May 1(Reuters) - A Washington state appeals court on

Wednesday overturned a $185 million verdict against Bayer's

Monsanto unit over chemical contamination at a

Seattle-area school, marking the second big legal win for the

company in as many weeks.

Monsanto spinoff Pharmacia, which sold now-banned chemicals

called polychlorinated biphenyls, was found liable in 2021.

Three teachers claimed they suffered brain damage from PCBs that

leaked from light fixtures at the Sky Valley Education Center in

Monroe, Washington.

On Wednesday, the state Court of Appeals agreed with Bayer

that the lower court improperly applied the laws of Missouri,

where Monsanto is based, which allowed the claims to be filed

decades after the company stopped producing PCBs in 1977.

The U.S. government outlawed the chemicals in 1979 after

discovering links to cancer.

Bayer argued Washington law limits liability if exposure

occurs outside a product's useful lifespan, which generally

means 12 years.

The case will go back to the lower court to determine

whether a new trial is warranted. Plaintiffs' attorney Richard

Friedman said in a statement they will retry the case if

necessary but hope the state Supreme Court "simply reinstates

the verdict" on appeal.

Bayer faces about 200 similar claims from the school, where

people allege PCBs caused cancer, thyroid conditions and other

health problems.

Juries in some of those cases have awarded more than $1.7

billion in compensatory and punitive damages. But another

Washington judge nearly halved an $857 million verdict against

the company last week in a small group of those claims.

The company has denied responsibility for the alleged harms

and says the school failed to heed repeated warnings to replace

the lights. It is appealing the verdicts.

Monsanto said Wednesday's ruling, which also found the lower

court wrongfully allowed punitive damages on some claims and

erroneously allowed certain expert testimony, is "significant,"

and many or all of the other trials from the school may have had

the same errors. The company said it will evaluate how to

proceed in those cases and others yet to be tried.

PCBs were once widely used to insulate electrical equipment

and found in other common products like caulking and paint.