Abstract: At approximately 8:30 p.m. on February 16, 1991, Employee #1 was using a 1/2 in. diameter by 18 in. long metal rod to unclog a bridge breaker. The bridge breaker was an apparatus installed between the hopper and the extruder to prevent the oil catalyst from hardening and clogging up the process. Since the bridge breaker was not used for all processes, it was not tied into the interlock system. When Employee #1 lifted the grate so that he could better unclog the bridge breaker, he could not see a vertical rotating screw underneath the hardened catalyst. The rod he was using contacted the vertical screw inside the bridge breaker and Employee #1's hand became caught between the screw and the rod. He suffered multiple fractures and lacerations to his hand. Employee #1 was not trained to operate the unit with the bridge breaker installed.