I merged footage from my “mask videos” from 9 Nov and 26 Nov 2021, into a new video
Face Masks — Best protection with N95 and KN95 masks. Dec 2021
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Face Masks, Tune-up your protection, Nov 2021 (use KN95 and N95 masks)
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Correction: The ALG White Molded Cup N95 masks have the headband straps (ultrasonically) welded to the mask — not glued.
The Teal N95 masks by ALG have the headband straps stapled to the mask.
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Ep 56 Osterholm Update COVID 19: Episode 56: From Checkers to Chess
May 23, 2021 1:01:27 [ Ссылка ]
Go to that “update” and then listen to the section from 31 min to 33 min.
It reveals this infection risk, based on the mask type you are wearing.
The time to infection, if you are in the presence of an infected person.
1. If you wear no breathing protection — within 15 minutes, you can get an infectious dose.
2. If the infected person is wearing no mask, and you are wearing a cloth face covering, it takes closer to 20 minutes to get an infectious dose.
3. If the infected person is wearing no mask, and you are wearing a surgical mask, it takes closer to 30 minutes to get an infectious dose.
4. If the infected person is wearing no mask, and you are wearing an N95 mask, it takes closer to 25 HOURS to get an infectious dose. (and the statistics in some past article I read, was that a KN95 mask was functionally very similar to the N95)
5. If both you and the infected person is wearing a fit tested N95 mask, it takes closer to 2,500 HOURS to get an infectious dose.
Or, to find more Osterholm presentations, try this link.
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3M Personal Protective Equipment Particulate Respirator model 8210, N95, 20/Pack $17.85 (from Amazon)
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[ Ссылка ] For N95 masks
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ALG Health Patriot N95 Mask - NIOSH Certified - Made In USA - Teal Cup - Reg. (Box of 25) $56.76 — They have regular size and small size masks. Teal color or in white.
I got a box of 25 (teal) for $60 from Amazon.
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WWDOLL KN95 Face Mask 25 Pack, 5-Layers Mask Protection, Breathable KN95 Masks, White (from Amazon) $24.74
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20-pack of N95, for $69.99, made by Protective Health Gear
N95 Mask, 20 Individually Wrapped Masks
N95 masks through PHG. [ Ссылка ]
N95 masks, model 5160 Box of 20: $79.80; Box of 50: $187.50
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The BELOW article seems to conclude that N95 and KN95 masks are very close to equivalent in filtration.
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What’s the Difference Between N95 and KN95 Masks? (2020-04-20) Thomas Talhelm
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I found this video that demonstrates and discusses the differences between 4 mask types — N95, KN95, surgical mask, and cloth mask. It was shot in May 2020, when N95 masks were not available.
KN95 VS N95 [ Ссылка ] (4 min)
N95 meets filtration standards by a US government organization.
KN95 is a Chinese design and meets filtration standards in China.
A surgical mask is not rated for filtration. It’s is mainly to catch droplets in case you sneeze.
A cloth mask is not for filtration or protection. It is used because “masks are required”
(He showed a thin mask. If you get enough layers of cloth, it can also catch droplets).
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Another method, is to let the mask “air out” for two or more days after use. The COVID virus does not survive very long when it can’t go from person to person.
The below article says 72 hours, before using the same mask (for hospital workers).
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A study in the New England Journal of Medicine uses a round robin rotation of masks so that each one is rested for at least 72 hours before being worn again. This relies on the widely held belief that the coronavirus should not survive more than 72 hours on an inhospitable host, like the surface of an N95 mask. The downside to this method is that you need four masks per wearer, and that's assuming you use only a single mask each day.
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CDC recommends limiting the number of donnings for an N95 FFR to no more than five per device. It may be possible to don some models of FFRs more than five times [2]. One study reported that fit performance decreased over multiple, consecutive donnings and fit varied among the different models of FFRs examined [3].
(That means, the straps stretch with each time you put a mask on, and eventually, the seal around the edges will work poorly when the elastics lose tension.)
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I found this video that demonstrates “fit testing” of face masks.
N95 and KN95 Mask Fit Testing (with OSHA Protocol)
[ Ссылка ] July 2020 (9 min)
