Is All Soap Antibacterial?
What Makes Soap Antibacterial?
Reading Time: 4 minutes
We are so often cautioned to wash our hands, with soap, for at least 30 seconds in order to have clean hands and get rid of the bacteria and viruses. What happens to the bacteria and viruses that were on our hands? Is all soap antibacterial? Does the soap kill them or just “wash them off?” What does it mean for something to be “antibacterial?”
“Antibacterial” as a description means that a substance either kills or slows the growth and reproduction of bacteria. There are many natural and man-made substances that are antibacterial or antimicrobial to varying degrees. In September of 2016, the FDA banned many antibacterial chemicals, such as triclosan, for household use in soap. Companies had one year to change formulas to comply with the new law. While healthcare settings still have access to antibacterial soap, the regular consumer does not. There were several reasons behind this ban, the first being that triclosan has been shown to disrupt hormones and other biological processes. It also has a negative impact on the environment, especially on algae growth in bodies of water. Other now-banned antibacterial chemicals have been proven harmful to humans or the environment in other ways. Before the ban, we were also beginning to see a rise in bacteria that were becoming resistant to triclosan and some of the other antibacterials.
What makes soap antibacterial or antimicrobial? Regular soap, without any antimicrobial additives, does not kill bacteria or viruses. So, how does soap work? According to Ben Shay, a pharmacist, “Soap has hydrophilic and lipophilic properties, which means it plays nice with both oil and water. Lathering with soap gets the bacteria to mix in with the soap, then the water rinses it away.” The longer and more vigorously you lather and scrub, the more bacteria will be dislodged. However, every last one of those bacteria or viruses are still alive as they go down the drain.
A study compared handwashing with water only to washing with soap with a control group who didn’t wash hands. In the control group, fecal (poop) bacteria were found on the unwashed hands 44% of the time. When those in the study washed with water alone, fecal bacteria were found on their hands 23% of the time. That is nearly half the number of bacteria found. The study group who washed their hands with plain soap and water (no antibacterial soap) only found fecal bacteria on their hands 8% of the time (Burton, Cobb, Donachie, Judah, Curtis, & Schmidt, 2011). It is clear that washing your hands works, even with only water. However, obviously using soap produces a much more desirable result. You are also more likely to wash for a little bit longer when using soap as opposed to water only.
The FDA and CDC claim that there is no significant difference between antibacterial and plain soap in their ability to clean the hands of dirt and bacteria. While some studies suggest a small difference, others are inconclusive. Some studies also suggested that having antibacterial soap caused people to wash their hands for less time. Perhaps the antimicrobial qualities lulled people into a false sense of security, thinking that as long as the soap touched their hands, the bacteria would be gone. Yet, that is not the case. The physical action of lathering and scrubbing is what coats the grime, viruses, and bacteria with soap so that they can easily slip off in the running water.
Can I add anything to my soap to make it even a little antibacterial? Well, many natural substances with antibacterial properties can be soap ingredients. Raw honey, for example, has excellent antibacterial properties. Many plants have antimicrobial properties as a natural defense against disease or insects. Some of these include aloe, chamomile, clove, cranberry, green tea, hemp, lemon verbena, thyme, and many others (Cowan, 1999). While the lye for soap in cold-process style would be harsh enough to kill bacteria, it, fortunately, gets neutralized by the saponification process. Otherwise, it would be incredibly harsh on your skin as well. It is difficult to know how much of the benefits of these botanicals would survive the saponification process and be present in your finished soap product, but we can hope that some would. If you sell your soap, do beware of labeling it is antibacterial. Doing so could land you in trouble with the FDA because they have not approved those natural substances for antimicrobial uses.
And what about bar soap vs. liquid soap? Does using a bar of soap contaminate your hands with germs, especially if several people use it? No, don’t worry. Any microbes that may have been on that soap wash down the drain and don’t spread to your hands.
While soap in itself is not antibacterial in the true sense of the word, it does remove the bacteria from our hands and bodies when used correctly. Due to recent FDA ruling, there are very few soaps with antibacterial chemicals added to them that the average consumer can buy. While we can use natural antibacterial plants or honey to give our soap antibacterial qualities, it actually isn’t needed. Soap does a really good job on its own without additives.
Remember to scrub between your fingers and smile because you are not only saving money by not buying antibacterial soap, you are saving the planet!
Burton, M., Cobb, E., Donachie, P., Judah, G., Curtis, V., & Schmidt, W. (2011). The effect of handwashing with water or soap on bacterial contamination of hands. Int J Environ Res Public Health, 97-104.
Cowan, M. M. (1999). Plant Products as Antimicrobial Agents. Clin Microbiol Rev, 564–582.