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Comment by kube-system | Hacker News Reader

Austria requires FFP2 which is not quite as strict of a standard as NIOSH N95. At the 95+% filtering rate, it’s really the mask’s fit that is making or breaking filtering ability.

N95 masks fit very tightly, come in different shapes and sizes to fit different people, and will leave imprint marks on a persons face. This is beyond what the general public is really willing to go through, so they’re really not used many places outside of medical settings, and it’s not really realistic to have them properly fit tested by the general public.

We do have real world data to show that properly fit tested N95s work very well when used by trained people, from the hospital settings in which this is done. But like any equipment, it’s only as good as it is used properly.

It may very well be possible that leaking FFP2 masks aren’t much different than other masks in effectiveness against highly transmissible variants.

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The linked study actually uses FFP2 masks, not N95. Here's a relevant part from the abstract regarding how an FFP2 performs:

> We find, for a typical SARS-CoV-2 viral load and infectious dose, that social distancing alone, even at 3.0 m between two speaking individuals, leads to an upper bound of 90% for risk of infection after a few minutes. If only the susceptible wears a face mask with infectious speaking at a distance of 1.5 m, the upper bound drops very significantly; that is, with a surgical mask, the upper bound reaches 90% after 30 min, and, with an FFP2 mask, it remains at about 20% even after 1 h. When both wear a surgical mask, while the infectious is speaking, the very conservative upper bound remains below 30% after 1 h, but, when both wear a well-fitting FFP2 mask, it is 0.4%.

Hmm. Thanks for pointing that out — that’s really bad reporting. These designations mean something.

> N95 masks fit very tightly, come in different shapes and sizes to fit different people, and will leave imprint marks on a persons face. This is beyond what the general public is really willing to go through, so they’re really not used many places outside of medical settings, and it’s not really realistic to have them properly fit tested by the general public.

That's not true. They're extremely common in construction for dealing with dust and paint aerosols. I wouldn't be surprise if that's the application they were actually developed for.

At the beginning of the pandemic, I had a bunch because I always use one when I sand or spraypaint.

You’re correct and I’m aware of their use in industry. I was unclear but what I meant was that they’re not commonly used by the general public for COVID protection outside of medical settings.

> You’re correct and I’m aware of their use in industry. I was unclear but what I meant was that they’re not commonly used by the general public for COVID protection outside of medical settings.

That's not actually true either, or not true for the reason you assume. I'd say I've seen about 5-10% of public mask-wearers with more-available KN95s, which does count as "common" (just not ubiquitous). N95s were extremely unavailable for a long time, but early in the pandemic, I saw at least that much N95 use (given lots people like me probably had a few laying around, that then got used up).

I am referring to actual NIOSH N95s when I say N95. They are certainly used by a slim minority of people on the street, and I am not stating otherwise. However, their lack of comfort is a reason many people would/do choose not to wear them. In the context of use by the general public, I'm implying that it is not really practical to expect mass use of (or mandate) N95s. It would not be received well, and they wouldn't be used properly anyway. In a world where we're struggling to convince people to cope with the inconvenience of wearing surgical masks -- you're definitely not going to convince them with a NIOSH N95. KNs/FFPs are reasonable compromises, and they're downright cozy by comparison.

KN95 masks are just rebranded PM2.5 masks that Asians wore mostly to avoid pollution particulates.

> paint aerosols.

A warning/clarification here - N95 masks will not protect you against paint fumes. You should never use them when spray painting. You need a respirator with a charcoal canister.

That said, even with a proper respirator it's really hard to get the fit right. I had a big painting project two years ago and I could often smell the paint, which means it wasn't working.

I wear N95, but... I have a beard. I'm painfully aware I'm sabotaging my own efforts and do not have a perfect seal.

I’m amazed at the number of people I see wearing N95s or KN95s with a clear gap at the top. Why bother?

I have a collection of various 94+% masks that I amassed towards the beginning of the pandemic. About 6 or 7 types. Only 1 of them doesn’t fog my glasses in the winter (and it’s a freakin Honeywell respirator) That means all of the others are leaking, even when I wear them “properly”

Water vapor is a lot smaller than viral particles and is likely to pass through even a N95 mask, which is good, as you'd drown pretty quickly if it didn't.

I wouldn't read too much into fogging.

(That said, I do wish there were better options for people with giant noses like mine.)

I mean, they’re fogging because the top of the mask leaks, and the breath takes the path of least resistance and goes around rather than out of the mask.

Yup, exactly. I use my glasses to seal the top. It's weird but it works.

Likely, but not necessarily. My silicone half-face (with disabled check valves) slightly fogs my glasses because enough water vapor is leaving the filter close to my glasses. I'm sure it's not leaking, because I can feel the silicone pull away from my face when it does.

For me, fogging my glasses means I have a leak and the air is being forced out gaps around my nose. Maybe under extreme weather conditions a perfect fit would still fog, but that's not what the op is talking about.

I think it's more about the direction of the water vapor than the fact that the masks can pass vapor. If there was no leakage one might expect vapor to leave through the mask uniformly or in the same pattern as it did without masking (e.g. mostly forward.)

I used to shave and use medical tape to seal KN95 masks around my nose. Since the vaccine came out, I don't bother anymore.

By my own very much baseless estimation of people wearing FFP2 in Germany: about 10% have their noses out, 60% have the mask completely unfitted, and 30% have at least tried to fit it.

> I’m amazed at the number of people I see wearing N95s or KN95s with a clear gap at the top. Why bother?

Uncharitably: People think it's a magical talisman; wear this mask and be protected. There's no grasp of the mechanism, so "wearing" the mask can be arbitrary.

Charitably: If people grasp how masks work, it's easy to forget, or not think of it, or not check that it's (still) on correctly.

(Bluntly, I think the former option more likely, but I try to think of charitable options)

I have a KN95. I can't get it to fit on the top. Always fogs my glasses. But when I breathe in, I can clearly see by the fabric's motion that air is substantially being pulled through the material rather than around it (edit: or that might just be pressure differential).

In any case, we are talking about mitigation of risk, minimization of exposure. If my mask is only filtering 80% of the air at 95%, that still a lot fewer viral particles I'm exposing myself to than otherwise. I don't think that its a matter of whether 1 viral particle gets through, but how many that determines likelihood of an infection or serious illness.

And its effectiveness is backed up by studies of unfitted 95s.

Depends on degree; I was thinking of people who aren't even covering their noses when I wrote my comment. Good point, though; I hadn't thought of "physically doesn't fit".

> I have a KN95. I can't get it to fit on the top. Always fogs my glasses. But when I breathe in, I can clearly see by the fabric's motion that air is substantially being pulled through the material rather than around it.

IIRC, KN95s were designed for flatter, asian noses. I think I read somewhere that one of the motivating factors for the design was that it's harder for asians to get a good fit with some types of N95, because they were designed for caucasian noses.

I have a big nose, so KN95s never work for me, unless I retrofit a really long and beefy metal strip for the nose.

> I can clearly see by the fabric's motion that air is substantially being pulled through the material rather than around it.

I suspect that the fabric’s motion doesn’t mean what you think. You’re just seeing motion from the pressure change. A non permeable plastic film will also move as the pressure changes. This doesn’t mean any air is going through it.

> If my mask is only filtering 80% of the air

If your mask is leaking around the edges, it is extremely unlikely that your mask is filtering anything close to 80% of the air.

You might be right about that.

My most important point though is that if your goal is to reduce your risk, then wearing an 95 type mask, even an unfitted one, achieves that goal. Its not all or nothing.

On the bright side, if you are vaccinated and reasonably healthy, the risk from COVID is quite low. I’m still wearing cloth masks.

Lately, I've been using FFP3 masks with N95-style double headbands. All the FFP3 masks I've seen have a foam nose bridge that makes it much easier to get a good seal than any of the KN95s I've seen.

FFP3 is a higher standard anyway, ~equivalent to the US's N99.

Interestingly, fog on glasses does not appear to be a strong indicator of a poor fit: https://www.ijccm.org/doi/IJCCM/pdf/10.5005/jp-journals-1007...

Consider how the fit can be pretty and still result in fogging up your glasses. In general but especially on cold days, you avoid fogging your glasses because the air you exhale is moving usually quickly enough that it is past your glasses by the time any of it starts diffusing and moving upward.

An N95 slows it down enough that some of the warm, moist air will make its way up to your glasses. It'll be especially noticeable if you're outdoors int he winter. Plus, the shape of some N95s and KN95s looks like it would cause some of your exhaled air to diffuse out through the mask in a more upward direction that it would if you were maskless.

Interesting!

So two of what I considered indicators of fit are probably wrong. I'll call that a good day. (:

Those are mostly the people just wearing a mask because they have to. Personally my thinking is "the mask mandate is here for a reason, and if I have to wear a mask anyway, I might as well wear it so it actually protects me", but even I have "misadjusted" an FFP2 mask for better ventilation when sitting in a 90% empty train on a hot day...

There is simply no system for random joe to find masks that fit them.

Suppose you buy a mask and it doesn't fit, what do you do, but random ones untill uou find one that works? They have no categorisation, even if you find one, often you cant but it again as shops change their stock randomly.

Also sometimes you buy a FP2 mask and if turns out it's not https://www.pcgamer.com/razer-rows-back-after-zephyr-face-ma...

I’m not talking about “poor fit”. I’m talking about a significant visible gap. As in I could probably put my pinkie between the mask and their face. I see this a lot and while I understand fitting masks can be hard, this it’s hard to explain like that.

This is sometimes an “optical illusion”. Good masks have a metal sheet there that you can bend to fit your nose. However, when you bend it, the outer cloth of the sheet pocket will not follow the curves as tightly, if at all. It appears as if the wearer had not attempted to bend the metal sheet at all.

I’m not sure what this means. The use of an N95 or equivalent provides value only when rightly fitting. It sounds like you’re describing a mask that gaps no matter how it’s fitted.

A lot of the people I see like this seem to have bent the nose piece so tight that it’s actually lifting the top edge off their faces (because the nose cannot fit in the tiny space created). I’m not sure if they think the absurdly tight nose piece is sealing better or if they are intentionally doing this to make it more “breathable”.

No. I’m saying that you cannot look below the mask around the nose to see whether there are gaps. The outer cloth is not an accurate indicator.

The too-tight nose piece is probably because that’s how the masks are packaged.

> The outer cloth is not an accurate indicator.

Ah, I see what you mean. I’m pretty sure that I’m not seeing an illusion most of the time, because I’m not looking at the cloth. I’m looking at the very visible skin beneath the gap. But it makes sense that the outer layer of cloth could be misleading.

> The too-tight nose piece is probably because that’s how the masks are packaged.

You’re probably right. I normally see this on the center-folded masks. This would mean that people are just throwing on the mask without fitting rather than doing an astonishing bad job at attempting to fit, or intentionally fitting to create a space. That’s certainly more understandable.

Humans learn quickest through mimeses (imitation of what they see). That is why airplane flights start with a certain ritual demonstration.

Why bother? In order to avoid punishment in places with mask mandates.

Most places are not mandating N95-equivalent masks. Certainly they are not in Seattle, where I live.

Rumors are that CDC might start recommending them. Which means states will follow suit. Anything to make it seem like they're doing something.

It could certainly happen. I hope not. We’re gonna see a lot of wasted n95s if so. Few people know how to fit them and a whole lot of people have beards.

Here in Czechia they're mandatory in public buildings.

They're still more effective than a surgical mask, even with a gap.

Are they? If most air is coming around the edges I’d expect that whether the mask is woven cloth, surgical, n95, or solid plastic just doesn’t matter much.

I'd have thought it's pretty straightforwardly a case that effectiveness is capped at the percentage that comes through the material; so as long as some is, a better material will do a bit better. For sake of argument if you're getting 80% effectiveness from a perfect fit, that's 40% if 50% air comes around the sides, and better than an alternative that's 20% effective however well it fits. (All made-up round numbers.)

Is it possible that "worse" masks actually perform better in this case, because more air actually passes through the material instead of through gaps? Not advising to use flimsy masks of course, just wondering.

I’m not sure if it is or not. It’s something I’d actually like to understand.

I would imagine that if there’s a significant gap, most air would actually bypass the mask entirely. And “significant” here is still fairly small. I’m thinking you only need a cross section as large as your nostrils for most air to flow around the mask. And as you make the mask less breathable/more resistive, more air will bypass the mask.

But I don’t know how accurate my assumptions are.

I mean, sometimes people don't really care and they have to just adhere to the rules. (Some of those people have already had covid and the vaccines and are at such low risk of spreading it or catching it, the reduction in risk posed by the mask is negligible.) People in the trades, or with similar hobbies tend to have them lying around. Plenty of times I've just grabbed a used up N95 dust mask I had lying in the truck because I had to run to the hardware store really quick and I forgot my more comfortable mask.

More often, it's probably just a lack of training / reading the instructions on how to press-fit the nose bridge.

Then there's people like me with weird faces that fail fit tests no matter how careful with basically everything except the duck masks.

It's the nose peeking over that gets me.

I've worn an FFP3 throughout, don't see the point in cloth or surgical masks. (With my nose firmly inside...)

Indeed! I doubt there are studies on this, but I wouldn't be surprised if wearing an N95 with a full enough beard is equivalent to not wearing a mask at all, or to wearing a t-shirt cloth mask.

Whenever I'm about to be in a place with people, I try to remember to fully shave that morning, so there's not even a day or two's worth of stubble preventing an N95 seal around my nose and mouth.

There has been a study! It didn't cover beards longer than 10 mm, however. Short answer: not as good as an N95 without a beard, but better than cloth.

https://pubmed.ncbi.nlm.nih.gov/34006963/

There are studies about how beards limit mask effectiveness.

https://www.nature.com/articles/s41370-021-00337-1

I got rid of my beard before a big (vaxx and mask required) convention in DC last weekend, wore an N95 to the best of my ability, and tested negative (PCR) more than 24 hours after, and I am still feeling fine.

The difference between N95 and cloth masks is so big that we should just treat cloth masks as no masks.

There's some truth to that, but if we try to mandate N95 masks and no longer allow cloth masks, that'll destroy the mandate altogether. The majority will simply ignore it.

There are studies; ultimately, nothing with COVID is binary - it's levels of protection, and even with a beard there are a lot of "depends" based on the length of beard, fit of mask, and proper wearing.

I do find that one kind of KN95 fits great even with my beard (which is short - ~5mm). I trim next to the nose so I have a good fit there, and my side/bottom are short enough that for the most part mask seems to "dig through" the hair and contact skin, kinda like the Studded tires dig through snow to get to ice.

But again, I'm aware that my protection is lower than if I shaved. Personal risks assessments are personal, mine is that I work remotely, am on video calls 6+ hours a day, and shaved I look like a 12 years old :). Meanwhile I very rarely go out, and if I do go out for groceries biweekly or so, and not at all now during omicron, distance + mask + booster provide a reasonable protection.

When the pandemic started, I had several of my friends jokingly tell me that it was time for my beard to go if I wanted to get the full protection of an N95. I jokingly told them that if it was between me loosing my beard and getting covid, I was getting covid (in my 20's for context).

Granted not the smartest decision but given my risk factors and the fact that I've never not had a beard since I could grow one, so people would likely not even recognize me without one. And two years on I have yet to be infected so I'll count my blessings as a stoke my glorious beard.

You could try the Singh Thatta method – basically, using a yoga/pilates elastic band as a headwrap, against which the N95 forms a tighter seal. I've done it a few times in higher risk situations, and while I feel a bit silly with it, the fit does seem significant better.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7532752/

Still better than a surgical mask. Would be better if you dropped the beard but don't let that discourage you from moving in the right direction.

> Would be better if you dropped the beard

It's unbelievable what the pandemic has caused people to think it's acceptable to say.

Or how quick to take offence to fairly benign statements a certain type of person is.

You're misreading that comment. "Better" refers to how well the mask functions at blocking the virus, not to a moral judgment that beards are sinful.

I'm the grandparent poster it was directed to, and I see it as a perfectly acceptable and correct thing to say given the context; if you feel the need to get offended on my account by taking it out context, it's a free world! :)

FWIW, my perspective: In context, I have implicitly stated my goal of self-protection and even indicated my awareness that beard is counter-productive. Saying N95's effectiveness would be improved by dropping the beard is merely factual and restating what I already said. I certainly don't find it an "unbelievable" statement :)

What is the "right direction" for dealing with a virus to which everyone will eventually be exposed? Why are people so lacking in humility that they're sure they know what's right? What are the odds that you're wrong?

https://www.medpagetoday.com/opinion/vinay-prasad/94646

Your article doesn't contradict the parent. Delaying exposure is the right direction.

Not sure I follow your line of questioning. It's a known fact that hospitals are overloaded. Anything we can do to reduce that load is a good thing. Hospitals are understaffed and overworked.

Masks provide positive ROI. Wearing a mask is really not asking a lot.

Hospitals were frequently overloaded by other seasonal respiratory viruses before 2020 but they just dealt with it and mandates weren't imposed on the rest of society. What's different now? It seems many physicians have a different perspective.

https://youtu.be/GklHGYY8vN8

(Not the parent post, but the bearded grandparent poster :)

Even if we want to deny existence of universal right, or societal right, there's still a personal right direction.

First, my goals (which are mandatory for any discussion of correct/incorrect approach, whether on personal or societal/policy level, to be even remotely productive. We can't discuss "what path is right for society" without being explicit about our priorities, goals, assumptions!): For me primary goal is to protect those vulnerable in my life, including my newborn, my elderly parents, my immunocompromised nephew. On path to that, as well as from selfish perspective (I have Asthma/Bronchitis and my lungs are crap), my effective goal is avoid getting COVID for as long as possible, ideally forever; and minimize its impact as much as possible.

Once those personal goals are laid out, the correct approach / right direction is easier to discuss and navigate. Certainly, at the very least, working toward postponing infection has so far been a brilliant decision - even today, getting omicron while vaccinated is better than a year ago getting delta while not vaccinated. My personal extrapolation is that postponing it further is even better, both for myself and for society (most health systems being comprehensively overwhelmed currently; in Toronto, Canada entire hospitals are shutting down and so my mantra is "don't get sick right now", not just Covid).

If you believe you have meaningful contribution to my right direction given my goals, I'm all ears :). I don't believe lack of humility is at issue here but again, let me know if I'm mistaken :).

Exactly. Two additions:

- N95's are used in many other industrial settings - medical is just where they're used to protect against covid. They're terrific masks when used appropriately.

- N95's do nothing to protect against getting covid through your eyes, which is a perfectly viable means of contracting SARS-CoV-2, as with any similar virus [1]. This makes the 75x reduction figure seem particularly silly.

(disclaimer, I make a mask with integrated eye protection)

[1] I cite some studies here: https://narwallmask.com/#h:why-is-eye-protection

FFP2 has more test then N95. [1] There are several shapes of FFP the one which is dominating in Austria (and Czechia and Slovakia) is not the only one.

[1]: https://www.wired.co.uk/article/what-are-n95-and-ffp2-face-m...

There are many shapes of all types of masks. Shape is important but only one part of proper fit.

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