You Should Not Be Wearing One of These Instead of a Face Mask, CDC Warns
This popular face mask alternative is unlikely to fully protect you from the coronavirus.
Now that most states have a mask mandate in place, many people are shopping for standard face masks as well as other forms of face coverings. While a surgical mask is the most common type of personal protection, a few people may look for options that are sleeker or more comfortable. However, if you're browsing around for a face mask alternative, be sure to avoid face shields.
Face shields are a tempting choice because they don't impede your breathing, and they keep you cooler than a mask would in the summer, but their effectiveness has not yet been studied thoroughly. The Centers for Disease Control and Prevention (CDC) does not recommend the use of face shields because "It is not known if face shields provide any benefit as source control to protect others from the spray of respiratory particles."
A study from the Journal of Occupational and Environmental Hygiene that examined the efficacy of face shields against cough aerosol drops concluded that face shields are not 100 percent effective. The study found that during a larger cough, the face shield "reduced the inhalational exposure of the worker by 96 percent in the period immediately after a cough. The face shield also reduced the surface contamination of a respirator by 97 percent." However, when a smaller cough was simulated "the face shield was less effective, blocking only 68 percent of the cough and 76 percent of the surface contamination," according to the study.
Even more concerning, "In the period from one to 30 minutes after a cough, during which the aerosol had dispersed throughout the room and larger particles had settled, the face shield reduced aerosol inhalation by only 23 percent," according to the study. So, if you wore a face shield and walked into a room after an infected person had coughed, you'd be more likely to contract the coronavirus than if you had been wearing a face mask. Basically, a face shield is decently effective in the short term, but not as much in the long term.
The CDC urges those that are determined to use a face shield without a mask to, "wrap [it] around the sides of the wearer's face and extend to below the chin." However, your best bet is to stick to cloth face coverings, as suggested by the CDC. And to learn about which face mask you should avoid, check out This Is the Face Mask the CDC Doesn't Want You to Wear.