Abstract: At about 5:00 a.m. on June 23,1989, a floor surfacing contractor applied three barrels (about 1,500 lbs) of Corve 8521, a polyester resin containing 33 percent styrene, to the IBP meat processing plant undergoing re-construction The fast-curing resin produced about 500 lbs of styrene vapors in the fourth cooler (420 by 60). The floor contractor placed two small (21-in.) box fans outside the fourth cooler in the box room, an adjacent room measuring 40-ft by 28-ft by 15-ft. Employees reporting for work in the box room at 7:00 a.m. complained of a strong "plastic" odor, nausea, and irritation to the eyes and nose. About 30 minutes after starting work, eleven employees working in the box room were overcome by the styrene vapor and left the building to get fresh air. Employees #1 through #11 were instructed to report to IBP's company nurse and then were transported to the Dallas County Hospital. Employees #1 through #11 were hospitalized and four employees were diagnosed with chemical pneumonia. The suspected cause of the accident was an accumulation of styrene vapor in the box room due to improper fan placement (i.e., not exhausting to the exterior) and insufficient air handling capacity.