SEP 18, 2015 4:59 PM PDT

Antibacterial soap doesn't live up to the hype

WRITTEN BY: Kerry Evans
Did you wash your hands today?  Did you use antibacterial soap?  If so, you probably didn’t get the antibacterial benefits you expected.  Sorry.

Researchers from South Korea published a study testing the “real world” effectiveness of antibacterial soap.  The results?  Regular soap was just as effective at eliminating bacteria as soap containing Triclosan, the active ingredient in many antibacterial products, when tested under real world hand washing conditions.

Regular soap is just as effective as antibacterial soap at eliminating bacteria.

Triclosan is a polychloro phenoxy phenol antimicrobial that was developed in the 1960s.  At the low concentrations used in commercial products (up to 0.3%), Triclosan targets a bacterial enzyme necessary for fatty acid synthesis.  It is the most widely used antimicrobial in soaps and other products like toothpaste, shampoo, lotion, kitchenware, and even toys.  It’s also big business.  Americans spend nearly $1 billion on antibacterial soaps annually.  

The authors conducted their study in response to a 2013 statement by the FDA requiring manufacturers to demonstrate that antibacterial products are more effective than products without antibacterial additives. Not to mention, there are conflicting views (Aiello et al. and Montville and Schaffner) when it comes to the effectiveness of antibacterial soaps, and plenty of people are convinced that Triclosan itself is a health hazard (video below).

In this study, published in the Journal of Antimicrobial Chemotherapy, the authors tested antibacterial soap against regular soap in two ways.  First, they tested the ability of each soap to kill 20 different strains of bacteria under conditions that simulated hand washing.  Among these were species of Enterococcus, Staphylococcus, Pseudomonas, and Shigella.  For this experiment, they exposed the bacteria to soap containing 0.3% Triclosan for 20 seconds at either 22oC (room temperature) or 40oC.  In the second experiment, they inoculated volunteers' hands with Serratia marcescens and compared the antibacterial activity of each soap after actual hand washing.  After each experiment, the remaining bacteria were collected and grown on plates to count colonies of surviving bacteria.

Their results showed that Triclosan was more effective at killing bacteria than regular soap, but only after 9 hours of exposure.  (That’s a lot of hand washing.)  Overall, they found no significant differences between the antibacterial activity of Triclosan or regular soap under real world hand washing conditions.  

What’s the take home message?  The next time you’re out to buy soap, don’t bother with the antibacterial stuff.  It seems plain soap works just fine.



Sources: EurekAlert, Journal of Antimicrobial Chemotherapy, FDA, Wikipedia
 
About the Author
  • Kerry received a doctorate in microbiology from the University of Arkansas for Medical Sciences.
You May Also Like
APR 13, 2021
Immunology
Food-borne Fungus Impedes Gut Healing
APR 13, 2021
Food-borne Fungus Impedes Gut Healing
In a recent study, researchers discovered that a fungus present in cheese, processed meats, beer, and other fermented fo ...
APR 25, 2021
Cell & Molecular Biology
Natural Molecules Can Stop Antibodies From Neutralizing SARS-CoV-2
APR 25, 2021
Natural Molecules Can Stop Antibodies From Neutralizing SARS-CoV-2
When we're exposed to a pathogen, our immune system normally mounts a robust response against it. Antibodies are generat ...
APR 29, 2021
Immunology
A Week for World Immunization
APR 29, 2021
A Week for World Immunization
The World Health Organization (WHO) is calling our attention to World Immunization Week, which comes in the last week of ...
MAY 07, 2021
Microbiology
How a Microparasite Can Improve Wastewater Treatment
MAY 07, 2021
How a Microparasite Can Improve Wastewater Treatment
There's water all over the world, but only a bit of it - 0.3% - is useful to us, making wastewater treatment an essentia ...
MAY 16, 2021
Microbiology
Organic Meat is Less Likely to Harbor Nasty Pathogens
MAY 16, 2021
Organic Meat is Less Likely to Harbor Nasty Pathogens
Organic food has been touted as healthier, but that's been debated. While meat that is produced organically now has to m ...
JUN 15, 2021
Immunology
Secrets of Immune Cell Movement Revealed
JUN 15, 2021
Secrets of Immune Cell Movement Revealed
Circulating immune cells are constantly on the lookout for the presence of any pathogenic intruders in the body. Once a ...
Loading Comments...