How Soap Works: The Science Behind Handwashing
pfizer.com
pfizer.com
It was difficult to grok on the first couple watches because water was taking the role of lipids and air was taking the role of water, but a fascinating and visceral demonstration.
The best link I could find is at https://www.youtube.com/watch?v=u_1RfqMH-KM
If soap has an extraordinary ability to destroy viruses on our skin ... can eating soap give us some of those benefits for viruses that are already in our bodies?
I'm not seriously envisioning chowing down on bar soap or using liquid hand soap as a salad dressing. But are there ways to use the _properties_ of soap that make it good for killing viruses in something that can be ingested? Or do those properties only work for surface-level viruses, and we need to use other strategies to kill viruses once they're in our bodies?
The bigger issue is that it would cause mass death of good cells as well as prevent proper cell functions.
That's why there's an entirely separate class of soap products formulated specifically for those among us who own and operate a vagina.
I think people should abandon this heuristic.
For this reason, I stick to either first-generation soap (made by saponification) or simple surfactants.
In general, as a precautionary principle, it is always good to stick to simple products that have been around for a long time.
(Skin is, in general, rather more sensitive to bases than acids. Even a fairly mild base will make skin feel unpleasant and a bit slimy, whereas holding an orange slice (quite acidic) is not particularly irritating to intact skin.)
https://www.sciencedirect.com/science/article/pii/S009167492...
And overuse of soap is definitely irritating to skin — this is not a particularly subtle effect.
And I think it will be neutralized by the acids inside the stomach.
unfortunately googling shows that mixups happen every so often, sometime due to what I’d call gross or willful negligence like storing it in a re-used food container in the fridge
> This is probably the stupidest question many of you will encounter today
We should all be so lucky that a well-intentioned but somewhat naive question is the stupidest thing we read all day.
> I'm not seriously envisioning chowing down on bar soap
If you want to find out, my dog will happily chow down on a bar of soap. He tried to eat one a few days ago, and he happily drinks soapy water out of the tub when my kids are in the bath.
You can dog sit him and clean up the mess when the soap comes out the other end.
I think the thing people are missing in a lot of these comments is that viruses are typically traveling from the skin to a mucus membrane in your body (which can be in the stomach but also in your lungs and nose), then infecting your cells. Eating soap might impact pathogens in your still in your stomach, but it's not going to dissolve in your blood and circulate through your body at high enough concentrations to impact viruses...
...and if it was high enough concentration: imagine snorting, inhaling or injecting dish soap.
I'm worried enough imagining the soap doing to my insides the things it does to organic residue on my hands or dishes.
Manually washing your hands with regular water eventually has the same degree of efficacy as with soapy water, it just takes a lot longer, so why don't more people conclude that they just need to drink more water to flush the viruses out when they're sick? Why should it be the soap plus the water that makes it magic?
By and large, you want to prevent the contamination that leads to viral infections by keeping the parts of you (or others) that interact with the environment away from the parts of you (or others) that viruses enter through. Because we can't do that all day, every day, we try to lower the odds of anything that might've gotten on us staying on us intact, and soapy water applied and rinsed at a sink is a pretty good way to do that.
Once the viruses are inside us, they're in the cells, and soapy water doesn't have the right properties that our cells and tissues need to maintain an environment that allows them function, largely for the same reasons it's good for cleaning. The biology of life relies on these properties universally, which is why we can't drink salt water or water that's "too pure" like deionized water; one takes water out of our cells, and other puts too much in.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9881715/
https://pubmed.ncbi.nlm.nih.gov/30307335/
> The most common symptoms were
> labial oedema (28%, n = 153)
> oropharyngeal irritation (10%, n = 56)
> salivation (10%, n = 53)
> vomiting (9%, n = 48)
> cough (8%, n = 45)
> Among symptomatic patients (n = 276), one patient died from aspiration pneumonia and one patient died from a cardiogenic shock following oropharyngeal oedema, vomiting, cough and bronchial obstruction.
I'd also like to add: don't ever ingest anything containing methanol. That group may include hand sanitizers.
I asked a similar question to a doctor about inhaling alcohol vapor, if that would kill bronchitis or pneumonia (obviously the answer is NO). I can't remember the specific response, but it's unfortunate because if biology were as simple as computer science: pneumonia/bronchitis is an infection, alcohol kills bugs, ergo breath alcohol vapor to stop infection. I also asked in good faith why an I.V. solution of alcohol wouldn't help with sepsis, and I'm pretty sure the answer is that it _would_ treat sepsis but the concentration would have to be so high that you'd have no liver in the end :(
Was my impression wrong?
https://www.unesco.org/en/articles/how-soap-kills-covid-19-h...
I was taught about the hydrophilic/hydrophobic nature of soaps and detergents in university decades ago; this is not new information, and is uncontroversial. As others have pointed out, it’s even easy to observe in simple home experiments.
I have never heard of soap disrupting the phospholipid shell of viruses; this is new and “interesting if true”.
The astoundingly bad handling of government communications during the pandemic makes me automatically skeptical of arguments from authority.
However, the takeaway of “wash your hands thoroughly to inhibit disease vector transmission” has amply been proven in the last century.
But in the specific case of COVID-19 soap happens to also destroy the virus particles and that turns out to be pretty valuable too. :)
We now know that people who are infected with Covid emit viral particles into the air while breathing normally. Those viral particles can float in the air for hours and the people who inhale them become infected.
> The most common way COVID-19 is transmitted from one person to another is through tiny airborne particles of the virus hanging in indoor air for minutes or hours after an infected person has been there.
https://www.whitehouse.gov/ostp/news-updates/2022/03/23/lets...
Previously we thought the only transmission route was that infected people who sneeze or cough spray large droplets that fall out of the air quickly, and the people who touch surfaces contaminated by those droplets and later touch a mucous membrane become infected.
So Covid has fully airborne transmission like the measles, not a droplet based spread like the flu. Hand washing is an effective mitigation for a virus with a droplet based spread, but not a virus with an airborne spread.
The Whitehouse post linked above discusses the sorts of mitigations that can be effective against an airborne virus.
Also, water alone does a lot to wash them away. Found this study of no-washing vs. water-washing vs. soap+water-washing with a quick search:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3037063/
No washing: 44% of hands intentionally touching doorknobs and railings had bacteria
Water alone: 23%
Water + soap: 8%
(edit: line breaks)
Covid news claimed loud that soap will disrupt virus membranes, killing it.
I worked on a Christmas tree lot through my winters as an undergrad and olive oil always worked well. Of course then you need soap and water to remove the olive oil.
“Magic All Natural Industrial Hand Cleaner (with walnut shells)”
Is downright the best thing I’ve ever encountered for cleaning anything on the hands. Anything sticky, greasy, non-newtonian… etc. it scrubs right off. Person who’s worked in grimy machine shops for 30 years introduced me to it. Fast Orange is a complete & utter disgrace comparatively.
Coffee grounds are nice, but walnut grounds are far superior.
I imagine there are variations in other places, I think it's mostly concentated citrus oils from oranges.
It the same for blood stains on clothing. They are not generally water soluble, you could get them out if you put it under cold water if the stain is still fresh. Hydrogen Peroxide can dissolve blood stains (fresh or old) since it can be used as a solvent.
Put differently, it breaks up the stain molecules into smaller molecules and causes other reactions that change them, it doesn't just dissolve them. You can dissolve resinous stuff with various solvents, you're right about that. Stays mostly the same, just goes into solution.
There are things that are much better at cleaning non polar molecules off of surfaces, alcohols, gasoline, lye, brake cleaner etc, but they’re not great at cleaning your hands because they strip the lipids that make up your skin off.
> washing your hands with soap and water is one of the most effective ways people can keep from getting sick, and from passing the [COVID-19] virus to others
So not to doubt handwashing, but I thought we overwhelmingly determined that COVID-19 doesn't thrive on surfaces (very long) and its primary transmission vector is through the air, from respiratory system to respiratory system, clinging to small moisture particles as it goes.
Also... this article is a bit of a stub. Diagrams would be nice. More detail would be nice, I'd expect better from a company like Pfizer, who I do trust to make vaccines, but this marketing content is low-effort.
There seem to be plenty of diseases that are commonly spread by inadequately washed hands. COVID does not appear to be one of them.
It can last from hours to days depending on what it lands on and the environmental conditions like light/heat/humidity. (for example see https://www.thelancet.com/journals/lanmic/article/PIIS2666-5...) Viral RNA can still be detected on surfaces for much much longer but that doesn't mean it's going to be getting anyone sick.
You're right that the primary transmission vector is through the air, and that the risk of getting it by other means is much lower but since people often cough and sneeze directly into their hands then wipe their wet (maybe virus filled) hands on things around them it's probably a good idea to keep washing your hands. In fact, it's probably a good idea to wash our hands more often even without Covid concerns. People are gross and spend a surprising amount of time rubbing their eyes or inserting fingers directly into their nostrils.
> “I want to be clear that nothing should change in terms of washing our hands and personal hygiene,”...In a piece for the Conversation, Vally said: “This isn’t to say surface transmission isn’t possible and that it doesn’t pose a risk in certain situations, or that we should disregard it completely. But, we should acknowledge the threat surface transmission poses is relatively small.”
https://www.theguardian.com/australia-news/2021/feb/28/clean...
Maybe with all that covid funding they could afford a better proofreader..
"Soap, which has been in around for thousands of years"
It's obviously an over-simplification for the purposes of education, but it works, as it has stuck with me.
Go down to "Solvent/detergent (S/D) inactivation".
There are some other considerations. Water temperature, water hardness, soap composition, handwashing technique.
Is this not the norm?