Why a clear face shield does not replace a mask to protect against COVID-19
Face shields are popular among people who find it hard to breathe in a mask. However, it’s important to know that on its own, a face shield does very little to protect you against COVID-19.
Your best chance at staying healthy is to wear a mask under your face shield and practice social distancing.
How face shields prevent the spread of COVID-19
COVID-19 spreads through respiratory droplets that are released from an infected person via sneezing, coughing and talking. The goal of the clear plastic face shield is that it should block the droplets from being inhaled by the wearer and infecting them.
Although face shields add extra protection when paired with a face mask, they offer little to no protection when used alone. The Centers for Disease Control and Prevention (CDC) explains that the role of a face shield is to safeguard the eyes from infection, not the nose or mouth.
When you look at someone wearing a face shield head-on, the person’s face may appear completely covered. However, the shield itself sits several inches from the face, which leaves gaps around the sides and bottom of the shield, near the nose and mouth.
Due to these gaps, if the person wearing the shield were to cough or sneeze, their respiratory droplets could escape through the gaps and expose others to infection. Similarly, if someone nearby were to cough or sneeze, the person wearing the shield could still inhale the droplets through the gaps and risk becoming infected.
Face shield vs. mask
Before you rely on a face shield as your only line of defense against infectious disease, please understand that wearing a face shield does not replace wearing a mask.
In a study done to compare how well different face coverings block respiratory droplets, researchers determined that wearing a face shield and no other protective covering only blocked 2% of respiratory droplets.
To replicate how humans spread respiratory droplets, researchers used a cough aerosol against various face coverings to see how well they blocked the aerosol.
Results showed an N95 mask blocked 99% of the aerosol, making it the most effective at filtering harmful particles. Surgical masks, cloth masks and single- or double-layered gaiters filtered similar percentages that were less than the N95 mask. However, they all did a much better job blocking aerosol particles compared to the face shield alone.
Wearing a face shield leaves users susceptible to 98% of airborne droplets, making them pretty useless as a means of protection on their own.
While N95 masks block nearly all potentially harmful droplets, you can also achieve maximum safety by double masking.
The CDC released information in February 2021 that explained the benefits of wearing a cloth mask or gaiter over a surgical mask. Researchers conducted lab testing with dummies to measure how effective the double mask method was in filtering aerosol particles. Results showed that wearing two tightly fitting masks filtered around 95% of aerosols.
Besides wearing a face shield or mask, you can prevent the spread of COVID-19 by washing your hands regularly and avoiding people who are sick. When in public, wear a mask (or two) over your nose and mouth and keep six feet of distance between yourself and others.
SEE RELATED: 7 ways to avoid foggy glasses while wearing a face mask
Tips when wearing a clear face shield
If you plan to use a clear face shield when around other people, follow the recommended tips below to get the most protection:
1. Always pair the face shield with a mask
As mentioned earlier, wearing a face shield by itself will not protect you or others. If you plan to wear a face shield, be sure to pair it with some type of face mask.
Face masks provide closer coverage, which makes them more effective in blocking contagious particles. Face shields cover the eyes and provide an added layer of defense against infection via the eyes.
An additional perk of a face shield is that it discourages people from touching their faces with contaminated hands or fingers — a habit that the CDC says can transmit the virus.
2. Disinfect the face shield after each use
It’s important to keep your face shield clean by disinfecting it after every use. The CDC recommends following the cleaning instructions provided by the face shield’s manufacturer.
If manufacturer instructions are not available, the CDC offers their own face shield cleaning instructions.
3. Make sure the face shield is the correct size
The CDC recommends wearing a face shield that wraps around the sides of your face and extends down below your chin. While this makes the face shield somewhat better at blocking infectious air particles, a mask is still recommended for ideal protection.
Are clear plastic face shields a better option for certain people?
For some people, wearing a face shield is more for necessity than convenience. Having a mask that covers the nose and mouth can cause difficulty in certain situations, such as:
People who read lips because they are deaf or hard of hearing
People with certain health issues and disabilities
Students learning a new language who benefit from seeing their teachers’ mouths
Children or students who are learning to read
People who need to observe mouth shape to determine how to pronounce certain vowels, such as when singing
Fortunately, there is an option that allows the world to see your face while providing better safety than a face shield alone. ClearMask is a fully transparent, FDA-cleared mask that provides thorough protection and clarity when communicating.
The mask has a patent-pending design focused on comfort and breathability, while providing guaranteed protection. The ClearMask has secure yet comfortable bumpers on the top and bottom of the mask, along the chin and nose, that seal any potential gaps. Its transparent, anti-fog barrier blocks sprays, fluids and aerosols while making your face visible to others.
Where to buy a clear face shield
If you’re interested in adding a face shield to your COVID-19 uniform, you can easily purchase them online or in-store for a reasonable price. Big box stores, including Walmart and Home Depot offer multi-packs and various face shield designs.
As far as online shopping goes, Amazon has a large selection of face shields with varying features and price ranges.
Again, wearing a face shield without also wearing a mask does not protect you or anyone else against the spread of COVID-19. So, before you venture out, pair your new face shield with your favorite mask, and explore the world safely.
READ MORE: Is your face mask causing eye problems?
COVID-19 overview and infection prevention and control priorities in non-US healthcare settings. Centers for Disease Control and Prevention. February 2021.
Guidance for wearing masks. Centers for Disease Control and Prevention. April 2021.
Efficacy of face masks, neck gaiters and face shields for reducing the expulsion of simulated cough-generated aerosols. Aerosol Science and Technology. January 2021.
Maximizing fit for cloth and medical procedure masks to improve performance and reduce SARS-CoV-2 transmission and exposure, 2021. Centers for Disease Control and Prevention. February 2021.
Understanding the differences between face masks & shields. St. Luke's Health. August 2020.
Page published on Thursday, June 24, 2021