Are face shields acceptable substitutes for masks? Pa., CDC give conflicting advice

Jay Howard Gross has no problem complying with the Pennsylvania’s face-covering order. But he won’t wear a mask.

With asthma and seasonal allergies, Gross has become a big fan of plastic face shields.

Still, occasionally, when he’s inside a store, employees insist that he wear a mask.

“A lot of people won’t cross over,” said Gross, who welcomes guidance from the Pennsylvania Department of Health that considers face shields an acceptable alternative to masks and other coverings. “They still have the fear that they will be kicked out of a store.”

Experts are split on the effectiveness of face shields as an interchangeable option.

The Pennsylvania Department of Health has ruled that they can be used instead of masks. The state’s “Universal Face Coverings Order” provides options that “include a plastic face shield that covers the nose and mouth.”

Yet the Centers for Disease Control and Prevention guidance doesn’t recommend use of face shields as a substitute for cloth face coverings, citing a lack of research. “It is not known if face shields provide any benefit as source control to protect others from the spray of respiratory particles,” the agency’s guidance states.

However, if face shields are used without a mask, the CDC recommends users should have a shield that wraps around the sides of the wearer’s face and extends below the chin.

Despite the conflicting advice, as face coverings become more ingrained in daily life, face shields — which users say provide more comfort and ease in communicating — are growing in popularity.

Doylestown business owner Mike Galanti knows why.

Serving homemade fudge in 90-plus degree temperatures at the New Britain farmers market Wednesday, he said, “They are more comfortable, breathable and people can see your face which is best for communication.”

"I have seen employees at Wegmans and Costco wearing face shields,“ said Galanti, who has only been asked at one store to wear a mask in addition to his face shield.

While some customers have complained of the shields being used instead of cloth masks, Galanti believes more education on the shields would lead to more acceptance of them.

The case to switch to face shields got a big boost recently, when Bucks County officials announced a plan to use federal CARES Act funds to purchase 200,000 face shields for students and teachers of public and private schools.

Their rationale is based on science, safety, and social behavior, said Bucks County Department of Health Director Dr. David Damsker, who believes that students who are required to wear face coverings will be more likely to keep a shield on for several hours than a cloth mask.

“We tried to come up with an option that would allow kids to have something on their face that they wouldn’t constantly play with and touch,” Damsker said. “It feels cooler, and it’s easy to sanitize ... We want people to use them, and a mask that’s not used or not used correctly is not a good mask.”

Damsker said other benefits of the face shield include offering eye protection and enabling users to speak and hear more clearly, and breath more comfortably.

“If you cough or talk, it stops the droplet spread,” he said, noting that, unlike cloth masks, “it blocks droplets from entering your eye.”

“With this option, you don’t have to yell through the mask or pull the mask down to have a conversation,” Damsker added. “Every time you touch a mask, especially on the outside, there’s a possibility of contamination. We are trying to provide a mechanism for the kids to wear something that is comfortable that makes education easier for teachers and the kids.”

Science of face shields

Little research has been done on face shields, but one study published in the Journal of Occupational and Environmental Medicine in 2014 showed that face shields can be highly effective, protecting study wearers from 96% of inhalation exposure of an "influenza-laden cough aerosol."

Though the Children’s Hospital of Philadelphia (CHOP) also recommends masks, a policy review for Pennsylvania school reopenings reports that face shields do provide a partial barrier to respiratory droplets and could be helpful in classroom environments where masking may interfere with teacher instruction "or when distancing 6 feet cannot be adequately achieved within a classroom setting.“

Dr. Ravina Kullar, an infectious disease specialist, epidemiologist and spokeswoman for the Infectious Diseases Society of America, said face shields protect your eyes, which is a point of entry for the virus, in addition to the nose and mouth. Shields also do not restrict breathing and are more comfortable than masks especially during the summer, while also preventing face touching.

“Importantly, in the school setting, shields allow facial expressions to be visible, which is very important for early childhood development,” she said.

However, Kullar added, she is not aware of any studies that have been conducted to date that have shown the benefits of face shields in containing a sneeze or cough when worn by asymptomatic or symptomatic infected persons.

“Until we have those studies in several patient cohorts, I recommend if you wear a face shield, to also wear that mask, as masks have been repeatedly shown to prevent SARS-CoV-2 transmission,” she said.

No time for a study

Waiting for studies that compare the effectiveness of both kinds of face coverings is not practical, Damsker said.

“There is not going to be time to do an in-depth efficacy study for face shields versus cloth masks,” he said. “Face shields are clearly allowed under the governor's order. It's an acceptable alternative, and we know that the face shields do a pretty good job of blocking droplet spread — a big component of this.”

Cloth face masks block droplet spread, too. But students are less likely to keep them on for lengthy periods of time, he said.

“If a kid isn’t going to wear a (cloth) mask all day or if he is going to pull it down off his nose every time a teacher wants to speak to him, it’s not effective,” Damsker said. “If a kid touches something with COVID and touches the mask, that mask is now contaminated.”

At the New Britain farmers market Wednesday, parent and teacher Lori Kesilman was talking to friends about the county’s purchase of face shields.

“As a teacher and a parent, I’m concerned,” she said. “I think face shields are fine — in addition to wearing a (cloth) mask.”

Damsker said the county purchased the shields as a public service, and students aren’t required to wear them. “Some parents may not want their kid to wear it, and that’s fine, but we’re going to make it so every kid who wants one has one.”

“Overall, people need to find what works for them,” he said. “Whatever the mask you are wearing, it only helps if you’re wearing it.”