An Air Transat Airbus A321-200, registration C-GEZD performing flight TS-782 from Quebec City, QC (Canada) to Fort Lauderdale, FL (USA) with about 185 people on board, was preparing for departure. The aircraft was being de-iced when a large number of passenger began to complain about feeling ill. The de-icing was stopped and the passengers disembarked back into the terminal. Local hospitals called code orange (large influx of patients), at least 11 passengers were taken to hospitals.
De-icing fluids consisting of propylene glycol (PG) and additives are widely used by airlines for de-icing aircraft. Ethylene glycol (EG) fluids are still in use for aircraft de-icing in some parts of the world because it has a lower operational use temperature (LOUT) than PG. However, PG is more common because it is less toxic than ethylene glycol.
When applied, most of the de-icing fluid does not adhere to the aircraft surfaces and falls to the ground. Airports typically use containment systems to capture the used liquid, so that it cannot seep into the ground and water courses. Even though PG is classified as non-toxic, it pollutes waterways since it consumes large amounts of oxygen as it decomposes, causing aquatic life to suffocate.
Anti-icing of aircraft is accomplished by applying a protective layer, using a viscous fluid called anti-ice fluid, over a surface to absorb the contaminant. All anti-ice fluids offer only limited protection, dependent upon frozen contaminant type and prevailing weather conditions. A fluid has failed when it no longer can absorb the contaminant and it essentially becomes a contaminant itself. Even water can be a contaminant in this sense, as it dilutes the anti-icing agent until it is no longer effective.
The airport reported the passengers suffered from itchy eyes, dizziness and a number vomited. 11 were taken to hospitals, their condition was not known to the airport. Emergency services took measurements of the cabin air immediately after being called on scene and found no issue with the cabin air quality. The airline has initiated an investigation into the occurrence, a ventilation problem during the de-icing is being suspected.
On Feb 6th 2019 the Canadian TSB reported: “While parked at the gate and undergoing de-icing, fumes were noticed in the flight deck as well as reported by the cabin crew. It was quickly attributed to de-icing fluid being ingested by the APU. The aircraft was deplaned and emergency services contacted. 11 passengers and 4 crew members were seen by paramedics and transported to the hospital for observations.”
Image © Andrew Holden