Soap School: Is Bar Soap Actually Germy?
Every so often someone asks me whether bar soap is sanitary.
Usually they're looking at the bar with just a tiny bit of suspicion, because apparently at some point we collectively decided that a perfectly innocent bar of soap might be running a bacterial Airbnb.
So. Let's talk about it.
Can bacteria get on a bar of soap?
Yep.
Bacteria are everywhere. They're on your hands. They're on your skin. They're in your bathroom. They're on your phone, and frankly, I wouldn't look too closely at your kitchen sponge if I were you.
Everybody okay?
Good.
Because the question isn't really whether bacteria can land on a bar of soap.
The question is whether those little buggers hop off the soap and back onto your hands when you wash.
And somebody actually studied this.
Somebody Put E. Coli on Soap. On Purpose.
Back in 1988, researchers took bars of soap and loaded them up with E. coli and Pseudomonas aeruginosa.
And when I say loaded them up, I mean loaded them up.
They put about 70 times more bacteria on those bars than had been reported on regular, used soap.
Then they handed the contaminated bars to 16 people and had them wash their hands normally.
Science is fun sometimes.
Afterward, researchers couldn't detect either of those bacteria on the participants' hands.
Now, before we announce THE SOAP HAS SPOKEN and never discuss this again, there are a couple things worth knowing. This was a small study. It was done in 1988. And the researchers worked for Dial Corporation.
So I'm not basing the entire case for bar soap on one 38-year-old study sponsored by a soap company.
But it does help explain something people get wrong about soap all the time.
Soap Doesn't Have to Murder the Germs
I think years of advertising antibacterial everything did a number on us.
We started thinking that "clean" means we need to kill every microscopic thing unfortunate enough to wander into the bathroom.
That's not what regular soap needs to do.
Soap contains surfactants that help lift oils, dirt and microbes away from your skin. Then the rubbing and rinsing does the rest of the work and sends the whole mess down the drain. That's also why washing with soap works better than just sticking your hands under running water and calling it good.
In other words:
Soap isn't a tiny bar-shaped flamethrower murdering every bacterium in its path. It's really good at helping you wash the little bastards down the drain.
Which is plenty.
The CDC isn't particularly worked up about antibacterial soap, either. For everyday handwashing, they recommend plain soap and water and say studies haven't found an added health benefit from antibacterial soap for regular consumers.
The FDA says essentially the same thing: there's not sufficient evidence that over-the-counter antibacterial soaps do a better job of preventing illness than plain soap and water.
Plain soap.
Water.
Twenty seconds.
Done.
Okay, But What About Sharing a Bar?
Yes, your husband can use the same bar.
I know.
After everything you've seen him do.
You're still fine.
For ordinary household handwashing, there's little evidence that a previously used bar of soap presents much of a hazard. That's exactly what the contaminated-soap study was looking at in the first place.
Obviously we're talking about normal household use here. Hospitals and other healthcare settings have their own infection-control rules because, well, they're hospitals.
Your bathroom is probably not an operating room.
If it is, we have bigger things to discuss.
For the rest of us, the important part is actually washing properly: wet your hands, lather them up, scrub the backs, between your fingers and under your nails, rinse them well, and dry them. The CDC recommends scrubbing for at least 20 seconds.
Which brings me to the thing I will nag you about.
For the Love of Soap, Let the Poor Thing Dry
Not because I'm worried your wet bar is plotting your demise.
Because I make soap, and watching someone leave a beautiful handmade bar sitting in half an inch of water makes a tiny part of my soul leave my body.
Give. Your. Soap. Drainage.
Handmade soap likes to dry out between uses. If you leave it sitting in water, it gets soft. It gets mushy. It disappears faster.
And if you've ever wondered why handmade soap sometimes seems to melt faster, I've got a whole Soap School lesson on that, too.
And then people tell me handmade soap doesn't last as long.
Ma'am.
You drowned it.
If several people are using the same bar, that's even more reason to put it somewhere it can dry between uses. Not because we're preparing for a bacterial apocalypse. We're just trying not to turn an $8 bar of soap into soup.
So...Is Bar Soap Germy?
Can bacteria exist on the surface of a bar?
Sure.
Does that mean you are rubbing a bacterial petri dish all over yourself every time you take a shower?
No.
The research we have suggests bacteria sitting on a used bar don't readily transfer to your hands during normal washing, and public-health guidance continues to recommend plain soap and water as an effective way to remove germs.
So use your soap.
Share it with the other humans who live in your house if that's what you do.
Actually wash for more than three seconds.
Rinse.
And then put the poor bar somewhere it can dry.
Wash your hands. Rinse the bar. Let it dry. Carry on with your life.
Class dismissed.
And if all this talk about soap has made you want a fresh bar, go pick your poison.
Sources
For my fellow nerds who would rather see the receipts than take the soap lady's word for it:
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Heinze, J.E. & Yackovich, F. Washing with contaminated bar soap is unlikely to transfer bacteria. Epidemiology & Infection, 1988. Read the study on PubMed
