As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DIRTY, CHEMICAL SMELL OCCURRED ON THE DECENT. VERY STRONG THROUGH THE FLIGHT DECK VENTS. STARTED AT 12000 FEET AND CONTINUED UNTIL LANDING. MAINTENANCE REPLACED HEPA FILTERS AND ACCOMPLISHED DECONTAMINATION OF THE ENVIRONMENTAL CONTROL SYSTEMS PER TASK CARD 26L00021013. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO ODORS NOTED.