
Why soap works so well on most viruses - jxub
https://threadreaderapp.com/thread/1236549305189597189.html
======
abainbridge
I thought it was cells that had a bi-lipid membrane and that viruses had a
capsid instead (made of proteins).

Wikipedia says "Some viruses are enveloped, meaning that the capsid is coated
with a lipid membrane" \-
[https://en.wikipedia.org/wiki/Capsid](https://en.wikipedia.org/wiki/Capsid)

I find the article confusing:

1\. Why does removing the lipid layer destroy the virus if most viruses don't
have one in the first place?

2\. How can soap be effective against "most viruses" (as the article claims)
if only "some viruses" (as wikipedia claims) have a lipid layer?

3\. Why doesn't TFA mention the capsid at all? I would have thought it should
be on the diagram at least.

Edit: A simpler explanation that doesn't have these problems and agrees with
all the facts I know is that soap destroys proteins, which is what viruses are
made out of. See [https://www.quora.com/How-do-detergents-denature-
proteins](https://www.quora.com/How-do-detergents-denature-proteins)

~~~
escape_goat
You're reasoning from first principles in contradiction of statements of
scientific fact that are being communicated to you, however imperfectly.
Resolving the contradictions in your own understanding does not constitute a
proof. The simplest explanation is that you do not yet correctly understand
and that you need further information.

~~~
RobertRoberts
You sound well reasoned, but are not countering or answering his questions
with anything of substance.

~~~
escape_goat
He is taking his current understanding and coming to the conclusion that the
mechanism by which soap renders viruses inactive is 'actually' because it
destroys proteins. I am pointing out that this exercise is futile and does not
result in useful knowledge.

If a domain expert says something that does not make sense to you, there is a
small chance that the domain expert is wrong, but it is more likely that what
the domain expert is saying is correct and your own knowledge is incomplete.

~~~
sizzle
Maybe lay people might also share this person's misconceptions/concerns, so
it's in the interest of the common person for a subject matter expert to
provide them with some citations or supplementary reading (where to go to
learn more on your own time).

Critical thinking and asking questions should be welcome and reinforced in the
public sphere to improve our collective intelligence and buy-in for hand
washing, proper respiratory etiquette, etc. towards containing and eradicating
this pandemic, among a multitude of many other greater societal good reasons.

~~~
escape_goat
Sure. You will notice that I was not criticizing anyone for thinking
critically or asking questions. I was pointing out something that I still
believe to be a failure of critical thinking, and that we could know a priori
that this was a bad way of reasoning about things without reference to prior
knowledge.

I notice that my opinion is unpopular with people interested in this topic,
and I'm certainly familiar with being wrong about things, but in my opinion
going from "an expert told me that envelope viruses are deactivated when soap
destroys the envelope" to "the real reason that soap deactivates viruses is
because it destroys proteins" on the basis of the semantics of a line from a
Wikipedia entry is categorically problematic on the face of it.

Most of us here are in the habit of relying on our ability to discover
knowledge by reasoning about limited information. It is how one solves
puzzles. It is not how one learns things about the world. Believing that we
know something which we don't know is dangerous in this situation. Convincing
others that we know something we don't know is also dangerous.

What I am doing right here is exactly attempting to improve our collective
intelligence. I am certainly not dissuading anyone from washing their hands. I
am encouraging people to second-guess themselves before they second-guess
others.

------
Anthony-G
> The soap dissolves the fat membrane and the virus falls apart like a house
> of cards and "dies", or rather, we should say it becomes inactive as viruses
> aren’t really alive.

I always presumed that viruses, similar to other microorganisms, are alive.
Until reading the above quote, I had never considered the idea there was any
question about this. I was intrigued by the concept that they many not really
be alive so looked up the Wikipedia article [1] which says that

> Viruses are considered by some to be a life form, because they carry genetic
> material, reproduce, and evolve through natural selection, although they
> lack key characteristics (such as cell structure) that are generally
> considered necessary to count as life. Because they possess some but not all
> such qualities, viruses have been described as "organisms at the edge of
> life", and as replicators.

One of the Wikipedia references is _Are viruses alive? The replicator paradigm
sheds decisive light on an old but misguided question_ [2] which looks at
different replication mechanisms as a continuum rather than a simple “life vs
non-life” dichotomy.

[1] [https://en.wikipedia.org/wiki/Virus](https://en.wikipedia.org/wiki/Virus)

[2]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5406846/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5406846/)

~~~
twic
As a biochemist, i think it's absolutely clear that viruses are not alive,
because they don't _do_ anything. No metabolism, no signalling, no changes in
structure, no use of energy or materials. They just float about! It's only
when they encounter a cell that anything happens, and then it's mostly the
cell's machinery doing it.

If i was a molecular biologist, i would probably think it was absolutely clear
that viruses are alive, because they contain a genome, and proteins encoded by
the genome, and they use the proteins to make more copies of the genome. What
else is life?

~~~
undersuit
The virus isn't the lifeform. The virus is just one component needed for the
lifeform to exist and reproduce. The lifeform is the infection.

~~~
pas
So the lifeform is the disease? I think assigning "lifeform" status to an
illness is not really helpful.

Viruses are just replicators. Grey/Green/Brown/Bio goo. They are just dumb
machines made by brute-forcing (fuzzing) more complex machines' immune
systems.

Viruses might be a different branch on the RNA-replicator tree. Probably when
the first replicators started some found - again via brute-forced mutations -
that there are some replicators that they can take advantage of to replicate
themselves.

And it just seems that closing this security hole is neigh impossible as long
as we don't start to seriously tinker with that low level of "life" (eg.
cellular machinery, transport, nucleus, messenger and transcription security).

~~~
undersuit
> They are just dumb machines made by brute-forcing (fuzzing)

But that's no different how the rest of biology works. A parasite like Giardia
is relatively just a dumb machine brute forcing itself through my immune
system.

~~~
pas
No, no, of course not. You're right. The same exploitation of complexity-
difference can be observed all the way up the hierarchy. But that doesn't make
it "living". (Or if you define liveness on a spectrum, like we sort of do with
sentience/consciousness, then viruses are alive like rust is conscious.)

It's very likely an invariant of complexity. Trade offs (and friendly turtles)
all the way. And of course evolution doesn't optimize for QALY at all. So it's
not surprising that it hasn't really spent much resources on closing the gap.
And now we try to do it because we do find it a better goal than "just"
thriving in every imaginable niche on whatever complexity it's possible. (We
want to maintain our complexity plus occupy more niches.)

------
gargs
The author wrote an article for Guardian -
[https://www.theguardian.com/commentisfree/2020/mar/12/scienc...](https://www.theguardian.com/commentisfree/2020/mar/12/science-
soap-kills-coronavirus-alcohol-based-disinfectants)

------
rrauenza
What I'd like to understand is why viruses are less prevalent in the summer
due to more humid air, but yet they can exist in the moist body and spread
from moist spray from coughs / sneezes.

I haven't been able to phrase the question just right to find the answer to
what seems like a conflict.

I think the spray is just a method of transmission with the virus "hoping" to
dry out quickly on a dry surface before it falls apart.

But inside the body?

~~~
xenospn
I was under the impression it was heat, not humidity, that caused viruses to
become less effective.

~~~
bufferoverflow
It's hotter inside your body on most days of the year, even if you live close
to the equator.

~~~
xenospn
Also more humid!

------
tomerbd
so this explains why 20 seconds, if anyone would explain that at the first
place and not just say out of the air wash for 20 seconds I would remember the
motivation and understand and do that otherwise I forget what I do not
understand. So typical of the shallow news not to explain.

~~~
Tomte
> so this explains why 20 seconds

Where? I've read the thread three times now and I still have missed the part
about 20 seconds. Why not 10 or 30?

~~~
wizzwizz4
It's a complex balance between the effectiveness of the behaviour and the
willingness of people to perform it. That's the usual reason, anyway.

So long as you're not stripping away layers of skin, I don't see why 30
seconds wouldn't be better.

~~~
Tomte
Sure, but grandparent spoke about an explicit explanation.

------
scoutt
I always wondered why surgeons wash their hands using soap (with extreme
attention) before operating and not with disinfectants/alcohol/etc.

~~~
jfarlow
The other way to think about it is the difference between 'clean' and
'sterile'; having no influential chemicals present (clean), and having no
living units capable of replication present (sterile). They are actually
different concepts that are caught up in the generic concept of 'clean'.

A surface full of massacred microorganisms might be 'sterile' \- nothing there
can support life, even if given sugar, water, energy, etc. But it's also
certainly not clean. If any of the debris from those dead microorganisms could
trigger your immune system, were poisonous, or were chemically active they
could alter the outcome of a chemistry experiment or trigger an immune
response.

Disinfectants by definition kill organisms, but don't remove the constituent
components of the organisms from the area. Bleach & alcohol in high
concentrations (but not pure!) will also destroy most any organisms (but will
not in itself remove the debris of those dead organisms).

Soaps will link chemicals and molecules to water that is flowed over them, and
will remove all of those constituent components along with the water. And if
the soap is strong enough, it will also dissolve and destroy smaller organisms
in the process. A surface washed with soap will no longer have any debris on
it.

------
Analemma_
I've always heard a different explanation from the one in the article: that
the soap isn't actually killing many viruses or bacterial cells, but rather
just getting them off your hands and down the drain so you're less likely to
infect yourself when you inevitably touch your face (I assume I'm not the only
one who has been discovering this week just how hard it is to not touch your
face). Is that not correct?

~~~
mcv
I think that's the case with bacteria, and maybe viruses that are put together
in a different way. But from what I understand, these particular viruses are
particularly vulnerable to soap.

------
seapunk
Dupe:
[https://news.ycombinator.com/item?id=22517397](https://news.ycombinator.com/item?id=22517397)

Original source:
[https://twitter.com/PalliThordarson/status/12365493051895971...](https://twitter.com/PalliThordarson/status/1236549305189597189)

------
throw7
This is fascinating and great information for a layman like myself. Especially
how the virus uses the cell's machinery to create the virus' own components
(rna/lipids/protein) which then self-assemble. incredible.

------
leemailll
Detergents always work, unless organisms have a thick layer of stuff other
than lipids just like human body. Btw, protein denaturants also work, such as
bleach

~~~
juandazapata
Washing your hands with bleach is not very convenient.

~~~
adrianmonk
It isn't, and it can also be really hard on your skin. If you want to avoid
infections, it's probably a good idea not to damage your skin too much.

However, bleach could be a good option for cleaning certain surfaces. For
example, countertops, hard floors, and bathrooms. I think restaurants also use
it to clean tables and maybe in their kitchens.

Since it's getting harder to obtain certain supplies, it's good to know all of
your alternatives.

~~~
chungus_khan
It's an essential cleaning supply for that sort of thing.

Another important point is that if you need something particularly sterile
(well beyond what is needed for everyday applications), pressure cookers are
essentially a home version of an autoclave, and many of the stronger ones are
actually pretty decent at it. Be careful of course though.

------
smcameron
I wonder if some soaps are better than others at destroying the virus. Dawn is
famously good at cutting grease, used for cleaning up oil spills off birds,
etc. I wonder if it's also better than other soaps at destroying the lipid
layer of the virus, or if something like Lava or GoJo would be even better.

~~~
twic
Shampoo might be best. Most shampoos contain sodium lauryl sulphate, also
known as sodium dodecyl sulphate, which is the gold standard for destructive
protein-unravelling detergents in laboratory work.

Might!

------
melenaos
Does anyone knows if liquid soap is as effective as soap bars?

I have this argument over and over agin with my wife.

~~~
flr03
Interesting! My girlfriend told me off recently after I washed my hands with a
soap bar because we ran out of liquid hand wash. For me it's the reaction of
water and soap all together that matters, this happens regardless of the state
of the soap (foam, hard, liquid...).

~~~
toufka
Foam ≠ good soap. Almost all commercial soaps are decent soaps (for the
purpose of killing organisms/viruses) that vary only in how nice they treat
your hands, and how they smell. Consumer soaps add foaming agents specifically
so people think "they're working" \- the foam does nothing. Bar soap is still
soap, and works' fine - it's just less convenient to use.

Go find an industrial or laboratory soap - that stuff is pure SDS/SLS, flows
like olive oil, will remove the top few layers of your skin, and doesn't foam
at all.

------
Leary
I have been washing my hands with the hottest temperature my skin could handle
given it is plausible that heat would inactive more of the viruses.

I have read studies saying this doesn't help.

The skin on the back of my hand is becoming irritated, i am applying lotion.

~~~
gibbonsrcool
Water temperature has to be about 60-65C and be applied for a period of
minutes (longer that bacteria) to harm viruses. Max water heater temperature
is about 48C. You're only damaging your skin which will make it more
susceptible to pathogens.

Source WHO:
[https://www.who.int/water_sanitation_health/dwq/Boiling_wate...](https://www.who.int/water_sanitation_health/dwq/Boiling_water_01_15.pdf)

~~~
nitrogen
At least some water heaters can be set a fair bit higher than 122F/50C (good
for dishwashers), but then you'd really want to use a temperature mixing valve
for anything you might touch directly.

------
oxymoran
Not that it particularly matters because it sounds like all soap is pretty
effective, but I wonder if a grease fighting dish soap would be the most
effective of all. Don’t mind me, I’ll just be doing dishes for the next few
months.

~~~
stronglikedan
Alternate soaps to avoid dry hands, since dish soap will strip the oils.

Tangentially, if you are handling raw chicken, and then try to use
antibacterial soap, it cannot penetrate the grease from the chicken. The trick
is to use dish soap first, followed by a second wash with antibacterial soap.

~~~
phonypc
Skip the second wash. Antibacterial soap is worthless at best and potentially
harmful.

------
mothsonasloth
Does anyone have any advice about using REST or RPC against viruses?

~~~
vardump
Enough XML can kill anything.

------
melling
Reading through the thread on Twitter, someone mentioned UV light is very
effective in killing viruses. is this true?

~~~
wyxuan
Washing hands is always the best option. UV might work but you probably would
have to do it for a long time and it wouldn't be as effective as soap

~~~
robjan
It would also potentially burn your hands.

~~~
nicoburns
Yeah, not a good idea for hands! It can be good for disinfecting inanimate
objects though.

~~~
SAI_Peregrinus
It needs to be a UVC disinfectant bulb/source though, so massive cancer risk
increase (and VERY bad for your eyes).

~~~
nojvek
Curious why UV is bad for eyes and skin ? The energy kills cells ?

~~~
SAI_Peregrinus
It's UVC, so it's ionizing radiation. The sort you put on sunscreen and wear
UV-blocking sunglasses to keep from getting skin cancer because of.

------
29athrowaway
Smart people of HN: what are your thoughts on the antiviral properties of
flavonoids like kaempferol?

------
dsfyu404ed
TL:DR Soap (and solvents, and alcohols for that matter) reacts with (and
therefore breaks down) the types of molecules that make up oils and fats and
the viruses in question are held together by fats.

~~~
undersuit
The ability for soaps to clean hinges on the same physical manifestation that
keep creates hollow cells for life:
[https://en.wikipedia.org/wiki/Micelle](https://en.wikipedia.org/wiki/Micelle)

~~~
dsfyu404ed
Depends on if your definition of clean is to render the contaminant inert
(which is going to basically always involve some sort of chemical reaction) or
to just move it elsewhere.

If you want to wash the problem down the drain then making large clumps out of
the offending molecules helps. If you want to actually alter the offending
molecules then you'll probably not want something that makes clumps.

This is why doctor's wash their hands while janitors wipe down surfaces with
disinfectants.

------
SubiculumCode
The use of twitter as a blogging app boggles my mind.

~~~
AgloeDreams
Why not?

It has millions and millions of users, is incredibly easy to share and
propagate info, linking is common and easy to understand. The format basically
requires concise summaries prior to longform content so you know what you are
getting into. You go where the people are.

~~~
rout39574
Because it's a terribly distracting method for presenting

~~~
rout39574
Ideas of any depth or nuance. This exacerbates an already-problematic tendency
towards trivialization on our communications.

~~~
JohnJamesRambo
I see what you did there and I like it.

~~~
ASalazarMX
I missed the 1/9, 2/9 and the prescience of counting how many tweets your
thread will take.

------
topaz0
*hydrophobic

------
jasonmp85
Why is this 25 tweets when something like “lipid envelope” would suffice?

------
RobertRoberts
Years ago the University of Oregon did research on bacteria and hand washing.

Their finding? It's not soap, it's scrubbing in water.

Scrubbing hands under water did all the work. Neither anti-bacterial agents or
soap had almost any effects at all.

I imagine it's not unlike why a stream is safe to drink but a non-moving
puddle is not.

~~~
jeffdavis
This article is specifically about viruses, not bacteria. It claims
specifically that water alone is not effective against viruses like COVID-19,
because they stick to the skin too strongly. It also claims that soap and
water together _are_ very effective by ripping the virus apart chemically.

Additionally, streams are not generally safe to drink from, despite how
pristine they may look[1].

[1]
[https://www.cdc.gov/healthywater/drinking/travel/index.html](https://www.cdc.gov/healthywater/drinking/travel/index.html)

~~~
RobertRoberts
How is no one is worried about viruses in moving water vs a puddle? (I've
learned a lot about survival over decades, you can't tell me this is new
information)

Just like the panic around COVID-19. China, who has more infections and more
deaths than anywhere else combined, is already calming down. Yet the rest of
the world is just starting in full panic mode.

Some people (medical leaders and scientists, not nut cases) are 100% convinced
we should panic. This is not rational.

We have _scientific_ proof that COVID-19 is not a big deal. Yet here we are.

~~~
triceratops
> We have _scientific_ proof that COVID-19 is not a big deal.

Are you one of those people who think Y2K was hyped up too?

China is calming down because of a _tremendous_ amount of hard work, and some
draconian restrictions on personal freedoms. The virus didn't just die down by
itself. We shouldn't panic. But we should also not be calling it nothing.

On a meta-level, this is why societies don't value prevention. And why
firefighters who pull people out of wrecked cars are considered heroes, but
Nils Bohlin, the inventor of the 3-point seatbelt, usually is not (I think
they're both heroes, in different ways). Because we have people who deny there
may problem in the future, and then after it's prevented through the
application of a ton of someone else's effort and ingenuity say "So it didn't
turn out all that bad after all. See? I told you."

~~~
RobertRoberts
> ...one of those people...

Ad hominem

Proof question: How many rats do you need to test to determine with a high
rate of accuracy a disease's CFR?

~~~
triceratops
It was a simple question. And you didn't answer the rest of my post. Are you
asserting that China would've had the same outcome if they had done nothing?

~~~
RobertRoberts
We already know how bad it can get. It's be tested and proven under lab-like
conditions.

If you want to panic and spread irrational noise, go ahead. There's no point
arguing with people that don't want to discuss the science side of things.

~~~
triceratops
> If you want to panic

Can you please explain where I said that? I'm pretty sure I said "We shouldn't
panic"
([https://news.ycombinator.com/item?id=22559590](https://news.ycombinator.com/item?id=22559590)).

I'll say it again. We _shouldn 't_ panic. It is counterproductive. But so is
passiveness, inaction, and complacency (such as saying "it's not a big deal"
as you did). Facing up to a problem, and dealing with it calmly and resolutely
isn't panicking.

> There's no point arguing with people that don't want to discuss the science
> side of things

I'm not certain what "science" you're talking about here. What "lab-like"
conditions? Are you saying containment efforts are unnecessary or unhelpful? I
seriously have no idea.

~~~
RobertRoberts
Argue with doctors, data and non-panic induced social media. Bring ur lazy
sideways anti-science arguing elsewhere.

One example of many, go argue with them.

[https://imgur.com/gallery/mAOTOI8](https://imgur.com/gallery/mAOTOI8)

~~~
triceratops
Seriously, what have I said that was "anti-science"? I'm in full, 100%
agreement with the link you posted. "Don't overcrowd hospitals, watch for the
symptoms, self-isolate, call doctors before going in, flatten the curve etc."
Those are the exact measures that need to be taken.

What I was disputing was your original statement "COVID-19 isn't a big deal."
If large portions of the population have to take all these measures to keep
this thing under control, it seems like a pretty big deal to me.

At this point I feel like you're just trolling. You aren't responding to
anything I've said at all.

~~~
RobertRoberts
Tell this data it's wrong:

[https://imgur.com/gallery/FETiDTV](https://imgur.com/gallery/FETiDTV)

Anti-hysteria from a _doctor_, argue with him:

[https://imgur.com/gallery/XN9pvQM](https://imgur.com/gallery/XN9pvQM)

(no point in actually discussing anything with you)

~~~
triceratops
> (no point in actually discussing anything with you)

I feel the same way. Not one thing I've said contradicts anything you've
posted. Definitely a troll. Or you took offense at the first thing I said and
are determined to ignore literally everything else I wrote.

------
class4behavior
I'm assuming he's talking about toilet soap, not liquid soap. Both are
surfactants, but I suppose, still behave a bit differently.

>Consequently, many antibacterial products are basically just an expensive
version of soap in terms of how they act on viruses.

In that case, this part would be wrong. You use up toilet soap a lot faster
than liquid soap, especially if the dosages of the liquid are managed
efficiently.

~~~
jplayer01
> I'm assuming he's talking about toilet soap, not liquid soap.

... what's toilet soap and how does it differ from liquid soap?

~~~
class4behavior
[https://en.wikipedia.org/wiki/Soap](https://en.wikipedia.org/wiki/Soap)

~~~
buckminster
Edit: this is nonsense. See comment below.

That says Toilet Soap is any soap used domestically for cleaning. So liquid
soap is toilet soap. What do you mean by it?

~~~
class4behavior
You didn't even read through the table of contents, nor the initial summary.
Both soaps have their own, named subsection, while in the abstract you'll find
a succinct explanation which will make sense once you've read that liquid soap
is a detergent.

>Soap is created by mixing fats and oils with a base, as opposed to detergent
which is created by combining chemical compounds in a mixer.

~~~
jplayer01
You're getting it wrong and you're confusing everybody. Detergent isn't non-
toilet soap. Toilet soap can _also_ be liquid soap. It took me all day to
figure this out and understand what you were talking about.

Under toilet soap:

> In a domestic setting, "soap" usually refers to what is technically called a
> toilet soap, used for household and personal cleaning.

I'm not sure if that also includes detergent like dish detergent, but it's
certainly not non-toilet soap.

Under non-toilet soap:

> Soaps are key components of most lubricating greases and thickeners. Greases
> are usually emulsions of calcium soap or lithium soap and mineral oil.[5]
> Many other metallic soaps are also useful, including those of aluminium,
> sodium, and mixtures thereof. Such soaps are also used as thickeners to
> increase the viscosity of oils. In ancient times, lubricating greases were
> made by the addition of lime to olive oil.[6]

> METALLIC SOAPS ARE COMPOUNDS OF ALKALINE metals or heavy metals and
> monobasic carboxylic acids containing from 7 to 22 carbon atoms. The water-
> insoluble metallic soaps are of particular interest to the coatings
> industry, although potassium and lithium soaps have limited water
> solubility.

They can also be lubricants for machines and you don't want to use any of this
for cleaning anything at home.

