COVID-19 - Coronavirus 2019-nCoV

[Mitch f]

6 minutes ago, BilletHead said:

               I opt to be an optimist. Too many pessimists on OAF lately. 

I agree, Just too many obvious and fixable things though. We had it by the short hair for a good while. 

[tjm]

That Murphy feller that made the "law" was an optimist too.

[Al Agnew]

Regarding masks...nope, from everything I've read, they aren't more than about 10% effective in screening out virus particles coming in through breathing.  Somewhat better than that screening out particles breathing out if you're already infected.  Good for keeping you from touching your face, good for slowing the velocity and thus the spread of particles with heavy breathing, talking, even sneezing and coughing.  Velocity and spread is important.  So no, they aren't great protection.  But they do some good.  They lessen the amount of the virus you might get in a single exposure, or that you might give others.  At the same time, they can make things worse if you aren't careful about the way you use them, clean them, etc.

The way I figure it, if you're wearing a mask, it's more likely that you are going to be careful and conscientious about the other things you might be doing to limit exposure to yourself and others.  I feel a lot more comfortable about being around somebody wearing a mask because of that.  And there are a whole lot of people who feel the same way, whether or not it is totally justified.  

[ColdWaterFshr]

2 hours ago, Al Agnew said:

Regarding masks...nope, from everything I've read, they aren't more than about 10% effective in screening out virus particles coming in through breathing.  Somewhat better than that screening out particles breathing out if you're already infected.  Good for keeping you from touching your face, good for slowing the velocity and thus the spread of particles with heavy breathing, talking, even sneezing and coughing.  Velocity and spread is important.  So no, they aren't great protection.  But they do some good.  They lessen the amount of the virus you might get in a single exposure, or that you might give others.  At the same time, they can make things worse if you aren't careful about the way you use them, clean them, etc.

The way I figure it, if you're wearing a mask, it's more likely that you are going to be careful and conscientious about the other things you might be doing to limit exposure to yourself and others.  I feel a lot more comfortable about being around somebody wearing a mask because of that.  And there are a whole lot of people who feel the same way, whether or not it is totally justified.  

Agreed.  Certainly no harm in wearing, and your point about those who do being more conscientious and generally careful, seems likely.  5 years from now we may know differently, but aside from some very minor inconvenience, what is the downside if there is only potential upside?  We need all the upside we can get.  

[ColdWaterFshr]

On 5/14/2020 at 10:26 PM, fishinwrench said:

Well good, we need a badass to come get this here Bar out of the neighborhood!   Preferably before he starts digging up Sugarbritches hostas. 

Paul Dallas can pertect sugarbritches hostas for a fee + uncorked bottle of Old Crow.  First paying job before he went on the bass circuit was to wrassle and shadow box them as a teenager under the big top.  Not skert.

 

[fishinwrench]

38 minutes ago, ColdWaterFshr said:

Paul Dallas can pertect sugarbritches hostas for a fee + uncorked bottle of Old Crow.  First paying job before he went on the bass circuit was to wrassle and shadow box them as a teenager under the big top.  Not skert.

 

Aight, but you might oughta let him know.....this ain't no run o' the mill carnival bear. To get here he had to swat his way through at least a dozen coon hounds, 3 warlock dobermans, and Morrison's stallions.  He's had a steady diet of fireball shooters, and is likely crashing on bathtub methamphetamine.    He isn't out scavenging for burn barrel scraps, he's looking for a fight.  👹

[ColdWaterFshr]

I’ll grant you this spessimen looks large and itching for a fight.  And hopped up on bathtub meth could be problematical.  These better be some special hostas.  You sure it ain’t your Mary Jane patch you been heavily fertiLizing all spring, just like this thread, that has this beasts interest?🤣

[Mitch f]

4 hours ago, Al Agnew said:

Regarding masks...nope, from everything I've read, they aren't more than about 10% effective in screening out virus particles coming in through breathing.  Somewhat better than that screening out particles breathing out if you're already infected.  

Are you talking N95? That’s not what I’ve read.

[bfishn]

i had to learn about N95s when OSHA's new Silica in Construction rule went into effect a couple years ago. For them to perform as specified, there's a lot more to it than just buying and wearing one.

Fit test. A trained & licensed mask tech checks several makes and models of N95 half-masks on the user to find the best fit for that person. The user is given a card to carry showing the make & model number they'll need to use.

Quick user fit test. Once a mask is selected, the user dons one and sharply inhales as much and as quickly as possible. When properly fit, the mask will suck up hard to his face, much like a solid covering would do. The user is instructed to perform this test every time he puts it on or adjusts it to insure its performance. 

Qualitative fit test. Also performed by the mask technician. The user dons and fits his mask, and is instructed to open his mouth and stick out his tongue (inside the mask). The tech then uses a nebulizer containing one of 4 approved test vapors (bitter, sweet, etc) and sprays the test vapor a specified distance from the mask, counting the metered doses until the user reports he can taste it. Each vapor type has a specified number of doses required to be acceptable. This test must be repeated annually.

The user must understand that the mask is a filter, and to be effective, 100% of their breath must pass thru it, with no leaks around the edges. That means facial hair, even a mid-day stubble, is out. 

The above is what a construction worker exposed to respirable, crystalline silica dust is now required to go thru. Keep in mind that silicosis is a cumulative disease that often takes years of exposure to manifest. That bears little resemblance to virus protection, where a single exposure could prove fatal.

The N95 specification requires them to catch at least 95% of respirable particles down to 0.3 microns in size. A naked covid particle (called a virion) can run from 0.06 to 0.14 microns, plenty small enough to penetrate an N95. Fortunately, virus particles of concern (those expelled with an infected person's cough, sneeze or speech) are encapsulated in spit/phlegm/body fluids, increasing their size to above the 0.3 N95 spec. The 95% @ 0.3 spec is the minimum requirement, and most N95s actually exceed that by a decent safety margin.

N95 users in construction that do it right typically hate them. Properly fit, they're pretty hard to breath thru at rest, and really bad when working enough to breathe hard. It's bad enough that concerned employers are spending a lot of money on alternative methods (like wet saw cutting & HEPA vac attachments on concrete drills).

Bottom line, if your N95 leaks around the edge (even just a little bit), they're no better at preventing COVID19 spread than a surgical mask.

 

[Mitch f]

20 minutes ago, bfishn said:

i had to learn about N95s when OSHA's new Silica in Construction rule went into effect a couple years ago. For them to perform as specified, there's a lot more to it than just buying and wearing one.

Fit test. A trained & licensed mask tech checks several makes and models of N95 half-masks on the user to find the best fit for that person. The user is given a card to carry showing the make & model number they'll need to use.

Quick user fit test. Once a mask is selected, the user dons one and sharply inhales as much and as quickly as possible. When properly fit, the mask will suck up hard to his face, much like a solid covering would do. The user is instructed to perform this test every time he puts it on or adjusts it to insure its performance. 

Qualitative fit test. Also performed by the mask technician. The user dons and fits his mask, and is instructed to open his mouth and stick out his tongue (inside the mask). The tech then uses a nebulizer containing one of 4 approved test vapors (bitter, sweet, etc) and sprays the test vapor a specified distance from the mask, counting the metered doses until the user reports he can taste it. Each vapor type has a specified number of doses required to be acceptable. This test must be repeated annually.

The user must understand that the mask is a filter, and to be effective, 100% of their breath must pass thru it, with no leaks around the edges. That means facial hair, even a mid-day stubble, is out. 

The above is what a construction worker exposed to respirable, crystalline silica dust is now required to go thru. Keep in mind that silicosis is a cumulative disease that often takes years of exposure to manifest. That bears little resemblance to virus protection, where a single exposure could prove fatal.

The N95 specification requires them to catch at least 95% of respirable particles down to 0.3 microns in size. A naked covid particle (called a virion) can run from 0.06 to 0.14 microns, plenty small enough to penetrate an N95. Fortunately, virus particles of concern (those expelled from an infected person's cough, sneeze or speech) are encapsulated in spit/phlegm/body fluids, increasing their size to above the 0.3 N95 spec. The 95% @ 0.3 spec is the minimum requirement, and most N95s actually exceed that by a decent safety margin.

N95 users in construction that do it right typically hate them. Properly fit, they're pretty hard to breath thru at rest, and really bad when working enough to breathe hard. It's bad enough that concerned employers are spending a lot of money on alternative methods (like wet saw cutting & HEPA vac attachments on concrete drills).

Bottom line, if your N95 leaks around the edge (even just a little bit), they're no better at preventing COVID19 spread than a surgical mask.

 

All day long^^^^^^