Abstract: At 7:15 a.m., a molecular sieve desiccant containing 80 percent methyl chloroform, 7 percent alcohol trichlorotrifluoroethane, 6 percent inhibitors (nitromethane and 1,4-dioxane), and 1,1-dichloroethane, was placed inside an American Scientific Products oven (Model No. DX-38) for drying. The 120-volt oven, operating at 220 to 230 degrees Fahrenheit, was located outside Building #809. At 7:30 a.m., employees within the building noticed a strange odor and called the safety office. At 8:06 a.m., the safety office determined that the oven was the source of the odor. Fumes had apparently been drawn into the main assembly and receiving inspection rooms while the oven was unattended. The oven door was opened and a flash or flame occurred; the oven was then unplugged and turned off. The building was evacuated at 8:30 a.m. after several employees complained of respiratory, eye, and throat irritation. No chlorine, hydrogen chloride, or phosgene could be detected in the oven at that time. As a precautionary measure, 35 employees (32 of the 165 main assembly room workers and 3 of the 7 receiving inspection room workers) were transported to the hospital for observation and evaluation. Based on their symptoms or previous medical conditions, five employees were hospitalized for observation. The lack of proper air-drying procedures before oven drying was among the factors causing the accident.