Unlike face coverings, surgical face masks are manufactured to a recognized standard and can be effective in blocking splashes and large-particle droplets.
Moreover, both face coverings and surgical masks do not provide complete protection from germs (viruses and bacteria) and other small contaminants in the immediate environment because of the loose fit between the surface of the mask or covering and your face.
You may notice that the edges of surgical masks are not designed to form a seal around the nose and mouth.
Surgical face masks are not to be shared and are normally designed to be worn in medical settings to limit the spread of infection. If worn properly, a surgical face mask is meant to help block large-particle droplets, splashes, sprays or splatter from reaching your mouth and nose. They also protect patients from the wearer’s respiratory emissions.
If your mask is damaged or soiled, or if breathing through the mask becomes difficult, you should discard it safely and replace it with a new one. Do not forget to wash your hands after handling the used mask.
The particle capturing capacity of the filter (nonwoven mats of fine fibers) used in modern surgical masks largely depends on its fiber diameter, porosity, thickness, etc. Due to the same characteristics, the performance of surgical face mask is superior to that of a cloth face covering.
Nevertheless, the filtration mechanism of a surgical mask does not provide the wearer with a reliable level of protection from inhaling smaller airborne particles (less than 2.5 microns).
Therefore the surgical face mask should not be considered a respiratory protection device.
A longer version of this article appears in https://www.spotlightnepal.com/2020/07/13/covid-19-outbreak-face-coverings-vs-surgical-masks-vs-n95-respirators/