The surgical mask is used to protect the surroundings of a person who coughs and a fortiori of a person who is manifestly suffering from Covid-19. Its protective effect for the person who wears it vis-à-vis those around him is weak, without any guarantee, because it is not designed for that (already, it is not waterproof).
The N95, KN95 for sale and FFP2 mask, is used to protect the person who wears it from contagious people – and who do not wear a surgical mask – who is in the immediate vicinity of them (within 1.5 meters).
In practice, N95, KN95, and FFP2 mask are reserved for healthcare professionals. But some people get them from merchant sites and wear them to get around town. There is also the possibility of obtaining these masks intended for the protection of workers in industry or construction, on commercial sites not related to health.
There is still a third category of masks intended to manage the infectious risk linked to the SARS-CoV-2 virus: these are the masks that have been called “barrier masks”. The principle of these masks is as follows: they are intended for the general public, have an acceptable filtering power, a fairly moderate cost, and are generally reusable; their ambitious vocation is to be versatile: anti-spray and personal protection, because they are already more waterproof than surgical masks.
What are the uses we can make of it?
Imagine a room of 100 m² in which there are 100 people, during an epidemic period. Let’s assume that three people are infected with CoVid-19 and are contagious. The safety distance (1.50 meters and not 1 meter) cannot be respected. If the three contagious people are not known and the 100 people correctly wear a surgical mask, the risk of contamination is well controlled; if the three contagious people are identified and only they wear a surgical mask, the risk is still well under control; if the three contagious people do not wear any mask and the other 97 people wear an N95, KN95 and FFP2 mask, the risk is still well under control; on the other hand, if the three contagious people do not wear a mask and the other 97 people wear a surgical mask, the risk is not well controlled. This is what you need to understand and remember.
The other preventive measure coupled with the wearing of the mask is the respect of the safety distance (1.50 meters), but this is not always possible and one cannot constantly anticipate an untimely rapprochement with another person. We are sometimes taken unawares and it is not even rare at all.
At present, the most reasonable solution is the systematic wearing of a “barrier mask” as proposed by many health professionals. This is probably what each country tend to do, as lockdown gradually eases because the collective immunity on which we founded hopes is very insufficient.
It must be stressed that a mask must be worn correctly or left aside: this is not a disguise. It should cover the mouth and nose, and be snug. Above all, it is crucial to respect the safety distance and to speak sparingly: two precautions are better than one (the mask and the distance).
