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This is horrendously incorrect. Surgical masks do not filter aerosolized particles at the same effiency as an N95. For an airborn virus, that's a pretty big dea

This is horrendously incorrect. Surgical masks do not filter aerosolized particles at the same effiency as an N95. For an airborn virus, that's a pretty big deal, especially for HCP who are constantly exposed to high viral loads.

kleiba 6y ago
Two opposing opinions. Are there relevant references to support one side or the other?
- hogFeast 6y ago
  Yes, the fact that the masks in questions are (it would appear) not certified as N95.
- sgc 6y ago
  Sure, one is certified by a professional body (NIOSH etc) and the other is not. Since it's not, the burden of proof in this case is one sided. For example: "Surgical N95 respirators are approved by NIOSH as to their respiratory protection efficiency and resistance and other NIOSH requirements. They are also separately cleared by FDA as medical devices. FDA clears surgical masks for sale in the United States but does not test and certify the respirator."
  - asdfasgasdgasdg 6y ago
    I think they have accepted that burden of proof? They are trying to go through the cdc testing process with their brace, according to the FAQ.
    - rovr138 6y ago
      What I would appreciate is more information on this part from them. What have they done? What testing? How are they measuring particles? What’s the process and what stage are they on? If they provided more information/transparency the conversation would be VERY different (if the numbers where close to n95 at least)
asdfasgasdgasdg 6y ago
When worn normally, or when well sealed? Are there tests of this? If they are both melt blown fabric then it seems at least plausible that this thing could work. It should be tested of course, but it seems like they are in the process of doing that.
- Aeolun 6y ago
  It seems to me the structure is a bit different. Much more material for the N95 rated ones. Though to be fair, my reusable KN95 (claimed), from China is just as thin as a surgical mask.
  - asdfasgasdgasdg 6y ago
    Tbh I don't know anything about it. Their blog post seems technical and well-thought out. They aren't offering these things for sale at $50 a pop, so they're not trying to gouge the public. They are going through the necessary testing. It doesn't seem like an effort that can be slapped down with internet comment outrage.
- ntenenz 6y ago
  http://aaqr.org/files/article/668/36_AAQR-13-06-OA-0201_991-1002.pdf http://aaqr.org/files/article/668/36_AAQR-13-06-OA-0201_991-...
  - asdfasgasdgasdg 6y ago
    Thanks. For those not following the link, this study shows that NaCl aerosols penetrate measured surgical masks at a much higher rate than n95 masks, even after creating a firm seal.
  - tssva 6y ago
    It is hard to tell what exactly was tested in this study. It mentions the standards which the tested respirators met but there is no mention of any standards regarding the tested surgical masks. Were they surgical masks that met the ASTM standards for surgical masks? If so the level 1, 2 or 3 standards? The solution Save The Face Mask proposes is designed to work with surgical masks which meet ASTM standards. Given the lack of information regarding the masks tested the quoted study is fairly useless in evaluating the proposed solution.
dragonwriter 6y ago
> Surgical masks do not filter aerosolized particles at the same effiency as an N95. For an airborn virus, that's a pretty big deal, Last I heard, COVID-19 transmission by aerosols vs. droplets was controversial, and only droplet rather than airborne precautions are generally seen as necessary for it. Also, a big reason (but, yes, not the only one) that surgical masks are less effective against aerosols is that they don't tightly seal, so the most effective part is routinely bypassed by aerosols.
- def8cefe 6y ago
  From my understanding aerosolized transmission is a greater concern in healthcare settings, especially where ventilators are being used.
- DanBC 6y ago
  That's what we thought a month or so ago. The science with SARS-CoV-2 is developing, and currently we think people need to be careful with large and small droplets. Large droplets fall out of the air quickly; small droplets can be blown further. The infectious dose for covid-19 is very small, so getting hit by a few large droplets or more small droplets is about the same. There's no real standard definition for "aerosol" which makes these conversations trickier.

kleiba 6y ago

Two opposing opinions. Are there relevant references to support one side or the other?

hogFeast 6y ago
Yes, the fact that the masks in questions are (it would appear) not certified as N95.
sgc 6y ago
Sure, one is certified by a professional body (NIOSH etc) and the other is not. Since it's not, the burden of proof in this case is one sided. For example: "Surgical N95 respirators are approved by NIOSH as to their respiratory protection efficiency and resistance and other NIOSH requirements. They are also separately cleared by FDA as medical devices. FDA clears surgical masks for sale in the United States but does not test and certify the respirator."
- asdfasgasdgasdg 6y ago
  I think they have accepted that burden of proof? They are trying to go through the cdc testing process with their brace, according to the FAQ.
  - rovr138 6y ago
    What I would appreciate is more information on this part from them. What have they done? What testing? How are they measuring particles? What’s the process and what stage are they on? If they provided more information/transparency the conversation would be VERY different (if the numbers where close to n95 at least)

asdfasgasdgasdg 6y ago

When worn normally, or when well sealed? Are there tests of this? If they are both melt blown fabric then it seems at least plausible that this thing could work. It should be tested of course, but it seems like they are in the process of doing that.

Aeolun 6y ago
It seems to me the structure is a bit different. Much more material for the N95 rated ones. Though to be fair, my reusable KN95 (claimed), from China is just as thin as a surgical mask.
- asdfasgasdgasdg 6y ago
  Tbh I don't know anything about it. Their blog post seems technical and well-thought out. They aren't offering these things for sale at $50 a pop, so they're not trying to gouge the public. They are going through the necessary testing. It doesn't seem like an effort that can be slapped down with internet comment outrage.
ntenenz 6y ago
http://aaqr.org/files/article/668/36_AAQR-13-06-OA-0201_991-1002.pdf http://aaqr.org/files/article/668/36_AAQR-13-06-OA-0201_991-...
- asdfasgasdgasdg 6y ago
  Thanks. For those not following the link, this study shows that NaCl aerosols penetrate measured surgical masks at a much higher rate than n95 masks, even after creating a firm seal.
- tssva 6y ago
  It is hard to tell what exactly was tested in this study. It mentions the standards which the tested respirators met but there is no mention of any standards regarding the tested surgical masks. Were they surgical masks that met the ASTM standards for surgical masks? If so the level 1, 2 or 3 standards? The solution Save The Face Mask proposes is designed to work with surgical masks which meet ASTM standards. Given the lack of information regarding the masks tested the quoted study is fairly useless in evaluating the proposed solution.

dragonwriter 6y ago

> Surgical masks do not filter aerosolized particles at the same effiency as an N95. For an airborn virus, that's a pretty big deal, Last I heard, COVID-19 transmission by aerosols vs. droplets was controversial, and only droplet rather than airborne precautions are generally seen as necessary for it. Also, a big reason (but, yes, not the only one) that surgical masks are less effective against aerosols is that they don't tightly seal, so the most effective part is routinely bypassed by aerosols.

def8cefe 6y ago
From my understanding aerosolized transmission is a greater concern in healthcare settings, especially where ventilators are being used.
DanBC 6y ago
That's what we thought a month or so ago. The science with SARS-CoV-2 is developing, and currently we think people need to be careful with large and small droplets. Large droplets fall out of the air quickly; small droplets can be blown further. The infectious dose for covid-19 is very small, so getting hit by a few large droplets or more small droplets is about the same. There's no real standard definition for "aerosol" which makes these conversations trickier.