As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUME EVENT DURING DESCENT STARTING AT 1,200 FT. TIL LANDING. SOURCE COULDN'T BE IDENTIFIED OR ISOLATED. RAN FUMES CHECKLIST AND AIR PACK 1 + 2 OFF CHECKLIST. SMELL OF CHEMICAL NATURE WOULD NOT DISSIPATE, SMELL IDENTIFIED IN FLIGHT DECK AND AFT GALLEY AREA. -PERFORMED DECONTAMINATION OF PACKS 1 & 2 IAW AMM 21-00-00-615-813-A. NO ODORS PRESENT. AIRCRAFT OKAY FOR CONTINUED SERVICE.