BAYER CROPSCIENCE, LP Pesticide Chemical Runaway Reaction Pressure Vessel Explosion

On August 28, 2008, at about 10:35 p.m., a runaway chemical reaction occurred inside a 4,500 gallon pressure vessel known as a residue treater, causing the vessel to explode violently in the methomyl unit at the Bayer CropScience facility in Institute, West Virginia. Highly flammable solvent sprayed from the vessel and immediately ignited, causing an intense fire that burned for more than 4 hours. The fire was contained inside the Methomyl-Larvin insecticide unit by the Bayer CropScience fire brigade with mutual aid assistance from local volunteer and municipal fire departments. The incident occurred during the restart of the methomyl unit after an extended outage to upgrade the control system and replace the original residue treater vessel. Two company employees who had been dispatched by the control room personnel to investigate why the residue treater pressure was increasing were near the residue treater when it ruptured. One died from blunt force trauma and burn
injuries sustained at the scene; the second died 41 days later at the Western Pennsylvania Burn Center in Pittsburgh, Pennsylvania. Six volunteer firefighters who assisted in the unit fire suppression activities and two contractors working at the facility were treated for possible toxic chemical exposure.