A330
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
During climb; Flight Attendant called and stated strong odor in aft cabin. Odor was like a dirty sock pack smell mixed with a metallic and slightly acidic smell. Sent IRO back to check and verify. It dissipated and then the smell was noticed by Flight Attendant again; IRO again went aft to check and confirmed slight smell. Smell noted in cockpit. Just after his return; Lead Flight Attendant called again and reported strong smell in First Class with a 'haze'.  Made decision to return to [departure airport]; [advised ATC]; donned O2 per QRH Smoke/Fumes Procedure and turned [back] direct. Contacted company. Made OVERWEIGHT landing using QRH procedure.  Had Emergency Personnel accompany aircraft to gate. Odor and fumes in aircraft.  Find and fix source of fumes and odors. Providing for dedicated Fumes (not Smoke) QRH procedure would help and address specific area. Educate Pilots and Flight Attendants for fumes in aircraft.
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A330 flight crew reported returning to departure airport after 'dirty socks' fumes were reported in the cabin.