By Brendan Pierson and Dietrich Knauth

(Reuters) – A Washington state jury on Tuesday ordered Bayer (OTC:) to pay $100 million to four people who say they were sickened by toxic chemicals known as PCBs at a school in Seattle-area, but found the company not liable for damages. accused by 11 others.

The verdict, which follows a two-month trial, is the latest in a series of trials against the chemical company over the alleged contamination of the Sky Valley Education Center in Monroe, Washington.

More than 200 students, employees and parents said they had cancer, thyroid conditions, neurological injuries and other health problems from polychlorinated biphenyls or PCBs that leaked from school lights. Chemicals are produced by Monsanto (NYSE: ), which Bayer acquired in 2018.

Monsanto said in a statement that it will pursue post-trial motions, and an appeal if necessary, to overturn the verdict or reduce the “excessive” damages awarded to the four plaintiffs.

Test evidence showed low to non-existent levels of PCBs, which could not cause the harms alleged, Monsanto said.

Verdicts in past trials of alleged school contamination, involving various groups of plaintiffs, have totaled more than $1.5 billion, although some have been reduced or overturned. The remaining rulings are also the subject of appeals, Monsanto said.

The company obtained a $185 million judgment in favor of three teachers and the teacher’s spouse that was overturned on appeal last year for several reasons.

A state appeals court agreed with Bayer that the trial court misapplied laws in Missouri, where Monsanto is based, that allowed claims to be filed decades after the company stopped producing PCBs in 1977. The company said the Washington law should be enforced instead, and that it would bar the plaintiffs’ claims because they were filed too late.

Washington’s highest court is expected to hear an appeal of that decision.

In August, an $857 million judgment was reduced to $438 million, after a judge found it included excessive punitive damages.

Bayer acquired Monsanto for $63 billion in 2018. Since then, lawsuits over PCBs, and more importantly claims that the weedkiller Roundup causes cancer, have weighed heavily on the shares of company.

PCBs were once widely used to insulate electrical equipment, and are also used in products such as carbonless copy paper, caulking, floor finishes and paint. The US government banned them in 1979 after being linked to cancer and other health problems. Monsanto produced PCBs from 1935 to 1977.

Plaintiffs say Monsanto has known about the dangers of PCBs for decades, but hid them from the public and from government regulators.

Bayer argued that the plaintiffs failed to prove their injuries were caused by PCBs, and that the levels found at the school were considered safe by the Environmental Protection Agency. It is also said that the school ignored warnings from government officials that the lights in the aging building should be retrofitted.