Saturday, February 6, 2021

N95 and KF94 Masks


I've been wearing N95 masks for more than a decade for doing dusty work. So I was fortunate to have a supply of some of these from before COVID-19 hit. I thought I'd do a post on my mask opinions.

First, About Reuse and other Details
My wife and I use our masks and then hang them in the open air. We let them sit at least 48 hours and then I consider them "clean" again. I try to leave them longer if possible, especially if I have worn them in close contact with other people. The bug is supposed to die on porous surfaces relatively quickly... but some say the virus may survive on the outside of masks for up to 7 days. Make your own decision on how long you need to let the mask air out between wearings.

Remember, you are sucking air in through the mask and the outer surfaces of the mask is where any virus would enter and get caught. And of course, if you have the virus, you would be blowing virus into the inside of the mask. So, immediately after you use them, handle the used masks like they are contaminated.

I've heard getting a mask wet will kill the mask's effectiveness. And it is possible for the masks to get very wet from your humid breath after a long wearing. They work with an electrostatic charge, but it is not clear to me what else besides being wet would break that down. In the box the masks last years, and note that many N95 do not come in a sealed container. The latest box I got says they expire in 2025... so extended exposure to the air would seem to be fine.

In a hospital setting they only use these masks a couple times with careful sterilization each time. But I think for our purposes they will last 12 to 30 short wearings (like a 20 minute visit to a store) or more, if they hold up mechanically.

Our masks eventually become unusable because they become too dirty or crinkled. You may wish to be careful not to stain them with makeup or colored face cream.

Watch out for fakes! I try to only buy from reputable sellers.

All of the N95 masks have straps that go behind the head. They are harder to learn to put on, but they make a much tighter seal with your face because of these behind the head straps. Read the directions as it really helps to don them correctly.

We wear the N95 masks when we expect to be in close with other people, like a trip to a doctor or a visit to the grocery store. For any meeting where we will be in a small room with someone else we wear the N95.

We wear the KF94 masks when we don't expect close contact with other people, like a distanced (6ft plus) meeting with a single other person that won't last long or even for outdoor walks were we might encounter other people. The KF94 is easier to pull on and off for quick distanced encounters.

Vintage Veloce's N95 picks
3M 8210 PLUS
These are a "formed shell" mask. Very durable. I consider these the "best". The "PLUS" in the name means they have a braided strap that will last a long time. These are now impossible to find; the ones I have were purchased by me in 2019 for workshop use.

3M 8210
Same as the plus version with a much less durable strap. These seem to be available on eBay. I'll be curious to see how the straps hold up, and may try to replace the straps when they wear out. Currently about $5 each on eBay in a pack of 10.

3M 8211
Just like the 8210 PLUS but with a VALVE. These are fantastic if you don't care about venting the virus on others. And they work great because of the valve, far better than the 8210 versions. It's easier to breath and the vent allows moisture to escape. What some people do is they wear these with another mask over the top to protect the vent. I've been wearing these for years in the workshop and wore them on a long airplane flight for many hours nonstop. We also have taped up the valve on a few, but people don't recognize that the valve is taped, so that is uncool. Not recommended for coronavirus use because of the valve.

3M Aura 9205+
These are a soft mask that comes packed flat. The straps are the less durable kind. We just got 10 of these and they fit great! But harder to put on because they are soft. Questionable durability. Currently about $5 each on eBay in a pack of 5.

Vintage Veloce's KF94 picks
These are the Korean standard, and many people trust these more than the Chinese (KN95) masks. When I first bought these they only came with Korean labelling, they now exist in English labeled packages that I personally mistrust. I only buy ones that are fully labeled in Korean. Note these are a "flat front" mask, and leave space in front of your mouth, very comfortable in my opinion. They are "ear strap masks" and this is the biggest failing of these in that they may not pull tight enough on your face to seal fully. (You can tie a knot in the strap or buy cord locks to tighten them.) Currently about $2 each on eBay from a US seller in a pack of 10. I have bought these brands: Wiicare, INT and HappyLife / Good Day with Korean language labels. The INT supposedly has a built in strap length adjustment but I found it doesn't hold particularly well (otherwise it is comparable to the other brands).  
There is LG brand KF94 mask that has a better length adjustment mechanism but those masks seem to command a premium price that gets close to the cost of a N95. I like the LG mask because I recognize the brand and the built in adjuster makes them ready to use. But I do prefer using the cord locks as they seem a little more secure and I'm not a big fan of how the extra loops on the LG look. 

LG Mask:

In my opinion: Nope. Some may be good, but I'm not trusting these. There are known incidents of fake KN95 masks.

Single layer cloth masks
These provide little protection.
But, I do wear these when exercising alone outdoors. When I bicycle and I wear a buff over my nose and face when riding. I do see people running, bicycling and walking without any mask at all, and in my opinion that doesn't show support for the mask wearing societal effort. So when I'm working out and need to breathe harder, I wear a thin single layer mask AND I make sure to keep my distance from other people. Wearing the mask shows that I agree with the effort to wear masks, and it helps people who see me feel more comfortable.

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