Les N95/KN95/FFP2/KF94/DS2 sont réutilisables. Il faut éviter de les mouiller, et les conserver au sec pendant 5 jours entre deux utilisations (donc tourner entre plusieurs masques/respirateurs).

C'est bon à savoir car ils sont sensiblement plus dispendieux que les masques chirurgicaux. Et puis ça fera moins de déchets.

Le N95 est un respirateur* (souvent rigide, avec des lanières qui passent derrière la tête), le KN95 est un masque*, avec des boucles qui passent derrières les oreilles. Ils ont un degré de filtrage similaire, mais le N95 assure une meilleure étanchéité sur les bords (pour peu qu'on n'ait pas de pilosité faciale).

Le KN95 est facile à trouver en commerce et est accessible au grand public, le N95 est en général réservé aux milieux professionnels (santé, construction, et maintenant éducation).

*En fait je ne sais pas si la distinction existe en français, mais elle existe en anglais, du moins pour l'Amérique du Nord.

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Un N95 bien ajuster filtre 95% des particulles plus gros que 0.3 micrometre...

@BitAcadie @kicou SARS-CoV-2 is one of the larger viruses and masks are more effective with it than other viruses. It's not 100% effective, but at least it will reduce the number of viruses entering your body. Hopefully, it will give you a milder illness or you may build resistance to it without coming down with it from just a couple of viruses.

@StampedingLonghorn @kicou SARS ncov2 measures 0.1 micrometre.

Let's run the numbers

The virus is 0.2 micrometre smaller than what a properly fitted n95 mask is designed to filter.

@BitAcadie @kicou Usually, the virus is not by itself but on booger particles that are larger than 0.3μm. If the virus is by itself, it would quickly die depending on temperature and humidity.

@BitAcadie if you blast sand through four of these shopping carts, even though they do have spaces that are many times larger than a grain of sand, you are going to deflect enough of the stream to noticeably reduce the damage to whatever is standing behind them. Granted, not the ultimate protection, but better than none.

If someone sneezes or simply breathes through a mask, or even a piece of cloth, chances that the amount of virus-loaded droplets you would have received without any sort of screen will be significantly lower.

Yes, stuff will go through, but the turbulence created may be enough to spare you.

Also, N95/KN95/FFP2 masks are charged electrostatically, to help trap smaller particles.

No one measure is perfect. The goal is to lower the risk as much as possible in a fashion that is economically feasible. We are already reaching the limit of what people can afford (N95s are not cheap).

It is the sum of partially ineffective measures that is hopefully helping everyone protect themselves and people around them.

Nobody is saying that it is perfect. But doing something is surely better than doing nothing.


@kicou @BitAcadie @StampedingLonghorn as Kicou is hinting, all virions are contained inside water droplets that are WAY bigger than them.

@BitAcadie @lutzray @kicou I've always wondered if using a mask that forces you to breathe thru your mouth is better than breathing thru your nose.

@BitAcadie @kicou @StampedingLonghorn a small reduction in transmission risks has large exponential effects on an epidemological level, reducing R0

@lutzray @kicou @StampedingLonghorn

You see the water vapor dispersing after he exhale that's how much is getting by the filters

@BitAcadie @lutzray @kicou Those aren't KN95 masks either. The last big white mask was donned wrong.

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Instance perso. Principalement en français. Personal instance, mainly in French. Linux, OSS, Santé Mentale, 3615 MaVie.