The study has looked at one popular ingredient for antimicrobial soap — triclosan — and considered the effectiveness on bacteria. Triclosan is an organic compound. It appears, until dissolved in solution, as a white powdered solid with a slight aromatic, phenolic odor (it is classed as a type of “phenolic”). The use of triclosan has long been controversial.
The controversy centers on whether triclosan is actually effective and also in relation to health and environmental impact. With the latter point Karen Graham recently reported on the danger hand sanitizers — many containing triclosan — pose to children who ingest them. Triclosan has also been connected with several adverse health and environmental effects including skin irritation, endocrine disruption, and negatively impacting aquatic ecosystems.
In new research, scientists examined the bactericidal effect in two ways. To begin with the scientists examined the bactericidal effects of triclosan in soaps against 20 different bacteria. Secondly, the researchers compared the ability of antibacterial soap (with triclosan) and non-antibacterial soap (without triclosan) to reduce bacterial populations from human hands. This involved the use of 16 healthy adult volunteers.
The results of the first part of the study showed that triclosan soap only had a moderate antibacterial effect. However, for a reasonable level of bacterial kill to be achieved, nine hours was required. This is far in excess the 10 or 20 seconds that a typical person might spend washing their hands.
With the second phase of the study, the results showed that there was no significant difference between the effects of standard soap and antibacterial soap, under practical conditions.
The study has been published in the Journal of Antimicrobial Chemotherapy. The research paper is titled “Bactericidal effects of triclosan in soap both in vitro and in vivo.”
Whether triclosan should continue to be used is open to medical debate. On the basis of this recent study, no evidence that triclosan in antibacterial soaps and body washes provides any benefit over washing with regular soap and water. Speaking with Cleanroom Technology magazine, Dr. M S Rhee, who led the research, warned that “advertisement and consumer belief regarding the effectiveness of antibacterial soaps needs to be addressed.”
