1:45 "How long do you recommend wearing a mask?" 2:20 Used mask filtration efficiency test #1 4:28 Test #1 data 5:53 Worst case scenario mask test results 7:50 "Do you recommend cleaning masks with isopropyl alcohol?" 9:18 "What if my mask gets wet?" 9:57 Used mask filtration efficiency test #2 11:05 Test #2 data 14:09 "Why does filtration efficiency decrease after use?" 16:28 "What does a good face fit feel like?" 19:13 "Why are my glasses still fogging up?" 21:07 "What is the risk of contracting coronavirus from a mask?" 23:49 "How do you recommend I handle and store my mask after use?" 27:11 "Do you recommend cloth or surgical masks?" 29:20 Upcoming test results 30:18 "Why don't you test reusable masks?"
I’ve been wearing BOTN mask everyday at work (I’m a physician). Because I’m seeing patients and do not necessarily know if they have Covid or not, I change it daily. Have to say, I really like it, feel more secure than most KN95s. Of course, if I’m working with someone who’s Covid positive, I’ll wear an N95. I have sent your videos to a couple of my colleagues as a reference. Thanks for doing these tests as it gives everyone more options and helps us as well be less wasteful...
@@ibrake4ants , 18 months into this pandemic, and probably more than a year using these kf94 masks, they have worked out really well for me.. even in my line of work.. but everyone does whatever they can to keep mental calmness and to protect themselves as well as their loved ones…
What did you mean by "of course" [...I'll wear an N95]. Do fit tests prove that everybody is better off with N95s? I find my N95 masks did not seal as well over the bridge of the nose. Given how many brands of masks there, is it proven that inter-type variation of fit (N95 vs KF94) is (statistically and consistently) far more than intra-type variation of fit between brands (e.g., Brand X and Y N95s surely both have better fits than Brand A and B KF94s)? I won't be buying tens of brands of masks to test, but I feel quite insecure hearing a doctor inform me that what for me seems obvious (the KF94 is a better fit) is OBVIOUSLY not the best choice. Or, was a single word - "obviously" - poorly chosen?
You’re my hero - seriously - your videos have been incredibly helpful in not only choosing masks but feeling safer in the pandemic. As a fellow scientist I appreciate your detailed and Thoughtful approach to your studies :)
I agree 100%. Ok, well I'm not a scientist, but his videos are truly game changing. Kudos to the folks at reddit.com/r/masks4all. That's how I found these videos. 😷👍
I know these videos are now quite old, but with Delta causing yet another wave, masks are becoming more relevant again and I expect more people will be watching and reading comments. Thank you for putting in the effort and producing these incredibly valuable, potentially life saving videos. Regarding reusing masks, 3M performed an excellent analysis on this near the beginning of the pandemic. I don't know why but the report and the press release discussing it have both disappeared off the 3M website. 3M tested, not only 3M respirators (masks) but also competitor masks and I believe even a few KN95's. What they found was the following: - Too much moisture degraded the filtration due to reduced electrostatic charge. They recommended replacing masks every 4 hours or less and either hanging them to dry or placing them in a breathable paper bag. - After 10 wearing sessions of 4 hours each (40 hours total) all of the masks were still filtering well. - The filtration performance reduced by an average of approximately 1% within the first 10 to 20 hours and then continued to degrade very slowly. - They suggested that for use in a healthcare environment that 40 hours was reasonable and that when used by the general public most likely 100 hours or more was likely reasonable (the 100 hour suggestion was actually in their blog to not the report). - They noted that as long as the masks looked clean and in good condition, the masks continued to perform well. - They did not recommend sterilizing the masks but noted another study that showed the virus broke down over several days in a dry environment. I can't recall exactly the number of days but they recommended allowing somewhere between 3 and 7 days between wearing sessions for the virus to become non-infectious. - In another study they found that masks stored in sealed plastic bags could develop mould so they recommended either hanging them to dry or placing them in breathable paper bags between wears.
Hi @Slider68 "I know these videos are now quite old, but with Omicron causing yet another wave, masks are becoming more relevant again and I expect more people will be watching and reading comments" :-) Do you know what the name of that report was? Wondering if it is possible to find it archived somewhere on the Internet?...
@@marktaylor1527 this is beyond ridiculous but I've now tried about a dozen times and there must be some word TH-cam doesn't like because my replies just keep getting deleted.
@@marktaylor1527 This is insanely frustrating. I'll try posting just a couple of words of the title in each reply and maybe you can use that to find the document. Note this is not the original document but one with some similar information on the bottom of page 9 and on page 10
My wife and I are huge fans of your videos and appreciate the evidence you're providing! We both work in healthcare in the US and wanted to be safe and ethical about not taking away n95s from our heathcare system... and because of your videos have bought hundreds of kf94s and have been giving them out to friends, family, and vulnerable people in the community. I hope you realize you're helping save lives by putting out this info! 🙏
This is spectacular. I just found this as we are re-analyzing masking for Omicron and I was digging for data. Thank you so much for all your fantastic work!!
Aaron, thank you so much for all the work you've put into creating these videos, executing these tests, and presenting this data to us. You're quite literally doing a great service for humanity and the planet (save lives while creating less waste!).
Thank you so much for all the hard work you have put into making this video. I bought some KN95 masks and was throwing them out after one wear to the supermarket so I found it quite expensive because I cannot work due to health issues. I am ordering again today. You are saving lives and I very much appreciate your efforts.
Another confound of the Danish study is that the majority of spread is likely occurring in unmasked gatherings, such as restaurants or homes. Most people (including those that were in the mask group) would not wear a mask in this scenario regardless, and could have been infected then. What you really want to know is if wearing a mask reduces the probability of getting COVID in a setting where it makes sense to wear a mask (e.g. supermarket, other public settings, etc...). You'd need complete contact tracing to determine what percentage of infections in the "mask" group occurred when they were wearing their masks. It does look like they equipped the mask group with surgical masks, so they're OK masks for protecting the wearer, but not great.
The "Adherence" section is also problematic. It states: "Based on the lowest adherence reported in the mask group during follow-up, 46% of participants wore the mask as recommended, 47% predominantly as recommended, and 7% not as recommended". This is simply based on self report, and doesn't dive deeper into *when* the participants wore masks, and when they didn't. In the Supplemental you can actually see the instructions for mask wearing and they are rather vague.
Aaron, thank you so much for taking the time to post these incredibly informative and helpful videos. They should be watched by everyone. I have ordered some KF94 masks from Korea based on your recommendations for myself and my family.
As a nurse, thank you. Your videos are amazing and I wish more of the public who didn’t believe in mask wearing would watch them. It’s disheartening to have people yell and scream about wearing one to protect others, knowing that if more people did wear something we would be better off. Thank you!
Great info about the filtration efficiency with prolonged usage! I also appreciate the point about some water vapor escaping through the breathable material at the top of the mask. It might explain why I noticed that my lab goggles would slowly fog up over the course of the day even though I didn't notice any gross leaks during my user seal check or my glasses fogging up with normal breathing. Looking forward to future test s!
Thank you for all your research and info. You are definitely included among all the COVID heroes. This is such valuable information. Thanks for being one of the people that "get it" when it comes to a global pandemic. I hope blessings just absolutely flow into your life for sharing all of this.
I’ve been using mask strap for the ear loop KF94s and they really improve the seal. Even with the adjustable ear strap masks. I throw one set of mask strings on the strap, and tighten the others and place them over the ears. Belt and “suspenders” as it were.
Thank you *so very much* for this indispensable information and for the tremendous public service you've been doing in testing these masks. It's frankly outrageous that this far into the Covid pandemic (1/27/21) this isn't already common knowledge in the US and that we don't yet have a system for distributing high-filtration masks to the entire population. I learned about your work by sheer accident via a Twitter link from Dr. Abraar Khan. Thank you again!
Thank you so much for all your work. You are truly helping save lives. I have given kf94s to co-workers, my parents, and at risk family members. Thank you again
Aaron, I have not been a fan of the adjustable ear loops on any of the KF94 masks that I have tried. I have gone to using cord locks for the ear loops, and as the ear loops stretch I simply adjust the cord lock to maintain the correct face fit. Great info, I've got everyone in my family and pretty much everyone I know using these KF94 masks. Thanks.
Bill thanks for sharing that, that's a good idea. Thanks for sharing and stay safe and hopefully will catch you in the park again for a beer soon(assuming this is the Bill Nelson I think it is judging by the picture)!
@@coll0412 Yep, it is me! Looking forward to catching up again in the park. Here's a link to the cord locks that I've been using: www.amazon.com/gp/product/B08FDNWJT2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1&fpw=alm
Thank you so much for your informative videos. Your expertise is so helpful during this dynamic time of uncertainty. You have taken the guesswork out of the difficult process of choosing high performing masks. Thank you!
You are awesome!! I bought a few Dr. Puri masks and just started wearing them at my new office job. I did worry about the fit since my glasses always fogged up, but you clarified every concern I had! I think I’ll buy medical tape to prevent the fog. I really appreciate this video and all the hard work that went into it. Thank you!
I’ve tried medicsl tape but it always comes off rather quickly. Bandaids, however, have worked brilliantly! Flesh colored ones virtually disappear where it sticks on your face. (I just don’t use then right under my eyes). Hope this helps.
Thank you so much for this and other videos. In my country, we got a very alarming situation with a record covid case pretty much being broken every day.
Thanks for the video!!! I keep reading from many sources that masks should be used just one. I have KN95 masks and now have information on how long I can wear one as I work at home and limit my trips to no more than one "establishment" at a time with most under 20-30 minutes. Will have to spend this weekend catching up on all of Aaron's videos.
I also use my car to store my masks. I put each used one in a paper bag. I have a system of using 3 big ventilated bags and recycling them in the car. I put the recently used masks (in their paper bags) into one bag. In the 2nd bag are those I wore in the previous week. And the 3rd bag contains the masks I wore 2 weeks before. This bag will be rotated next to the drivers seat and I will re wear those. This is working out well. Another thing I would like to suggest is to wear a strap around the back of your head, pulling the 2 ear loops from the masks together. This creates a very tight fit and it is comfortable (no sore ears).
Thank you for all your work to keep us safe and informed. We were only wearing homemade cloth masks and when it got more dangerous I made my husband wear two when shopping. Currently he is not going out except to pick up curbside. Seeing your videos gave me hope and a sense of security. I have ordered some KF94 masks you recommended. I now feel safe for my 70 year old to go to Costco or our local grocery store. However, I’m unsure how long we can use one mask. You refer to a “clean office environment “ for how long you can wear a mask how does that compare to a grocery store setting? Thanks again!
A grocery store would also fit in that category. Reality is even if you wore it longer or in a dirty/dusty conditions you are still going to get way better protection than a cloth mask. Thanks for watching!
I agree that KF94s are great, but if we're talking about a solution that can genuinely scale to meet global demand, we need to talk about sealing flat surgical masks to users faces rather than assembling and forming these masks with complex shapes. KF94/N95/KN95s waste 20-40% of the material used to make them compared to surgical masks which have nominal material waste. What's more, surgical masks are less than half the price per unit. When combined with a re-usable mask fitter - you have a solution that can really scale. Your degradation results are really surprisingly good - I would have expected the electrostatic charge to degrade much faster. Could you repeat your methods for a surgical mask? From our tests, masks with similar density melt blown fabric, but different electrostatic charges showed closer to a 40% reduction when tested to the NIOSH standard at 85 L/min compared to your 10% reduction. Do you think the difference here is that there is something special with KF94s, or that at low flow rates the differences aren't that apparent? Totally agree with your analysis of the Danish Mask study. The quality of the source control is critical. Totally agree with your stance on reusable masks as well - cost is prohibitive for the majority of the world, with nominal environmental impact benefit. Thanks for putting out this content!
In regards to the degradation, my test is nowhere near the NIOSH spec of 200mg of NaCl since I am just breathing in ambient air in an office for 40hrs which will consistent of a lot of different materials. Most electrostatic media have a hard time with NaCl aerosols and static charge loss. Assuming a 14 breaths/minute, 0.5L tidal volume, and say 20 µg/m^3 office concentration, in 40hours we are talking 360 µg of mass collected so nearly 1/500th the amount of mass collected compared to the NIOSH spec,so I was not surprised that it still performed well. THe NIOSH standard is really meant for industrial use, which is why the mass collection requirement is so high. Probably doesn't make sense as a standard for a general population mask. The media used in KF94/FPP2/KN95/N95 masks is also better, and this is a by product the test requirements. The surgical mask requirements are much less stringent than KF94/FPP2/KN95/N95 In regards to the discussion of cost and meltblown usage, I would agree that a surgical mask is cheaper and uses less material, but also has much lower performance characteristics compared to KF94/FP2/KN94/N95 masks. We are about to get a flood of KN95's into the US so I am not sure that getting meltblown material is a really the constraint as much as it was in the spring. Thanks for watching!
Aaron.. I love your nerdy detail... but cannot imagine sending your videos to others who just want the bottom line Therefore I suggest that you make a video that is intentionally brief as possible Mat Maybe suggesting a specific mask available on Amazon. For convenience and availability And then the demonstration of how to wear it Then a review of how long to wear, rotate etc You can refer viewers to other videos if they want more detail or a defense of your recommendations Just give people the absolute basics in this video
Just discovered your channel after reading article about you on Yahoo. What you do is terrific. I wear a mask about 6 hrs./day. So 30-40 hours is about 5-7 days max., though I don't think you recommend that long. But seems to be possible, based on your data.
I think HCWs should be using 3Ms full face or half face respirator with 6035 FFP3/HEPA filters. Those filters can last for months. Both the respirators and the filters are wildly available.
Finally, I was waiting for another video by Aaron Collins! You have helped me more than you know, thank you. BTW, can you do a 3M N95 vs the KF94 and KN95?
Aaron, great content. If you edit your video descriptions and add a 0:00 timestamp directly above the "1:45 "How long do you recommend wearing a mask?"" time stamp it will automatically update your video progress bar to segregate by chapters. Make sure to save the edit.
@Aaron Collins Have you tested the effect of a mask soiled with makeup (like foundation that has rubbed onto the mask from the face?) or from a drippy nose? Have you tested it while wet, and then again after the mask is to removed and dried? TSC sells Tommie Copper reusable masks - assuming we have a good seal, are they good?
You should try a KF94 mask (a genuine KF94 is made in South Korea and certified by the KFDA) it's widely considered to be one of best type of mask in terms of protection and comfort because the mask is largely designed not to touch your mouth due to it's design which leaves a large pocket of open air in the middle of the mask.
Hi Aaron, Your videos are literally lifesaving. Thank you for everything you do! I have one question. What mask do you recommend for children? Around 12 years old
I would recommend either the Bluna kids face mask, or the Blue 3D masks depending on the face shape. The Blue Kids 3d(with a tiger on it) will likely be too small.
What are your thoughts on dry heat decontamination? This is the first of your channel I've seen, so maybe you've discussed it, but there's been videos showing people sticking their N95's in their Instant Pots (in a nest of towels so the mask doesn't contact a heated surface) - The rule of thumb I heard was 100 degrees C for 50 minutes. What I've been doing is wearing my Powecom one day at work, and then, because I notice after even a full day of wear the ear loops seem like they're not keeping the mask as snug, I tie a knot near the end of each loop to shorten it a bit, and at the end of the week when I have a handful of them in "used" condition, I Instant-Pot them. I found my powecoms tended to leak at the nose bridge no matter how carefully I adjusted them, so I do add a foam adhesive strip to the inside of the mask on the nose-wire area, much like you'd see on some N95's and that seems tor really help the fit for my face. I re-wear it once and then trash it after the second wearing. Here's a link to one publication that talks about the dry heat decontamination: pubs.acs.org/doi/full/10.1021/acs.estlett.0c00534 Thanks for the channel, I'll be checking out some of your other videos!
From my perspective I just don't see the need to sterilize the masks, the virus dies on its own over 3-4 days, so simply letting the masks sit around for that amount of time is sufficient. I think all the different techniques(Dry Heat, H2O2, Microwave) all have impacts on the masks, even if small, and add a lot of complexity and if done wrong damage the masks. That's my perspective at least.
based on studies and studies on studies DRY HEAT at 165 degrees F for 35 minutes is ample for disinfection and importantly maintains fit for many cycles.
I tested the Filti NF95 awhile back, it didn't perform too well. docs.google.com/spreadsheets/d/1M0mdNLpTWEGcluK6hh5LjjcFixwmOG853Ff45d3O-L0/edit?usp=sharing
Aaron, I wish you could see my mask collection. I wear one for a couple of days. Then switch to a new one. And then a new one. So my desk is littered with all kinds of N95 masks and surgical masks. It's pretty funny. my favorite N95 is from Milwaulkee Tools. It has a rubber gasket on the inside and has a really nice close contact on my face. They have the valve so I have to wear a surgical mask on top of them.
I've been using mask extenders to tie the ear loops of my masks behind my head. This makes it more comfortable to wear my masks for long periods of time and also makes it easier for me to maintain a proper face fit. I guess mask extenders for ear loop masks might be a rough substitute for masks/respirators with headbands. However, I've never seen studies or experiments on how much (if any) improvement mask extenders have on ear loop masks (cloth, surgical, kn95, kf94, etc). Have you looked into this?
If you get a better face fit then you will improve the mask performance. The media of almost all KF94 masks is 99.8+%, so the dominant mechanism is leakage around the mask. If you reduce leakage you improve performance.
About a month after this video, the journal of JAMA Internal Medicine looked at how making modifications to cloth and surgical masks improved their filtration. They compared them to N95s. It included extending loops to back of head. The article is entitled "Evaluation of Cloth Masks and Modified Procedure Masks as Personal Protective Equipment for the Public During the COVID-19 Pandemic'". I would post the link but YT deletes any comment I have that posts links.
@@MrWebster helpful, thanks! Although it looks like even with modifications, neither cloth masks nor surgical masks are really that effective. They improve, but they're nothing like the kf94s. I have pretty much stopped using other masks and just reuse my BOTN masks! (Up to 40ish hours, of course).
Thank you, Aaron! Did you end up making that video on the fogging eyeglasses problem and tips & tricks to fix it? It's been a constant problem to me despite what feels like a good seal. Help!
Most helpful mask videos on TH-cam, I do wonder though. How effective is a surgical mask at protecting yourself if you have a perfect seal? I can do that with a knot & tuck + a piece of medical tape across the nose
I work at a public elementary school (the kids are in session, in person full time) and I am being told by the nurse to wear my KN95 mask for 2 weeks before they’ll give me a new one.
It will still likely provide fairly good protection over that time frame, but I would recommend thinking about augmenting with small supply of your own.
Please discuss electrostatic charge/ relevance to reusability. Reputable sources indicate that the charge strongly contributes to the effectiveness of the media to trap and suspend virus size particles. According to the same sources, the static charge depreciates rapidly over a 24-hour use cycle and that alcohol washes in particular destroy the charge. I am not aware of anyone testing the process of static charge over time/use cycles. So if the static charge degrades, and also the effectiveness of the filtration media over time, what does this effectively mean for overall safety, particularly on the subject of mask reuse? Your thoughts? From one nerd to another, I thank you for all of your efforts and your wonderful information which I'm sure has reduced illness and perhaps even deaths.
Hey Colin big fan. I am on Mask4All a lot so thats where i learned about you. My question is what do you feel about Ear Savers? I find when i use an ear saver it makes the fit of the mask much tighter. Is that something people can use when the fit on the ears become loose?
Sorry for the slow reply, had missed a bunch of messages due to a TH-cam setting. So yeah you can use an ear saver to help keep the mask tight if its comfortable for you.
Thanks for these videos! You have such a fantastic, relatable approach. I'm curious if you have any opinions on double masking, though I realize testing efficacy would present a challenge. I'm considering layering my linen/silk/600tc cotton behind the head masks over the botn kf94 for cleanliness and even better face fit. (Currently layering 4 layer astm 3 surgical+cloth) I work in a fairly public, high risk setting and I'm often exposed to indoor, unmasked conversation, hence the layers upon layers and wanting to protect myself. Even if this is out of your realm, thank you again for the info and great explanations!
My recommendation is one mask that fits well with no leaks, adding more masks doesn't necessarily make it better. The surgical under a cloth masks is just a way to improve protection of a surgical alone, but it's far from ideal. Will cover it in my next video. If you are around unmasked people and less than 6ft I would also recommend a face shield.
Aaron: Thanks very much for your information. Re fogging glasses: You said moist air coming through nose piece fogging the lenses. Might it be possible to make that limited area impermeable to air. I suspect a piece of clear packing tape across the nose piece would accomplish this. Thanks again
I’ve been using the KF94 for about 4 weeks total, when new will use them in high risk cases indoors then as they age will use them in less risky situations.
I hope at some point you may be able to add the new CE FFP2 certified Air Queen Breeze to your roster of masks you're testing. I'll be interested to see if Toptec have fixed their subpar nano filtration in their new CE certified mask.
Hi Aaron, Thank you for all the great information! Your videos have been so helpful. I wear a kn95 Powecom. Do you think moisture from talking loudly decreases efficiency?
Last year on the cruise ship that was stuck in japan, many on board died of covid, the aircon was circulating it. After everyone left the ship, the went into the cabins after 3 week and still had virus in the cabins. Never underestimate the virus.
It's important to distinguish between viable virus, and finding viral RNA. What we care about is if the virus is still viable, ie. alive. Think of this the same as finding the bones of a animal 3 weeks after, sure it was present and was certainly there, but it's no longer alive. What we care about is how long does the virus stay viable, which depends on a lot of factors, but roughly 3-5 days on most surfaces and a massive fraction of it is dead. Also fomite spreading is not really an issue, the virus needs a direct route to cells with ACE2 receptors so this means inhalation is the primary mechanism. This is why the CDC has come out to say that fomite transmission is very rare.
I have been making ear savers to ear with FLTR95 masks I got. I've noticed the elastic stretching issue and I suspect these will help with that. I've never had a good seal around my nose with a mask. I have no bridge. I'm hoping this will help.
Is it ok to hang the mask on a coat rack or door knob or does it have to be stored in a bag? Would the ambient airflow in the room degrade the filtration media?
They add some level of protection, but from an aerosol standpoint they don't offer much, if any at all, protection. It doesn't hurt to wear it along with a KF94/KN95 mask though, adds some level of eye protection as well.
My doctor said I could re-use a KN95 mask if I let it sit for 72 hours before wearing it again. I put them in individual brown paper bags and mark the date on the outside. She said I could re-use a mask this way for up to 6 or 7 times. Do you think this is a good method? Thank you.
Yes, it's the same thing I recommend as well. 40hrs or until the masks doesn't seal well to your face, whichever is first. Let them rest for 3 days before re-wear(conservative approach).
My family and I only buy mask from your recommendations. Thanks for the help! Would you happen to have a name for the Korean mask that doesn’t have the breathable nose interface? I’m turning into a mask nerd... 😃
If I ever run into again I will be sure to get it. I was deep into a KF94 search using Google Translate and have not been able to find it again as it was an all Korean text name. Will let you know if I do.
I don't bother sterilizing my masks anymore. I have a kf94 mask for every day of the week. By the time I reach for a mask at least 7 days have passed. Any virus that might be on it is already dead.
I would love to know how many total hours one can wear the same N95 mask? I see articles saying 1 time, 3 times, 5 times, but wearing a mask in and out to pick up food is very different than hours indoors at work. Have you tested this? Is it the same as a KF94 in this regard (30-40 hours total before a decrease in filtration efficiency)? Thanks! You rock!!!
I was wondering if you would be able to do a study with surgical masks, and if we layered surgical masks would it be as effective as wearing a n95? I current work in a hospital where I care for covid patients, and the nurse manager called me out for wearing a n95. She said that I should wear 2 surgical masks and a faceshield which is "apparently" equivalent to wearing a n95. what do you thinkl?
I can pretty much guarantee you that two surgical masks will never get close to an N95 for the simple reason that surgical masks don't provide a good face seal. I cover the two mask concept in the link below. My recommendation is if they won't let you wear a N95, then I would say just wear your own KF94 that fits well. Some are FDA approved equivalents to surgical masks. Shame on them for doing that though. th-cam.com/video/Z93BoeCuIE4/w-d-xo.html
Consider wearing a mask frame on top of the surgical mask to hopefully reduce leakage. www.gardentowerproject.com/products/diy-face-mask-frames-family-6-pack?_pos=1&_sid=ae776fd19&_ss=r
I am so glad I found your videos! We've been using surgical and cloth masks, in spite of the fact that I've had some nagging doubts about them, because of the fit issue. It's good to know there is an alternative to the N95s that need to be reserved for the heroes staffing our medical facilities. I do have one question. Having learned that doubling up surgical masks, or wearing a cloth mask over a surgical does not increase the effectiveness of either, I am wondering - is it safe to wear a cloth mask over one of the KF94s? I know my cloth masks aren't terribly effective, but they are pretty. >.
Thanks for watching! If wearing a cloth mask over the KF94/KN95 does not compromise the seal then its fine, but won't provide any extra protection. Mostly just for a fashion perspective.
Got a question. Botn, airqueen, some other masks have their logo in the front of the mask. If you look closely, it looks sort of transparent but not. Looks like the logo part of the mask does not have the outer layer, just the inner layer? Or is it some other material completely. How does that affect the filtration where the logo is?
No impact the filtration. THe masks are joined together using a heat sealing method where they basically get "stitched" together with a hot metal rollers. They can also emboss a logo using the same technique so that's why you see the logos. All the masks I test as is, so if they did have an issue they would show low filtration performance. Hope that helps!
I personally would have no concern using them, tests from 9+ year old masks tested just as good as new. The elastic and foam are the first to fail but takes many years. www.cdc.gov/niosh/npptl/ppecase/pdfs/PPE-CASE-Stockpile-4-v2-03012020-508.pdf
I have not seen any data that says it does, I left mine in the car for those long term tests, with the abused BOTN having sat on my passenger side seat for about 3 months. So I don't see much a risk at all in doing that.
Thanks for the great info, do you notice a difference in breathing efficiency/difficulty with extended mask use? Thanks for putting the time into making these videos, they have been a big help. I was wearing N95's at work and reusing them/disinfecting them with UVC or heating them as per the data I have read. Switched to the BOTN and they are much more comfortable and affordable enough that I can use clean masks. Based on your data, I guess I should start cycling and reusing them and cut down the waste a bit.
Can sweat reduce the filtration efficiency of masks? I usually sweat a lot if I'm wearing mask. I'm worried that it might significantly reduce the efficiency of the mask when I reuse it.
Hi Aaron-- Not sure if you're still checkin the comments on this. First of all: thank you for all of your mask videos-- they have done so much to help other people. I had a question about expiration dates: I received a bunch of masks recently with expiration dates that are about to pass. If the expiration date passes and the masks have been unopened in their packaging, does that affect their filtration efficiency (i.e., does the electrostatic media degrade)? If so, do you have a ballpark (or scientific) sense of what sorts of efficiency losses would occur within which time periods? Thank you again for what you do.
If they are in a sealed package I would have no worries about it. There have been studies to show no change to the filter media, it's really just the rubber in the ear loops that goes bad and that takes like 5+ years.
Great videos Aaron. Quick question ! Does the 30-40 hours apply to a setting like Walmart?? Or would you recommend using a new mask every day to work for that setting?
The BOTN masks has adjustable earloops. For my face I can manage to fit both the primary loop you are supposed to use, and the extra material around my ears. Effectively on the masks I have two loops on each ear pulling it in. Not supposed to do that, but for me it is just a happy accident that I have enough extra earloop to work with. Does that make sense?
@@coll0412 Yes, absolutely! Thanks so much for clarifying. And thanks again for all the work you do to help us. I've used your videos to help inform me throughout the pandemic. You're a gem
Does UV-C light decrease the filtration level of the KF94? I'm considering getting a UV-C sanitation box (fits things like keys, wallets or masks). But i have no idea if UV-C light has an effect on the electrostatic charge of the mask. Any thoughts on that?
Is there a video of how a wearer's sneeze or cough (like my allergen-sensitive kid) affects the life of such masks? I think prior guidance was just to toss the mask after the wearer sneezes or coughs into masks.
Any other common vapour/fumes that would reduce the filtration/electrostatic? Just thinking about how much 70% ethanol and acetone vapour I'm exposed to at work.
Thanks for making this helpful video. I teach at a college in a regular classroom (not a lecture hall), and I think I will start using a KN95 and cycling through them until I am eligible for a booster. Is there information on whether sound will be muffled/inaudible with a KN95 compared to a surgical mask? I tried double masking with a cloth mask on top of surgical and that definitely muffles the sound a lot. Thanks!
I would recommend a KF94 mask for sure, and one that fits. I usually recommend starting with the Bluna FaceFit and seeing how that fits to start, BOTN's are larger so if it feels small then you can go larger.
Hi, I'm thinking about cycling the BOTN masks to reduce cost, what if I work at a job where I take the mask off and put back on about 4-5 times a day(retail job), can I still use it for 40 hours, that's about 20-25 times taking it on and off, I read on the CDC website for reusing N95s they only recommend about 5 times taking it on or off since the elastic wears off
With adjustable earloops you can adjust the tension over the life of the mask, so I see no issue with using it 40 hrs but taking it on and off many times. Will be fine
Would be VERY interested in data regarding cleaning the masks in a solution of oxidative laundry detergent, or other cleaners (e.g., hydrogen peroxide/water solution of verious concentrations). Please?
In general it's tough to get more than 40 hours out of them before the earloops stretch and it stops fitting well. In terms of filtration, they will do a great job for a long time.
@@coll0412 ive heard about the 40 hours! But the packaging says 8 hours so I wasn't sure if it was accurate ( If the mask still fits well, and isnt dirty that is)
I didn't notice anything from my masks after having worn many for 40+hrs each. I think since you can't really eat or drink with them on it really helps keep down the nastiness.
DenTec Safety claims their N95 filters last up to a year and I hear similar things about P100 filters. Is this true? Why is it different than the more traditional KN95s and N95s your cover here?
1:45 "How long do you recommend wearing a mask?"
2:20 Used mask filtration efficiency test #1
4:28 Test #1 data
5:53 Worst case scenario mask test results
7:50 "Do you recommend cleaning masks with isopropyl alcohol?"
9:18 "What if my mask gets wet?"
9:57 Used mask filtration efficiency test #2
11:05 Test #2 data
14:09 "Why does filtration efficiency decrease after use?"
16:28 "What does a good face fit feel like?"
19:13 "Why are my glasses still fogging up?"
21:07 "What is the risk of contracting coronavirus from a mask?"
23:49 "How do you recommend I handle and store my mask after use?"
27:11 "Do you recommend cloth or surgical masks?"
29:20 Upcoming test results
30:18 "Why don't you test reusable masks?"
Awesome work thanks!
Thanks for taking the time to do this!
Wow. That's amazing. Thanks!
😂😂😂
Thank you 🙃
I’ve been wearing BOTN mask everyday at work (I’m a physician). Because I’m seeing patients and do not necessarily know if they have Covid or not, I change it daily. Have to say, I really like it, feel more secure than most KN95s. Of course, if I’m working with someone who’s Covid positive, I’ll wear an N95. I have sent your videos to a couple of my colleagues as a reference. Thanks for doing these tests as it gives everyone more options and helps us as well be less wasteful...
@Bella Dama Otto said he changes it daily.
If I were in your line of work I would wear an n95 always. Seems too risky to wear kf94s because they simply do not seal as well as an n95.
@@ibrake4ants , 18 months into this pandemic, and probably more than a year using these kf94 masks, they have worked out really well for me.. even in my line of work.. but everyone does whatever they can to keep mental calmness and to protect themselves as well as their loved ones…
What did you mean by "of course" [...I'll wear an N95]. Do fit tests prove that everybody is better off with N95s? I find my N95 masks did not seal as well over the bridge of the nose. Given how many brands of masks there, is it proven that inter-type variation of fit (N95 vs KF94) is (statistically and consistently) far more than intra-type variation of fit between brands (e.g., Brand X and Y N95s surely both have better fits than Brand A and B KF94s)? I won't be buying tens of brands of masks to test, but I feel quite insecure hearing a doctor inform me that what for me seems obvious (the KF94 is a better fit) is OBVIOUSLY not the best choice. Or, was a single word - "obviously" - poorly chosen?
You’re my hero - seriously - your videos have been incredibly helpful in not only choosing masks but feeling safer in the pandemic. As a fellow scientist I appreciate your detailed and Thoughtful approach to your studies :)
I agree 100%. Ok, well I'm not a scientist, but his videos are truly game changing. Kudos to the folks at reddit.com/r/masks4all. That's how I found these videos. 😷👍
My pleasure, and thanks for watching!
I know these videos are now quite old, but with Delta causing yet another wave, masks are becoming more relevant again and I expect more people will be watching and reading comments. Thank you for putting in the effort and producing these incredibly valuable, potentially life saving videos.
Regarding reusing masks, 3M performed an excellent analysis on this near the beginning of the pandemic. I don't know why but the report and the press release discussing it have both disappeared off the 3M website.
3M tested, not only 3M respirators (masks) but also competitor masks and I believe even a few KN95's.
What they found was the following:
- Too much moisture degraded the filtration due to reduced electrostatic charge. They recommended replacing masks every 4 hours or less and either hanging them to dry or placing them in a breathable paper bag.
- After 10 wearing sessions of 4 hours each (40 hours total) all of the masks were still filtering well.
- The filtration performance reduced by an average of approximately 1% within the first 10 to 20 hours and then continued to degrade very slowly.
- They suggested that for use in a healthcare environment that 40 hours was reasonable and that when used by the general public most likely 100 hours or more was likely reasonable (the 100 hour suggestion was actually in their blog to not the report).
- They noted that as long as the masks looked clean and in good condition, the masks continued to perform well.
- They did not recommend sterilizing the masks but noted another study that showed the virus broke down over several days in a dry environment. I can't recall exactly the number of days but they recommended allowing somewhere between 3 and 7 days between wearing sessions for the virus to become non-infectious.
- In another study they found that masks stored in sealed plastic bags could develop mould so they recommended either hanging them to dry or placing them in breathable paper bags between wears.
This is so helpful!! Thank you!
Hi @Slider68 "I know these videos are now quite old, but with Omicron causing yet another wave, masks are becoming more relevant again and I expect more people will be watching and reading comments" :-) Do you know what the name of that report was? Wondering if it is possible to find it archived somewhere on the Internet?...
@@marktaylor1527 I'm sorry but I've posted an answer 5 times and my posts keep getting deleted for some bizarre reason.
@@marktaylor1527 this is beyond ridiculous but I've now tried about a dozen times and there must be some word TH-cam doesn't like because my replies just keep getting deleted.
@@marktaylor1527 This is insanely frustrating. I'll try posting just a couple of words of the title in each reply and maybe you can use that to find the document.
Note this is not the original document but one with some similar information on the bottom of page 9 and on page 10
Genuinely appreciate the hours and hours you've spent here and are sharing with everyone. THANK YOU
Yes, definitely!
My wife and I are huge fans of your videos and appreciate the evidence you're providing! We both work in healthcare in the US and wanted to be safe and ethical about not taking away n95s from our heathcare system... and because of your videos have bought hundreds of kf94s and have been giving them out to friends, family, and vulnerable people in the community. I hope you realize you're helping save lives by putting out this info! 🙏
Coronavirus is a healing process taking place worldwide caused by solar activity ☀️ much love
This is spectacular. I just found this as we are re-analyzing masking for Omicron and I was digging for data. Thank you so much for all your fantastic work!!
This is a man who is passionate about particles
what about micro water droplets that linger for hours that are main cause covid.... these are consider vapours or particles?
Fast forward to Feb 14 2022, no shortage at all of N95s, were a 3M Aura 9205+ and protect yourself.
Aaron, thank you so much for all the work you've put into creating these videos, executing these tests, and presenting this data to us. You're quite literally doing a great service for humanity and the planet (save lives while creating less waste!).
Very helpful for those of us working full days in the public sphere right now. Thanks for putting these out there.
Thank you so much for all the hard work you have put into making this video. I bought some KN95 masks and was throwing them out after one wear to the supermarket so I found it quite expensive because I cannot work due to health issues. I am ordering again today. You are saving lives and I very much appreciate your efforts.
This is EXACTLY what I've been looking for. Oh my god thank you.
Another confound of the Danish study is that the majority of spread is likely occurring in unmasked gatherings, such as restaurants or homes. Most people (including those that were in the mask group) would not wear a mask in this scenario regardless, and could have been infected then.
What you really want to know is if wearing a mask reduces the probability of getting COVID in a setting where it makes sense to wear a mask (e.g. supermarket, other public settings, etc...). You'd need complete contact tracing to determine what percentage of infections in the "mask" group occurred when they were wearing their masks.
It does look like they equipped the mask group with surgical masks, so they're OK masks for protecting the wearer, but not great.
The "Adherence" section is also problematic. It states: "Based on the lowest adherence reported in the mask group during follow-up, 46% of participants wore the mask as recommended, 47% predominantly as recommended, and 7% not as recommended".
This is simply based on self report, and doesn't dive deeper into *when* the participants wore masks, and when they didn't. In the Supplemental you can actually see the instructions for mask wearing and they are rather vague.
Aaron, thank you so much for taking the time to post these incredibly informative and helpful videos. They should be watched by everyone. I have ordered some KF94 masks from Korea based on your recommendations for myself and my family.
As a nurse, thank you. Your videos are amazing and I wish more of the public who didn’t believe in mask wearing would watch them. It’s disheartening to have people yell and scream about wearing one to protect others, knowing that if more people did wear something we would be better off. Thank you!
Great info about the filtration efficiency with prolonged usage! I also appreciate the point about some water vapor escaping through the breathable material at the top of the mask. It might explain why I noticed that my lab goggles would slowly fog up over the course of the day even though I didn't notice any gross leaks during my user seal check or my glasses fogging up with normal breathing. Looking forward to future test s!
You provided excellent Public service! Peace and Light to you and your family
Thank you for all your research and info. You are definitely included among all the COVID heroes. This is such valuable information. Thanks for being one of the people that "get it" when it comes to a global pandemic. I hope blessings just absolutely flow into your life for sharing all of this.
I’ve been using mask strap for the ear loop KF94s and they really improve the seal. Even with the adjustable ear strap masks. I throw one set of mask strings on the strap, and tighten the others and place them over the ears. Belt and “suspenders” as it were.
Thank you *so very much* for this indispensable information and for the tremendous public service you've been doing in testing these masks. It's frankly outrageous that this far into the Covid pandemic (1/27/21) this isn't already common knowledge in the US and that we don't yet have a system for distributing high-filtration masks to the entire population. I learned about your work by sheer accident via a Twitter link from Dr. Abraar Khan. Thank you again!
Wow awesome, I am still new to Twitter but he is blasting out so much mask content its great! Thanks for watching and sharing how you got here!
Thank you so much for all your work. You are truly helping save lives. I have given kf94s to co-workers, my parents, and at risk family members. Thank you again
Aaron, I have not been a fan of the adjustable ear loops on any of the KF94 masks that I have tried. I have gone to using cord locks for the ear loops, and as the ear loops stretch I simply adjust the cord lock to maintain the correct face fit.
Great info, I've got everyone in my family and pretty much everyone I know using these KF94 masks. Thanks.
Bill thanks for sharing that, that's a good idea. Thanks for sharing and stay safe and hopefully will catch you in the park again for a beer soon(assuming this is the Bill Nelson I think it is judging by the picture)!
@@coll0412 Yep, it is me! Looking forward to catching up again in the park.
Here's a link to the cord locks that I've been using:
www.amazon.com/gp/product/B08FDNWJT2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1&fpw=alm
Thank you so much for your informative videos. Your expertise is so helpful during this dynamic time of uncertainty. You have taken the guesswork out of the difficult process of choosing high performing masks. Thank you!
Thank you for creating these videos!
You are awesome!! I bought a few Dr. Puri masks and just started wearing them at my new office job. I did worry about the fit since my glasses always fogged up, but you clarified every concern I had! I think I’ll buy medical tape to prevent the fog. I really appreciate this video and all the hard work that went into it. Thank you!
I’ve tried medicsl tape but it always comes off rather quickly. Bandaids, however, have worked brilliantly! Flesh colored ones virtually disappear where it sticks on your face. (I just don’t use then right under my eyes). Hope this helps.
@@Person-mh6xq I’ll definitely try the band aids! thanks :-)
How is tape or bandaid used?
Thank you so much for this and other videos. In my country, we got a very alarming situation with a record covid case pretty much being broken every day.
Thanks for the video!!! I keep reading from many sources that masks should be used just one. I have KN95 masks and now have information on how long I can wear one as I work at home and limit my trips to no more than one "establishment" at a time with most under 20-30 minutes. Will have to spend this weekend catching up on all of Aaron's videos.
I also use my car to store my masks. I put each used one in a paper bag. I have a system of using 3 big ventilated bags and recycling them in the car. I put the recently used masks (in their paper bags) into one bag. In the 2nd bag are those I wore in the previous week. And the 3rd bag contains the masks I wore 2 weeks before. This bag will be rotated next to the drivers seat and I will re wear those. This is working out well. Another thing I would like to suggest is to wear a strap around the back of your head, pulling the 2 ear loops from the masks together. This creates a very tight fit and it is comfortable (no sore ears).
Always provide a potential life saver.. God bless.. love from Indonesia
Thank you for all your work to keep us safe and informed. We were only wearing homemade cloth masks and when it got more dangerous I made my husband wear two when shopping. Currently he is not going out except to pick up curbside. Seeing your videos gave me hope and a sense of security. I have ordered some KF94 masks you recommended. I now feel safe for my 70 year old to go to Costco or our local grocery store. However, I’m unsure how long we can use one mask. You refer to a “clean office environment “ for how long you can wear a mask how does that compare to a grocery store setting? Thanks again!
A grocery store would also fit in that category. Reality is even if you wore it longer or in a dirty/dusty conditions you are still going to get way better protection than a cloth mask. Thanks for watching!
I always thank you for these useful informations during this pandemic. Two thumps way up for u Aaron.
Very informative I been throwing them out after 24 hours of use, now i can safety stretch it another day.
Thank you!
I agree that KF94s are great, but if we're talking about a solution that can genuinely scale to meet global demand, we need to talk about sealing flat surgical masks to users faces rather than assembling and forming these masks with complex shapes. KF94/N95/KN95s waste 20-40% of the material used to make them compared to surgical masks which have nominal material waste. What's more, surgical masks are less than half the price per unit. When combined with a re-usable mask fitter - you have a solution that can really scale.
Your degradation results are really surprisingly good - I would have expected the electrostatic charge to degrade much faster. Could you repeat your methods for a surgical mask? From our tests, masks with similar density melt blown fabric, but different electrostatic charges showed closer to a 40% reduction when tested to the NIOSH standard at 85 L/min compared to your 10% reduction. Do you think the difference here is that there is something special with KF94s, or that at low flow rates the differences aren't that apparent?
Totally agree with your analysis of the Danish Mask study. The quality of the source control is critical.
Totally agree with your stance on reusable masks as well - cost is prohibitive for the majority of the world, with nominal environmental impact benefit.
Thanks for putting out this content!
In regards to the degradation, my test is nowhere near the NIOSH spec of 200mg of NaCl since I am just breathing in ambient air in an office for 40hrs which will consistent of a lot of different materials. Most electrostatic media have a hard time with NaCl aerosols and static charge loss. Assuming a 14 breaths/minute, 0.5L tidal volume, and say 20 µg/m^3 office concentration, in 40hours we are talking 360 µg of mass collected so nearly 1/500th the amount of mass collected compared to the NIOSH spec,so I was not surprised that it still performed well. THe NIOSH standard is really meant for industrial use, which is why the mass collection requirement is so high. Probably doesn't make sense as a standard for a general population mask. The media used in KF94/FPP2/KN95/N95 masks is also better, and this is a by product the test requirements. The surgical mask requirements are much less stringent than KF94/FPP2/KN95/N95
In regards to the discussion of cost and meltblown usage, I would agree that a surgical mask is cheaper and uses less material, but also has much lower performance characteristics compared to KF94/FP2/KN94/N95 masks. We are about to get a flood of KN95's into the US so I am not sure that getting meltblown material is a really the constraint as much as it was in the spring.
Thanks for watching!
Aaron.. I love your nerdy detail... but cannot imagine sending your videos to others who just want the bottom line
Therefore I suggest that you make a video that is intentionally brief as possible
Mat
Maybe suggesting a specific mask available on Amazon. For convenience and availability
And then the demonstration of how to wear it
Then a review of how long to wear, rotate etc
You can refer viewers to other videos if they want more detail or a defense of your recommendations
Just give people the absolute basics in this video
Just discovered your channel after reading article about you on Yahoo. What you do is terrific. I wear a mask about 6 hrs./day. So 30-40 hours is about 5-7 days max., though I don't think you recommend that long. But seems to be possible, based on your data.
Outstanding video and information. Thanks man, you rock!
Yay!! I have been looking forward to a new video from you! And these topics are right on target! THANKS so much!!!
I think HCWs should be using 3Ms full face or half face respirator with 6035 FFP3/HEPA filters. Those filters can last for months. Both the respirators and the filters are wildly available.
Thanks for these videos! Information on masks are crucial in our time.
When you dropped that you're from Minnesota I was utterly shocked
Finally, I was waiting for another video by Aaron Collins! You have helped me more than you know, thank you. BTW, can you do a 3M N95 vs the KF94 and KN95?
Please tell me my comment was a decision maker on your new video lol
It was all you... and about 50 other people who emailed me, but you were part of it!
@@coll0412 I knew it was me 🤣😂, thanks to you I have my whole family wearing BOTN masks, appreciate it always.
Aaron, great content. If you edit your video descriptions and add a 0:00 timestamp directly above the "1:45 "How long do you recommend wearing a mask?"" time stamp it will automatically update your video progress bar to segregate by chapters. Make sure to save the edit.
@Aaron Collins Have you tested the effect of a mask soiled with makeup (like foundation that has rubbed onto the mask from the face?) or from a drippy nose? Have you tested it while wet, and then again after the mask is to removed and dried?
TSC sells Tommie Copper reusable masks - assuming we have a good seal, are they good?
You should try a KF94 mask (a genuine KF94 is made in South Korea and certified by the KFDA) it's widely considered to be one of best type of mask in terms of protection and comfort because the mask is largely designed not to touch your mouth due to it's design which leaves a large pocket of open air in the middle of the mask.
Thank you so much for your research. Fantastic content and delivery.
Hi Aaron, Your videos are literally lifesaving. Thank you for everything you do!
I have one question.
What mask do you recommend for children? Around 12 years old
I would recommend either the Bluna kids face mask, or the Blue 3D masks depending on the face shape. The Blue Kids 3d(with a tiger on it) will likely be too small.
What are your thoughts on dry heat decontamination? This is the first of your channel I've seen, so maybe you've discussed it, but there's been videos showing people sticking their N95's in their Instant Pots (in a nest of towels so the mask doesn't contact a heated surface) - The rule of thumb I heard was 100 degrees C for 50 minutes.
What I've been doing is wearing my Powecom one day at work, and then, because I notice after even a full day of wear the ear loops seem like they're not keeping the mask as snug, I tie a knot near the end of each loop to shorten it a bit, and at the end of the week when I have a handful of them in "used" condition, I Instant-Pot them.
I found my powecoms tended to leak at the nose bridge no matter how carefully I adjusted them, so I do add a foam adhesive strip to the inside of the mask on the nose-wire area, much like you'd see on some N95's and that seems tor really help the fit for my face. I re-wear it once and then trash it after the second wearing.
Here's a link to one publication that talks about the dry heat decontamination: pubs.acs.org/doi/full/10.1021/acs.estlett.0c00534
Thanks for the channel, I'll be checking out some of your other videos!
From my perspective I just don't see the need to sterilize the masks, the virus dies on its own over 3-4 days, so simply letting the masks sit around for that amount of time is sufficient. I think all the different techniques(Dry Heat, H2O2, Microwave) all have impacts on the masks, even if small, and add a lot of complexity and if done wrong damage the masks. That's my perspective at least.
based on studies and studies on studies DRY HEAT at 165 degrees F for 35 minutes is ample for disinfection and importantly maintains fit for many cycles.
You are saving lives!! Thank you!!
Thank you for your hard work. See you next time!
Just wondering if you’ve done any testing on Filti masks and their mask inserts.
Great video. Thanks!
I tested the Filti NF95 awhile back, it didn't perform too well.
docs.google.com/spreadsheets/d/1M0mdNLpTWEGcluK6hh5LjjcFixwmOG853Ff45d3O-L0/edit?usp=sharing
@@coll0412 oh bummer. Thanks so much for the reply. I just ordered a box of them yesterday 😂 Oops!
Aaron, I wish you could see my mask collection. I wear one for a couple of days. Then switch to a new one. And then a new one. So my desk is littered with all kinds of N95 masks and surgical masks. It's pretty funny. my favorite N95 is from Milwaulkee Tools. It has a rubber gasket on the inside and has a really nice close contact on my face. They have the valve so I have to wear a surgical mask on top of them.
I've been using mask extenders to tie the ear loops of my masks behind my head. This makes it more comfortable to wear my masks for long periods of time and also makes it easier for me to maintain a proper face fit. I guess mask extenders for ear loop masks might be a rough substitute for masks/respirators with headbands. However, I've never seen studies or experiments on how much (if any) improvement mask extenders have on ear loop masks (cloth, surgical, kn95, kf94, etc). Have you looked into this?
If you get a better face fit then you will improve the mask performance. The media of almost all KF94 masks is 99.8+%, so the dominant mechanism is leakage around the mask. If you reduce leakage you improve performance.
About a month after this video, the journal of JAMA Internal Medicine looked at how making modifications to cloth and surgical masks improved their filtration. They compared them to N95s. It included extending loops to back of head. The article is entitled "Evaluation of Cloth Masks and Modified Procedure Masks
as Personal Protective Equipment for the Public During the COVID-19 Pandemic'". I would post the link but YT deletes any comment I have that posts links.
@@MrWebster helpful, thanks! Although it looks like even with modifications, neither cloth masks nor surgical masks are really that effective. They improve, but they're nothing like the kf94s. I have pretty much stopped using other masks and just reuse my BOTN masks! (Up to 40ish hours, of course).
Thank you, this was very helpful. Can you recommend some brands that are smaller, for women?
Top Picks for Small Faces here-->th-cam.com/video/Gu0GkjOpOj0/w-d-xo.html
Thanks for watching!
I love the BOTN kf94 mask in size medium. I'm a fairly petite woman. It's also highly adjustable! :)
Thank you, Aaron! Did you end up making that video on the fogging eyeglasses problem and tips & tricks to fix it? It's been a constant problem to me despite what feels like a good seal. Help!
I haven't, but a good reminder for me to look at it again.
Most helpful mask videos on TH-cam, I do wonder though. How effective is a surgical mask at protecting yourself if you have a perfect seal? I can do that with a knot & tuck + a piece of medical tape across the nose
I work at a public elementary school (the kids are in session, in person full time) and I am being told by the nurse to wear my KN95 mask for 2 weeks before they’ll give me a new one.
It will still likely provide fairly good protection over that time frame, but I would recommend thinking about augmenting with small supply of your own.
Please discuss electrostatic charge/ relevance to reusability. Reputable sources indicate that the charge strongly contributes to the effectiveness of the media to trap and suspend virus size particles.
According to the same sources, the static charge depreciates rapidly over a 24-hour use cycle and that alcohol washes in particular destroy the charge. I am not aware of anyone testing the process of static charge over time/use cycles.
So if the static charge degrades, and also the effectiveness of the filtration media over time, what does this effectively mean for overall safety, particularly on the subject of mask reuse?
Your thoughts?
From one nerd to another, I thank you for all of your efforts and your wonderful information which I'm sure has reduced illness and perhaps even deaths.
You should watch this whole video, it literally covers this exact discussion.
Hey Colin big fan. I am on Mask4All a lot so thats where i learned about you. My question is what do you feel about Ear Savers? I find when i use an ear saver it makes the fit of the mask much tighter. Is that something people can use when the fit on the ears become loose?
Sorry for the slow reply, had missed a bunch of messages due to a TH-cam setting. So yeah you can use an ear saver to help keep the mask tight if its comfortable for you.
Thanks for these videos! You have such a fantastic, relatable approach. I'm curious if you have any opinions on double masking, though I realize testing efficacy would present a challenge. I'm considering layering my linen/silk/600tc cotton behind the head masks over the botn kf94 for cleanliness and even better face fit. (Currently layering 4 layer astm 3 surgical+cloth) I work in a fairly public, high risk setting and I'm often exposed to indoor, unmasked conversation, hence the layers upon layers and wanting to protect myself. Even if this is out of your realm, thank you again for the info and great explanations!
My recommendation is one mask that fits well with no leaks, adding more masks doesn't necessarily make it better. The surgical under a cloth masks is just a way to improve protection of a surgical alone, but it's far from ideal. Will cover it in my next video. If you are around unmasked people and less than 6ft I would also recommend a face shield.
@@coll0412 thank you! I really appreciate your perspective and advice here.
Would you we willing to test a couple of cloth masks made with a non-woven filter layer? Also, have you considered using ozone to clean masks?
Aaron:
Thanks very much for your information.
Re fogging glasses: You said moist air coming through nose piece fogging the lenses. Might it be possible to make that limited area impermeable to air. I suspect a piece of clear packing tape across the nose piece would accomplish this.
Thanks again
I’ve been using the KF94 for about 4 weeks total, when new will use them in high risk cases indoors then as they age will use them in less risky situations.
Great info! Thank you!
I hope at some point you may be able to add the new CE FFP2 certified Air Queen Breeze to your roster of masks you're testing. I'll be interested to see if Toptec have fixed their subpar nano filtration in their new CE certified mask.
Answer will come soon, just got my hands on some
Thank you! This is so helpful!
Hi Aaron,
Thank you for all the great information! Your videos have been so helpful. I wear a kn95 Powecom. Do you think moisture from talking loudly decreases efficiency?
No, it will have no appreciable effect. They filtration media was designed specifically for this application. Thanks for watching!
Last year on the cruise ship that was stuck in japan, many on board died of covid, the aircon was circulating it. After everyone left the ship, the went into the cabins after 3 week and still had virus in the cabins. Never underestimate the virus.
It's important to distinguish between viable virus, and finding viral RNA. What we care about is if the virus is still viable, ie. alive. Think of this the same as finding the bones of a animal 3 weeks after, sure it was present and was certainly there, but it's no longer alive. What we care about is how long does the virus stay viable, which depends on a lot of factors, but roughly 3-5 days on most surfaces and a massive fraction of it is dead. Also fomite spreading is not really an issue, the virus needs a direct route to cells with ACE2 receptors so this means inhalation is the primary mechanism. This is why the CDC has come out to say that fomite transmission is very rare.
Actually a lot of the cases appeared to be during the process of leaving the ship. They should have staggered it better.
I have been making ear savers to ear with FLTR95 masks I got. I've noticed the elastic stretching issue and I suspect these will help with that. I've never had a good seal around my nose with a mask. I have no bridge. I'm hoping this will help.
YESS both KF94 and KN95 can be worn up to 36hrs .in normal casual condition 👌👌👌
Is it ok to hang the mask on a coat rack or door knob or does it have to be stored in a bag? Would the ambient airflow in the room degrade the filtration media?
Nope should be just fine to do that. Thanks for watching!
how about face shields ? What do you think about them ?
They add some level of protection, but from an aerosol standpoint they don't offer much, if any at all, protection. It doesn't hurt to wear it along with a KF94/KN95 mask though, adds some level of eye protection as well.
My doctor said I could re-use a KN95 mask if I let it sit for 72 hours before wearing it again. I put them in individual brown paper bags and mark the date on the outside. She said I could re-use a mask this way for up to 6 or 7 times. Do you think this is a good method? Thank you.
Yes, it's the same thing I recommend as well. 40hrs or until the masks doesn't seal well to your face, whichever is first. Let them rest for 3 days before re-wear(conservative approach).
My family and I only buy mask from your recommendations. Thanks for the help! Would you happen to have a name for the Korean mask that doesn’t have the breathable nose interface? I’m turning into a mask nerd... 😃
If I ever run into again I will be sure to get it. I was deep into a KF94 search using Google Translate and have not been able to find it again as it was an all Korean text name. Will let you know if I do.
How about uvc sterilization of masks? Do they destroy it or reduce filtration efficiency?
Not sure, I just think cycling the masks through on a 3-4 day basis effectively self-sterilizes so not much added bonus to UV sterilizes
I don't bother sterilizing my masks anymore. I have a kf94 mask for every day of the week. By the time I reach for a mask at least 7 days have passed. Any virus that might be on it is already dead.
I would love to know how many total hours one can wear the same N95 mask? I see articles saying 1 time, 3 times, 5 times, but wearing a mask in and out to pick up food is very different than hours indoors at work. Have you tested this? Is it the same as a KF94 in this regard (30-40 hours total before a decrease in filtration efficiency)? Thanks! You rock!!!
I was wondering if you would be able to do a study with surgical masks, and if we layered surgical masks would it be as effective as wearing a n95? I current work in a hospital where I care for covid patients, and the nurse manager called me out for wearing a n95. She said that I should wear 2 surgical masks and a faceshield which is "apparently" equivalent to wearing a n95. what do you thinkl?
I can pretty much guarantee you that two surgical masks will never get close to an N95 for the simple reason that surgical masks don't provide a good face seal. I cover the two mask concept in the link below. My recommendation is if they won't let you wear a N95, then I would say just wear your own KF94 that fits well. Some are FDA approved equivalents to surgical masks. Shame on them for doing that though.
th-cam.com/video/Z93BoeCuIE4/w-d-xo.html
@@coll0412 informative as always, thank you.
Consider wearing a mask frame on top of the surgical mask to hopefully reduce leakage.
www.gardentowerproject.com/products/diy-face-mask-frames-family-6-pack?_pos=1&_sid=ae776fd19&_ss=r
I am so glad I found your videos! We've been using surgical and cloth masks, in spite of the fact that I've had some nagging doubts about them, because of the fit issue. It's good to know there is an alternative to the N95s that need to be reserved for the heroes staffing our medical facilities. I do have one question. Having learned that doubling up surgical masks, or wearing a cloth mask over a surgical does not increase the effectiveness of either, I am wondering - is it safe to wear a cloth mask over one of the KF94s? I know my cloth masks aren't terribly effective, but they are pretty. >.
Thanks for watching! If wearing a cloth mask over the KF94/KN95 does not compromise the seal then its fine, but won't provide any extra protection. Mostly just for a fashion perspective.
Got a question. Botn, airqueen, some other masks have their logo in the front of the mask. If you look closely, it looks sort of transparent but not. Looks like the logo part of the mask does not have the outer layer, just the inner layer? Or is it some other material completely. How does that affect the filtration where the logo is?
No impact the filtration. THe masks are joined together using a heat sealing method where they basically get "stitched" together with a hot metal rollers. They can also emboss a logo using the same technique so that's why you see the logos. All the masks I test as is, so if they did have an issue they would show low filtration performance. Hope that helps!
@@coll0412 Thanks! That helped a lot.
Hi Aaron, is there any data on the effectiveness of expired masks? (e.g., 1 year past the expiry date)
I personally would have no concern using them, tests from 9+ year old masks tested just as good as new. The elastic and foam are the first to fail but takes many years.
www.cdc.gov/niosh/npptl/ppecase/pdfs/PPE-CASE-Stockpile-4-v2-03012020-508.pdf
Hi, will exposure to sunlight like leaving it in a car damage a mask?
I have not seen any data that says it does, I left mine in the car for those long term tests, with the abused BOTN having sat on my passenger side seat for about 3 months. So I don't see much a risk at all in doing that.
Thanks for the great info, do you notice a difference in breathing efficiency/difficulty with extended mask use?
Thanks for putting the time into making these videos, they have been a big help. I was wearing N95's at work and reusing them/disinfecting them with UVC or heating them as per the data I have read. Switched to the BOTN and they are much more comfortable and affordable enough that I can use clean masks. Based on your data, I guess I should start cycling and reusing them and cut down the waste a bit.
I didn't do any pressure drop measurements but to be honest its certainly not noticeable after 40hrs, feels the same to me.
@@coll0412 Thanks, thats great, I will start cycling the masks!
This was so helpful, many thanks for doing this test, greatly appreciated🙂
Can sweat reduce the filtration efficiency of masks? I usually sweat a lot if I'm wearing mask. I'm worried that it might significantly reduce the efficiency of the mask when I reuse it.
There is no risk of sweat ruining your mask, so no worries there.
Thank you very much. I've learned a lot from your videos.
Hi Aaron-- Not sure if you're still checkin the comments on this. First of all: thank you for all of your mask videos-- they have done so much to help other people. I had a question about expiration dates: I received a bunch of masks recently with expiration dates that are about to pass. If the expiration date passes and the masks have been unopened in their packaging, does that affect their filtration efficiency (i.e., does the electrostatic media degrade)? If so, do you have a ballpark (or scientific) sense of what sorts of efficiency losses would occur within which time periods? Thank you again for what you do.
If they are in a sealed package I would have no worries about it. There have been studies to show no change to the filter media, it's really just the rubber in the ear loops that goes bad and that takes like 5+ years.
@@coll0412 Oh. Great! Thank you, Aaron!
Great videos Aaron. Quick question ! Does the 30-40 hours apply to a setting like Walmart?? Or would you recommend using a new mask every day to work for that setting?
Yes this would apply to Walmart too. Basically anything that's not a construction type environment. Thanks for watching!
Hey, Aaron. When you refer to the double ear loop thing around 15:00 minutes can you clarify what you mean by double ear loop? Just wondering, thanks!
The BOTN masks has adjustable earloops. For my face I can manage to fit both the primary loop you are supposed to use, and the extra material around my ears. Effectively on the masks I have two loops on each ear pulling it in. Not supposed to do that, but for me it is just a happy accident that I have enough extra earloop to work with. Does that make sense?
@@coll0412 Yes, absolutely! Thanks so much for clarifying. And thanks again for all the work you do to help us.
I've used your videos to help inform me throughout the pandemic. You're a gem
Does UV-C light decrease the filtration level of the KF94?
I'm considering getting a UV-C sanitation box (fits things like keys, wallets or masks). But i have no idea if UV-C light has an effect on the electrostatic charge of the mask. Any thoughts on that?
Not sure to be honest, I find the cycling mask on a 4 day basis the easiest option.
Is there a video of how a wearer's sneeze or cough (like my allergen-sensitive kid) affects the life of such masks? I think prior guidance was just to toss the mask after the wearer sneezes or coughs into masks.
Any other common vapour/fumes that would reduce the filtration/electrostatic? Just thinking about how much 70% ethanol and acetone vapour I'm exposed to at work.
What about for a barber? Thanks!
Have you tested cloth masks properly fitted with a non-woven filter layer made of oly-fun (polypropylene) or Halyard H600 Surgical Sheeting?
How about easy flow usa personal air purifier attached to masks?
Thanks for making this helpful video. I teach at a college in a regular classroom (not a lecture hall), and I think I will start using a KN95 and cycling through them until I am eligible for a booster. Is there information on whether sound will be muffled/inaudible with a KN95 compared to a surgical mask? I tried double masking with a cloth mask on top of surgical and that definitely muffles the sound a lot. Thanks!
No direct measurements, but yes masks that doesn't touch your lips and mouth don't muffle your speech. A big reason why KF94/KN95/N95's are so nice.
Thanks! I didn't know that, but it makes sense.
Do u recommend the Botn for me? I work in the medical field specially in a doctors office.
I would recommend a KF94 mask for sure, and one that fits. I usually recommend starting with the Bluna FaceFit and seeing how that fits to start, BOTN's are larger so if it feels small then you can go larger.
Hi, I'm thinking about cycling the BOTN masks to reduce cost, what if I work at a job where I take the mask off and put back on about 4-5 times a day(retail job), can I still use it for 40 hours, that's about 20-25 times taking it on and off, I read on the CDC website for reusing N95s they only recommend about 5 times taking it on or off since the elastic wears off
With adjustable earloops you can adjust the tension over the life of the mask, so I see no issue with using it 40 hrs but taking it on and off many times. Will be fine
Would be VERY interested in data regarding cleaning the masks in a solution of oxidative laundry detergent, or other cleaners (e.g., hydrogen peroxide/water solution of verious concentrations). Please?
To be frank I probably won't have time, I want to focus on keeping the supply chains fat with masks right now.
For the breatheteq masks, how many hours can you wear them for before needing to change them?
In general it's tough to get more than 40 hours out of them before the earloops stretch and it stops fitting well. In terms of filtration, they will do a great job for a long time.
@@coll0412 ive heard about the 40 hours! But the packaging says 8 hours so I wasn't sure if it was accurate ( If the mask still fits well, and isnt dirty that is)
have you been using the same Moldex N100 for this whole time? if so approximately how long have you worn it total?
I have used the same N100 control since July, but only has about maybe 1hr of total wear time on it.
What about the issue of mildew growth from the super humid and hot environment from a full day of breathing in the masks?
I didn't notice anything from my masks after having worn many for 40+hrs each. I think since you can't really eat or drink with them on it really helps keep down the nastiness.
DenTec Safety claims their N95 filters last up to a year and I hear similar things about P100 filters. Is this true? Why is it different than the more traditional KN95s and N95s your cover here?