The Transportation Safety Board says the only thing it can order airlines to do to ensure that everyone in the cabin can breathe clean air is to require people to wear their masks.
In a statement, the agency said airlines have a “responsibility” to make sure everyone is able to breathe.
The board’s director, Robert Guggenheim, said there’s no evidence to support the airlines claim that the masks can be worn by people with chronic obstructive pulmonary disease.
The agency said it was concerned about the number of people wearing masks and how many of them could become infected by airborne particles.
The agency also noted that the mask is usually not needed, but there are instances in which it may be needed.
The air cabin, known as a “bubble” in aviation parlance, can be a dangerous place for those who breathe in air contaminated with asbestos, but the agency says the safety of those who wear the masks is “the highest priority.”
The agency also said there is no evidence that masks can prevent people from developing airborne asbestos-related illnesses.