What was found
AFT LAV CHEMICAL ODOR INTENSIFIED IN FLIGHT.SOURCE IS UNKNOWN.THE CHEMICAL ODOR ORIGINATING FROM AFT LAV. FA REPORTED THAT IT INTENSIFIED IN FLIGHT. MIA MTX CONFIRMED THAT THE ODOR IS THE CONCENTRATE SANITIZER THAT RAMP USES WAS POSSIBLY USED WITHOUT BEING DILUTED. THEY THOROUGHLY CLEANED THE LAV INCLUDING UNDER THE TOILET SHROUD. SENT UP ON AN FCF FOR AN HOUR WITH NO ODOR NOTED. AIRCRAFT WILL BE RELEASED FOR REVENUE SERVICE."TRANSFERRED TO NRWC 092-MIA-00788"-C/A-REF NRWC 092-MIA-00788 FOR WORK ACCOMPLISHED.C/W FIM TASK 25-40-00 AND WORKSCOPE REV 1,2.3 . NO DISCREPANCIES NOTED.