BFE is an indicator tested by Labs in Salt Lake City, Utah, USA. It refers to the filtration efficiency of bacteria in maks testing. The test used Staphylococcus aureus with an average particle size of 3 μm as the object. Most BFE masks use polypropylene (PP) as the main protective material. Mainly improve the durability of the mask. Please note that it is "durability", not "protection". Since the standard only uses 3µm test samples, we cannot know in detail the ability of BFE masks to protect against viruses below 3µm. As I said above, the diameter of the droplet is 1~5μm. This is not to say that BFE masks are not anti-virus, but the standards used in the tests are relatively loose. We cannot quantify the protective effect of this mask on coronavirus, but the BFE test does protect the bacteria. It is standard, so if you only prevent the spread of coronavirus, there is no problem. If you are not sure, please use other standard masks.

    N95 is not a specific product name. As long as it meets the N95 standard, and products that pass the NIOSH review can be called N95 masks. This standard is one of 9 types of particle protective masks certified by the National Institute of Occupational Safety and Health (NIOSH). "N" indicates oil-resistant particulate matter, and "95" indicates the filtration efficiency of particles with an aerodynamic diameter ≥ 0.3 μm. Above 95%, it can effectively filter out non-oily particles, such as dust, acid mist, paint mist, microorganisms, etc. As can be seen from the above, the N95 mask can prevent coronavirus.

    Generally speaking, the higher the protective performance of the mask, the greater the impact on the comfort performance. When people wear masks to inhale, the masks have a certain resistance to the flow of air. When the inhalation resistance is too large, some people will feel dizzy, chest tightness and other uncomfortable conditions. Therefore, the basic principle of wearing a mask is to wear it scientifically and reasonably, to use it in a standardized manner, and to effectively protect it.