Original title: Should a layer of mask be added to the particulate matter protective mask to prevent viruses? Some special occupations, such as manufacturing industry, have to wear protective masks to protect against occupational harmful factors such as dust and smoke even if they are not in the epidemic period. Do you need to wear another layer of mask to block the virus now? The object of the protection COVID-19 virus is mainly transmitted by attaching to the droplet nucleus, which belongs to particulate matter, and the dust, smoke and fog produced in the production environment also belong to particulate matter, specifically, "non-oily particulate matter". Since they are all particulate matter,Antivirus Disposable Mask with CE Certificate, the masks we choose need to have a better filtering effect on particulate matter. Classification of masks Common masks can be roughly divided into four categories: medical protective masks, particulate protective masks, surgical mask and disposable medical masks. The four types of masks have different standards and use scenarios. Here is a brief introduction. 1. Medical protective mask ? Its filtration efficiency for non-oily particles is ≥ 95%, and it can prevent splashing liquid from penetrating; 2. Particulate protective mask : This kind of mask is most common in the production environment. KN90 or KN95 will be printed on the mask package or on the outer surface of the mask. KN90 and KN95 indicate that the filtering efficiency of the mask for non-oily particles is ≥ 90% and 95% respectively; 3. surgical mask : It can effectively block the penetration of splashing liquid and filter bacteria, Virus Prevention Mask 3 Ply with Earloop ,KN95 Face Mask, and the filtration efficiency of non-oily particles is not less than 30%; 4. Disposable medical mask Bacteria can be filtered, but there is no technical requirement for the filtration efficiency of non-oily particles. How to choose masks for workers in special occupations such as manufacturing industry We recommend that workers wear medical protective masks, KN90 and KN95 particulate protective masks that meet relevant standards. These masks can effectively filter all kinds of particulate matter, including droplet nuclei and dust, and can prevent COVID-19. Workers do not need to wear additional masks after wearing particulate protective masks. It is not recommended that workers wear surgical mask and disposable medical masks, which are inadequate for particulate matter protection. Precautions for Use of Particulate Mask 1. It depends on the filtering efficiency of the mask to particulate matter. For example, KN90 and KN95 mentioned above are effective protective masks with filtration efficiency of not less than 90% for non-oily particles; 2. Do not breathe during the epidemic. 。 The function of the breathing valve is to reduce the resistance of exhalation without affecting the protective effect of the mask, but because the exhalation will be discharged directly from the valve, what if you are an asymptomatic patient? It will not protect other people around, so in order to block the potential risk of disease transmission, masks without breathing valves should be chosen; 3. The mask should fit the wearer's face well. Air will leak through the filter material of the mask rather than the edge of the mask, thus playing a protective role; 4. Once the filter cotton of the particulate protective mask is wet, ? Expiratory resistance will increase and should be replaced immediately; 5. Wearing a protective mask can prevent the virus from invading from the mouth and nose. However, the possibility of virus infection through other ways can not be ruled out. The wearer should also wash his hands frequently, protect the eye mucosa,Full Body Disposable Coverall, do not rub his eyes, pick his nose, and do a good job of personal hygiene. Return to Sohu to see more Responsible Editor:. zjyuan-group.com