The CDC warns of counterfeit N95/KN95 masks

How does that diminishment compare to the different risk profile people are normally in?

Walking in a grocery store, or even being on an airplane, shouldn’t have the same risk profile as actually working in a healthcare setting. So, is the risk decreasing at the same or faster than the reduced performance, or is the reduced performance going down faster than the risk reduction?

I don’t think I’ve seen anyone with the valves taped over. Whenever I see someone with a valved mask I think “what a selfish asshole.” Because they obviously know masks are needed and will wear one but the valved ones (sans tape) do not protect anyone from the wearer.

Lots of places with masks requirements, like clinics and airplanes, are requiring surgical or N94, KF95, or KF94. No cloth, no valves.


I have no data. The obvious variable is “how bad is the fit, or how egregious is the improper wearing?” Since a lot (but not all) of the shortcomings of surgical and cloth masks revolve around gapping and leaking, those are the spots where these misapplications enter in. N95 masks, in and of themselves, are excellent and should be used whenever possible. As usual, it’s the addition of humans into the equation that screws things up.


Yeah, that was always my take, too. But the fact of the matter shown by the CDC/NIOSH study is that the valved N95 FFR masks do protect protect people from the wearer, just as much or more than a cloth mask or surgical mask - not that most people wearing them with the valves untaped knew or cared, though.

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It’s a lot harder to dick nose a cup style N95. Just the shape and tight fit of the mask makes wearing it wrong harder - but not impossible. I’ve seen people wearing respirator grade tri-fold KF94s (similar shape to 3M Auras) over their mouth with the mask still folded. :frowning: Sigh…


A few of my FFP2 masks came with these clips. I save them whenever I come across them and use them on all my FFP2 masks. The fit is markedly improved by them. Even when I thought a mask sat tightly with just the ear loops, when I first put on one of these, I realised how much more tightly it could sit. The bridge of my nose still hurts when touched after having travelled with an FFP2 mask with such a clip for a whole day last week.


In addition, those that wear them are probably less likely to do that anyway, as they’re more likely to actually want protection and believe in the efficacy of masks.


They do! Dead people can no longer buy the counterfeit masks. The ones who survive buy the masks that kept them alive. Several million deaths later, the counterfeits are quickly and efficiently replaced by legitimate masks.


The high-low dual elastic straps tend to hold the mask tighter (and leave deeper marks) than the ear loops, as well as hurting the ears less, although they seem to hurt the face more. We’ve beat the N95 vs other masks topic to death repeatedly and I am not planning on entering that fruitless debate again. Suffice it to say that there is no PPE so perfectly designed that a sufficiently motivated idiot can’t misuse it.


This is what my spouse and I have been doing. Not for fashion reasons but because we’re both small people (I wear a child’s size sun hat, for example) and anything with ear loops will gap or fall off. Our cloth masks have behind-the-head ties and help hold everything in place. I wish more people realized that no only do you have to wear a mask, it has to fit, dammit.


(I know the original comment was sarcastic but I think about this all the time) I think the free market as it is imagined where consumers influence brands to be better only works with things that are immediately obvious to the purchaser. Like let’s say a guy opened a store selling masks and the straps broke when you first put them on. Well in a case like that surely the customer wouldn’t come back and would tell other people not to shop there. But in reality it’s not that simple. Its hard to judge the effectiveness of a mask against disease on a person level. and even the way we buy stuff on Amazon now a seller may use deceptive marketing and disappear in the night after thousands of sales and pop up again with a different name selling a different looking product. free market is also terrible in situations where the consumer gets instant gratification and suffering and destruction happens hidden far away or in the future. Like fossil fuels and the environment or bad factory working conditions in foreign countries. The consumer won’t make best choices except on a very personal and immediate level. if two sellers are selling handmade kites next to each other and one makes cooler looking designs for a lower price with better quality materials, maybe yeah they free market works. But in most market situations in the modern world the best consumers can do is choose a lower price and that doesn’t take into account the whole picture of a product.


In a similar vein, I think it only works in really small communities where there are few products and few sellers. There is just no reasonable way for consumers to keep track of and evaluate millions of sellers and millions of products.


From CDC research: adjusting the nose strap properly is pretty important, but an un-adjusted N95 is still better than a 3-layer surgical.

Full paper here:


You’re absolutely right. It’s something that a lot of thoughtful economists think about as well. It’s called the Principal–agent problem - Wikipedia.


I’ve had good luck (at least, I think so) buying KN95s from… they’re distributing directly from the manufacturer, so hopefully it keeps the prevalence of counterfeits low. The NYTimes had the powecom masks independently tested at one point and they checked out: Where to Buy N95s, KN95s, and Surgical-Style Masks in 2022 | Reviews by Wirecutter

The head-strap only approach makes sense for N95 certification… but my young kids really struggle with taking them on/off, so they’re more likely to wear the KN95’s properly when they’re at school. Maybe I’ll try headstraps again with some of the clips mentioned.


I would say “with deer slugs”, but that would produce too clean a hole. #8 bird shot, on the other hand…


I have a N95 with valves that I originally got for use while operating a laser cutter (esp. while cutting plexiglass).

The company that makes it has an accessory that replaces the vents with sealed off nubs, which I bought because the mask is easier for me to wear for long stretches of time then the disposable KN95s. Then my office decided the valves were bad, and didn’t want to make an exception for the sealed off ones because nobody can know just by looking at it that I’m not trying to kill everyone.

Which is fair, but sad.

Oh, that is good to know!


It is kind of surprising, but it’s primarily because cloth and surgical masks suck so much. :-/

All the time everyone in cloth and surgical masks were giving the stink eye to people with valved N95s they should have been giving it to each other.

That’s why I use really conspicuously colored tape over the valves instead of using white tape that would look nicer.

The elastomeric NIOSH respirators with source control now available all have a similar problem. They were all made from valved respirators and they still look like they have valves.

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I found Honeywell general-purpose N95s at a hardware store near me and picked up a couple of boxes. The store was very well stocked (the week before Christmas), but I probably ought to swing by and get a few more boxes if they aren’t all gone.

Grrrr: people are still not taking this seriously. Last night at the store, I was the only one in the whole place wearing an N95. The joke of it is, the N95s are easier to breathe through than the cloth masks I was using.


Yeah, around this section of GA you’d never know there was a pandemic raging in some areas. I’m now avoiding grocery stores in ‘red’ neighborhoods because there’s nary a mask to be seen. Meanwhile in the poorer and artsy neighborhoods folks are wearing masks everywhere.