Welcome to BrainStuff, a production of I Heart Radio.

Hey Brain Stuff, Lauren Vogelbaum here with a classic episode from our erstwhile

host Christian Seger.

This is one that I wrote in the way back for our YouTube

series because once the question occurred to me I couldn't get it out of my head.

How dirty is soap. Soap.

Hey Brains stuff, it's Christian Seger.

It's good hygiene to wash your hands after using the restroom and after touching kind of gross stuff, you know, like raw meat, snakes,

cat litter, cats, biomedical waste, and any number of shared surfaces from door knobs to countertops, but what about soap?

Bars of soap are also shared surfaces, so how dirty is soap?

Soap is absolutely seething with bacteria, but you know so's your face and so so's my face and

Everything we come into contact with all day every day really organism for organism microbes outnumber humans on the planet at least 131 quintillion to

one.

Cell for cell, the microbes in and on our bodies outnumber us 10 to one, and human hands can

have up to 100,000 microorganisms per square centimeter of skin. Most of them are harmless or you know even helpful but

yeah there's a lot of them and some of them get transferred to your soap. One study

from 1984 reported that of the bar soaps they tested, 92 to 96 percent cultured

positive for microorganisms.

The antibacterial soap they tested actually had a bit more

microbial activity than regular soap. The soaps in question were in use by the

staff of clinics and laboratories over the course of seven days and

samples were taken on five of those days. But the interesting and

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