The CEO of a major airline suggested during a congressional hearing this week that face masks are of little value on planes – a claim that was quickly amplified online.

Citing high-quality filtration systems on board planes, Southwest Airlines CEO Gary Kelly said “masks add little, if anything, to the cabin environment.”

But experts strongly disagree. Here are the facts.

ALLEGATION: Wearing a mask on airplanes is not necessary because advanced air filtration systems sufficiently reduce the risk of transmission of COVID-19.

THE FACTS: While it is true that the common air filtration and distribution systems used in modern airplanes are very effective in reducing the risk of COVID-19 transmission between passengers, masks add another layer of protection for air travelers, experts told The Associated Press.

Kelly’s comments came during a hearing Wednesday before the Senate Committee on Commerce, Science and Transportation. After returning from the hearing, Kelly tested positive for COVID-19, a Southwest spokesperson confirmed to the AP on Friday.

Kelly made his comment on the masks in response to a question from Senator Roger Wicker, a Republican representing Mississippi, who asked Kelly and another airline CEO if they thought air travel without masks could ever to resume.

Kelly said “99.97% of airborne pathogens are captured” by high-efficiency particulate air filters, or HEPA filters, in airplanes, before suggesting masks are not needed during air travel.

“Yeah, I think the argument is very strong and that masks don’t add much, if anything, to the cabin environment,” Kelly said. “It’s very safe and of very high quality compared to any other indoor environment. “

American Airlines CEO Doug Parker seemed to agree and said, “I agree, the plane is the safest place you can be.” He noted that all of his company’s planes have the same HEPA filters.

The comments were quickly picked up by media and blogs, and posted on social media.

“The CEOs of Southwest and American Airlines both said in Senate testimony today that face masks on planes are useless,” the tweet said more than 3,500 times.

The two CEOs clarified their comments to say they support the current federal policy requiring masks on flights. After returning from the hearing on Friday, Kelly tested positive for COVID-19, the Southwest spokesperson confirmed to the AP.

Southwest Airlines provided AP with a message Kelly sent to employees in which the CEO apologized for any “confusion” resulting from the hearing, saying Southwest continued to “support the current federal mandate of masks at airports and in planes “.

Kelly said the airline adopted a mask requirement on board its flights in May 2020, before the federal government required it, and that employees and customers “felt it was an important layer of protection, and I certainly agree with that. ” He said the airline “would continue to rely on the advice of our medical experts regarding the need for the masks.”

Parker later said on social media that he “agrees with my fellow CEOs that being on a plane has proven to be a safe and healthy indoor environment.” But he said his statement at the hearing was unclear and that he supported the federal mandate of the “full stop” mask.

While HEPA filtration systems are very effective at reducing the transmission of viruses, they do not completely eliminate the risks on board flights, according to Linsey Marr, aerosol scientist at Virginia Tech.

“The problem is, they only work on air as it passes through the filter,” she said in an email. “If you’re sitting near someone who releases a lot of viruses into the air, you might end up inhaling them before they’ve had a chance to pass through the filtration system. “

Marr said it takes a few minutes for the air to completely pass through the filtration system. She said requiring everyone to wear a mask reduces the amount of virus an infected person can release into the air and helps reduce the amount of virus a person wearing a mask can breathe.

Leonard J. Marcus, director of the Aviation Public Health Initiative at Harvard University, agrees.

“Yes, the airplanes ventilation system is amazing. They are comparable to what you might find in an operating room, ”he said. But “it’s the multiple layers, it’s not a single thing. “

Marcus said masks are especially important when people get on and off planes or move around the cabin of the plane. The increase in COVID-19 cases and the threat posed by the omicron variant also make wearing the mask on airplanes essential, he said.

“People are on the move, people turn to talk to someone, people sometimes take their masks off to drink,” said Marcus, whose initiative released a report in October that supported a “layered” approach to reduce the risks. “If everyone wears the mask, there will be much less transmission of the disease. “

The Association of Flight Attendants-CWA, AFL-CIO, a union representing some 50,000 flight attendants, also called masks a “key component” of flight safety, noting that not all planes have systems HEPA filtration.

Kelety reported from Phoenix; File from Philadelphia.

This is part of AP’s efforts to tackle widely shared disinformation, including working with outside companies and organizations to add factual context to the deceptive content circulating online. Learn more about fact checking at AP.

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