EE WAS REPAIRING A CEMENT PUMP. THEY NEEDED TO DISASSEMBLE THE PUMP AND REMOVE 8 INCH SCREW SHAFT. THEY ATTACHED CHAIN IN A CHOKING MANNER ON THE SCREW. HE THEN PROCEEDED TO PULL SCREW OUT WITH THE HOIST. CHAIN CAME LOOSE AND LASHED TOWARDS HIM, HITTING HIM IN THE MOUTH AND PUNCTURING THE SKIN ON HIS UPPER LIP. RECEIVED 7STITCHES ON HIS TOP LIP.