As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAV SMOKE ON EICAS AFTER TAKEOFF. SMOKE ODOR FILLED THE FLIGHT DECK AND CABIN. DECLARED AN EMERGENCY AND RETURNED TO FIELD, LANDED WITHOUT INCIDENT. TROUBLESHOT IAW FIM 21-20-00-810-801-A. ISOLATED TO DE-ICE FLUID IN THE NR 1 A/C PACK. RAN ENGINES SEVERAL TIMES AND THE ODOR DISSIPATED.