One doctor said on the SNS platform that breathing valve masks cannot be used to prevent viral infections. The reason he gave was, “It is difficult to reach the N95 protection level at the breathing valve.” This sounds reasonable. In addition, many people see pictures of doctors wearing masks without breathing valves. It is natural to think that it is safer without breathing valves. It is a pity that this statement seems reasonable, but in fact it has no scientific basis.
First of all, no matter whether it is the US FDA, CDC or NIOSH, the definition of N95 masks has never excluded the “breath valve”. On NIOSH’s page of previously certified N95 masks, we can see a large number of masks with breathing valves. Here only take some 3M products as an example.
Secondly, N95 test items are divided into salty and oily media, and the filtration efficiency of particles as small as 0.3 microns can reach 95% or more to pass the test standard. Take the LIFAair with the best protection among the mask samples we tested before as an example. The protection efficiency for 0.3um particles is more than 99%. Regardless of adult or child models, are equipped with breathing valve.
Third, the principle of breathing valve. Many people are led away because they think the breathing valve can also inhale air. On the contrary, the design of the breathing valve is very clever, similar to the air cylinder, but more delicate. When air is discharged from the mask compartment, the valve diaphragm is pushed out and opened at a certain angle to facilitate the rapid export of air and water vapor, so that it will not suffocate.
According to the previous recommendation of the US CDC, as long as it is a certified N95 mask, it is the best choice for preventing viral infections, which includes both with and without a breathing valve.
Others say that the main reason why it is not recommended to wear a breathing valve mask is to consider that if the person wearing the mask is already a virus carrier, it is not safe for the surrounding people.But in real life, no matter whether you wear a medical surgical mask with no airtightness, or a N95 mask without a breathing valve, the air we exhale cannot be without contacting the outside environment. Medical surgical masks that leak everywhere can also spread germs when they exhale.
The conclusion is that ordinary people wearing masks for breathing valves can be used with confidence, but it is not suitable for use in hospitals.
We believe that for ordinary people, as long as they are qualified N95 masks, even if they are not medical grade, they can also effectively protect against virus intrusion, and N95 face masks with breathing valves can also effectively protect against virus infections.