DIGESTION OPERATOR WAS WORKING IN R-30 WHEN HE STRUCK HIS LOWER LEFT LEG WITH SUFFICIENT FORCE TO CAUSE A 2"" BY 3"" LACERATION WITH A PUNCTURE WOUND. THE LACERATION REQUIRED SEVEN SUTURES TO CLOSE. EMPLOYEE WAS ASCENDING A STAIRWAY AND ENCOUNTERED A WET/SLIPPERY STEP. HIS FOOTING SLIPPED, CAUSING HIM TO FALL FORWARD AND STRIKE HIS LOWER LEG ON THE STEP GRATING.