• Delta Airlines said that passengers who wear masks with an exhaust valve will not be able to board flights.
  • Masks with valves have been shown to provide little to no protection to others from potentially dangerous droplets in the air.

Like most airlines across the globe, Delta Airlines during the coronavirus pandemic implemented a rule requiring passengers to wear masks during flights. Delta, however, went one step further and also implemented a rule which demands travelers wear a face covering while checking in and while on jet bridges. Masks are also required for anyone in the boarding gate area and for those with access to Delta Sky Clubs.

Not all face coverings are created equal, however, and Delta recently clarified its mask-wearing protocol to exclude masks with an exhaust valve. What’s more, Delta notes that travelers can wear a face shield in addition to a face mask, but not in replacement of. Hardly a surprise, the CDC last month cautioned that face shields are not as effective as face masks when it comes to preventing the coronavirus from spreading rapidly.

Delta’s decision to expressly prohibit passengers from wearing masks with exhaust valves, or one-way valves as they’re also known, shouldn’t come as much of a surprise. Though the masks are slightly more comfortable than standard surgical masks, it’s been shown that they do a horrible job of preventing droplets from traveling through the air from person-to-person. In short, they help filter air coming in but not air going out. And while regular face masks or face coverings aren’t 100% effective, they’re still far more effective than masks with a one-way valve.

More precisely, wearing a mask with a valve can help protect yourself from droplets in the air, but will not do anything to protect people around you. And as studies have shown, the best way to effectively prevent the coronavirus from spreading is to have as many people wear masks as possible.

To this point, an article published by the University of California San Francisco notes:

An experiment using high-speed video found that hundreds of droplets ranging from 20 to 500 micrometers were generated when saying a simple phrase, but that nearly all these droplets were blocked when the mouth was covered by a damp washcloth. Another study of people who had influenza or the common cold found that wearing a surgical mask significantly reduced the amount of these respiratory viruses emitted in droplets and aerosols.

Put simply, deciding to wear a mask is a step in the right direction, but it’s equally as important to pick out an effective mask. This is especially important to keep in mind if you’re flying as you may not be able to board your flight with the wrong type of mask.

That aside, it’s somewhat bizarre that wearing a face mask in public — in the midst of a global pandemic, no less — has somehow become something of a divisive political issue. With the CDC’s stance on the matter is clear cut, it’s strange that we’re still seeing a lot of pushback against wearing masks in public. The good news is that many popular retail chains have started demanding customers wear masks before being allowed to enter.

All told, masks will likely remain a CDC recommendation until we can firmly put the coronavirus behind us. Unfortunately, that won’t happen until an effective vaccine is developed. Even in an optimistic scenario, a coronavirus vaccine likely won’t be available and widely disseminated to the public until early-mid 2021.

A life long Mac user and Apple enthusiast, Yoni Heisler has been writing about Apple and the tech industry at large for over 6 years. His writing has appeared in Edible Apple, Network World, MacLife, Macworld UK, and most recently, TUAW. When not writing about and analyzing the latest happenings with Apple, Yoni enjoys catching Improv shows in Chicago, playing soccer, and cultivating new TV show addictions, the most recent examples being The Walking Dead and Broad City.