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Are you a bit of a germaphobe? Maybe think twice about using antibacterial soap.

Hosted by: Michael Aranda
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Sources:
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Michael: Whether it’s a sniffly cold, a headache, or the flu, nobody likes getting sick. And one of the best ways to fight germs is pretty simple: wash your hands. Soapy water can get rid of bacteria and viruses, but antibacterial soaps have extra chemicals to kill microbes, so wouldn’t they be even better for you? Well... probably not.

In September 2016, the U.S. Food and Drug Administration banned companies from making and marketing antibacterial soaps for people like you or me. And that’s because, according to lots of research, there’s no benefit and even some possible harm from using these soaps. The FDA report named 19 chemicals that are routinely added to soaps.

One of the most common is triclosan, a molecule that contains chlorine. There’s evidence that triclosan messes with bacterial cell walls or even prevents them from making fatty acids. Both of these things are a microbial death sentence.

But according to lots of studies, including a review of 27 different papers across nearly three decades, triclosan and other antibacterials don’t work any better than good ol’ average soap. Soap is really good at cleaning. It’s a surfactant, which means soap molecules have a hydrophilic side that likes bonding to water, and a hydrophobic side that likes bonding to not-water things like dirt and oils. So when you wash your hands, the hydrophobic parts of soap attach to all the junk on your hands, including bacteria. And when you rinse with water, the soap gets washed away with all that stuff in tow.

In 2013, the FDA asked companies to find scientific evidence of the safety and effectiveness of antibacterial soaps – basically, how well they kept people from spreading sickness around. But most research found that there was just as much bacteria left over on people’s hands as when they used normal soap, and they got sick just as often.

Not only that, but some studies found that these antibacterial chemicals might be doing some harm. Some researchers are concerned that using these chemicals for a long time may accidentally create more antibiotic-resistant bacteria.

Bacteria reproduce really quickly, so there’s always a chance that one might develop a random genetic mutation that protects it from the deadly effects of an antibiotic, like triclosan. So then, even though most of the bacteria would get killed by the antibiotic, the one super bacterium could survive and pass on that resistance, so you’d be stuck with a new generation of nastier microbes.

Chemicals like triclosan have also been found to affect algae photosynthesis and build up in the bodies of wildlife, like dolphins. In studies on rats, triclosan changed the amount of estrogen, testosterone, and especially some thyroid hormones in their bodies. That could mean these chemicals mess with reproductive development or metabolism. But we don’t know yet if similar effects happen in humans.

So, we’re not entirely sure how antibacterials might affect the health of lots of living things, including us. But if plain soap and water does the trick, we might as well stick with the basics.

Thanks to Patreon Patron Benjamin E. for asking, and thanks to all of our patrons who keep these answers coming. If you’d like to submit questions to be answered, go to Patreon.com/scishow. And don’t you forget to go to youtube.com/scishow and subscribe!