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The hospitals have been doing this from the beginning. There must be some truth to it. I think it's simple probability. A n95 mask lets in 5% of particles getti
by fasteddie31003 6y ago
The hospitals have been doing this from the beginning. There must be some truth to it. I think it's simple probability. A n95 mask lets in 5% of particles getting though. Layering two masks should effectually make a n99 mask ((1/20) * (1/20)) = 0.9975 The added mask only adds n4.9. It's probably a more effective use for second mask to go to someone who has a surgical mask.
Let's do the math for surgical masks which are like n20. Adding two n20's gives you a n40, which is marginally better than the n95 double masks.
Let me vent by saying I was on the pro-mask side when the CDC and WHO were against them, I made a website that went viral and got 7 million view letting people know your government officials were wrong. I had my account banned from Reddit and Facebook over being pro-mask. I even got contacted by the CDC to think about taking down the site. I told them to fuck off. When this pandemic is over and we can do a post-mortem on the pandemic the CDC and WHO will have blood on their hands for the poor messaging around masks.
I for one have been double masking n95's for a while.
- victor106 6y agoKudos to you. I agree with you a 100%. It was such a common sense thing. I was telling my friends back in Feb/March that they should make it mandatory. Sometimes experts get it wrong and it costs millions of lives. So sad..
- AstralStorm 6y agoDid they really? We all know more layers is better for this kind of diffusion filter. However, the other key variables are fit and leakage, where double masking tends to not help at all with respirators, but may with very soft masks. We don't have any data that it does, though. Usually people use sub par (cloth, surgical), badly fitted (loose rubber bands, misfitting nasal) masks or wear them wrong - the classic being a mask not covering the nose.
- deleted 6y ago[deleted]
- AstralStorm 6y agoThat's not how masks work. The masks rating is mostly a function of leakage not filter material for the particles of concern (biological aerosols) and using multiple harder respirators can compromise fit or provide no benefit. The rating percentage is for specific test setup. For biological aerosols, the result is quite different in that small particles are stopped by diffusion, and the filter rates tend to be better than rated for masks, as long as leakage is low. Now, the situation is different with weak filtering materials such as used in surgical or cloth masks, but the result is not additive either. Have you actually tested that the specific double N95 configuration even provides single N95 protection? (Esp. leakage) No? Then better not mess with the design.
- collyw 6y agoMost people are not wearing n95 masks, and the airflow seems to come out of the side of the normal ones.
- DanBC 6y ago> the poor messaging around masks. Your advice is going to kill people. > I for one have been double masking n95's for a while. 1) You don't have the equipment to check that those are actually N95s that meet the spec 2) You don't have the equipment to do a correct fit-test 3) Modifying safety critical equipment is dangerous. You haven't doubled the safety, you've made these masks less safe. I'm pretty sure you're not wearing the masks tight enough. Here are example photos from people who spend a day in PPE: https://twitter.com/LondonNurse2015/status/1247275055987425289 https://twitter.com/LondonNurse2015/status/12472750559874252... https://twitter.com/jbon93/status/1247626644208189444 https://twitter.com/jbon93/status/1247626644208189444 https://twitter.com/RochesterKaren/status/1246445956515627009 https://twitter.com/RochesterKaren/status/124644595651562700... https://twitter.com/gabbyjackson95x/status/1247939178962325505 https://twitter.com/gabbyjackson95x/status/12479391789623255...