JetBlue has announced that it is updating its Safety from the Ground Up program, the airline’s safety commitment during the COVID-19 pandemic.

The airline said in a statement that it is “extending its commitment to seat distancing for flights through at least October 15 by blocking middle seats in rows where parties are not traveling together.”

JetBlue is also extending the waiver of change and cancellation fees for tickets purchased by October 15. Travel Bank credit expirations will be extended to a 24-month period for credits issued between Feb. 27 and June 30.

The airline also said that it is now prohibiting masks “with vents or exhalation valves, and will no longer allow customers to claim exemptions from wearing a face covering altogether.”

To date, Jet Blue is the first airline to ban a specific type of mask. The masks with exhalation valves or vents have become a popular type of face covering that users feel allows more air to pass through, but infectious disease specialists say are ineffective at preventing the spread of the coronavirus.

The move comes as other major carriers have also tightened their mask protocols. American Airlines is no longer allowing any exemptions to its mask policy. United mandates customers with medical exemptions speak to a United representative prior to boarding and Delta requires medical exemptions to be screened through the airline’s own phone-in medical provider.