EMPLOYEE WAS REPAIRING AN AIR HOSE IN THE FIELD. HE USED A BACK SCREW TO CUT THE STEEL BAND THAT SECURES THE HOSE TO THE FITTIN. WHEN HE ATTEMPTED TO PRY OPEN THE BAND. THE SUDDEN MOVEMENT OF THE STEEL BAND CAUSE DHIM TO INADVERTANTLY CUT HIS LEFT THUMB WITH THE KNIFE HE WAS HOLDING.