EMPLOYEE WAS CLEANING IN PLANT ON HIS KNEES. EMPLOYEE KNELT IN A MIXTURE OF WATER AND CEMENT DUST. SKIN REACTED TO MATERIALS ND STUCK TO EMPLOYEE'S KNEES. (HIS PANTS HAD HOLES IN THE KNEE AREA ) EMPLOYEE DID NOT NOTICE AREA OF REACTION, HIS SUPERVISOR DID, HE SENT HIM TO HAVE HIS KNEES EXAMINED. EMPLOYEE WAS GIVEN PRESCRIPTION MED TO PREVENT INFECTION AND ASSIGNED LIGHT DUTY.