Questions and answers about smog and protective masks


Q: What kind of mask can prevent smog? A: The hazards o […]

Q: What kind of mask can prevent smog?
A: The hazards of smog mainly come from the fine particulate matter, that is, the particulate matter suspended in the air with an aerodynamic particle size less than or equal to 2.5 microns. Choose professional particulate protective masks for effective protection. Ordinary thermal masks, cotton/gauze masks, and disposable non-woven masks (medical or non-medical) cannot effectively resist haze. At present, the country has not issued relevant product standards in the field of civilian masks. However, in the GB2626-2006 "Self-priming filter anti-particulate respirator" standard, it is required that the filtration efficiency of KN90 and KN95 level anti-particulate masks should be at least greater than or equal to 90% , Such as 3M 9001V particulate protective mask, 3M 8210V particulate protective mask.

Q: How bad is the air condition? Should I wear a particulate respirator when I go out?
A: According to the "Ambient Air Quality Index (AQI) Technical Regulations (Trial)" (HJ 633-2012), the air pollution index is divided into 0-50, 51-100, 101-150, 151-200, 201-300 and More than 300 six levels, each level of AQI index corresponds to the air quality, such as the concentration of PM2.5, the larger the index, the higher the concentration of pollutants, the more obvious the impact on human health. my country's current air quality standards are the best air quality indicators recommended by the World Health Organization, and there is still a certain distance from the safest indicators. The public should pay close attention to the air quality monitoring results released by the local government, and choose whether they need protection based on their own conditions.
Q: Can traditional cotton masks and gauze masks effectively protect against PM2.5?
A: No, because the particle size of PM2.5 particles is extremely small, it will penetrate the pores of cotton and gauze masks. Cotton and gauze masks use multi-layer mechanical filtration to intercept particles. The pores of the gauze are too large compared to 2.5 micron particles, and PM2.5 can easily penetrate. Moreover, the current common structure of cotton and gauze masks prevents the mask from being able to effectively adhere to the wearer's face. Particles can not only penetrate through the mask, but also through the gap between the mask and the face.

Q: Can ordinary medical disposable non-woven masks effectively protect against PM2.5?
A: No. As the name suggests, medical masks are designed to be used in medical systems. Medical disposable non-woven masks can prevent the droplets produced by the wearer from polluting the environment of the medical place. Under normal circumstances, what we can buy in pharmacies is this kind of ordinary medical disposable non-woven masks. This kind of masks are generally made of one or more layers of non-woven fabrics. There is no requirement for the filtration of particulate matter. The general medical disposable non-woven masks generally cannot fit the face completely. In terms of filtering effect and wearing tightness, they cannot guarantee that they can effectively filter PM2.5. Medical protective masks are different. Medical protective masks have strict requirements on tightness and particle filtration efficiency. At the same time, they can protect against infectious body fluids or blood splashes, and can be used in operating rooms. In theory, medical protective masks can protect against PM2.5, such as 3M 1860 or 9132 masks, but usually non-medical protective masks can meet the requirements of PM2.5 protection, so people do not need to spend more money to buy medical treatment Medical protective masks dedicated to the system.

Q: What is the function of the exhalation valve on the 3M protective mask?
A: There is a small one-way exhalation valve on many 3M protective masks, which is 3M's unique cold flow exhalation valve. When inhaling, the valve plate is closed, effectively blocking the inhalation of PM2.5; when exhaling, the valve plate is opened to discharge moisture and hot air, reducing expiratory resistance and making it more comfortable to wear.

Q: What are the activated carbon masks used for?
A: Adding a thin layer of activated carbon or other gas-absorbing materials on the particulate protective mask can reduce some low-concentration gas with unpleasant smell, that is, reduce odor and improve breathing comfort. Such as: the smell of putrefactive substances (mainly organic substances). When the concentration of odorous gas is so high that it is harmful to your health, you need to use a gas mask.

Q: Are activated carbon masks superior to non-activated carbon masks in terms of particle protection performance?
A: No, activated carbon only increases the reduction of certain odors. In terms of the performance of protecting particles, there is no difference with or without carbon. Activated carbon masks that can reduce odors do not increase the protection of particles.

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