
You Probably Should Be Wearing a Face Mask If You Can - miles
https://kottke.org/20/03/you-probably-should-be-wearing-a-face-mask-if-you-can
======
petilon
We are thinking about masks wrong. You want _every one else_ to wear a mask
because _they_ might have the virus, and if they do, the mask will stop
droplets and aerosols from entering the air you breath and landing on surfaces
that you may touch.

And of course, you should wear a mask too -- to protect _others_.

Had we all worn masks right when this started (simple cloth masks would do)
this virus would not have spread so much and so easily.

~~~
benjohnson
The filtering also works in the other direction - when a healthy person wears
one and inhales air with contaminated droplets in it.

------
bravura
Here is a writeup on the topic that I prefer, from my friend Matt Bell who has
been a constant stream of COVID-19 insight on his facebook wall:
[https://medium.com/@llebttam_45762/masks-work-wear-
them-b450...](https://medium.com/@llebttam_45762/masks-work-wear-
them-b450ac9f3b7d)

It includes a variety of evidence for masks, including for impromptu masks and
their quality.

Some key points from my linked article:

* You _should_ (like many doctors and care staff) re-use your good quality masks, and the article explains how. (e.g. put it in a breathable bag, like paper, date it, and wait four days)

* If you have a good mask, like an N95, wear a lower quality mask over it, to preserve re-use of the good quality mask.

* For good fit, the mask should not touch the lips.

------
wnissen
As it notes in the article, wearing a mask can be bad if it causes you to
touch your face more. Though at the moment there has not been a single
documented case of "smear" (person to object to person) transmission. And
there was a 2.5 hour choir rehearsal with minimal touching that caused 75% of
the attendees to become infected. So I have an old N100 respirator from
wildfires a couple years ago that I am wearing when out.

One of the interesting side effects is that you can smell the ambient ozone
when you take it off, since the respirator has been removing it. Don't be
fooled, a typical suburban area reeks of ozone, but it's not perceptible
because your nose ignores it as background.

~~~
entee
It’s misleading to say there’s no evidence of smear transmission. Take that
choral rehearsal you mention. Could have been that they breathed in droplets,
also could have been that a droplet found their way to a shirt, the person
touched their shirt, touched their face, bingo. The virus is known to survive
on surfaces for several hours. In close, confined quarters the answer to smear
vs droplet is likely “yes”.

Masks are most useful in stopping droplets from people who are actively
shedding virus. This is probably the key driver for why in some mask wearing
societies transmission is far lower.

Masks are clearly helpful in confined spaces and in the immediate radius of
someone who coughed a few seconds ago. These conditions are what medical
personnel face daily, hence they wear masks. Similarly people like Uber
drivers or grocery clerks likely would benefit if well fitted and they don’t
touch their face more.

Masks are maybe useful when around those who aren’t coughing (you make
droplets when you breathe or talk) but generally that social distancing 6ft
should cover that. Still, if you don’t touch your face more, it doesn’t hurt
and might help a little.

Masks aren’t doing a whole lot walking around the street. As you and the
article note if a mask makes you touch your face more, it could even be
harmful.

In almost all of these cases, social distancing and hand washing is likely far
more effective than masks. “Are masks useful?” is a complicated question, but
as the article suggests, it’s probably, “a little, wash your hands, keep
distant, that helps much more.”

------
crispinb
On the DIY mask issue: I've tried making a couple, based on online
instructions. It's very obvious in use that without literally taping the
filter material to my face, the airflow goes around the edges.

Anyone who's done any rural polypipe plumbing knows how hard it is to control
water flow. Air is harder. None of the DY mask designs I've tried are worth a
pinch of the proverbial.

Anyone here know of any better designs? I'm not fussed myself (live in the
sticks, very easy to avoid people), but I'd like to make something useful for
my elderly mother.

~~~
m4rtink
If you have a 3D printer or know someone with one, there are a couple designs
that can be 3D printed or the 3D printed parts can be combined with commonly
available materials:

[https://www.prusa3d.com/covid19/](https://www.prusa3d.com/covid19/)

[https://www.forbes.com/sites/tjmccue/2020/03/24/calling-
all-...](https://www.forbes.com/sites/tjmccue/2020/03/24/calling-all-makers-
with-3d-printers-join-critical-mission-to-make-face-masks-and-shields-
for-2020-healthcare-workers/#1d6bff717500)

[https://onezero.medium.com/people-around-the-world-
are-3d-pr...](https://onezero.medium.com/people-around-the-world-
are-3d-printing-face-shields-to-battle-the-coronavirus-6b44146ca1f3)

[https://www.dezeen.com/2020/03/29/creality-3d-printed-
buckle...](https://www.dezeen.com/2020/03/29/creality-3d-printed-buckle-face-
mask-coronavirus/)

[https://3dprintingcenter.net/2020/03/19/scientists-from-
the-...](https://3dprintingcenter.net/2020/03/19/scientists-from-the-czech-
technical-university-in-prague-are-working-on-protective-masks-3d-printed-on-
hp-in-mjf-technology/)

[https://rp95.cz/en/](https://rp95.cz/en/)

~~~
crispinb
Thank you - I'll check them out.

(Ironically, the only friend I have with a 3d printer is over the nearby
NSW/QLD border that has been closed due to the pandemic crisis. Not an
insuperable problem however).

------
SiNTEx
Wearing a face mask is compulsory here in Czech Republic for a third week now
and you can even get fined for not doing so. According to our government this
is one of the most important measures introduced to slow down the spread of
the virus. Our PM is even trying to convince other EU governments to do the
same. People are advised not to touch their face and clean their mask by
washing it in boiling water every day. It’s not too complicated and hopefully
will be effective.

------
jacob019
KN95 masks are available from China. Those are an excellent choice for the
general population and do not affect the supply of N95 masks to medical
personnel. More people need to step and and distribute.

~~~
ardit33
Like the defective ones that were returned back by Holland?
[https://www.dw.com/en/coronavirus-netherlands-recalls-
defect...](https://www.dw.com/en/coronavirus-netherlands-recalls-defective-
masks-bought-from-china/a-52949216)

~~~
bgee
tl;dr: This is misinfoformation; Netherlands tests masks against the wrong
specification and blamed on China.

KN95 marks that are bought by the Dutch government are not resistant to oily
particles (the N stands for Not resistant to oil)[0]; while the European FFP2
standard specifies the mask has to be able to block oil particles [1].

[0]: [http://multimedia.3m.com/mws/media/433598O/european-
standard...](http://multimedia.3m.com/mws/media/433598O/european-
standards.pdf)

[1] “Last Saturday, the first shipment from a Chinese manufacturer was
delivered in part. These are masks with a KN95 quality certificate.”:
[https://www.scmp.com/news/china/diplomacy/article/3077428/ne...](https://www.scmp.com/news/china/diplomacy/article/3077428/netherlands-
recalls-600000-face-masks-china-due-low-quality)

Disclaimer: I'm a China national.

~~~
gruez
>Netherlands tests masks against the wrong specification and blamed on China.

>KN95 marks that are bought by the Dutch government are not resistant to oily
particles (the N stands for Not resistant to oil)[0]; while the European FFP2
standard specifies the mask has to be able to block oil particles

Both of these statements are contradicted by the scmp article you've linked:

>The problem with the Chinese masks was first discovered by hospitals that
received them, with health workers finding the masks did not fit properly
[...] Dutch broadcaster NOS cited a source saying that the Chinese face masks
were “not FFP2 quality nor of the lesser safety level of FFP1 – some sort of
FFP0.8 at best”, meaning they had less than half the filter efficiency
required for the FFP2 designation.

~~~
bgee
KN95 is not the same thing with FFP2 due to KN95 can not filter oil particles
well.

Dutch government bought KN95 and tested it against FFP2 and claims it's
defective.

Updated to have better sentence structure.

~~~
gruez
>Dutch government bought KN95 and tested it against FFP2 and claims it's
defective.

The SCMP article says

>Dutch broadcaster NOS cited a source saying that the Chinese face masks were
“not FFP2 quality nor of the lesser safety level of FFP1 – some sort of FFP0.8
at best”,

While I can understand that it can be taken to mean that the masks were
subjected to to FFP2 testing (including oil penetration), that would be a very
uncharitable/cynical interpretation. A more charitable interpretation of that
would be that the FFP2/FFP1 standards are being referenced _without_ oil
penetration testing involved, since europe doesn't seem to have separate
standards for oil/non-oil like with N95/P95 in north america. This theory is
consistent with them comparing against a fictitious standard/rating of FFP0.8.

Also, I did some research myself and found the original statement by the
health ministry[1]. It actually made no mention of FFP ratings, and only
acknowledged that the masks carried a KN95 rating, and that the masks "did not
meet the quality standard", which I've taken to mean KN95 rating, not FFP2
rating. I could not find any source that directly said the masks were tested
against FFP2 (with oil penetration) and failed.

[1] [https://nos.nl/artikel/2328673-honderdduizenden-chinese-
mond...](https://nos.nl/artikel/2328673-honderdduizenden-chinese-mondmaskers-
teruggeroepen-uit-nederlandse-ziekenhuizen.html)

~~~
bgee
The NOS article clearly mentioned FFP2 rating in the second paragraph (from
Google Translate): "This concerns almost half of a batch of 1.3 million so-
called FFP2 masks, 600,000 pieces. "

Am I missing something?

~~~
gruez
>"This concerns almost half of a batch of 1.3 million so-called FFP2 masks,
600,000 pieces. "

That's a quote by the newspaper, not the government agency. Also like I
mentioned earlier, it's understandable to call them "FFP2" masks since the
average european reader might not have a point of reference for what (K)N95
is.

~~~
bgee
It really boggles one's mind that a mask would be referred as FFP2 repeatedly
and somehow be tested under KN95 that only existed in China* and was only
recently approved in the Netherlands.

But it's all just speculation at this point without more information from the
health minister.

* Granted it doesn't differ from the American standard by far.

------
fasteddie31003
Yes. I have been promoting this message nonstop for the past few days. I
created [https://www.maskssavelives.org/](https://www.maskssavelives.org/) to
help promote the benefits of mask-wearing in reducing COVID-19' virality.

~~~
starpilot
That's painful to read, it does not address the blatant lack of causality
demonstrated in the FT chart with masks / no mask regions. You can't make that
claim at all. If masks were _that_ effective, SK and other countries wouldn't
have engaged in their massive testing, quarantining programs at all.

~~~
collinmanderson
It probably wasn't masks alone, but why not throw everything we have at the
problem?

------
scythe
You should probably consider covering your mouth and nose because:

\- you don't know if you're infected

\- if you _are_ infected, even a terrible mask like a handkerchief reduces the
risk that you'll spread to someone else

You should probably _not_ try to obtain and wear a medical-grade mask if those
are in short supply in your region.

Source:
[https://jamanetwork.com/journals/jama/fullarticle/2762694](https://jamanetwork.com/journals/jama/fullarticle/2762694)

> _There are 2 main types of masks used to prevent respiratory infection:
> surgical masks, sometimes referred to as face masks, and respirators. These
> masks differ by the type and size of infectious particles they are able to
> filter. Face masks are used more commonly for respiratory viruses that
> spread via droplets, which travel short distances and are transmitted by
> cough or sneeze. Face masks often fit loosely, and prevent the wearer from
> spreading large sprays and droplets, as well as preventing hand-to-face
> contact. N95 respirators block 95% of airborne particles. They are tight
> fitting and prevent inhalation of smaller infectious particles that can
> spread through the air over long distances after an infected person coughs
> or sneezes_

The difference right now is that everyone _might_ be carrying a lethal
pathogen that we have no treatments for.

------
jandrese
At the same time you shouldn't be wearing one because they're a scarce
resource and doctors/nurses/first responders need them more.

To be fair the article does suggest making your own and then helpfully links
to this [1] dead website.

[1] [https://www.consumer.org.hk/ws_en/news/specials/2020/mask-
di...](https://www.consumer.org.hk/ws_en/news/specials/2020/mask-diy-
tips.html)

Edit: fixed a typo

~~~
Wowfunhappy
This. If you're wearing a mask, then there's a healthcare worker somewhere who
you're preventing from wearing a mask. That healthcare worker is taking care
of patients who _definitely_ have the Cornavirus, and is getting up close to
them while they're coughing. They need that mask more than you do.

And I don't mean this in an abstract way. There are numerous places accepting
mask donations right now. If you have a mask, you should donate it. Stat.

~~~
rubidium
“ There are numerous places accepting mask donations right now.” Honestly
asking where? I haven’t heard of that.

~~~
advisedwang
[https://www.acceleratemed.org/supporting-our-
covid-19-respon...](https://www.acceleratemed.org/supporting-our-
covid-19-response-through-in-kind-giving/) for UW medical center (Seattle)

------
jacquesm
A friend of mine is setting up a manufacturing line for masks here in NL.
They're sourcing raw materials from abroad, where masks are interdicted but
materials are not, and then go on to make the actual masks locally. Super
interesting project and I'm proud of him for getting off his butt and making
an actual difference here.

~~~
hirundo
interdicted?

~~~
jacquesm
Ah yes, sorry, will fix. Thank you.

------
mc32
Before we do this, we have to establish a culture of wearing masks during flu
season so that there is always enough stock when people "must" wear masks for
public health reasons. Right now may not be the best time to tell people they
must because that siphons masks from the first responders.

~~~
lucisferre
The article specifically states not to buy/wear N95 masks for that reason and
because most people don't know how to wear them properly.

~~~
bamboozled
They could learn how to right ?

~~~
derefr
Not if doctors still mostly fail to wear N95 respirators correctly after
explicit professional training, no.

------
zozbot234
And if you can't wear a mask for some reason, you should still be covering
your face with _something_. Even a bandana is a lot better than wearing
nothing at all.

------
xkapastel
Masks do protect the wearer! And you do not need an N95 mask to do this. Even
a simple homemade mask offers some degree of protection. This[0] was a good
explanation of both of these ideas.

tldr: There is reason to believe that large droplets, not the tiny droplets
that N95s are designed to filter, are the primary threat, and any sort of
physical barrier between those and your mouth/nose will help.

I see a lot of people saying that we shouldn't wear masks in order to preserve
the supply for healthcare workers, but I think this is ridiculous. You _need_
a mask when you go out both to protect yourself and to protect others. A
better message is, to preserve the supply for healthcare workers, make your
own mask, or use a simple dust mask or a rave mask.

[0]: [https://medium.com/@Cancerwarrior/covid-19-why-we-should-
all...](https://medium.com/@Cancerwarrior/covid-19-why-we-should-all-wear-
masks-there-is-new-scientific-rationale-280e08ceee71)

~~~
entee
Very few viruses are true aerosol transmitted (measles is), it’s likely COVID
is droplet based so coarse masks will help. Even with an N95, true aerosols
can make it through, though obviously not 100% transmission (95 means block
95% of 0.3 micron particles, individual viruses are a factor of 2-3 smaller
usually).

------
huangc10
I think the path forward is clear (if there was enough supplies to go around):
1) Stay at home or 2) wear a face mask. If there was enough supply, I don't
think we should argue with this. It's for everyone's safety. So let's ramp up
supply and do either 1) or 2)

------
seltzered_
Prior (flagged) discussion on a similar topic:
[https://news.ycombinator.com/item?id=22706216](https://news.ycombinator.com/item?id=22706216)

------
Ancalagon
Question: is there a recommended way to clean a cotton mask or mask of other
material? Does running it through the wash risk contaminating other clothes?
Should I instead spray it down with alcohol or wet-and-zap it in the microwave
for 30 sec, similar to sponge disinfecting?

~~~
SiNTEx
Washing it in boiling water for 5 minutes should be enough but you should do
it at least every day. This is what our government advise us here in Czech.

------
savanaly
Don't see it linked in this thread yet, but it's worth noting Slate Star Codex
looked at the literature and decided on a weak "yes" [0], assuming your use of
a face mask isn't depriving a medical worker of one.

[0] [https://slatestarcodex.com/2020/03/23/face-masks-much-
more-t...](https://slatestarcodex.com/2020/03/23/face-masks-much-more-than-
you-wanted-to-know/)

------
jcroll
Link for making a mask is broken. Anyone have a good link how to make your
own?

------
ProAm
Lets go ahead and save the mask supply for medical personnel.

Also this blog is Monday morning arm chair medical advice from a blogger, a
respectable blogger, but a blogger nonetheless.

~~~
angry_octet
Exactly, it has no more weight than water cooler talk. In a number of aspects
it exhibits wishful thinking that is counter-factual, especially in regard to
home-made masks.

