Date: 201601
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: 0.5
Light: Night
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ramp ZZZ
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting; Physiological - Other
Second reporter function: First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: Taxi
Result: Flight Crew Became Reoriented; Flight Crew Returned To Gate; General Maintenance Action; General Physical Injury / Incapacitation
Contributing factors: Weather; Procedure; Human Factors
Primary problem: Procedure

Narrative: After pushback we were deiced. Running the After Deice Checklist; we turned on the APU and Engine Bleed Air Switches; and 'mist' started pouring out of the cockpit vents quickly. We immediately shut them off and waited a couple more minutes before turning the APU Bleed Air Switch back on again. The 'mist' started pouring out of the vents again. We turned the switch back off and tried to call Operations to get towed back to the gate. Unable to raise anyone on that frequency we talked to the 'Iceman' Crew who was then deicing another aircraft of the situation and had them relay to the Company that we needed to be towed back into the gate. We were towed back to gate and deplaned the Passengers and the Flight Attendants. We called Dispatch and (through them); Maintenance Control and followed their instructions. The position A Flight Attendant stated the Flight Attendants and Passengers were all fine and that the 'smoke' (really 'mist') she had seen in the cockpit had not really made its way to the Cabin yet. The mist had been contained mostly in the cockpit. The First Officer (FO) was coughing pretty badly and started to feel a little nausea; and I had started coughing and had an itchy and dry throat; so we requested a Materials Safety Data Sheet (MSDS) from the Station. They did not have one in their book. The newest one they had was not the same name Type IV. The Agent was great. He went downstairs and found the right MSDS. The sheet states on page two after inhalation; to get medical advice/attention. I called my Domicile Chief Pilot's office and talked to one of the folks there that told us he thought it was a good idea to be checked out. We requested and got the on field Medics to give us advice and check us out. They checked our Oxygen Level and Pulse and advised us to continuously hydrate with water and to get fresh air. We followed instructions and started feeling better in a little while (about an hour). With the concurrence of the Medics and the Chief Pilot on Call; we were able to continue duty. Maintenance Control sent out Mechanics and had us run the APU and each engine with the bleed air turned on; to be sure the liquid had cleared and there was not a problem continuing with the aircraft. We departed the gate; deiced; and took off and finished the flight without further problems.Training conducted to be sure that deice fluid is not sprayed into the APU or engines. It took an unusual long time to be deiced the first time; so the 'Iceman' applicator may have been fairly new. Even if he wasn't; it doesn't hurt to stress the procedures to them again.


Second narrative: Perhaps an accident by Deicer or it points to an inexperienced Ground Person placed in the bucket to deice us. I was concerned at how long the procedure took; so that is why I came to that conclusion.


Synopsis: When the B737-800 engine and APU bleeds were opened after de-icing; the cockpit filled with a thick white mist so the aircraft was towed back to the gate and deplaned. The pilots became ill and were treated according to the MSDS guidelines then departed after recovering from de-ice fluid ingestion.