Triclosan Hand Cleansers No More Effective Than Regular Soap

A new study suggests that hand cleaners laden with the antibiotic triclosan are no more effective than regular soap at killing bacteria.

Researchers at Korea University (Seoul) conducted a study that exposed 20 strains of bacteria to both plain and antibacterial soaps—with the same formulation, but containing 0.3% triclosan—for 20 seconds, once at 22 °C (room temperature) and again at 40 °C (warm temperature). Both temperature and time were selected to simulate the hand washing conditions and procedures used by everyday consumers. The decontamination efficacy of plain soap and antibacterial soap was further examined in vivo, with the hands of volunteers artificially inoculated with Serratia marcescens.

The results showed there was no significant difference in bactericidal activity between the plain soap and the antibacterial soap, at either test temperature. On the other hand, the antibacterial soap continued to show significantly greater bactericidal effects after 9 hours. The results suggest that although triclosan-containing soap does have prolonged antibacterial activity, the effects are not apparent during the short time required for hand washing. The study was published in the September 2015 issue of the Journal of Antimicrobial Chemotherapy.

“Antibacterial activities of triclosan have been well documented. However, its risk remains controversial since various adverse effects have been reported, including allergen, antibiotic resistance, carcinogenic impurities, and bioaccumulation,” concluded lead author Min-Suk Rhee, PhD, and colleagues of the department of food bioscience and technology. “Our study indicates there was no significant difference in antiseptic effects between soaps that contain triclosan and those that don’t.”

Triclosan is a polychloro phenoxy phenol antibacterial and antifungal agent in use since 1972. Showering or bathing with a 2% triclosan solution has become a recommended regimen in surgical units for the decolonization of patients whose skin is carrying methicillin-resistant Staphylococcus aureus (MRSA). On the negative side, triclosan has been found to decrease circulating levels of thyroxine hormone (T4), which could lead to altered behavior, learning disabilities, and/or infertility.

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