Topline
The Federal Aviation Administration (FAA) has done little to address the rise of “fume events,” where toxic jet engine fumes have leaked into an aircraft cabin, leaving flight crews and passengers with symptoms ranging from headaches and nausea to the sort of longer-term neurological symptoms seen in concussed football players.
Thousands of “fume events” have been reported to the FAA since 2010, sometimes leaving flight crew members and passengers with neurological damage resembling concussion victims, a Wall Street Journal investigation revealed Saturday.
The events have mainly occurred on Airbus A320s, which the three largest U.S. legacy airlines use, and to a lesser extent on Boeing aircraft.
In an emailed statement provided to Forbes, the FAA noted its “strict cabin air standards” but acknowledged “in rare instances, mechanical issues such as failures of an engine oil seal or recirculation fan bearings can cause fumes to enter the cabin,” in which case airlines are required to report these incidents so the FAA can investigate.
The FAA referred Forbes to its cabin air quality fact sheet, which references a 2015 report estimating that engine contaminant leaks happened at a rate of “less than 33 events per million aircraft departures,” or 0.0033%.
But the Wall Street Journal’s analysis of more than 1 million FAA reports over a decade revealed these incidents had “soared in recent years,” and happened nine times more often in 2024 than a decade earlier.
A 2023 Los Angeles Times report revealed how airlines and aircraft manufacturers often detected oil and hydraulic fluid contamination in the air supply by a tell-tale “dirty socks” or “gym locker” odor.
In addition to formal reports filed by airlines, seven anonymous safety reports referencing “dirty sock” fumes were filed between January 2023 and May 2025, according to a review by Forbes of NASA’s Aviation Safety Reporting System (ASRS), a program that lets aviation workers file confidential reports without fear of punishment.
Most commercial aircraft use a “bleed air” design that draws air from outside the plane and circulates it through the engine while it is heated and pressurized before being pumped into the aircraft cabin. If a faulty engine seal leaks toxic fumes, crew members and passengers breathing cabin air can experience a variety of symptoms ranging from nausea, headaches, dizziness and cognitive impairment to more chronic neurological issues, according to multiple studies. Airbus and Boeing both use the “bleed air” design for most large passenger aircraft, with the exception of the Boeing 737. The Wall Street Journal analysis found the number of fume incidents surged 660% between 2016 and 2024 for JetBlue Airways and Spirit Airlines, which both primarily use Airbus aircraft.
For years, aircraft manufacturers and airlines have downplayed the risks of inhaling these toxic fumes, according to the Journal’s reporting. Meanwhile, the FAA has also responded slowly to the issue. In response to the FAA Reauthorization Act of 2018, the agency submitted a 17-page interim report to Congress in December 2020 “on the feasibility, efficacy, and cost effectiveness of certification and installation of systems to evaluate bleed air quality.” The FAA estimated that a comprehensive study would cost up to $1.4 million and take up to 54 months to complete, noting that aircraft manufacturers contended “that an acceptable cost-to-benefit ratio should be demonstrated before the FAA mandates installation of contaminant sensors on their airplanes.”
Very few. For years, Rep. John Garamendi, D-Calif., and Sen. Richard Blumenthal, D-Conn., repeatedly introduced legislation for the Cabin Air Safety Act, which sought to provide sensors on aircraft and require more thorough investigations of fume events. Following industry pushback, a watered-down version of the law passed requiring more research and better reporting on fume events but ditching the sensor requirement. Last month, Rep. Maxwell Frost, D-Fla., reintroduced the Safe Air on Airplanes Act, which would require airlines to add filters to bleed air systems on existing planes within seven years and eventually end bleed air systems in new commercial aircraft design altogether. That bill is heading to the Transportation and Infrastructure Committee for markup, Frost’s office told Forbes.
“We have known for decades that current bleed air systems can dump toxic chemicals and fuels into the aircraft cabin, poisoning the air for everyone on board,” Sara Nelson, president of the Association of Flight Attendants (AFA), which represents over 55,000 flight attendants at 20 airlines, said in a statement. “Instead of making simple changes to protect us, manufacturers and airlines have prioritized corporate profits.”
While flight crews are not required to report every fume event to the FAA, some of the seven anonymously reported fume events Forbes reviewed resulted in an emergency landing or, if the flight had yet to take off, a deplaning. For example, in April 2025, a pilot requested priority handing from air traffic control after smelling “a dirty, musty gym sock odor followed by a burning rubber smell with a hint of electrical burning” and becoming “momentarily lightheaded with some moderate throat irritation.” In May 2024, a flight attendant reported a “very strong and distinct bandage smell or dirty gym sock smell” and experienced “watery eyes, congestion, and tightness in my chest,” later seeking medical attention. In April 2024, a flight attendant reported “a locker room dirty sock smell” during boarding, which resulted in deplaning passengers and delaying the flight.
FAA Urges Airlines To Strengthen Warnings About Lithium Battery Fire Risk On Planes (Forbes)