EMPLOYEE WAS SHOWING ANOTHER EE HOW THE NEW GREASE WHEEL WORKS THAT IS LOCATED IN THE LUBE ROOM OF THE SHOVEL. THE BALL VALVE THAT SHUTS OFF THE HOSE REEL HAD PRESSURE AND THE HOSE REEL BLEW A PART CAUSING GREASE TO SHOOT OUT HITTING THE EE IN THE FACE, NECK AND TORSO.