As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ATB- PERFORMED AN AIR TURN BACK DUE TO ODOR IN THE CABIN AFTER TAKEOFF. TROUBLESHOT PER MSI WORKCARDS. FOUND EVIDENCE OF DE-ICE FLUID IN BOTH ENGINE INLETS. PERFORMED ECS DUCT DECONTAMINATION AND REPLACED RECIRC FILTERS. PERFORMED ENG RUNS NO ODORS PRESENT. (LP# 7699358)