Study Finds Significant Reduction in Bacteria When Using Antibacterial Soap

Handwashing with antibacterial soap produces statistically greater reductions in bacteria on the skin when compared to using non-antibacterial soap. Those are the findings of a review of two dozen relevant published studies analyzing the effectiveness of antibacterial soaps  featured in the November 2011 edition of the Journal of Food Protection.

Researchers Donald Schaffner and Rebecca Montville of Rutgers Universitys (New Jersey) Food Science Department conducted a quantitative analysis of existing data in order to determine if there was a difference in effectiveness between antibacterial and non-antibacterial soaps.

A difference in the effectiveness of antimicrobial and non-antimicrobial soaps appears to exist and is repeatedly observed through a variety of analyses; antimicrobial soap is consistently and statistically always more effective than non-antimicrobial soap, the researchers wrote.

The research article, A Meta-Analysis of the Published Literature on the Effectiveness of Antimicrobial Soap, reviewed a total of 25 publications containing 374 observations found to have examined use of both antibacterial and non-antibacterial soap in the same study.

Although differences in efficacy between antimicrobial and non-antimicrobial soap may be relatively small, they do exist, and small but significant differences in pathogen levels on hands can have a significant effect on public health, wrote Schaffner and Montville.

Adds Schaffner:  In addition to our findings on antimicrobial effectiveness, I was really struck by the similar behavior of very different species of bacteria in response to antibacterial soap.  In other words, we found that antibacterial soap did its job against a variety of bacteria, including E. coli and Staph.

The research in the Journal of Food Protection (Vol. 74, No. 11 2011, Pages 1875-1882) was supported by the Topical Antimicrobial Coalition, which consists of the American Cleaning Institute and the Personal Care Products Council.