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Comment by sterlind | Hacker News Reader

we should be pushing for N95 masks to be cheaper and more available. those masks block aerosols when they're properly fitted (and we should make them easier to fit.)

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> and we should make them easier to fit

Not to mention make versions for unusual face sizes (big and small). I cannot find one large enough for my face.

And my wife can't find ones small enough to fit her face properly. In her home country masks come in all sizes and shapes, in Europe there seems to be only a single size. At least every type I've looked at is the same size as all the others.

I found one with an amazing fit from China that was large enough. Then I googled the name and found out it’s listed under the fake/mislabeled category on the CDC site [0] with filtration efficiency between 8 and 94% (over 2 ten sample test runs):(

[0]: https://www.cdc.gov/niosh/npptl/respirators/testing/NonNIOSH...

3M N95 9210 should be big enough to cover anyone's face, methinks.

They are also pretty expensive for a single-use product.

They are but I believe to will protect anyone extremely well.

I 100% agree that the conversation should shift to how we can get more particulate masks into people's hands. That said, N95 masks are not the gold standard many people claim they are.

N99 and P100 masks typically include a gasket which improves the seal dramatically. They also come with the bonus of filtering substantially more fine particles. Given than the size of the aerosols in question are less than 5 microns and that the ratings are in relation to 0.1 microns, getting a higher rating is probably a good idea.

Even better still is a silicone mask which is trivial to leak test by covering the filter cartridge inlets (negative pressure) or exhaust valve (positive pressure).

PAPRs (powered air purifiying respirators) would be far more effective and efficient, especially on a long-term basis. People who are at risk of becoming severely ill from a respiratory infection (i.e. Pneumovax 23 recipients), especially in the developed world, should be able to have their national/public/private health insurance pay for a PAPR. After the pandemic, this really should be the case. There are also more compact, more convenient, and better designed PAPRs coming out, such as the Optrel Swiss Air [1] and the CleanSpace Halo [2]. Most PAPRs do not require fit tests to ensure the seal, while N95/N99/P100 masks do. The PAPRs I list can easily be adapted, either formally or informally, to have source control (covering of the exhaust valves).

[1] Optrel Swiss Air: https://industrial.optrel.com/fileadmin/optrel/redaktion/pdf...

[2] CleanSpace Halo: https://cleanspacetechnology.com/wp-content/uploads/2019/11/...

There has been a large push for N95 masks in Germany. They are now mandatory when doing grocery shopping. You're allowed to use a "surgical mask" instead, however. I think those offer few less protection to the wearer.

I would love for N95 usage to become more widespread, but that is hampered by the dogmatic clinging to the belief that cloth masks actually work, unfortunately.

Do N95s work for source control though? They certainly do work for self infection but I haven’t personally read any N95 studies on source control so am not sure.

If cloth masks don't work, they aren't doing much for source control either. They don't magically filter better in one direction than the other.

If everyone was wearing a particulate mask (e.g. N95), source control wouldn't matter as much. Masks with an exhaust valve are significantly more comfortable and comfort is the reason the CDC is currently citing in regard to their recommendation for people not to wear particulate masks.

If your protection plan relies on everyone else doing something complicated correctly, you have already lost. I think controlling the spread of a virus in the general population using source control is not something our species is capable of.

To be clear, I agree. I think the whole concept of source control is silly. Actually I’ll go one step further and say I think the whole concept of trying to artificially slow transmission of SARS-2 in the general population is a bad idea period.

Where are you from that FFP2 usage is not common?

Sure, cloth masks were widespread for about a year but by now usage of FFP2 masks is becoming extremely widespread, especially since the supply is by now overwhelming.

I live in California. I see maybe 95% cloth masks in public.

the ones without exhalation valves do. the barrier is bidirectional. the ones with valves bypass this which is why those shouldn't be used for source control but are popular for wildfires etc.

Thanks. That was my thinking but glad to see it confirmed.

Kind of ironic that you’re not allowed to wear an N95 with an exhale valve, but are encouraged to wear a surgical mask, bandana, cloth mask, or dirty T-shirt, none of which provide any source control.

Again, the elephant in the room is respiratory viruses in general, and SARS-2 in particular, spread via aerosols. Non-N95 face coverings cannot block aerosols. Indeed mask wearing leads to deeper breaths to maintain homeostasis (this has been studied), therefore lead to a greater net volume of air, therefore lead to increased aerosol emission before even accounting for the potential to nebulize large droplets into a shower of tiny aerosol particles. But I digress.

A surgical mask, bandana, cloth mask, or dirty T-shirt over a particulate mask (e.g. N95) is typically allowed. There are serious benefits to the wearer to having an exhaust valve. Wearing a second, less effective face covering over the particulate mask retains the benefits of the particulate mask and exhaust valve while maintaining the same level of source control as without the particulate mask.

Cloth masks work better than no mask, so they made sense early on when surgical masks couldn't be found. There are certainly better options now though.

There is no RCT that shows cloth masks work any better than no mask. You’re relying on mechanistic studies at best (or crappy associative studies).

Masks incur costs; at a minimum you must admit they alter risk appraisal if nothing else.

Anyway, nobody in this thread has addressed the point that masks don’t even work in theory if aerosol transmission is the dominant transmission mode. That’s before accounting for the incredible cross contamination and misuse of masks that you see in the community.

In Texas, the mask mandate has been lifted for weeks.

There has not been a surge of new cases.

Throughout 2020, Broken Bow, OK received millions of tourists, it was the #2 short-term vacation rental destination in the country, according to VRBO.

It's a small town with crowded bars. Very few locals or visitors wore masks.

There was not a significant rise in severe Covid cases, and schools mostly kept masking optional.

In Germany, you are required to use surgical or FFP2/(K)N95 masks (in 2 states surgical ones are not allowed) to enter any store. At least in my city, the majority of people wear FFP2 masks.

I'm curious why there hasn't been a push for this.

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