A: NOT RECOMMENDED.
As more businesses open up, we’re aware of reports of employees wearing ONLY Face Shields/Visors for protection (for example many hairdressers in the UK).
This approach is NOT recommended.
While face shields provide some additional protection to the wearer, especially for the eyes, they should be used as a complement to face masks, not a substitute. This is because masks absorb outbound droplets when we sneeze or cough, while face shields don’t. On the inbound side, smaller aerosol particles can flow around a face shield.
Health care workers treating patients with COVID-19 often wear added protective gear, including face shields to protect the eyes, nose and mouth from contamination from respiratory droplets, ALONG with masks or respirators.
In an experimental study using a “coughing patient simulator” (gotta love science!), face shields were shown to substantially reduce the short-term exposure of healthcare workers to large infectious aerosol particles, but smaller particles could remain airborne longer and flow around the face shield and were more easily inhaled.
Thus, “face shields provide a useful adjunct to respiratory protection for workers caring for patients with respiratory infections. However, they cannot be used as a substitute for respiratory protection when it is needed.”
A recent outbreak investigation at a hotel in Switzerland found that all of the staff who were infected wore plastic face shields, while those who avoided infection wore face masks.
“It has been shown that only those employees who had plastic visors were infected. There was not a single infection among employees with a mask.”
We will continue to monitor and update the science on PPE as it emerges.
For now, face shields can be a helpful extra layer of protection during times when close contact cannot be avoided, but should be used TOGETHER with face masks to prevent transmission.
