Antibacterial soaps containing the chemical triclosan are no more effective at removing bacteria from your hands than regular soaps, according to new research published in the Journal of Antimicrobial Chemotherapy. Such a conclusion raises the question of the necessity of using that chemical, which is marked as potentially dangerous.
The antibacterial soap market is very strong and is worth a billion dollars a year, and that's just in the US.
The most common antiseptic agent used in these soaps, triclosan, has been linked to antibiotic resistance, allergies, and interference with mammalian hormone systems. Worryingly, one study has proven that triclosan is potentially carcinogenic. Those potentially dangerous effects have prompted the US Food and Drug Administration to better investigate these soaps and, if possible, ban them.
Scientists investigated the effect of antibacterial soap on 20 dangerous bacteria, such as Escherichia coli, Listeria monocytogenes and Salmonella enteritidis. The team of scientists placed the bacteria in petri dishes with antibacterial or ordinary soap. After that, they heated those containers to 20 or 22 °C for 40 seconds, which represented a simulation of exposure to warm and hot water.
After that, they tested the antibacterial soap in real life, not just in the lab. Volunteers allowed their hands to be covered with the bacteria Serratia marcescens (a species commonly found in bathrooms) and were asked to wash their hands for thirty seconds using either regular soap or antibacterial soap containing 0,3% triclosan, the maximum allowed in products sold in EU, Canada, Australia, China and Japan.
After failing to find a difference in effectiveness in this regard between the soaps, the scientists tested how much triclosan was needed to kill the bacteria. Using the same concentration as before, they proved that it was only effective after the microorganisms had been immersed in it for over nine hours.
The scientists therefore suggest that consumers should be warned that antibacterial soap containing triclosan may not be as effective as claimed.
"Soap should be banned and it is necessary to investigate the effects of products that can confuse users," said Min Suk Rhee, co-author of the study.
Bonus video:
