Aerotoxic Syndrome: A Hidden Health and Safety Hazard


Due to the negligence of airplane manufacturers, thousands of pilots, flight attendants, and passengers around the world have been exposed to toxic cabin air. The exposure can cause an array of permanent and catastrophic illnesses and injuries, known collectively as aerotoxic syndrome. In this article, we’ll examine the root cause of aerotoxic syndrome and review the action you can take if you think you’re among the 30% of all air travelers who have been poisoned by toxic cabin air.

What is aerotoxic syndrome?

The term “aerotoxic syndrome” first appeared in 1999 in a paper authored by Jean-Christophe Balout, Ph.D., Dr. Harry Hoffman, and Professor Dr. Chris Winder. It describes both acute and chronic health problems caused by exposure to pressurized air on a commercial jet that has been contaminated by oil fumes.

How does cabin air become contaminated?

A supply of pressurized air is mandatory to sustain life at high altitudes when flying. This air is supplied directly from the compressors located in the jet engine. These air compressors have two “sides,” a dry side and a wet side. The “dry” side helps supply oxygen to passengers. This pressurized air, known as “bleed air,” is extremely hot (between 200 to 250 degrees Celsius). After leaving the engine and passing through an ­air-conditioning pack, the bleed air is combined with recirculated cabin air at a ratio of 50/50 before it enters the cabin. The air may also pass through a high-efficiency particulate air (HEPA) filter to remove dust, pollen, mold, bacteria, and any other airborne particles. It’s important to note that a HEPA filter does not separate gases from the air, only solid matter.

On the “wet” side, the engine’s air compressor acts as an exhaust system. The component parts of a jet engine are lubricated by synthetic oils that contain a percentage of highly toxic organophosphate additives. These chemicals function as anti-wear agents, but as they become super-heated by the engine, they become chemically altered and generate toxic gas. This gas is pumped out of the engine housing by the air compressor.

As you might imagine, the wet and dry sides of this air compression system should theoretically never mix. “Wet seals” are used to keep the toxic exhaust fumes and bleed air separated so toxic gases are not released into the cabin. However, wet seals aren’t true seals – they are controlled leakage devices. In other words, a certain amount of toxic gas mixes with the cabin air by design – in fact, it’s been established that bleed air is contaminated with at least 127 toxic substances. The “low” toxicity levels affect different people in different ways and for airline professionals like pilots and flight attendants, repeated exposure over time can have serious consequences. In addition, more acute effects can be felt during and after fume events.

What’s a fume event?

If not properly maintained, wet seals have been known to fail entirely, suddenly, and without warning, while the airplane is miles from the ground, traveling hundreds of miles per hour.  During these major failures, known as “fume events,” the cabin air becomes highly toxic, and passengers have reported abnormal odors, smoke, haze, or fumes in the cabin. This occurs as often as five times per day in the United States alone.  

It’s important to note that, while the term “fume event” adequately describes sudden failures of the wet seals, it is misleading to think that the air is only contaminated after a wet seal failure. Pressurized cabin air is at least mildly toxic at all times in most commercial airplanes.

What are the symptoms of aerotoxic syndrome?

The symptoms of aerotoxic syndrome vary from person to person and can manifest after just one flight. They can include (but are not limited to):

  • Headache
  • Dizziness
  • Nausea and vomiting
  • Breathing problems (shortness of breath, coughing, tightness in the chest, etc.)
  • Disorientation and balance problems
  • Impaired memory
  • Personality changes and mood swings
  • Tinnitus (ringing in the ears)
  • Eye irritation and vision problems
  • Increased heart rate
  • Cardiac arrhythmias

Many victims have summarized the experience as feeling intoxicated or “zombie-like”. The toxic and chemical substances contaminating the cabin air typically have the biggest impact on the central nervous system, which controls all major organs. For those who experience repeated and prolonged exposure (usually pilots and flight attendants), aerotoxic syndrome can cause permanent disability.

What can I do if I experience a fume event or develop symptoms of aerotoxic syndrome?

The only way to protect yourself during a fume event is to put on a respirator, but these masks aren’t typically available to commercial airline travelers. Therefore, your best course of action is to seek medical attention for your symptoms as soon as possible after landing. Be sure to be detailed in your description of what you experienced on the aircraft, as aerotoxic syndrome is often misdiagnosed and mistreated by doctors often who are unfamiliar with this type of poisoning.

Even though there have been repeated calls for change by victims and advocacy organizations, there are currently no bleed air filtration systems that have been approved for modern jets that can stop this form of contamination. Careful, routine maintenance of the engines is a great prevention measure, but unfortunately, people and companies can be negligent.

KJC Law Firm is currently accepting suspected cases of aerotoxic syndrome for investigation so that manufacturers and airlines can be held accountable for the harm they have caused. If you or a loved one think you have been exposed to toxic cabin air, please schedule a free consultation with our team. Our firm has more than 125 years of experience litigating major personal injury cases. We have the resources to investigate your claim, hire the necessary experts, and get you the compensation that you deserve.

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