Wash your hands with plain soap, not antibacterial

So many products these days are sold as “germ free”: soaps, sponges, toys, even hands-free hand cleaners. But do these antibacterial products do any good, or do they make things worse?

On of the most commonly used antibacterial chemicals in consumer products is triclosan, or if you prefer, 5-chloro-2-(2,4-dichlorophenoxy)phenol. It’s quite effective against bacteria, inhibiting the action of enzymes used in fatty acid synthesis. Enzymes which, crucially, are not used by humans, so it shouldn’t affect us the same way.

Tube of Dettol antiseptic cream, containing 0.3% triclosan (click to embiggen)
Tube of Dettol Antiseptic Cream, with active ingredients chloroxylenol and triclosan, both at 3mg/g, or 0.3% concentration, the recommended safe amount.

But there are other problems. Thanks to the wonders of natural selection, over-use of antibacterial chemicals can lead to the bacteria evolving resistance, which can then limit our ability to control them in future.

Triclosan also seems to spread throughout the environment, which is potentially bad news for “good bacteria” and even photosynthetic algae. It also means that if there is any danger to humans, it’s hard to avoid.

So far there isn’t any proof that it’s hazardous to humans, but some studies have shown harmful effects on animals, like liver damage in mice and disruption of growth hormones in frogs. Again this raises environmental concerns – particularly for freshwater species – but also the question of whether there is a yet-to-be-discovered risk for humans.

For this reason, the United States Food and Drug Administration (FDA) is currently reviewing the safety of triclosan. Australia doesn’t have a directly equivalent body, but the National Industrial Chemicals Notification and Assessment Scheme (NICNAS) has recommended labelling and adopting a maximum safe concentration of 0.3% in cosmetics, which is consistent with the European Union (see the NICNAS report – PDF 140 KB).

But still, triclosan does kill bacteria, so should you use it to keep yourself clean despite these unverified risks?

Interestingly, some studies have shown that washing your hands with antibacterial soap – containing triclosan – is no more effective at removing bacteria than ordinary soap (see for example Aiello AE, Larson EL & Levy SB 2007, “Consumer Antibacterial Soaps: Effective or Just Risky?”, Clinical Infectious Diseases, 45 (Supplement 2): S137-S147, doi: 10.1086/519255).

So drop the hands-free hand wash, and keep yourself clean the old-fashioned way.


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