Jetblue says it is extended its seat distancing policy until at least October 15, and banning face masks with vents or exhalation valves starting August 10.

The US carrier is also no longer allowing customers to claim exemptions from wearing a face covering altogether.

Jetblue says middle seats are blocked on its Airbus aircraft, and aisle seats are blocked on its smaller Embraer 190 aircraft. The airline notes that it does allow customers traveling together to sit in middle and aisle seats.

The airline says in line with information provided from the Centers for Disease Control (CDC) and Jetblue’s own medical experts, it will no longer allow face masks with vents or exhalation valves.

“The simple act of wearing a proper face covering is one way we can all help ensure the safety of all Jetblue crew members and customers,” said Joanna Geraghty, president and chief operating officer, Jetblue.

“Our terminals and airplanes are a shared space, and every customer must wear a proper face covering or will need to delay their travel on Jetblue until face coverings are no longer required. Our policy is meant to offer the strongest level of protection for everyone given all that we currently know about how Covid-19 is transmitted,” she added.

An acceptable face covering or mask must cover a customer’s nose and mouth and is required to board all Jetblue flights, the carrier says.

Jetblue added that if a crew member identifies a face covering or mask that does not meet the airline’s criteria, they will provide a mask for the customer to use instead.

“The airlines customers who do not agree to wear a face covering will not be allowed to board any aircraft, and customers who do not follow crew member requests to wear a face covering while in flight will be reviewed for future travel on Jetblue,” reads a statement from the carrier.

Customers two years and younger will not be required to wear a face covering if they cannot maintain one.