bayer has prevailed in 14 of the last 20 Roundup trials, but it also racked up a string of losses in late 2023 and early 2024, resulting in more than $4 billion damages awarded in verdicts.

Some of those verdicts have seen the amounts awarded reduced but the cases shattered investor and company hopes that the worst of the Roundup litigation was over.

The company faces more than 50,000 outstanding claims in the United States. A request for an agreement to prevent future cases was denied by a U.S. court.

Roundup was originally produced by U.S. agrochemical compan...