Soap study scrubs anti-bacterial claims
New research suggests antibacterial soaps do not do as much as some might expect.
A study published in the Journal of Antimicrobial Chemotherapy found that hand cleaners that contain the antibiotic triclosan are not more effective at killing germs than regular soap.
In short – almost any soap acts as a surfactant, and when combined with the mechanical action of washing they remove microbes with equal effectiveness.
A team from Korea University performed a range of tests on regular and anti-bacterial soaps.
They exposed 20 strains of bacteria to one formulation of regular soap and another containing 0.3 per cent triclosan; the maximum legal amount.
They counted the amount of bacteria killed by the soaps and found no difference between the two.
In fact, it took nine hours of exposure for the triclosan-containing soap to have a significantly greater effect in killing germs.
The research team then asked 16 participants to coat their hands with special red bacteria.
The participants used both soaps in a normal washing routine, before the experts counted the number of bacteria that were rinsed off their hands.
Again, no significant difference between the two was revealed.
It is important to note however that the temperature and time were selected to simulate the hand washing conditions and procedures used by consumers.
The study was intentionally not directed at soap use in hospital or food preparation situations, where hands should be washed longer and more thoroughly.
“Antibacterial activities of triclosan have been well documented,” says researcher Min-Suk Rhee.
“However, its risk remains controversial since various adverse effects have been reported, including allergen, antibiotic resistance, carcinogenic impurities and bioaccumulation.”
“Our study indicates there was no significant difference in antiseptic effects.”
The study is important because of the potential risks that come with seemingly-ineffective triclosan antibacterial soap.
The chemical is the subjects of an ongoing safety review by the Food and Drug Administration in the US for its reputed ill health effects.
It reportedly causes skin rashes and allergic reactions in some people, and has been blamed for increasing the incidence of antibiotic-resistant bacteria.