An N95 mask/respirator is a facepiece that filters out at least 95% of airborne particles. They’re medical grade, which means they meet the standards of NIOSH, the U.S. National Institute for Occupational Safety and Health.
N95 masks are the most common facepiece and are particulate filters. They don’t filter out vapors or gases. There are different classes of face masks for different levels and types of protection. They’re made of a fine mesh of synthetic polymers fibers to trap very fine particulates, such as dust and viruses. The particulates measured in tests are 0.5 micrometres.
In fact, any efforts should keep in mind the following eight qualities that a N95 mask or the equivalent should have:
The mask has to actually filter out the virus:The mask is called N95 and not “N let’s see what can and can’t get through the mask.” N95 means that the mask can filter out at least 95% of particles of all sizes from the air.Basically, the mask needs keep the virus from reaching your nose and mouth, which is why wearing panty hose over your head like a gangster isn’t going to do the trick.
The mask should have more than one filtering mechanism:The report described three general mechanisms that N95 masks have to pull particles from the air stream: inertial impaction, diffusion, and electrostatic attraction.
The mask shouldn’t suffocate you:have to make sure the breathing resistance is not too high for a mask;
The mask has to fit and form a seal with your face:Wearing a mask that filters out the virus but does not form a tight seal with your face can be like locking the front doors of your car but not the back. Any gaps between the mask and your face can allow the virus to sneak into your nose or mouth.
The mask should be reasonably comfortable to wear: The edges of the mask can’t be so sharp or abrasive that they cause substantial irritation, sores, or cuts. The mask can’t be so tight that you feel like your head is going to explode.
The mask shouldn’t shed:Anything that breaks off or sheds from your mask such as fibers and little particles can go straight up your nose and potentially down into your lungs.
The mask must be durable enough:The mask has to be reasonably resistant to all of these possibilities and maintain its integrity and filtering capabilities at least for a while.
The airstream and filtering portion of the mask need to be large enough：Coleascing water droplets can make the filter wet and thus decrease its effectiveness.
