[uxp]

It's not about the money. PPE like face shields are specifically used during procedures that involve significant bodily fluid, like intubation, which is the process of pulling or pushing a tube down a patient's esophagus. Going to to the grocery store does not require a shield.

Secondly disposable medical equipment, when used properly within a healthcare environment, is extremely wasteful. For most consumable items used in a hospital, they are covered in packaging with specific serial numbers and lot numbers that allow reconciliation if it's found that the goods are not sterile or have deficiencies. There is also a provenance or chain-of-command aspect that allows attestation of safety throughout the entire supply chain. While we might be talking about how to sterilize n95 masks, reuse face shields, and asking for donations of PPE from the public right now during a pandemic, the fact remains that in normal circumstances there is massive liabilities that hospitals and clinics would be subjected to if they started sourcing protective equipment from the public that could have been tampered with, may be slightly used and broken, or otherwise could cause harm to the patient and they'd be unable to identify the source of those resources. Everybody stocking a "handful" of PPE isn't a scalable solution to maintain a national supply.

This is one reason why we pay federal taxes.

[roenxi]

> It's not about the money. PPE like face shields are specifically used during procedures that involve...

There is currently a global pandemic afoot that is spread by droplets expelled from people's mouth and nose. What a tool was being used for 2 months ago isn't relevant; the situation is different now.

> Everybody stocking a "handful" of PPE isn't a scalable solution to maintain a national supply.

If masks or face-shields could be cleaned fairly easily then it probably is a scalable supply. Particularly if medical professionals are allowed to supply their own work tools.

[mbreese]

> What a tool was being used for 2 months ago isn't relevant

It is very relevant. These face shields wouldn't protect anyone from airborne/aerosol pathogens or viruses. They have a very specific purpose and that isn't one of them.

If you're talking about adapting construction grade shields (like used for painting, etc) for medical use -- sure. But you aren't going to use a face shield as a replacement for a face mask, which is what it seems like you're arguing for.

If you're saying that you should wear a face shield in public to protect yourself from aerosolized virus -- that's not the point of a face shield. The particles can travel around the sides of the mask too easily. If you want to protect from small, airborne particles, you need a mask.

[dillonmckay]

Nobody is advocating for a face-shield as a replacement for an N-95 mask, but using them together, would reduce the odds of infection.

According to the MIT paper, a typical sneeze will travel over 20 feet.

Additionally, there is mention of the velocity of the particles may be able to penetrate the mask, so a face-shield could help with that, too.

[awaythrower]

Yes. Defense-in-depth. In China, most hospital red zones required 3 layers of PPE, whether that's two masks and a face shield or such. One layer alone is not very good, and a face shield alone is no good. A mask and a face shield are very good, especially for confined spaces like subways and busses where there are jerks coughing and sneezing all over without hygiene or manners.

[woofie11]

What if I want to protect myself and my facemask from large droplets. I also want to protect myself from accidentally touching my face. Is a face shield okay then?

And if so, why not drop $300 million to get one for everyone in the US? They're cheap, wash easily, and that's less than 0.02% of the last stimulus.

[roenxi]

If someone is facing me and a stream of airborne particles hits a plastic shield instead of streaming out to me, it seems pretty likely that I will be protected.

I'm certainly open to the idea that fluid mechanics are complicated and somehow air currents are going to do unhelpful things, but until I find someone with a paper on the topic I'd much rather be talking to someone wearing a face shield than not.

Plus obviously wearing a face shield will protect against self-inflicted infections from a contaminated finger.

[mbreese]

> it seems pretty likely that I will be protected

And you'd be wrong. Sure, a face shield will protect you from liquid streaming out at you (partially). However, it isn't a liquid that you need to protect yourself from in this instance... it is aerosolized particles. And those travel in the air. So when you breathe in, that air can and will move around the face shield.

The sibling comment about smoke moving is exactly right. Smoke is a great example of how small particles can move and travel in the air. If you think that a face shield will protect you from something in the air, you'd be wrong.

Side note: this is how N95 masks are actually fit. (Well, not using smoke, but similar test). If you can smell the chemical used in the test, the fit is wrong.

If you really want to protect yourself from other people sneezing -- stay away from other people. That's why social distancing is still the primary, and best, recommendation.

[BalinKing]

Isn't the recommendations by many countries to wear even cloth masks (e.g. the recent reversal by the CDC) _because_ there's a good chance COVID-19 can spread via large (i.e. non-aerosolized) respiratory droplets? (Not that it doesn't also spread in other ways, but removing even one vector would be better in this case than not doing so.)

[mbreese]

I'm not sure why there is a recommendation to wear cloth masks in other countries (not discounting it, I just haven't looked). However, I believe that the primary rationale for the CDC switching their recommendation that everyone should wear masks has to do with the great numbers of asymptomatic carriers. In this scenario, wearing a mask is not designed to protect the wearer from others. Wearing an ill-fitting mask is not protective to the individual. Instead, wearing a mask is designed to protect others from the wearer. Because people are carriers before they exhibit symptoms (if they ever have symptoms), you can't know if you are infected or not. If you are wearing a mask, you are limiting the potential spread of virus from you. This way, you are keeping any potential virus closer to you so that others are more protected. This goes hand in hand with social distancing. If you use a mask and don't distance yourself, you aren't helping at all. I'm looking for a CDC reference, but this was also the rationale presented in local media reports.

If you're really curious, Ars Technica has a really good writeup of all of the relevant studies.

https://arstechnica.com/science/2020/04/should-you-wear-a-fa...

Most of the research above assumed either surgical or N95-style masks. There was one study that looked at use of cloth (non-medical, non N95) masks, and this was the key finding (from Ars, not the paper):

Wearing cloth masks resulted in significantly higher rates of infection, the authors found. They also noted that in their test, the cloth masks were only 3 percent effective at blocking particles.

Regarding everyone wearing (surgical) masks to protect others:

In a study published April 3, 2020 in Nature Medicine, researchers found that surgical masks reduced the detection of respiratory viruses in aerosols generated by infected people breathing or coughing in a breath-collecting machine.

[Dylan16807]

A cloth mask can capture some sizes of droplet, but a flat wall that the all the air goes around is not really going to do anything.

[roenxi]

You say that with great confidence and a lack of sources; and I'm guessing we are equally ignorant on the actual physics of how small droplets move.

The details aren't clear on how the virus is spreading. The virus might have multiple modes of transmission. Closing 2 of them reliably a great deal. There are important things to do with "catching COVID" that aren't binary; starting doses likely matter as well.

I'd rather not talk to you in person if you aren't going to cover your face, tyvm :)

[ksk]

> starting doses likely matter as well.

That is something that I've been wondering about too. I work in biotech but not as a scientist. These things are tricky to nail down as they seem to be very individual specific. Theoretically, in an exponential growth model, it wouldn't matter if you were inoculated with 20000 or 200000 virons, after the incubation period post-infection, you're going to be generating a huge amount, millions and millions, of virus particles in either case. Certainly, if you keep getting exposed, you're immune system is going to get overwhelmed quickly, but for a single event, I don't think it matters.

[brirec]

> The virus might have multiple modes of transmission. Closing 2 of them reliably a great deal.

Sounds reasonable, but how is a face shield a reliable way to close a mode of transmission if people aren’t spitting liquid in your face?

[brodie]

It’s okay to admit you’re wrong. It’s okay to not understand everything. It’s okay to defer to experts.

So many people on HN and in tech have the same attitude that if they just spend 5 minutes thinking about something then they can intuit an answer and that they must be right. This is a dangerous way of thinking. If anyone took what you’ve been saying as correct they’d be endangering themselves and depriving medical professionals of tools they need.

[pertymcpert]

This is just common sense. Aerosolized particles are not impeded by a shield. A shield is intended to obstruct ballistic projectiles. If those projectiles are aerosolized and are in the air that you breathe, then the shield will offer no protection at all. Even an N95 mask still can let in up to 5% of these particles. What efficacy is a piece of plastic in front of your face going to do against that?

[seletz]

Stop spreading FUD.

[barry-cotter]

> this is how N95 masks are actually fit. (Well, not using smoke, but similar test). If you can smell the chemical used in the test, the fit is wrong.

And if the smell is less strong than it would be if you weren’t wearing the mask the viral load you’ve been exposed to is smaller. You are less likely to be infected and if you are infected your immune system has more time to ramp up so you’re more likely to fight it off.

[chrischen]

Go light a cigarette or incense and and see if a face shield prevents you from inhaling any smoke.

[ajxs]

Viruses don't diffuse through the air like smoke. Viruses are contained within the aerosolised droplets of your bodily fluids that are ejected through sneezing, coughing, blowing the nose. The survival of the virus outside of the body exposed to the elements is limited. Viruses have limited lifespans and can only reproduce within the medium of the bodily fluid. Every virus has different characteristics, and may have a longer or shorter lifespan. These characteristics are more or less universal for viruses though. It's not impossible for them to travel longer distances through the air. For the most part they are limited to the initial propulsion from the body. A better analogy would be spraying an aerosol can and watching how the droplets settle.

[lancesells]

Light a cigarette and see if you can smell it from six feet away.

[dlubarov]

I think a better comparison would be to try inhaling wet steam (i.e. a suspension of liquid H2O) from behind a face shield. You'll probably inhale some, but a lot of it will adhere to the shield.

[roenxi]

Yeah, that is pretty much what I'm imagining. If someone tried to smoke behind a facemask it seems pretty likely that most of the smoke will be caught behind the mask then drift out behind them like a comet trail, or move up/down. Only small wisps would end up traveling forward to where I'd be standing for conversation. The doses of virus would be diluted very rapidly which is helpful.

Ideal scenario would be most of the smoke gets pushed down in a knee-wards direction, which is well within the realm of the imaginable.

[Talanes]

>If someone tried to smoke behind a facemask it seems pretty likely that most of the smoke will be caught behind the mask then drift out behind them like a comet trail, or move up/down. Only small wisps would end up traveling forward to where I'd be standing for conversation.

You ARE the person in the faceshield (I assume you meant that instead of facemask), you don't control what other people do so assume they uncovered. The smoke is in the air, it can reach you. Will it get around that shield or not?

[rumanator]

> it seems pretty likely that most of the smoke will be caught

If your plan is to only block most of the virus then perhaps you should rethink it.

It's like stating that a hole in the hull is not a problem because the rest of the ship keeps most of the water out.

[awaythrower]

Strawman and wrong.

[rumanator]

> There is currently a global pandemic afoot that is spread by droplets expelled from people's mouth and nose.

Do you have any source on how face shields are an effective tool against atomized covid19 viruses? The general guidance is that facial masks are effective at barring infected people from emitting contaminated particles, but not good at stopping healthy people from having contact with the virus. Therefore why would an open face shield, which filters zero, be a better solution?

[woofie11]

That's the general guidance in countries getting overrun by COVID-19. In countries which have stopped it, everyone wears facemasks. Chinese scientists have good data that surgical masks help in both directions.

Face shields reduce flow of air around you. Think of the six foot rule, but add a few more feet. They also reduce projectile sneezes (and "say-it-don't-spray-it" talking, coughs, and even breathing) by quite a bit. Think about sneezing in your elbow, only much better.

[mxcrossb]

I hear mask promoters say the “it’s to protect others from you” line, only to turn around and say “masks are obviously useful, that’s why doctors wear them.” The truth is, mask use is built on incredibly shaky evidence, so it’s no surprise that now face shields will become part of the hype. Both may indeed be useful, but without a clear model of effectiveness, it’s hard to make good assessments.

[blendergeek]

You seem to conflate so many things here. Doctors wear mulitiple types of masks. Surgical masks (as are recommended for the general public) prevent a doctor from spitting on a patient accidentally (just as they prevent an infected individual from expelling virus laden spit droplets). Surgical masks provide limited (if any) protection from airborne droplets. Rather an N95 masks (with a seal and filter) is used. To make this effective to protect the wearer, goggles must also be worn. The general public does not wear goggles. Further,training on putting on and taking off masks is provided to medical professionals. Face shields protect from yet another class of dangers (splashing of contaminated fluid). The general public has little reason to wear these.

[logarhythmic]

I thought the entire point of wearing a mask was precisely because we don't have clear evidence as to it's effectiveness. With such a degree of uncertainty (we are literally in the midst of an epidemic) it's not very practical to wait around for perfect information and evidence before you act

[jrochkind1]

Also, tin foil hats. You can't prove they DON'T work, can you? Even if they only add marginal protection, every bit counts. And they might, so can it hurt? This is why we are recommending tin foil hats to all Americans. That and a nice contribution from the tin foil lobby. We expect all Americans to commence procuring and constructing tin foil hats, and arguing about it on social media, and hope that this distracts them from noticing that their government is practically a failed state.

It turns out that "feeling safe" isn't the same thing as being safe, and feelings of safety will not actually effect infection rates, but Americans can't quite grasp that. And, hey, feelings of safety are about all we've got now, so.

[GoodOldNe]

Pedantic point: If you’re intubation the esophagus, you’re doing it wrong. :-)

[Angostura]

Might this explain the poor survival rate?

[brodie]

I hope a doctor or nurse or respiratory therapist can correct me, but my layman’s impression is that intubation itself isn’t causing deaths as much as having to be intubated means you’re already in dire straits.

I was recently intubated 3 times in the last month and had no ill effects. I know that’s just an anecdote but no doctor ever told me it would be super risky. The alternative to not getting it however usually meant death.

[jnbiche]

> pulling or pushing a tube down a patient's esophagus

No, that's another procedure. Intubating respiratory patients involves targeting the trachea and avoiding the esophagus. An esophageal intubation can be Very Bad.

That said, as an early advocate for face masks for the general public, I'm in 100% agreement that face shields are pointless for the general public. We don't need them.

[DanBC]

What's the point of wearing a face mask if you're going to leave your eyes unprotected?

[jnbiche]

Mostly, to help prevent you the asymptomatic carrier, from spraying your respiratory droplets into the environment.

https://www.theguardian.com/world/2020/apr/02/face-masks-cor...

The CDC is recommending then now. Do you disagree with their expert opinion (nevermind their stand a week ago)?

Finally, with respect to the mask wearer's protection, look into viral load.

[jnbiche]

To go into a little more depth (I assume you'll see this given that you appear to be monitoring my threads):

You seem to have a mental model whereby any viral particle that bypasses your body's physical barriers has "won" - game over. But that's now how the immune system works. We want to minimize the viral load as much as possible, since with all known infectious organizations there's a dose-response relationship: the larger the dose, the worse the illness often is. Tiny loads are often effectively fought off my the immune system.

We this is vividly in a bacterial illness like TB. In TB, there's little risk if you pass a coughing TB patient in the hall. But if you spend the day with them in a poorly-ventilated office, your risk increases. If you live with the patient, your risk is very high.

The same principle applies with viral illnesses like Covid-19. And given that the only access route that is actively pulling viral particles into the body is the respiratory tract, it stands to reason that protecting that route has a higher payoff than protecting a lower risk route like the eyes.

That's not to say that people in high risk situations like Covid-19 wards of hospitals shouldn't cover their eyes! Obviously, they should and do. However, for most of us, the best protection we can use without using BL4 protection gear (obviously, not practical or needed for the general public) is to wear a mask. Mostly, the mask is to protect others from you, but depending on what kind of mask it is, it can also protect you from the virus.

Finally, most health authorities are now recommending that the general public wear masks. CDC changed their recommendations a week or two ago to recommend wearing masks. As usual, the WHO is moving slowly as large bureaucracies often do, but I don't doubt they'll also recommend them in the end as more evidence of their efficacy emerges.

[catblast]

> which is the process of pulling or pushing a tube down a patient's esophagus.

In the context of intubation that is most definitely a bad outcome.

[FireBeyond]

> intubation, which is the process of pulling or pushing a tube down a patient's esophagus

Hope not. It's endotracheal intubation. Tubing the gut (accidentally) leads to gastric distention as we ventilate the patient, leads to aspiration, leads to aspiration pneumonia, leads to huge increase in morbidity.

[gwright]

There is a shortage right now and we are collectively trying to address that but it is strange to say that this particular product and the safety practices you describe is the "reason why we pay federal taxes".

Your more general point that having a national stockpile of <insert-critical-item-here> for disasters of various kinds is of course valid, but that is true irrespective of the particular nature of the normal use of those particular items.

And we've learned that the federal government isn't particularly good at stockpiling. I hope we can find a way to have some non-partisan after-action committees to figure out how to do better for the next disaster.

[RcouF1uZ4gsC]

> like intubation, which is the process of pulling or pushing a tube down a patient's esophagus.

Hopefully you are intubating a patient’s trachea and not not the esophagus.

[brodie]

Does esophageal intubation happen much? I was intubated a month ago due to non-COVID respiratory failure. I also ended up getting pneumonia but no one knows when I got it. If that happened to me would my medical team have told me? Speaking generally obviously since you don’t know my case of course.

[DanBC]

> If that happened to me would my medical team have told me?

I don't know where you are. In England healthcare professionals and their organisations have a statutory "Duty of Candour". They have to tell you when something went wrong, why it went wrong, what they're going to try to do to fix it for you, and what they're doing to prevent it happening again in future.

https://www.cqc.org.uk/sites/default/files/Duty-of-Candour-2...

[RcouF1uZ4gsC]

In general esophageal intubation results in death. The patient is not getting oxygen, and so they die. I believe esophageal intubation gets reported to the Board of Medicine and is a really big deal for the hospital and doctor involved.

[dillonmckay]

I used a face-shield in October when I was using an HVLP paint sprayer indoors, so there are definite uses besides the current pandemic.

It definitely cost more than a few dollars and is not disposable.

Also, according to the documentation, these are re-usable and can be sanitized w/ alcohol or H2O2.

[epicureanideal]

"Everybody stocking a "handful" of PPE isn't a scalable solution to maintain a national supply."

No, but there's no harm in it either, and some potential benefit in case it takes a few days for the federal government to organize a response.

We all assume the government is going to make sure the food supply is maintained, but everyone is also buying some extra food just in case there's a temporary gap.

We don't need to choose just one way of preparing for the unknown.

Also, I was just saying the general public might purchase a few of these masks for themselves for their own use, not that hospitals might rely on the public for supplies.

[electricviolet]

The harm right now is that there's not even enough PPE for hospitals, so anyone buying a face shield for themselves, if that were possible, would keep a face shields from going to a health worker who needs it more.

A couple months from now, when pressure on the healthcare system is lower and manufacturing capacity is ramped up? Sure, I'm all for it.

[epicureanideal]

That is a completely different situation from what I'm discussing.

I'm not talking about who should get priority for PPE right now. I'm just talking about the idea of the general public having a couple uses worth of PPE just in case. Is now the right time for them to prioritize buying PPE for themselves over hospital workers? No.

[taxidump]

I printed my own frame and cut the shield a large plastic piece from a leftover toy package.

That being said, if I owned a commercial face mask, I would not feel bad. Hording/gouging is not equal to owning your own set of PPE.

[staticautomatic]

Based on a number of reports I've read about the N95 market, there seems to be plenty of PPE available domestically, but it's all being sold to foreign buyers because the government refuses to institute export controls.

[uxp]

For what, though? And I'm 100% being honest here, what is the specific situation you are envisioning that requires a face shield in your home?

In a medical setting, shields are typically used in conjunction with eye goggles and respirators when performing procedures that have a tendency to cause or be around splashing body fluids. Outside of someone sneezing or spitting on you directly, I can't think of an analogous situation that I come into on even a rare circumstance that a face shield would protect me from.

[marcus_holmes]

It's the same mentality as people buying guns.

What situation that could conceivably arise from a pandemic requires an automatic rifle?

It's a generalised sense of "bad things are happening, I need to be prepared for bad things to happen to me".

[ThrowawayR2]

> "What situation that could conceivably arise from a pandemic requires an automatic rifle?"

Good thing that automatic rifles aren't available for sale to the civilian market[1] then, I suppose.

[1] Yes, the pedants will point out that it's theoretically possible with special licensing but it's very uncommon.

[marcus_holmes]

Apologies for not understanding the differences between various types of gun and misusing the term.

Still, the point remains - what situation could possibly arise from a pandemic that would require a <insert any type of gun here>?

[ThrowawayR2]

How about this? https://www.newsweek.com/coronavirus-gun-sales-asian-califor.... Asians don't exactly fit the traditional stereotypes for firearms purchasers but the attacks described and similar bad behavior directed at international students from Asia on college campuses certainly show that there are people out there willing to attack them based on imagined threats and therefore some level of concern by Asians for their personal safety is merited.

[staticautomatic]

I don't think that's why people prep and buy guns.

[briandear]

> What situation that could conceivably arise from a pandemic requires a [semiautomatic] rifle?

Rioting, looting, people breaking into your home, police “sick outs.”

See what happens if the electricity goes out or all stores are forced to close.

[marcus_holmes]

I've seen what happens when the electricity goes out and stores are forced to close - people are really nice to each other and help each other out whenever they can.

Let me put it another way: if you owned a gun, would "the electricity is out" be a reason to shoot someone?

[WillPostForFood]

You store it in your home, then wear it when you go line up for food in case the person next to you turns and coughs or sneezes.

[beerandt]

Imagine being at the gas pump, and the person next to you sprays gasoline at you. A faceshield might keep your face from getting soaking wet, but if you smell the fumes, it hasn't prevented exposure to your sinuses or lungs.

Except you can't smell a virus.

[WillPostForFood]

For the most part, the virus is carried in the droplets, so if you protect yourself from the droplets, you're way ahead of the game.

[rhexs]

I'm hoping Doctors aren't being hosed down with concentrated gallons of trillions and trillions of virus. PPEs aren't going to do much in that situation.

[mbreese]

That isn't what a face shield is for and it won't protect you in that scenario.

[WillPostForFood]

It is exactly what it is for, to protect from droplets sprayed out of sick people. Particularly to keep it out of your eyes.

[frogpelt]

"We all assume the government is going to make sure the food supply is maintained"

Do you assume this? I assume that capitalism is keeping the food supply maintained. When that fails, I think we're up the creek.

[nicbou]

The government already has its hand in the food supply with all the farming subsidies it hands out. It can either change the subsidies to match the situation, or get heavily involved into the resource allocation as it has done in wartime.

As a good example, European agriculture is currently threatened because there are no foreign workers in the fields. The German government responded by better connecting unemployed workers to local farms, and by changing the rules to allow some foreign workers to come in.

That's just a hint of what governments are capable of. It pales in comparison to a war economy.

[cayblood]

All it takes is one accidental sneeze in a grocery store for a face shield to become useful.

[zbrozek]

Stanford hospital, for example, throws away one N95 per patient doctor visit. They are not sterilizing and reusing. So my friend who works there is using many dozens of them per day. It seems like they could come up with material-preserving procedures like sterilization, but they're not.

[prostheticvamp]

Because best data to date is that sterilization procedures damage the mask in ways that render it unsafe.

When someone comes up with data finding a safe way to do so, the masks won’t go in the trash. In the meantime, I’d you have the masks to spare, you -should- be using them safely. Masks are pointless if you use them in a way that will get you sick.

[klipt]

Says something about our society, though, that doctors at Stanford can use a mask per chat "just in case", while just across the bay at Oakland Kaiser nurses are working with multiple confirmed coronavirus patients on a single mask...

[lonelappde]

It's says that some people can't resist spreading rumors and jumping to conclusions. You have no idea how long standard docs are stretching masks.

[Thorrez]

zbrozek says his/her friend works at Stanford and says this. Is there a reason to doubt this?

[gwright]

What does it say?

It seems to me that pretty much every society has struggled to deal with this. Perhaps because it isn't something that has many reasonable direct analogues in our collective experience?

It is very easy to spot deficiencies after the fact. Much harder to spot them before.

[jonplackett]

It says that there's massive inequality?

[gwright]

I don't think it says that at all. You can't cherry pick two particular institutions and draw some sort of conclusion about "society". In this particular case it seems like the entire conclusion is based on nothing other than preconceived notions of what reactions "Stanford" and "Oakland" trigger in the reader. There doesn't seem to be any particular details about the actual situation at either location and how those institutions are managed.

[ficklepickle]

This is untrue. Stanford Medicine released a study around March 22.

The TLDR is 70°C heat for 30 mins. Avoid alcohol, it kills the static charge in the mask fibres.

https://m.box.com/shared_item/https%3A%2F%2Fstanfordmedicine...

[prostheticvamp]

No, THAT’s untrue. Look at your own link. You can sterilize the mask to preserve its filtration ability, but no one has shown it maintains fit. A poorly fit N95 is no protection at all, which is why hc workers get formally fit tested when starting a new gig. Which is why That link makes “no one knows what it does to fit” one of its top line bulletpoints.

[barry-cotter]

> A poorly fit N95 is no protection at all

There’s no plausible mechanism of action for masks under which this is true. A properly fitted N95 will block 95% of particles which is less than the kind of hazmat spacesuit with face shield and positive air pressure you’d ideally be wearing if working with someone with Ebola or similar. Maybe it really is impossible to get proper fit on a reused mask. Perhaps it’s only as good as a normal surgical mask which blocks just under 90% of virus sized particles.

Every reduction in the amount of virus that gets into your lungs makes it less likely that you’ll get infected and if infected gives your immune system more time to ramp up. That’s why people care about viral load. Running through someone’s cough is less likely to kill you than being in a small poorly ventilated room with someone coughing uncontrollably for minutes at a time.

[ricardobeat]

Maybe someone like the CDC? https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/d...

[lonelappde]

You seem confused. This is a complicated topic. That CDC says sterilizing masks is not a safe practice, but in a crisis it's better than having no mask.

[ricardobeat]

> When someone comes up with data finding a safe way to do so

There's the data and very clear recommendations by the CDC on when and how to do it. Whats' the confusing part? I don't think anyone is suggesting this approach during non-crisis times.

[ksk]

>Because best data to date is that sterilization procedures damage the mask in ways that render it unsafe.

There are multiple sterilizing procedures, and multiple material compositions for masks. Which ones were you referring to?

[icebraining]

The problem is that there isn't a known safe procedure for sterilization. Universities are working on that: https://news.engin.umich.edu/2020/04/engineers-work-to-decon...

[bolasanibk]

Like this one: https://news.ycombinator.com/item?id=22680799

[favorited]

They're setting up one of these[0] in Boston, allowing hospitals to sterilize and reuse 80k masks / day. There's an article[1] in the Boston Globe about it, but I'm not sure what the paywall situation is there.

[0] https://www.battelle.org/inb/battelle-critical-care-decontam...

[1] https://www.bostonglobe.com/2020/04/02/metro/boston-hospital...

[andrei_says_]

> disposable

This is reusable, easy to sterilize w alcohol.