Are Antibacterial Soaps More Effective Than Regular Soap?
What you need to know about the germ-blocking abilities of products labeled antibacterial
Even during a typical cold-and-flu season, public health officials bang the drum about the importance of proper hand-washing technique. And in the midst of the Covid-19 pandemic, the nitty-gritty elements of hand hygiene have taken on an added layer of life-and-death significance.
The Centers for Disease Control and Prevention (CDC) puts thorough hand-cleaning at the top of its list of helpful measures that everyone should take to slow the spread of Covid-19. But the CDC does not specify the type of soap people should use. Those concerned consumers who go shopping for soap may wonder whether products labeled “antibacterial” offer virus-blocking abilities above and beyond plain-old soap.
“We don’t know, is the short answer,” says Donald Schaffner, a microbiologist and distinguished professor at the Rutgers School of Environmental and Biological Sciences.
When applied to soap, the term “antibacterial” is a little misleading. An antibacterial soap contains one or more ingredients deemed by federal regulators to have antiseptic properties, which means the ingredient in question has been shown to kill or otherwise prevent the spread of illness-causing bacteria or other microscopic pathogens. And that includes viruses.
For a 2011 research review published in the Journal of Food Protection, Schaffner and his colleagues looked at the existing studies comparing antibacterial soaps to plain soap. “We found that antibacterials were slightly more effective than bland soaps,” he says. He explains that neither was 100% effective at killing or clearing away germs, but the antibacterial soaps consistently outperformed the plain soap — albeit by small margins — when it came to getting rid of pathogens.
As long as a person is taking the time to thoroughly work soap into the hands’ nooks and crannies, standard soap will get the job done.
His study was looking at bacteria, not viruses. But he and others say it’s possible — though not proven — that the antibacterial ingredients in some soaps may possess some virus-slaying properties.
“The antibacterial agents in soap are properly termed antimicrobials, and viruses are microbes,” says Dr. Adam Friedman, a professor and interim chair of dermatology at George Washington University. He says that antimicrobial soap ingredients vary in how they kill or clear away pathogens, but many create positive chemical charges that can bind to and possibly disrupt the protective outer layers of virus particles and other germs. “So there is this added element that standard soaps don’t have,” he says.
But will this added element offer people greater protection from Covid-19? Friedman says he doesn’t think so. All soap contains surfactants, which are foaming compounds that bind to dirt, fat, and other pathogen-containing debris found on the skin. Once bound up by surfactants, this debris can be washed away with water. As long as a person is taking the time to thoroughly work soap into the hands’ nooks and crannies, standard soap will get the job done, he says.
This view is backed up by real-world research. A 2007 review in the journal Clinical Infectious Diseases found that people who used antibacterial soaps were not less likely to get sick than those who used plain soap. “These antibacterial soaps don’t cut down on infections,” says Allison Aiello, co-author of the study and a professor of epidemiology at the University of North Carolina at Chapel Hill’s Gillings School of Global Public Health.
This finding may seem at odds with Schaffner’s research, which found that antimicrobial soaps were slightly more effective than plain soaps at removing germs. But this difference, though statistically significant, may not lead to real-world reductions in illness transmission. Schaffner says he believes that antibacterial agents can help cut down on foodborne illness if used by food workers. But when it comes to at-home use in the battle against Covid-19, he says antibacterials likely don’t outperform plain soap. “We don’t know for sure, because the work hasn’t been done on viruses, but there is probably not a meaningful difference in benefit,” he says.
On the contrary, antibacterials may come with some risks. In 2016, the U.S. Food and Drug Administration ruled that soap manufacturers could no longer market soap products containing certain antibacterial ingredients, most notably the chemicals triclosan and triclocarban, which at that time were widely used. Based in part on Aiello’s research, the FDA determined that the effectiveness of these chemicals was unproven. They also pointed to research that found long-term use of these chemicals may cause unhealthy hormone changes.
“When triclosan interacts with sunlight, it turns into dioxin, and some types of dioxin are very carcinogenic,” says Patrick McNamara, an associate professor of environmental engineering at Marquette University who has studied the potential risks of antibacterials — including their ability to encourage antibiotic resistance and disrupt healthy microbe communities. Some animal research has also linked adult exposure to the antibacterial chemical triclocarban to unhealthy microbiome alterations in their offspring.
While today’s antibacterial soaps don’t contain triclosan, triclocarban, or any of the other banned ingredients, McNamara says the replacement antibacterial chemicals may turn out to have risks of their own. “I think soap companies pretty much know you don’t need this stuff, but they keep making them because they know there’s a market for it,” he says. “People would be better off using regular soap.”
For those who want to take every step possible to rid their hands of Covid-19 particles, experts say it’s possible that washing your hands and then using hand sanitizer may provide greater protection. “Washing hands physically removes the virus, while hand sanitizer inactivates the virus,” McNamara says. Done properly, either one should get the job done. But doubling up could lead to a slight reduction in risk.
Just be sure to wash your hands before applying sanitizer, not vice versa. UNC’s Aiello says that if a person has physical grime on their hands — dirt, the remnants of a snotty sneeze, sticky gunk left behind after grocery shopping — that grime may contain virus particles that hand sanitizer can’t get to. “It’s hard to kill a virus that’s encapsulated in dirt or body fluids, so you need to wash before you sanitize,” she says.
To sum all this up, following the CDC’s recommendations — washing hands for at least 20 seconds with soap and water, and taking care to work the soap into the nails, gaps between fingers, and other neglected places — is the best way to rid mitts of pathogens. Researchers haven’t shown that antibacterial soaps are better at blocking the spread of viruses, and these products may come with health risks.