Fear of Future Liability Could Sink Roundup Settlement Talks

A settlement of 43,000 claims in U.S. courts that the weed killer Roundup causes cancer is unlikely to happen if manufacturer Bayer AG insists on being absolved from future legal claims, according to legal experts.

Originally developed by Monsanto, Roundup is the most widely used herbicide in the world. Ever since Bayer acquired Monsanto in 2018, the company has suffered a series of courtroom losses from plaintiffs alleging glyphosate—Roundup’s active ingredient—causes cancer.

On Dec. 13, Bayer’s lawyers asked the U.S. Court of Appeals for the Ninth Circuit to reverse a $25 million judgment for Edwin Hardeman, a Californian who blames ...