Abstract: Employees #1 through #5 and approximately 95 coworkers were packing cherries on three packing and sorting lines when they were exposed to carbon monoxide in quantities sufficient to induce generally recognized symptoms. The primary source of the carbon monoxide was thought to have been propane-powered forklifts, but the facility also had propane-fueled hot water heaters and an apple dryer, both of which contributed to the presence of carbon monoxide. An investigation revealed no other potential sources of carbon monoxide. At the time of the incident, one of the facility's ventilation exhaust fan systems was shut down.