The Aerotoxic syndrome is a medical condition combining physical and neurological symptoms, caused by the short- and long-term effects of exposure to air from airplane cabins contaminated with atomized engine oils or other chemical agents.
Where does the air in a cabin come from?
The air breathed on airplane comes from a system called “Bleed Air” which collects unfiltered air at the compressor of the reactor.
The first pressurized Aircraft where built with a mechanical compressor system but quickly, at the end of the sixties to gain mass and efficiency the engineers imagined a system where the air is deducted at the reactor compressor.
Why the air in the cabin can be polluted?
On the shaft who drives the compressor, the sealing of the bearing seals is not perfect, and some oil particles can escape. The
engine oil contains some TCP (Tri Cresyl Phosphate) when pyrolyzed, the TCP is transformed in ToCP (Tri orthocresyl Phosphate). These ToCP are neurotoxic organophosphorus compounds that cause air pollution.
The air cabin can also be contaminated during aircraft deicing procedures.
What is the Fume Event?
When a large amount of oil particles is mixed with the hot compressed air a typical smell of “dirty socks” will be perceived by the crew and passengers. In the most severe cases, smoke will be visible we named it a FUME EVENT.
Following a study done by the Norvegian University of Science and Technology at Trondheim it appears that the incident rate is around 0.24 events per day or 0.2 events per 1000 flight.
What can the symptoms?
Visual changes blurred or tunnel vision, headache, concentration difficulty, cough, nausea.
What are the solutions?
Solutions are possible such as installing a filter after the bleed air. The replacement of the antiwear agent TCP in oils. Solution adopted by the B787 who use electric compressors instead and place of the bleed system.
Alex.roman@surfeo.eu
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