WHILE ATTEMPTING TO LIFT SIEVE WITH A 1 1/2TON CHAIN HOIST THE SLACK BOUND UP IN THE HOIST. TECH. GAVE THE CHAIN A HARD TUG & THE HOIST CAME LOOSE & STRUCK THE EMPLOYEE IN THE FACE LEAVING A LACERATION THAT REQUIRED SEVERAL STITCHES TO CLOSE. RELEASED W/OUT RESTRICTION. CHAIN HOIST WAS NOT PROPERLY SECURED & THE SAFETY LATCH NOT ENGAGED.