Abstract: An explosion occurred in the Dowtherm still reactor used in solvent recovery. Employees #1 and #2 were working at least 55 to 80 ft away from the epicenter of the explosion or in other areas of the plant. Employee #1 was in the process of emergency escape and Employee #2 was reportedly on a ladder and was thrown to the ground. The explosion occurred because of an unexplained temperature increase during the process. The only relief, a 25-psi rupture disk, blew during efforts to control the chemical reaction. The column and the condensor blew away from the reactor and the manway was separated from the system.