MONDAY A.M. ROUTINE SERVICE WAS BEING COMPLETED BY EE. THE MILLS AND RELATED MACHINERY WERE SHUT DOWN. HE OPENED THE SAFETY GATE, REACHED AROUN BELOW THE MILL FEED CHUTE TO OPEN THE TRUNNION F ILL LID. HE STEPPED OFF THE DECK ONTO THE TRUNNION WITH HIS LEFT FOOT AND HELD THE SAFETY GATE OPEN WITH HIS RIGHT FOOT. HE FILLED THE 1 GAL. JUG OF 01 TO THE FILL AND FELT CATCH IN HIS BACK.