As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL350, F/A'S REPORTED STRONG FUMES AFT OF ROW 17 IN MAIN CABIN. TURNED OFF RECIRC FAN AND RIGHT PACK AND CLOSED ISOLATION VALVE. RETURNED TO BWI. FUMES WEAKENED NOTICEABLY. DEFERRED RIGHT PACK MEL. REPLACED BOTH COALESCER BAGS. OPERATED LEFT PACK WITH ENGINES AND APU, NO ODOR NOTED. REMOVED AND REPLACED ACM AND AIR SEPARATOR, OP CHECK GOOD PER MM.