N95 mask is one of nine kinds of anti-particle masks certified by NIOSH in the United States. Its biggest feature is that it can prevent droplet infection caused by patients.
In fact, there are two kinds of ordinary N95 masks, those with breathing valves and those without breathing valves. Breathing valve is considered to reduce the protection against viruses, but it is not suitable for long-term wear because of its poor air permeability and laborious breathing. Everyone can choose according to the actual situation when purchasing.
It should be specially reminded that "bacterial filtration ≥95%" indicated on the packaging of some brand masks is not equal to "N95 protection level". At the same time, there is no so-called 3M standard mask, 3M is just a mask brand, and not all 3M masks can reach N95 protection level. KN95 mask and N95 mask are actually the same thing, but the certification bodies are different. The former N95 is a standard formulated by the United States, and the latter KN95 is a level stipulated by the China standard. N95 mask is suitable for doctors and nurses in fever clinics, isolation wards or metastatic confirmed cases.
02
Medical surgical mask
Medical surgical masks are often used in operating rooms and other environments where there is a risk of body fluids and blood splashing, which can prevent blood and body fluids from polluting the wearer through the mask, and at the same time, the filtration efficiency of bacteria should be not less than 95%. However, the filtration efficiency of particles is limited, and most of them are rectangular designs, which are not as close to the face as medical protective masks.
When you buy, you must pay attention to the words "medical surgical mask" or masks that implement standards. Medical surgical masks are suitable for patients with suspected cases, bus drivers and sanitation workers. , and used in invasive operating environments, such as operating rooms.
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Disposable medical mask
There are many names for ordinary medical masks, and those without the words "protection" and "operation" are all ordinary medical masks. Generally speaking, this level of mask does not need to block blood, so it is only suitable for wearing in general medical environment.
04
Ordinary mask
Ordinary masks may be made of cotton cloth, gauze, sponge, canvas, velvet and so on. Because the material itself is not dense enough to prevent infection. As for how to choose, the first thing to say is that you don't need to wear N95, because these viruses actually don't exist alone. They often exist in the form of droplets. Ordinary masks, surgical masks, etc. can still prevent most viruses with droplets from entering the respiratory tract, so it depends on the specific situation.
Figure 1 | Sponge Mask
Figure 2 | Cotton Mask
A mask that can't prevent infection.
To sum up, N95 and KN95 masks have the strongest protective effect, followed by medical surgical masks, disposable medical masks and ordinary masks. But N95 mask also has some practical problems, such as uncomfortable to use, difficult to buy and high price. If you go to a general open-air public place without contact with patients, you can choose to wear a medical surgical mask or a disposable medical mask without excessive protection.