Antibacterial soap

Antibacterial soap is any cleaning product to which active antibacterial ingredients have been added. These chemicals kill bacteria. They do not kill viruses.

Many, or even most, liquid hand and body soaps contain antibacterial chemicals. Triclosan is a common ingredient, as is alcohol. Since there is a great variety of bacteria, effectiveness against any given type of bacteria does not ensure that it is effective against unrelated types.

Overuse of chemicals like triclosan have been suggested to cause sensitive bacteria to evolve resistance to its antibacterial action. Should any antibiotic be discovered that works similarly to triclosan, this antibiotic's effectiveness to combat infections will be reduced because people will be hosting resistant bacteria already due to their use of soaps containing triclosan.

Studies have examined the purported benefits of antibacterial soap. Some studies have concluded that simply washing thoroughly with plain soap is sufficient to reduce bacteria and, further, is effective against viruses. Other studies have found that soaps containing antimicrobial active ingredients remove more bacteria than simply washing with plain soap and water (J.C. Lucet (2002), Hand Contamination Before and After Different Hand Hygiene Techniques: a Randomized Clinical Trial, Journal of Hospital Infection; L.L. Gibson (2002), Quantitative Assessment of Risk Reduction From Hand Washing with Antibacterial Soap, Journal of Applied Microbiology). Food and Drug Administration published reports that questions the use of antibacterial soap and hand sanitizers saying that it found no medical studies that showed a link between a specific consumer antibacterial product and a decline in infection rates.

At one conference, Dr. Stuart Levy, a microbiologist at Tufts University, cites these studies to conclude: "Dousing everything we touch with antibacterial soaps and taking antibiotic medications at the first sign of a cold can upset the natural balance of microorganisms in and around us, leaving behind only the 'superbugs'."1

However, Dr. Levy's most recent research (Aeillo, et al. (2005) Antibacterial cleaning products and bacterial resistance; Emerging Infectious Diseases) concludes that "The results from our study do not implicate the use of antibacterial cleaning and hygiene products as an influential factor in carriage of antimicrobial drug-resistant bacteria on the hands of household members." The paper's authors call for continued research in this area.

Some soaps contain tetrasodium EDTA which is a chelating agent that sequesters metals that the bacteria require in order to grow. Other microbes also require metals and so it is actually an anti-microbial agent that is widely used even as a preservative. It appears to be fairly harmless in the environment.

There are other chemicals used in cleaning agents to kill germs but their purpose seems more directed at marketing an untested feature than in promoting hygiene.