[M T]

Given how crucial super spreaders are to the spread and speed of the outbreak, ...

A study from China may clarify the nature of the spreading:

Three hundred and eighteen outbreaks with three or more cases were identified, involving 1245 confirmed cases in 120 prefectural cities. We divided the venues in which the outbreaks occurred into six categories: homes, transport, food, entertainment, shopping, and miscellaneous. Among the identified outbreaks, 53.8% involved three cases, 26.4% involved four cases, and only 1.6% involved ten or more cases. Home outbreaks were the dominant category (254 of 318 outbreaks; 79.9%), followed by transport (108; 34.0%; note that many outbreaks involved more than one venue category). Most home outbreaks involved three to five cases. We identified only a single outbreak in an outdoor environment, which involved two cases.



Most of the 254 home outbreaks included three to five cases (145 with three cases, 66 with four cases, and 25 with five cases). The average number of cases was 3·7 for the home outbreaks, 3·8 for transport, 4·9 for food venues, 3·6 for entertainment venues, 8·7 for shopping venues, and 4·4 for miscellaneous venues. The proportion of large outbreaks was high for shops and food venues, possibly because more susceptible individuals were present



The emergence of homes as the most common COVID-19 outbreak venue in China is not surprising. During the COVID-19 epidemic in mainland China, homes became temporary quarantine places. Our estimated home dominance of 79·9% is close to the official estimate of 83% of the so-called household clusters among the nearly 1000 clusters (not outbreaks) defined by the China National Health Commission. . . . Most Chinese families have one child, and some families may also include grandparents. The relatively low number of cases in these home outbreaks might be considered an advantage of compulsory home quarantine because transmission was limited to the small number of family members.



The second salient feature of the 318 identified outbreaks is the relatively small number of outbreaks that involved 10 or more cases. The largest outbreak occurred in a Tianjin shopping mall and involved 21 cases, although Wu et al.5 reported that 25 cases were involved.



The occurrence of many small outbreaks (in number of cases) in the COVID-19 pandemic suggests a different transmission pattern from that of the 2003 SARS-CoV epidemic. Some virus, epidemiological, and environmental factors could have contributed to this observed difference between the 2003 SARS-CoV epidemic and the current COVID-19 pandemic.

 

This study has limitations. We only studied outbreaks in China, where very strict intervention measures were implemented. . . .

The report raises issues about the state of ventilation within Chinese buildings & homes (characterized as poor).



I believe super spreading (and, indeed, R0) is more about society than the disease.   Super spreading is the reason that the (10+, 25+, 200+, 1000+, 5000+, 50,000+) gatherings are going to be a problem as long as many people do not have the disease, but some do.  Such events (from birthday parties to football practices to crowds for athletic events) are bound to be super spreading events.





I'd love to be wrong, but all the opening up, especially before large areas (20M or so in SoCal) have even stabilized, is likely going to be costly.

(The yearly death count for LA County 2015-2017 was just under 63,000.  The most recent 2 week COVID death toll in L.A. County was 532.  Annualized, that is 13,870 COVID deaths, or 22% of the normal total.)

[M T]

Given how crucial super spreaders are to the spread and speed of the outbreak, ...

A study from China may clarify the nature of the spreading:

Three hundred and eighteen outbreaks with three or more cases were identified, involving 1245 confirmed cases in 120 prefectural cities. We divided the venues in which the outbreaks occurred into six categories: homes, transport, food, entertainment, shopping, and miscellaneous. Among the identified outbreaks, 53.8% involved three cases, 26.4% involved four cases, and only 1.6% involved ten or more cases. Home outbreaks were the dominant category (254 of 318 outbreaks; 79.9%), followed by transport (108; 34.0%; note that many outbreaks involved more than one venue category). Most home outbreaks involved three to five cases. We identified only a single outbreak in an outdoor environment, which involved two cases.



Most of the 254 home outbreaks included three to five cases (145 with three cases, 66 with four cases, and 25 with five cases). The average number of cases was 3·7 for the home outbreaks, 3·8 for transport, 4·9 for food venues, 3·6 for entertainment venues, 8·7 for shopping venues, and 4·4 for miscellaneous venues. The proportion of large outbreaks was high for shops and food venues, possibly because more susceptible individuals were present



The emergence of homes as the most common COVID-19 outbreak venue in China is not surprising. During the COVID-19 epidemic in mainland China, homes became temporary quarantine places. Our estimated home dominance of 79·9% is close to the official estimate of 83% of the so-called household clusters among the nearly 1000 clusters (not outbreaks) defined by the China National Health Commission. . . . Most Chinese families have one child, and some families may also include grandparents. The relatively low number of cases in these home outbreaks might be considered an advantage of compulsory home quarantine because transmission was limited to the small number of family members.



The second salient feature of the 318 identified outbreaks is the relatively small number of outbreaks that involved 10 or more cases. The largest outbreak occurred in a Tianjin shopping mall and involved 21 cases, although Wu et al.5 reported that 25 cases were involved.



The occurrence of many small outbreaks (in number of cases) in the COVID-19 pandemic suggests a different transmission pattern from that of the 2003 SARS-CoV epidemic. Some virus, epidemiological, and environmental factors could have contributed to this observed difference between the 2003 SARS-CoV epidemic and the current COVID-19 pandemic.

 

This study has limitations. We only studied outbreaks in China, where very strict intervention measures were implemented. . . .

The report raises issues about the state of ventilation within Chinese buildings & homes (characterized as poor).



I believe super spreading (and, indeed, R0) is more about society than the disease.   Super spreading is the reason that the (10+, 25+, 200+, 1000+, 5000+, 50,000+) gatherings are going to be a problem as long as many people do not have the disease, but some do.  Such events (from birthday parties to football practices to crowds for athletic events) are bound to be super spreading events.





I'd love to be wrong, but all the opening up, especially before large areas (20M or so in SoCal) have even stabilized, is likely going to be costly.

(The yearly death count for LA County 2015-2017 was just under 63,000.  The most recent 2 week COVID death toll in L.A. County was 532.  Annualized, that is 13,870 COVID deaths, or 22% of the normal total.)

[M T]

Ineffective at preventing the wearer from acquiring the disease. Which they are. But they're apparently pretty effective at preventing the wearer from spreading the disease.

Stupac, can you point me to data that supports the view that masks are effective at preventing the wearer from spreading the disease?  The studies I mostly see are of whether mask wearers get ill.  There is an Australian  study of household use of masks after an influenza case in the household, that showed effectiveness against spread where both the ill and healthy wore masks (or, rather, it showed that IF they actually wore the masks).

I would NOT say that masks are ineffective at preventing the wearer from acquiring the disease.  The studies that I've seen are mostly among healthcare workers, but those workers are usually using other factors (PPE, or behavioral differences) when they wore masks than when not.  I think it was BC that pointed to such a study on the Cardboard in the last week.  When they wore masks (and whatever else they may have done when they took that precaution), they had fewer infections.

We will probably soon see at least anecdotal evidence from superspreading events where the people were exposed, some who were wearing masks and some who weren't.  Some of those experiments have unfortunately been conducted over the past week.  But, even with that data, it would be hard to ascertain whether a person who was infectious and wearing a mask prevented the spread to others.

[M T]

Ineffective at preventing the wearer from acquiring the disease. Which they are. But they're apparently pretty effective at preventing the wearer from spreading the disease.

Stupac, can you point me to data that supports the view that masks are effective at preventing the wearer from spreading the disease?  The studies I mostly see are of whether mask wearers get ill.  There is an Australian  study of household use of masks after an influenza case in the household, that showed effectiveness against spread where both the ill and healthy wore masks (or, rather, it showed that IF they actually wore the masks).

I would NOT say that masks are ineffective at preventing the wearer from acquiring the disease.  The studies that I've seen are mostly among healthcare workers, but those workers are usually using other factors (PPE, or behavioral differences) when they wore masks than when not.  I think it was BC that pointed to such a study on the Cardboard in the last week.  When they wore masks (and whatever else they may have done when they took that precaution), they had fewer infections.

We will probably soon see at least anecdotal evidence from superspreading events where the people were exposed, some who were wearing masks and some who weren't.  Some of those experiments have unfortunately been conducted over the past week.  But, even with that data, it would be hard to ascertain whether a person who was infectious and wearing a mask prevented the spread to others.

[OutsiderFan]

I’m as appreciative about data as anyone, but where the hell is common sense and reasoning? If everyone is so obsessed with data that they want to argue everything and not act unless there is data to support it, Rome still burns. Mask wearing is not like a drug trial. There literally is no risk to wearing one, so why not wear one?

I’ve said it before, I’ll say it again. Having something over your mouth and nose is going to reduce what can come out of it vs. nothing at all. Keeping physical distance between people is going to reduce the chances of whatever does come out from reaching others. You don’t need fancy studies to be done for the logic of this to resonate.

Yes, the ‘don’t tread on me” mentality has absolutely led to spread. Claiming New York doesn’t have that, but look at their numbers, as an example, is misguided, because New York didn’t resist wearing masks and stayed in lock down with great discipline. Now look at New York’s cases declining. Compare to states like Texas, Florida, Georgia, Arizona. Those states have large populations who didn’t take precautions because they see mask wearing as a political issue. I have friends who have told me this. So just because we don’t see mask wearing and distancing as a political issue, some absolutely do.

I don’t need data about mask and distance efficacy specifically, to tell me if everyone wore a mask and kept distance that the U.S. numbers would be lower and declining across the board. It’s just common sense. For those same reasons, the protests, even though most people are wearing masks and outside, are logically going to produce more infections that would not have existed otherwise. Most of those protestors were demonstrating the same “don’t tread on me” attitude by ignoring curfews and not keeping distance. The only hope we can have is the places that had protests were on the decline with their outbreak and there wasn’t much virus to spread. But the fact they went on for days isn’t comforting.

However, if we don’t see spikes in new cases within a week or two in the cities that had protests, it would seem we’d have enough anecdotal data to show outdoor sports can have crowds or maybe reduced crowds with distancing without much concern, if everyone in stadiums wears a mask.

[OutsiderFan]

I’m as appreciative about data as anyone, but where the hell is common sense and reasoning? If everyone is so obsessed with data that they want to argue everything and not act unless there is data to support it, Rome still burns. Mask wearing is not like a drug trial. There literally is no risk to wearing one, so why not wear one?

I’ve said it before, I’ll say it again. Having something over your mouth and nose is going to reduce what can come out of it vs. nothing at all. Keeping physical distance between people is going to reduce the chances of whatever does come out from reaching others. You don’t need fancy studies to be done for the logic of this to resonate.

Yes, the ‘don’t tread on me” mentality has absolutely led to spread. Claiming New York doesn’t have that, but look at their numbers, as an example, is misguided, because New York didn’t resist wearing masks and stayed in lock down with great discipline. Now look at New York’s cases declining. Compare to states like Texas, Florida, Georgia, Arizona. Those states have large populations who didn’t take precautions because they see mask wearing as a political issue. I have friends who have told me this. So just because we don’t see mask wearing and distancing as a political issue, some absolutely do.

I don’t need data about mask and distance efficacy specifically, to tell me if everyone wore a mask and kept distance that the U.S. numbers would be lower and declining across the board. It’s just common sense. For those same reasons, the protests, even though most people are wearing masks and outside, are logically going to produce more infections that would not have existed otherwise. Most of those protestors were demonstrating the same “don’t tread on me” attitude by ignoring curfews and not keeping distance. The only hope we can have is the places that had protests were on the decline with their outbreak and there wasn’t much virus to spread. But the fact they went on for days isn’t comforting.

However, if we don’t see spikes in new cases within a week or two in the cities that had protests, it would seem we’d have enough anecdotal data to show outdoor sports can have crowds or maybe reduced crowds with distancing without much concern, if everyone in stadiums wears a mask.

[OutsiderFan]

Here's someone who has some Earthly idea about the impact protests will have.  But make sure to see the video of a Las Vegas casino in that thread. Hardly anyone wearing a mask and no effort at all to promote distancing. Looks like a disaster in the making to me. One, L.A. County has high numbers and many people from L.A. go to Vegas. Two, people come from all over the country and world to go to Vegas, and stay inside with others most of the time there. but there is a lot of outdoor crowding in pools too. Continued evidence of why the U.S. was always going to be hit hardest by this pandemic.  There are just too many jurisdictions, no federal leadership, and too many "I'll do want I want" attitudes among the people.

[tweet]https://twitter.com/trvrb/status/1269395236490326016[/tweet]

[OutsiderFan]

Here's someone who has some Earthly idea about the impact protests will have.  But make sure to see the video of a Las Vegas casino in that thread. Hardly anyone wearing a mask and no effort at all to promote distancing. Looks like a disaster in the making to me. One, L.A. County has high numbers and many people from L.A. go to Vegas. Two, people come from all over the country and world to go to Vegas, and stay inside with others most of the time there. but there is a lot of outdoor crowding in pools too. Continued evidence of why the U.S. was always going to be hit hardest by this pandemic.  There are just too many jurisdictions, no federal leadership, and too many "I'll do want I want" attitudes among the people.

[tweet]https://twitter.com/trvrb/status/1269395236490326016[/tweet]

[BobK]

I’m fine. Don’t go out much grocery store almost the only place.
But at the store less than half wear masks. Thankfully going early means few people.

I always wear a mask.

The Area congressman is still in denial on the virus and his “leadership “ gives entitlement to freedom now thus no masks.

Now the fact more people are being tested certainly results in more positive cases

[BobK]

I’m fine. Don’t go out much grocery store almost the only place.
But at the store less than half wear masks. Thankfully going early means few people.

I always wear a mask.

The Area congressman is still in denial on the virus and his “leadership “ gives entitlement to freedom now thus no masks.

Now the fact more people are being tested certainly results in more positive cases

[BostonCard]

Yes, the ‘don’t tread on me” mentality has absolutely led to spread. Claiming New York doesn’t have that, but look at their numbers, as an example, is misguided, because New York didn’t resist wearing masks and stayed in lock down with great discipline. Now look at New York’s cases declining. Compare to states like Texas, Florida, Georgia, Arizona. Those states have large populations who didn’t take precautions because they see mask wearing as a political issue. I have friends who have told me this. So just because we don’t see mask wearing and distancing as a political issue, some absolutely do.

The data says otherwise.  Weekly deaths in those states have been flat since April with the possible exception of Arizona, and even there, deaths peaked three weeks ago.  There was a small jump in deaths last week, but even then, it didn't reach previous highs.  California, has broadly the same pattern.



And mind you, per capita none of these states have particularly high death rates per million inhabitants (Arizona at 143, Florida at 126, Georgia at 205, Texas at 64) are all below the US average, and are comparable to California 118 per million.  I don't dispute that some people don't see mask wearing and social distancing as a political issue; the thing is, it doesn't seem to translate to a growing death rate from COVID-19 so far.  Maybe if there is a fall return, those states will be hit much harder, but right now there is no evidence that a "don't tread on me" attitude is leading to more people dying from COVID-19.

I don’t need data about mask and distance efficacy specifically, to tell me if everyone wore a mask and kept distance that the U.S. numbers would be lower and declining across the board. It’s just common sense.

While I think there is enough data to support the use of masks, I vehemently disagree with your attitude about it.  The medical literature is filled with things that were self-evidently obvious to the point where high profile scientists said it would be unethical to test in a randomized, controlled study, until someone tested it in a randomized, controlled study and showed that what we thought ain't so.  Now, I don't disagree with your conclusion.  I do think masks work, and I think there is enough evidence to support their use (especially because the risk and cost is pretty negligible).  I posted a meta analysis that suggested masks, as well as physical distance, could reduce transmissions substantially.  There was also this study, using hamsters, from Hong Kong:

https://afludiary.blogspot.com/2020/05/h...study.html

• When naive (unifected) hamsters were exposed to the air flow from an infected hamster's cage, 66% (10 of 15) became infected with COVID-19 after a 7 day exposure.
  

• When a surgical mask was place at the inlet of the naive hamster's cage, 4 or 12 (33.3%) were infected. [p = 0.18]
  
• When a surgical mask was placed at the outlet of the infected hamster's cage, that number dropped to just 16.6% (2 of 12). [p = .027]
  

Though formally, if you adjust for multiple hypothesis, the experiment should be considered non-significant.  My problem is not your conclusion; it's your process for getting there.  Because just as you might say "I don't need any data to conclude that masks work..." plenty of people will say "I don't need any data to conclude that masks don't work..."


BC

[BostonCard]

Yes, the ‘don’t tread on me” mentality has absolutely led to spread. Claiming New York doesn’t have that, but look at their numbers, as an example, is misguided, because New York didn’t resist wearing masks and stayed in lock down with great discipline. Now look at New York’s cases declining. Compare to states like Texas, Florida, Georgia, Arizona. Those states have large populations who didn’t take precautions because they see mask wearing as a political issue. I have friends who have told me this. So just because we don’t see mask wearing and distancing as a political issue, some absolutely do.

The data says otherwise.  Weekly deaths in those states have been flat since April with the possible exception of Arizona, and even there, deaths peaked three weeks ago.  There was a small jump in deaths last week, but even then, it didn't reach previous highs.  California, has broadly the same pattern.



And mind you, per capita none of these states have particularly high death rates per million inhabitants (Arizona at 143, Florida at 126, Georgia at 205, Texas at 64) are all below the US average, and are comparable to California 118 per million.  I don't dispute that some people don't see mask wearing and social distancing as a political issue; the thing is, it doesn't seem to translate to a growing death rate from COVID-19 so far.  Maybe if there is a fall return, those states will be hit much harder, but right now there is no evidence that a "don't tread on me" attitude is leading to more people dying from COVID-19.

I don’t need data about mask and distance efficacy specifically, to tell me if everyone wore a mask and kept distance that the U.S. numbers would be lower and declining across the board. It’s just common sense.

While I think there is enough data to support the use of masks, I vehemently disagree with your attitude about it.  The medical literature is filled with things that were self-evidently obvious to the point where high profile scientists said it would be unethical to test in a randomized, controlled study, until someone tested it in a randomized, controlled study and showed that what we thought ain't so.  Now, I don't disagree with your conclusion.  I do think masks work, and I think there is enough evidence to support their use (especially because the risk and cost is pretty negligible).  I posted a meta analysis that suggested masks, as well as physical distance, could reduce transmissions substantially.  There was also this study, using hamsters, from Hong Kong:

https://afludiary.blogspot.com/2020/05/h...study.html

• When naive (unifected) hamsters were exposed to the air flow from an infected hamster's cage, 66% (10 of 15) became infected with COVID-19 after a 7 day exposure.
  

• When a surgical mask was place at the inlet of the naive hamster's cage, 4 or 12 (33.3%) were infected. [p = 0.18]
  
• When a surgical mask was placed at the outlet of the infected hamster's cage, that number dropped to just 16.6% (2 of 12). [p = .027]
  

Though formally, if you adjust for multiple hypothesis, the experiment should be considered non-significant.  My problem is not your conclusion; it's your process for getting there.  Because just as you might say "I don't need any data to conclude that masks work..." plenty of people will say "I don't need any data to conclude that masks don't work..."


BC

[oldalum]

I always wear a mask.  

I hope it's an N95 mask: that will protect you better than a cloth mask. They are available now to the public (e.g., Ace Hardware has had them in stock for weeks, limit 2 per customer).

[oldalum]

I always wear a mask.  

I hope it's an N95 mask: that will protect you better than a cloth mask. They are available now to the public (e.g., Ace Hardware has had them in stock for weeks, limit 2 per customer).

[burger]

Yes, the ‘don’t tread on me” mentality has absolutely led to spread. Claiming New York doesn’t have that, but look at their numbers, as an example, is misguided, because New York didn’t resist wearing masks and stayed in lock down with great discipline. Now look at New York’s cases declining. Compare to states like Texas, Florida, Georgia, Arizona. Those states have large populations who didn’t take precautions because they see mask wearing as a political issue. I have friends who have told me this. So just because we don’t see mask wearing and distancing as a political issue, some absolutely do.

The data says otherwise.  Weekly deaths in those states have been flat since April with the possible exception of Arizona, and even there, deaths peaked three weeks ago.  There was a small jump in deaths last week, but even then, it didn't reach previous highs.  California, has broadly the same pattern.

BC, I think you're missing the point.  First, increases in deaths in multiple states is worrisome in itself.  Second, many states (and some entire regions: https://twitter.com/COVID19Tracking/stat...36/photo/1) are showing increases in cases and/or positive rates from tests.  That's even scarier.  If the increase in case numbers is real, deaths will take a few weeks to catch up.

There is plenty of reason to be concerned that things are getting worse now.  If we are at the beginning of another cycle of rapid spread, we'd expect the numbers to still be relatively low and for there to be some noise.  So, nothing is certain yet.  But if these trends continue, then we're in trouble.

[burger]

Yes, the ‘don’t tread on me” mentality has absolutely led to spread. Claiming New York doesn’t have that, but look at their numbers, as an example, is misguided, because New York didn’t resist wearing masks and stayed in lock down with great discipline. Now look at New York’s cases declining. Compare to states like Texas, Florida, Georgia, Arizona. Those states have large populations who didn’t take precautions because they see mask wearing as a political issue. I have friends who have told me this. So just because we don’t see mask wearing and distancing as a political issue, some absolutely do.

The data says otherwise.  Weekly deaths in those states have been flat since April with the possible exception of Arizona, and even there, deaths peaked three weeks ago.  There was a small jump in deaths last week, but even then, it didn't reach previous highs.  California, has broadly the same pattern.

BC, I think you're missing the point.  First, increases in deaths in multiple states is worrisome in itself.  Second, many states (and some entire regions: https://twitter.com/COVID19Tracking/stat...36/photo/1) are showing increases in cases and/or positive rates from tests.  That's even scarier.  If the increase in case numbers is real, deaths will take a few weeks to catch up.

There is plenty of reason to be concerned that things are getting worse now.  If we are at the beginning of another cycle of rapid spread, we'd expect the numbers to still be relatively low and for there to be some noise.  So, nothing is certain yet.  But if these trends continue, then we're in trouble.

[magnus]

I always wear a mask.  

I hope it's an N95 mask: that will protect you better than a cloth mask. They are available now to the public (e.g., Ace Hardware has had them in stock for weeks, limit 2 per customer).

Are these KN95 or N95?  I am hearing that N95s are the preferred (allowed?) version to use in hospitals but I don't know the exact reason (KN95s are from China, so quality control may be a part of it)

[magnus]

I always wear a mask.  

I hope it's an N95 mask: that will protect you better than a cloth mask. They are available now to the public (e.g., Ace Hardware has had them in stock for weeks, limit 2 per customer).

Are these KN95 or N95?  I am hearing that N95s are the preferred (allowed?) version to use in hospitals but I don't know the exact reason (KN95s are from China, so quality control may be a part of it)

[M T]

I always wear a mask.  

I hope it's an N95 mask: that will protect you better than a cloth mask. They are available now to the public (e.g., Ace Hardware has had them in stock for weeks, limit 2 per customer).

Are these KN95 or N95?  I am hearing that N95s are the preferred (allowed?) version to use in hospitals but I don't know the exact reason (KN95s are from China, so quality control may be a part of it)

Oldalum, thanks for the pointer.  I had heard masks were becoming available but I hadn't chased it down.  I have two (K?)N95 with exhaust valves from the time of the smoky fires that I've been saving in case I had to go somewhere risky.  (These aren't considered adequate face coverings in San Mateo county, so I would wear a second mask on top of them.)

There's not much difference between N95 and KN95.  (In the two places I looked, neither mentioned quality control as an issue.)

See this comparison.  N95 masks have slightly less resistance to inhalation and exhalation.  KN95s are fit tested by the manufacturer on people to have a maximum about of leakage.  (I believe in the US, (some?) healthcare workers are required to be fitted for their N95 masks, but I don't know the details.)

Ace Hardware's web site lists 3 types of such masks:
1.  Available for pickup (tomorrow at my store) or ship or delivery:  World Tech's KN95 Face Mask features a BFE (Bacteria Filtration Efficiency) and PFE (Particle Filtration Efficiency) of 95%, ensuring a high level of protection.

• = 95% Filter performance
  
• 85 L/min flow rate
  
• = 8% inward leakage
  
• = 350 Pa Inhalation resistance - max pressure drop
  
• = 250 Pa Exhalation resistance - max pressure drop
  

EDIT: I believe this mask is distributed by World Tech Toys out of Valencia. They have a rating of F by the BBB. Their web page seems to have no association of medical supplies.

2. Available for pickup (in a few days at my store) or ship or delivery:   Annie Sterile K95
The KN95 is a standard for respiratory equipment which filters 95% of particulates greater than 0.3 microns. KN95 masks are a PPE. They offer significant protection over standard surgical blue 3 ply masks and are approved by the CDC as acceptable replacements if N95 masks are unavailable.

• 3D perfect fit technology
  
• Moldable nosepiece
  
• Easy breathing
  
• 5 Layers of protection
  

(See www.annieinc.com, a US company that supplies both N95 and KN95 wholesale.)

3. Unavailable:  3M N95 Sanding and Fiberglass Cup Disposable Respirator White  (3M 8200HA1, no valve)

Of the two available, the Annie Inc mask has more complete information (pictures of packing where you can read the instructions, description of each of the 5 layers).
Both cost between $8.50 and $9 for a pair of masks

[M T]

I always wear a mask.  

I hope it's an N95 mask: that will protect you better than a cloth mask. They are available now to the public (e.g., Ace Hardware has had them in stock for weeks, limit 2 per customer).

Are these KN95 or N95?  I am hearing that N95s are the preferred (allowed?) version to use in hospitals but I don't know the exact reason (KN95s are from China, so quality control may be a part of it)

Oldalum, thanks for the pointer.  I had heard masks were becoming available but I hadn't chased it down.  I have two (K?)N95 with exhaust valves from the time of the smoky fires that I've been saving in case I had to go somewhere risky.  (These aren't considered adequate face coverings in San Mateo county, so I would wear a second mask on top of them.)

There's not much difference between N95 and KN95.  (In the two places I looked, neither mentioned quality control as an issue.)

See this comparison.  N95 masks have slightly less resistance to inhalation and exhalation.  KN95s are fit tested by the manufacturer on people to have a maximum about of leakage.  (I believe in the US, (some?) healthcare workers are required to be fitted for their N95 masks, but I don't know the details.)

Ace Hardware's web site lists 3 types of such masks:
1.  Available for pickup (tomorrow at my store) or ship or delivery:  World Tech's KN95 Face Mask features a BFE (Bacteria Filtration Efficiency) and PFE (Particle Filtration Efficiency) of 95%, ensuring a high level of protection.

• = 95% Filter performance
  
• 85 L/min flow rate
  
• = 8% inward leakage
  
• = 350 Pa Inhalation resistance - max pressure drop
  
• = 250 Pa Exhalation resistance - max pressure drop
  

EDIT: I believe this mask is distributed by World Tech Toys out of Valencia. They have a rating of F by the BBB. Their web page seems to have no association of medical supplies.

2. Available for pickup (in a few days at my store) or ship or delivery:   Annie Sterile K95
The KN95 is a standard for respiratory equipment which filters 95% of particulates greater than 0.3 microns. KN95 masks are a PPE. They offer significant protection over standard surgical blue 3 ply masks and are approved by the CDC as acceptable replacements if N95 masks are unavailable.

• 3D perfect fit technology
  
• Moldable nosepiece
  
• Easy breathing
  
• 5 Layers of protection
  

(See www.annieinc.com, a US company that supplies both N95 and KN95 wholesale.)

3. Unavailable:  3M N95 Sanding and Fiberglass Cup Disposable Respirator White  (3M 8200HA1, no valve)

Of the two available, the Annie Inc mask has more complete information (pictures of packing where you can read the instructions, description of each of the 5 layers).
Both cost between $8.50 and $9 for a pair of masks

[Snorlax94]

Are these KN95 or N95?  I am hearing that N95s are the preferred (allowed?) version to use in hospitals but I don't know the exact reason (KN95s are from China, so quality control may be a part of it)

I would clarify KN95 are the Chinese-version, pretty much all the masks are "from China." 

This article discusses how the FDA banned some KN95 masks that failed FDA tests:
https://www.dentalproductsreport.com/den...ed-testing

Here is the list of FDA-approved N95 and KN95 masks:
https://www.fda.gov/media/136663/download

Here is a list of FDA (known) manufacturers that are NOT aproved:
https://www.fda.gov/media/137928/download

And a reminder that masks with a little plastic respirator valve are not encouraged in public settings -- they protect the wearer but enable the wearer to easily breathe out virus. I have a few of these from previous years (due to forest fire concerns) and the recommendation is to wear a surgical mask over the valve to protect others.

[Snorlax94]

Are these KN95 or N95?  I am hearing that N95s are the preferred (allowed?) version to use in hospitals but I don't know the exact reason (KN95s are from China, so quality control may be a part of it)

I would clarify KN95 are the Chinese-version, pretty much all the masks are "from China." 

This article discusses how the FDA banned some KN95 masks that failed FDA tests:
https://www.dentalproductsreport.com/den...ed-testing

Here is the list of FDA-approved N95 and KN95 masks:
https://www.fda.gov/media/136663/download

Here is a list of FDA (known) manufacturers that are NOT aproved:
https://www.fda.gov/media/137928/download

And a reminder that masks with a little plastic respirator valve are not encouraged in public settings -- they protect the wearer but enable the wearer to easily breathe out virus. I have a few of these from previous years (due to forest fire concerns) and the recommendation is to wear a surgical mask over the valve to protect others.

[BostonCard]

Here you go:

https://smartairfilters.com/en/blog/what...n95-masks/

N95s and KN95s are both rated to capture 95% of particles. Among the minor differences, only KN95 masks are required to pass fit tests, while N95 masks have slightly stronger breathability standards.

BC

[BostonCard]

Here you go:

https://smartairfilters.com/en/blog/what...n95-masks/

N95s and KN95s are both rated to capture 95% of particles. Among the minor differences, only KN95 masks are required to pass fit tests, while N95 masks have slightly stronger breathability standards.

BC

[BobK]

N 95 mask. Bought about FEB 20. Box of 10 for family. Just in case

[BobK]

N 95 mask. Bought about FEB 20. Box of 10 for family. Just in case

[oldalum]

Ace Hardware's web site lists 3 types of such masks

2. Available for pickup (in a few days at my store) or ship or delivery:   Annie Sterile K95

I have the Annie Inc. ones. I called Annie Inc., which is just a distributor, and asked which manufacturer in China made these masks. They refused to say. I've emailed ACE Hardware to see if they know (seems like they should!).

[oldalum]

Ace Hardware's web site lists 3 types of such masks

2. Available for pickup (in a few days at my store) or ship or delivery:   Annie Sterile K95

I have the Annie Inc. ones. I called Annie Inc., which is just a distributor, and asked which manufacturer in China made these masks. They refused to say. I've emailed ACE Hardware to see if they know (seems like they should!).

[M T]

Ace Hardware's web site lists 3 types of such masks

2. Available for pickup (in a few days at my store) or ship or delivery:   Annie Sterile K95

I have the Annie Inc. ones. I called Annie Inc., which is just a distributor, and asked which manufacturer in China made these masks. They refused to say. I've emailed ACE Hardware to see if they know (seems like they should!).

I bought some  (4 packs of 2 masks each).  There is no marking that I can find that indicates the manufacturer.  I compared the masks to all those tested by the CDC recently, but none are perfect matches.  Those that look VERY close to the mask are in the table below, but none of those indicate they are 5-ply. (Not all 5-ply have a minimum filtration efficiency above 95%.)

I took one pair out of the distributor's packaging.  I noticed that one of the masks was miss-struck by the press(?) that made the outer seam (against the face).  There is supposed to be two rows of weld dots, but only one dot is on the mask for about half the seam.  I judge that mask as likely to fail.

Annie International Inc's development of the face mask line is described in this article.  I note that it talks about "beginning" the process to get NIOSH certification, and about the need to streamline that process, but it never says the certification has been achieved.  (The product I received does not indicate any certification.)

Manufacturer	Product	Max %	Min %
Dongguan Xianda Medical Equipment Co., Ltd.	KN95 Protective Mask	35.0	24.10
Dongguan Sengtor Plastics Products Co., Ltd.	KN95 Foldable Protective Earloop Mask	99.94	98.43
FuJian Pageone Garments Co., Ltd.	KN95 Protective Mask	99.80	98.75
Guangdong Nuokang Medical Technology Co., Ltd.	KN95 Particulate Protective Mask	98.22	91.33
Guangdong Nuokang Medical Technology Co., Ltd.	KN95 Non-Surgical Disposable Particulate FFR	97.72	95.13
COUNTERFEIT Dongguan Sengtor Plastics Products Co., Ltd.	Foldable Protective Earloop Mask (Non-Medical)	70.80	59.10
COUNTERFEIT Shenzhen Hangsen Star Technology Co., Ltd.	Alchemy KN95 Face Mask A1	92.77	56.00

[M T]

Ace Hardware's web site lists 3 types of such masks

2. Available for pickup (in a few days at my store) or ship or delivery:   Annie Sterile K95

I have the Annie Inc. ones. I called Annie Inc., which is just a distributor, and asked which manufacturer in China made these masks. They refused to say. I've emailed ACE Hardware to see if they know (seems like they should!).

I bought some  (4 packs of 2 masks each).  There is no marking that I can find that indicates the manufacturer.  I compared the masks to all those tested by the CDC recently, but none are perfect matches.  Those that look VERY close to the mask are in the table below, but none of those indicate they are 5-ply. (Not all 5-ply have a minimum filtration efficiency above 95%.)

I took one pair out of the distributor's packaging.  I noticed that one of the masks was miss-struck by the press(?) that made the outer seam (against the face).  There is supposed to be two rows of weld dots, but only one dot is on the mask for about half the seam.  I judge that mask as likely to fail.

Annie International Inc's development of the face mask line is described in this article.  I note that it talks about "beginning" the process to get NIOSH certification, and about the need to streamline that process, but it never says the certification has been achieved.  (The product I received does not indicate any certification.)

Manufacturer	Product	Max %	Min %
Dongguan Xianda Medical Equipment Co., Ltd.	KN95 Protective Mask	35.0	24.10
Dongguan Sengtor Plastics Products Co., Ltd.	KN95 Foldable Protective Earloop Mask	99.94	98.43
FuJian Pageone Garments Co., Ltd.	KN95 Protective Mask	99.80	98.75
Guangdong Nuokang Medical Technology Co., Ltd.	KN95 Particulate Protective Mask	98.22	91.33
Guangdong Nuokang Medical Technology Co., Ltd.	KN95 Non-Surgical Disposable Particulate FFR	97.72	95.13
COUNTERFEIT Dongguan Sengtor Plastics Products Co., Ltd.	Foldable Protective Earloop Mask (Non-Medical)	70.80	59.10
COUNTERFEIT Shenzhen Hangsen Star Technology Co., Ltd.	Alchemy KN95 Face Mask A1	92.77	56.00