The airline industry would be forced to take new measures to protect passengers and crew members from toxic gases on planes under a bill introduced in Congress this month.

The legislation is intended to address a basic fact of flying: The air you breathe in airplanes comes directly from jet engines. Under normal conditions, air is safe, but if there is a mechanical problem, heated jet engine oil and other aviation fluids can leak into the air supply, potentially releasing toxic gases into the plane.

While homes and offices across the country are required to have carbon monoxide detectors, airplanes don’t have that requirement.

“We all breathe polluted air,” said Rep. John Garamendi (D-Walnut Grove), a House sponsor of the bill.

Like many members of Congress, Garamendi is a frequent traveler and has long been concerned about his own cumulative exposure to toxic gases, he said. Often, “there’s a strong odor that you’re breathing in something that you shouldn’t,” Garamendi said. “Anyone who has been in a plane when it starts the engine knows exactly what I’m talking about.”

he legislation it would create new mandates for crew training and for reporting and investigating smoke events. Planes would be required to be equipped with sensors to detect air pollution.

The lawmakers cited a Los Angeles Times investigation that found dangerous fumes contaminate the air supply on planes with alarming frequency, sometimes sickening passengers and crew and incapacitating pilots during flights. Over a two-year period, nearly 400 pilots, flight attendants and passengers reported receiving medical attention after these “smoke events,” and four dozen pilots were described as incapacitated to the point of being unable to perform their duties, it found. The Times.

“Our legislation takes action where the FAA and the airline industry have not: requiring air detectors and monitoring equipment, incident reporting, and investigations of these events to ensure a safer travel experience for all Americans.” Sen. Richard Blumenthal (D-Conn.), the bill’s Senate sponsor, said in a statement.

The bill is also co-sponsored by Sens. Edward J. Markey (D-Mass.) and Dianne Feinstein (D-Calif.) and Rep. Brian Fitzpatrick (R-Pa.).

Major industry unions representing pilots, flight attendants and mechanics are backing the legislation.

“It is unacceptable that passengers and airline crew members could be exposed to toxins during flight, toxins that can lead to respiratory and neurological conditions, including shortness of breath, headaches and fatigue,” the Transportation Workers president said. of America International, John Samuelsen, in a statement.

Scientists have long warned about the potential dangers of breathing jet engine oil, which contains tricresyl phosphate, or TCP, a highly toxic chemical that can damage the nervous system. Effects like tremors and memory problems, experts say. Some pilots and flight attendants have experienced serious health problems, including brain damage, after the smoke events, The Times found.

The bill would require a major overhaul of current practices. No government agency tracks smoke events or how often people get sick or deteriorate.

Without sensors to measure air quality, planes rely on a low-tech method: smell testing. Internal documents from airlines and aircraft manufacturers provide detailed instructions for identifying oil and hydraulic fluid contamination in the air supply by odors such as “dirty socks,” “musty” and “pungent,” The Times found.

The legislation would require planes to have sensors that “warn the pilot and flight attendants of poor air quality that is dangerous to human health,” and would require airlines and manufacturers to develop procedures on how to respond to alarms.

The proposed Aviation Cabin Safety Act is not the first time lawmakers have addressed the issue. Congress has twice held hearings on aircraft air quality, in 1994 and 2003. Similar bills have repeatedly languished in committee.

Supporters of the new bill hope it can be included in the FAA Reauthorization Act, a potentially easier vehicle than passing a single bill.

It is unclear what, if any, opposition the bill may face. Plane makers Boeing and Airbus did not respond to questions about their positions on the legislation.

“Mandatory regulations and monitoring requirements are premature in the absence of scientific studies to validate a health concern, reliable and accurate sensor technologies, and detection standards,” wrote Marli Collier, a spokeswoman for Airlines for America, the lobbying arm of the airlines. a declaration.

Studies of aircraft air quality have focused solely on normal flights in which no smoke events were reported. No major research has measured the chemicals in smoke events as they occur.

In 2003, Congress directed the FAA to measure levels of toxic chemicals in such events, but airlines refused to allow flight attendants to bring air samples on board, according to an FAA-funded investigative report.

The FAA declined to comment on the pending legislation. “Studies have shown that cabin air is as good as or better than the air found in offices and homes,” the agency previously told The Times.

“Cabin air inside Boeing aircraft is safe,” a Boeing spokesperson previously wrote in a statement to The Times. “Due to the high rate of air exchange and the HEPA recirculating filtration system, the air quality in Boeing aircraft compares favorably with other indoor air environments such as schools, office buildings, and homes, as has been found by numerous impartial third-party studies.

But HEPA filters can filter particles only above a certain size. They are not effective against gases.

Boeing previously told The Times that scientific studies have not shown a link between smoke events and health problems. The company previously said it has not equipped its planes with air sensors because vendors have not “demonstrated the existence” of devices that can “reliably detect contaminated bleed air.”

But the Times investigation found that Boeing managers had legal concerns that went beyond technology shortcomings. Boeing senior engineers were concerned that sensor data could prove damaging if used as evidence in lawsuits brought by sick passengers and crew members, according to internal emails and affidavits.

An internal Boeing memo described giving air sensors to even a single airline as a “risk,” according to a statement from a Boeing executive.

“Flight attendants, pilot unions and congressional supporters could use this effort as evidence that sensors are needed and … to push their agenda to require air bleed sensors on all aircraft,” he said. the 2015 memo, which Boeing delivered in litigation.

Garamendi, the bill’s sponsor in the House, said the air monitoring equipment is “readily available.”

“For the airlines, ignorance is money. If the toxic exposure were known, then it would be looking at long-term health effects that can lead to workers’ compensation claims, lawsuits and requirements that manufacturers change “the design of the planes,” Garamendi said.

“Watch out, Boeing.”