How to use the mask correctly?

The types of masks include N95 masks, medical protective masks, medical surgical masks, ordinary medical masks, ordinary cotton masks, etc.

N95 mask

The protective effect of N95 masks is better. N95 is not a product model. It is a standard set by the National Institute of Occupational Safety and Health N10SH. Letters represent blocked particles (N stands for non-oily particles), and numbers represent the level of filtering effect, the higher the number The higher the protection level, the N95 mask is capable of filtering 95% of non-oily particulate matter with a size of 0.3 microns and above. The maximum diameter of dust particles is 5 microns, the diameter of bacteria is generally between 0.5 and 5 microns, and the diameter of most viruses is 20 to 200 nanometers (0.02 to 0.2 microns), of which the diameter of coronavirus is about 80 to 140 nanometers (0.08 to 0.14 Micron). Respiratory tract infectious diseases are mainly spread through droplets (diameter greater than 5 microns) containing bacteria and viruses, so wearing N95 masks can effectively prevent infection of respiratory tract infectious diseases. If worn correctly, the filtering ability of N95 masks is better than medical surgical masks and ordinary medical masks. However, even if it is fully compliant with the requirements, it will not be able to eliminate infections of infectious diseases 100%. There is also a KN95 mask, which has the same protective effect as the N95 mask. The difference is that KN95 is one of the levels specified in the Chinese standard GB2626-2006, and N95 is one of the levels specified in the American standard 42 CFR 84. The technical requirements and test methods of these two levels are basically the same, and the filtration efficiency reaches 95% under the corresponding standard.

Medical protective mask

The highest level of protection is the medical protective mask, which is based on the N95 and adds medical protection requirements such as surface moisture resistance and blood barrier, and has a good fit. National Standard GB 19083-2010 “Technical Requirements for Medical Protective Masks” stipulates that the filtration efficiency of medical protective masks should meet the following standards for non-oily filter particles when the gas flow rate is 85 liters / min: Level 1: Filter Efficiency ≥95%; Grade 2 ≥99%; Grade 3 ≥99.97%.

Medical surgical mask

The filtering effect of medical surgical masks is not exactly the same, generally can filter particles of about 5 microns. The protection level is lower than that of N95 masks, but higher than that of ordinary medical masks. It can be used as a preferred option without N95 masks.

Ordinary medical mask

Most medical masks on the Internet are ordinary medical masks, which lack the filtration efficiency requirements for particles and bacteria, or require lower medical surgical masks and medical protective masks, and the protection level is lower.

Cotton mask

It can only filter larger particles, such as soot, powder, etc., and cannot prevent the infection of bacteria and viruses.