How are the masks graded?

- Apr 25, 2020-

1.According to the user's mask, it is divided into three categories: industrial, medical and civil

The masks currently on the market are divided into three categories: industrial, medical and civilian. It is understood that most of the industrial masks on the market implement American standards beginning with N95, N90, etc., or European standards beginning with FFP. The national standard for masks in China is GB2626-2006, which is suitable for industrial masks. It is similar to the American standard, and is divided into KN type suitable for filtering non-oily particulates, and KP type used for the protection of oily particulates. Among them, the filtration rate of KN90 is required to be greater than or equal to 90%, while the filtration rate of KN95 is required to be greater than or equal to 95%, and the filtration rate of KN100 is greater than or equal to 99.97%.

In fact, in addition to poor breathability, industrial masks are also not good for the prevention of viruses and bacteria. Although industrial masks can effectively filter fine particles of PM2.5 or below. But on the other hand, the water vapor carried in human breath easily adheres to the inner wall of the industrial mask, which nourishes the bacteria and viruses attached to PM2.5, making the industrial mask a petri dish for bacteria and viruses, and the health of consumers It is easily threatened by the secondary pollution of industrial masks. Long-term wearing of industrial masks can easily cause permanent damage to people's respiratory system, especially children and the elderly.

The implementation standard of medical protective masks is GB19083-2003, which is suitable for the protection of airborne respiratory infectious diseases by medical staff and related staff. The key to respiratory protection is to prevent bacteria and fine particles.

Civil masks are not as good as industrial masks in terms of tightness, but they are easy to clean, suitable for long-term wear, multiple use, and have little damage to the body. Some brands of masks have antibacterial functions, which can be passed through the outer layer of Kanglun antibacterial fabric and inner. The attached micro-filtration filter resists the "two fines" in the air (ie fine particles represented by PM2.5 and bacterial viruses represented by N1N1, NDM-1), thus achieving a comprehensive and effective protection.

2. Divided into four levels according to air pollution

The new standard to be implemented for the first time classifies the protection level of masks into A, B, C, and D levels from low to high according to air pollution. Class A masks are suitable for use when the PM2.5 concentration reaches or exceeds 500 micrograms per cubic meter, that is, serious pollution or above; Class B masks are suitable for serious pollution (PM2.5 concentration ≤350 micrograms per cubic meter) and below; Class C is suitable for severe (PM2.5 concentration ≤250 micrograms per cubic meter) and below pollution; Class D is suitable for moderate (PM2.5 concentration ≤150 micrograms per cubic meter) and below pollution. At the same time, the corresponding protective effects at all levels are required to be no less than 90%, 85%, 75%, 65%.

In other words, you can look at the air pollution before going out, and then choose the mask to wear according to the actual situation. Sun Yang, a researcher at the Institute of Atmospheric Physics of the Chinese Academy of Sciences, reminded that the introduction of the new standard only gives everyone a reference value. The public must be flexible when choosing masks, which varies from person to person. Like the American standard N95 mask that "filters non-oily particles with an efficiency of more than 95%" (Whether to mention N95 here, this is the American standard), it is not necessary to wear it when the air pollution is at the highest level, if you are against smog If the requirements are high, the wearing level can be increased appropriately. For example, in the case of heavy pollution of 250 micrograms per cubic meter, the national standard recommends that C-level air quality standards can be achieved after wearing, but wearing a Class A mask can meet the daily average health standard recommended by the World Health Organization (WHO) of 25 micrograms per cubic meter.