A Washington Court of Appeals decision that reversed a $185 million verdict against Monsanto over PCBs this month could wipe out much of the $1.6 billion in jury awards obtained over the past three years in the state.

The May 1 decision reversed the first verdict to come out of litigation in King County Superior Court brought by 200 students, teachers and parents at the Sky Valley Education Center alleging Monsanto, now owned by Bayer, was liable for exposing them to PCBs, or polychlorinated biphenyls, from fluorescent light ballasts. They complained of headaches, fatigue and memory and neurological problems.