EMPLOYEE HAD REMOVED 6"" BY 40"" PIPE STOOL IN ORDER TO UNCHOKE A VERTICAL SECTION OF CLEAN UP SUMP PUMP LINE. THE MATERIAL BEGAN TO EXIT SLOWLY AND THE EMPLOYEE LOOKED OFF FOR A MOMENT. ANOTHER CO-WORKER YELLED TO CAUTION HIM THAT THE MATERIAL HAD BROKEN LOOSE AND WAS COMING OUT FASTER. HE THEN TURNED TO MOVE OUT OF THE WAY AND MATERAIL STRUCK AN ANGLE IRON ON HIS LITTLE FINGER.