Narrative:

Approximately two hours [after take-off] flight attendant reported an odor in the rear section of the aircraft around rows 28 to 33. I suggested that they investigate lav trash bins; etc. Fumes dissipated. Later the flight attendant again reported fumes in the aft area of the aircraft. I suggested turning off the aft chiller and the coffee makers and pulling the C/B on these units. Again the fumes dissipated. After 4:30 hours of flight fumes were again reported; but with much greater intensity. I requested that the flight attendant turn off all overhead lighting and requested that the first officer go to the rear of the aircraft to determine what type of fumes were present. No fumes were apparent on the flight deck. When the cockpit door was opened it was very apparent that the fumes were strong and a precautionary diversion was requested to ZZZ. [A] radar vector was given to the outer marker. En-route to the airport the lead flight attendant called the flight deck and indicated that the fumes were intensifying. A request for fire and rescue was requested as a precaution in the event of a possible fire/smoke event. First officer donned his O2 mask and continued as pilot flying. The QRH procedures were initiated; and a visual approach to the runway was uneventful. Fire and rescue followed the aircraft to gate; passengers were deplaned; fire and rescue was released; and aircraft was turned over to maintenance. Cause of fumes has yet to be determined.

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Original NASA ASRS Text

Title: A321 Captain was alerted by a Flight Attendant of smoke in the rear cabin area. Captain suggested the flight attendants explore several areas of possible sources to no avail; and the fume condition appeared to be worsening. Flight diverted to the nearest suitable airport and landed uneventfully.

Narrative: Approximately two hours [after take-off] Flight Attendant reported an odor in the rear section of the aircraft around rows 28 to 33. I suggested that they investigate lav trash bins; etc. Fumes dissipated. Later the Flight Attendant again reported fumes in the aft area of the aircraft. I suggested turning off the aft chiller and the coffee makers and pulling the C/B on these units. Again the fumes dissipated. After 4:30 hours of flight fumes were again reported; but with much greater intensity. I requested that the Flight Attendant turn off all overhead lighting and requested that the First Officer go to the rear of the aircraft to determine what type of fumes were present. No fumes were apparent on the flight deck. When the cockpit door was opened it was very apparent that the fumes were strong and a precautionary diversion was requested to ZZZ. [A] radar vector was given to the outer marker. En-route to the airport the lead Flight Attendant called the flight deck and indicated that the fumes were intensifying. A request for Fire and Rescue was requested as a precaution in the event of a possible fire/smoke event. First Officer donned his O2 mask and continued as Pilot Flying. The QRH procedures were initiated; and a visual approach to the runway was uneventful. Fire and Rescue followed the aircraft to gate; passengers were deplaned; Fire and Rescue was released; and aircraft was turned over to Maintenance. Cause of fumes has yet to be determined.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.