Sorry to burst your bubble, germaphobes, but unless you feel like spending nine hours scrubbing your hands at the bathroom sink, you might as well use plain ol' regular soap.
Antibacterial soaps have been under the microscope for a while, but the latest research published in the September 2015 Journal of Antimicrobial Chemotherapy is the first study that put antibacterial soap and typical soap up against 20 strains of bacteria — including listeria, salmonella and staphylococcus — in petri dishes.
Researchers from Korea University exposed the bacteria for 20 seconds at 68- and 104-degree temperatures to both ordinary soap and soap that contained a 0.3 percent concentration (the maximum percentage allowed by law) of triclosan, the most commonly used active antiseptic ingredient in antibacterial soap. The two soaps were the same formula except for the presence of triclosan in the antibacterial version.
The antibacterial soap was better at killing bacteria… after nine hours. So you'd only get the extra benefit from triclosan if you spent most of your day washing your hands nonstop, which is probably not a great plan. Otherwise there was no significant difference between the two types of soap.
To be sure this finding applied to the real world, the researchers also asked 16 volunteers to use both soaps to wash their hands under warm water for 30 seconds. Again, no significant difference. So the next time you're trying to choose between what looks like millions of different types of hand soap, there's probably no need to look for the word "antibacterial" on the bottle.
"This study shows that presence of antiseptic ingredients (in this case, triclosan) in soap does not always guarantee higher anti-microbial efficacy during hand washing," said senior author, Min-Suk Rhee, researcher of food bioscience and technology at Korea University in Seoul, South Korea, in an email to Live Science. "If the manufacturer would like to advertise the antiseptic efficacy of their products, they should supply scientific evidence to support the claims."
If all this sounds familiar, that's because this isn't the first time we've been advised to ditch antibacterial soaps. Back in December 2013, the FDA announced that it was taking a closer look at this type of cleanser and challenged the soap-making companies to prove their products' safety and effectiveness. In fact, triclosan has been linked to liver and inhalation toxicity as well as disrupted thyroid function, according to the Environmental Working Group.
Sounds like grandma's hygiene advice might've been right all along — simple suds work just fine.