Does ordinary hand soap have any chemical effect on viruses or bacteria? If not, does the use of soap just facilitate their mechanical removal in some way that using water alone does not?
Yes, although it depends on the specific virus or bacteria. I don’t have a reference handy, but I’ve read that the coronavirus has a lipid shell that soap disrupts, for instance. Many bacteria can protect themselves from that sort of insult, but even tough bacteria can be washed off by soap and water.
In general, soap is a molecule that binds to water at one end and to lipids at the other, which is why it’s good at breaking up grease and washing it away.
Does dish detergent work as well as soap, especially the kinds that say “antibacterial”?
What about those waterless cleaners like Goop. Made for cleaning up after working in the garage, they are excellent at removing grease from your hands. It’s significantly better than regular soap at removing the black gunk you get from working on an engine. Do those kinds of cleaners work using the same molecular technique as regular soap or are they doing something different?
Once I got some powdered graphite on my bare hands, which gave a nice and sobering visual demonstration of how well and how long you have to soap up and scrub your hands to get stuff off rather than smear it all over the back of your hands, between your fingers, around the cuticles and under your fingernails, etc.
Both dish detergent and hand soap are effectively soaps, and should have similar effects—they’re both amphipathic, which is to say they act as solvents for both polar and nonpolar substances.
COVID-19 is a virus, so I wouldn’t expect antibacterial soaps to work any better than regular soap. Plus, antibacterial soaps are not a great idea in the first place…antibiotic resistance to triclosan is one reason:
When I was turning wrenches in bike shops, I became well-acquainted with Goop and similar soaps. They typically have hard particulates (silica? Aluminum oxide?) to get into the warp and weft of your fingerprints. To emulsify grease and oil, they also contain actual soaps, AFAIK.
To be clear, I’m speculating. That said: the soap in Goop and similar products should work about as well as other soaps, but I’d be surprised if they worked better than regular hand soap. I’d also be surprised if they weren’t about 90% as good as whatever conventional soap you care to name.
By coincidence,here’s a piece from yesterday’s Guardian
Note that the attached article says that no soaps currently being sold over-the-counter in the United States contain triclosan, so antibiotic resistance to triclosan is not currently a problem for hand soaps in the United States.
It’ll probably work too well, meaning dish detergent is harsher than regular hand soap and will strip a lot of the good natural oil on your hands. You like your hands smooth, don’t you?
I’ve also used Goop and similar hand cleaners which work very effectively for cleanup after car repair. I just looked up the MSDS (material safety data sheet) and was a bit surprised to see the composition. There are no soaps or conventional detergents in it. The main ingredient is petroleum distillates, a vague term for a complex mixture hydrocarbons. It also contains some longer-chain alcohols, glycerine, and triethanolamine. The latter is a surfactant, like soap and detergent.
That’s good to see how soap+water can break up the virus, but what would happen with just soap? Would the virus end up having a soap molecule stuck to it and would that degrade its ability to infect you?
In terms of liquids, the soap isn’t 100% pure soap. There’s going to be some water and other compounds, so it’s sort of a theoretical question.
In terms of bar soap, there’s no way to get the soap into contact with crevices and whatnot in your skin.
And then there’s the question of how do you get the soap off your skin without using water? Remember: washing off stuff is one the key benefits of using soap. It flushes away a lot of the little bad things.
A lot of dish soaps these Days have skin moisturizers.
These days? Most of us on this board are old enough to remember the Palmolive commercials from the 1970s.
And there’s a magic time machine for those who may have forgotten.
Yeah, if people wash properly then all the viruses end up down the drain. But it seems like there can be situations where you come in contact with a virus attached to soap. Sometimes washing is incomplete or insufficient and there’s some soapy viruses left behind. They could be on your hands, the faucet, the towel used to dry your hands, etc. It seems probable that you could occasionally end up in contact with those soapy viruses and end up getting them in your system.
I did some looking up about this scenario but all I can find are articles about soap+water. It seems like in a lab setting it could be investigated if a soap molecule binds to the virus if the virus is still viable.
It is not just that the soap binds to the lipid layer surrounding the viral DNA/RNA - it disrupts it, exposing the nucleic acids to the environment. This is what disrupts the virus - without the lipid layer the virus cannot penetrate cells to infect them, and the nucleic acid itself gets broken up by chemicals in the environment.
Madge! I soaked in it!