CEMENT WOULD NOT FLOW FROM A CEMENT SILO. THE EE WAS PROBING A CHECK VALVE WITH A SMALL ROD. WHEN DEBRIS AND CEMENT BEGAN TO FLOW, HE TURNED AWAY, THE CEMENT STRUCK THE SIDE OF HIS HEAD AND WA S DEFLECTED INTO HIS EAR AFTER STRIKING HIS SAFETY GLASSES. EE WAS NOT WEARING SIDE SHIELDS. NEITHER SIDE SHIELDS OR GOGGLES WERE REQUIRED TO PERFORM THIS TASK.