EMPLOYEE WAS INJURED WHILE WORKING WITH THE BULK ROCK-DUSTING SYSTEM. HE ATTEMPTED TO BLEED DOWN THE PRESSURE IN THE DUST TANK, AN UNSECURED VENT HOST SLID OUT OF THE STOPPING AND STRUCK HIM O N THE SIDE OF HIS FACE, CAUSED A LACERATION TO HIS FOREHEAD, CHIPPING A TOOTH AND CORNEAL ABRASION.