Face Shields or Masks? Which Is Better for Coronavirus Protection?
There’s no question that people should wear face coverings in public to protect themselves against the coronavirus disease 2019 (COVID-19). The question up for debate is whether a face mask or a face shield provides the best protection against the potentially fatal illness.
Since the coronavirus disease spreads from person to person, the Centers for Disease Control and Prevention (CDC) recommends wearing cloth face coverings to slow the spread of the virus and help people who have the virus—but do not know it—from transmitting it to others.
The national health agency also asks the public to reserve medical-grade masks, like surgical masks or N95 respirators, for frontline healthcare workers and first responders. Medical-grade masks create a barrier so that large droplets, splashes or sprays containing viruses and other germs cannot reach the wearer’s nose and mouth.
Some argue that face masks that are not medical grade do not offer the same protection like a plastic face shield, which covers the entire face. Plastic face shields are usually worn by dentists, dental hygienists, doctors, nurses, and medical technicians when performing procedures that could send blood or other substances into the air.
A face shield has a curved, rigid plastic or Plexiglas panel held in place by an elastic headband. The shield fully covers the face and ends well below the chin. The CDC does not recommend face shields for daily use or as a substitute for cloth face coverings.
According to the CDC, it is not clear whether face shields are effective at “source control,” which is stopping the spray or respiratory particles contained in a cough or a sneeze from spreading to others. The coronavirus can spread when respiratory droplets from a person infected with COVID-19 land in the mouth or noses of people nearby or be inhaled into their lungs, the CDC said.
Are Cloth Face Coverings Effective?
Face masks have definite public health benefits, according to Joe Allen, assistant professor of exposure assessment science at the Harvard T.H. Chan School of Public Health and director of its Healthy Buildings program.
For one, other people are protected from mask wearers with COVID-19 symptoms and those who have COVID-19 but do not show any signs of the disease. Besides that, Smith said, a mask can:
- Catch large droplets from a cough or sneeze and prevent them from infecting others.
- Acts as a physical barrier since studies show that some droplets can carry up to 20 feet.
- Acts as a reminder to wearers not to touch their eyes, nose or face.
There are also a variety of face cloth coverings available, from disposable after one use to reusable, machine-washable masks.
Some materials for cloth masks filter better than others. For instance, the CDC recommends using cotton material since masks made of cotton and towel offer better protection than masks made of gauze.
Smith said a 100-percent cotton T-shirt is perfect for making a mask since science says that cotton is not only “fairly effective” for capturing large droplets, but for filtering some of the smaller virus particles.
Plastic Shields as Alternatives to Cloth Coverings
People who are tired of having foggy glasses or have difficulty breathing when wearing a face mask may opt for wearing a face shield for protection.
Proponents of face shields say the covering has many advantages, particularly for people with hearing loss. For instance, a face shield allows others to see the wearer’s mouth. A face mask covers the mouth and muffles the wearer’s voice.
An editorial in the April JAMA Network journal noted that studies have not evaluated the potential benefits of face shields for source control. However, a simulation study found face shields reduce exposure to a virus by 96 percent when worn within 18 inches of a cough, and by 92 percent when worn within 6 feet, the CDC’s recommendation for social distancing.
What’s more, the editorial mentioned that face shields:
- Can be reused indefinitely
- Are easily cleaned with soap and water, or common household disinfectants
- Protect the eyes, nose, and mouth (the portals through which viruses can enter)
Face shields are also more comfortable to wear and people do not have to constantly adjust the shield as wearers do with face masks, said Dr. Amesh Adalja, a pandemic preparedness expert at the Johns Hopkins Center for Health Security. Constantly adjusting face masks means touching your face and increasing the possibility of transferring the virus from your hands to your face, Adalja said.
Some people are wearing a face mask underneath a face shield for added protection. Adalja believes the general public doesn’t need to wear both pieces because it’s not likely that viral particles will float up under the face shield.
Face Coverings: A Preventive Measure Against COVID-19
Whether you prefer a face mask or a face shield, health experts stress the importance of wearing face coverings in public settings and when it’s difficult to social distance or keep 6 feet or more away from others to reduce the risk of COVID-19 infection.
Besides face coverings, frequent handwashing, and cleaning and disinfecting frequently touched surfaces, are other steps the CDC encourages the public to take to reduce the risk of exposure to COVID-19.