Choosing a bottle of hand soap sounds, understandably, mundane. The options are pretty straightforward: Ocean fresh or citrus, maybe a little aloe, or just grab the color that goes best with the paint in the bathroom.
What about this: antibacterial or not?
The average consumer probably thinks this is a clear decision. One washes their hands in order to get rid of germs, ergo: antibacterial.
The logic makes sense, but no aspect of healthcare is above scrutiny. Case in point: the recent FDA decision that will affect the use of some antibacterial chemicals, like triclosan, in hand soap.
That’s right. In a world with virtual-reality and hover-boards, humanity still cannot quite figure out how to wash its hands.
Joking aside, this decision reflects a growing concern over the use of antibiotics and shines a new light on the potential dangers of the everyday use of antibacterial chemicals in hand soap.
Why the sudden change?
The scientific community is looking at the issue at the macro-scale. Instead of looking at how hand-washing behavior affects the “hand washer,” consideration has been given to the bigger picture. That perspective gives a very different picture of hand washing and human health.
Triclosan: What Is That?
Triclosan is an antimicrobial substance – sometimes referred to as “antibacterial” or “bactericide” – that has been used in a variety of personal hygiene products. Research has shown it to be extremely effective against bacteria like E. coli and salmonella – some of the biggest culprits contributing to foodborne disease outbreaks (and recently, the reason why Chipotle has been giving out free burritos like Halloween candy), without appreciable side effects.
Because of its benefits, Triclosan was added to variety of consumer goods. Soap, deodorant, and other personal hygiene products often contain triclosan in order to kill bacteria commonly found on human skin.
Sounds great. Unfortunately there is little evidence suggesting that this strategy is actually beneficial. The companies that were using antibacterial chemicals in soap, for example, were unable to prove that these products were more effective than plain soap and water in terms of hygiene and health outcomes.
Conversely, triclosan used in some toothpaste formulas will be allowed to remain in use, because those manufacturers were able to show that it increased the effectiveness of their products.
Why Is Triclosan Not Effective In Hand Soap?
This seems counter-intuitive – if the antibacterial chemicals in soap are proven effective against bacteria, why would they not show benefits for hygiene?
The answer may be in the research.
One study showed that triclosan was effective for removing s. aureus from the skin – staphylococcus aureus bacteria are the cause of staph infections and are touted as one of the most dangerous of the staphylococcal bacteria – but its results may not be generalizable – meaning that while an effect was seen within the study itself, the study conditions may not reflect what occurs in the larger population.
The study on s. aureus looked at bacteria on the skin of leukemia patients who were given two full-body washes with triclosan each day for two weeks. They ultimately were cleared of the bacteria, but it seems unlikely that anyone outside of a hospital intensive care unit would thoroughly wash themselves with triclosan… twice a day… for two weeks.
This sort of issue may be the underlying reason why many of the antibacterial chemical used in hand soap do not make the soaps more effective.
According to the Minnesota Department of Health, the antibacterial chemicals in hand soap – like triclosan – are only effective if the soap is on someone’s hands for two minutes or longer. While everyone knows that they should be dedicating a few minutes to washing their hands, most people probably do not actually spend two or three minutes at the sink.
In other words, the issue with triclosan may have less to do with its inherent effectiveness and much more to do with how it is used.
The U.S. Center for Disease Control recommends scrubbing for at least 20 seconds, well-under that two minute mark. This advice is drawn from the results of numerous studies performed under conditions that are more applicable to the average person than, say, the s. aureus study.
The Case Against Triclosan
If triclosan can be effective, some will question whether it is worth the trouble of removing from products.
That is a tricky question. While triclosan, and numerous other antibacterial chemicals used in hand soaps, may provide some benefits – say, to the rare individual who washes their hands for two minutes every time – those benefits do not out-weigh the potential risks.
Triclosan was proven safe for human use at the individual level; the risk of toxicity is incredibly low and it does not cause skin irritation. However, those conclusions do not consider the potential ramifications of widespread usage.
One study conducted in Sweden found that triclosan was present in appreciable levels in the aquatic environment (they tested the bile of fish caught in municipal waters). While their study did not provide evidence that these levels put human safety at risk, the results were nonetheless alarming. The safety of hand washing has always been considered in the context of human health, but what if it is harming the environment?
If that was not large enough cause for concern, the same study found that triclosan was present in human breast milk.
The questions surrounding triclosan and other antibacterial chemicals used in hand soap are only growing in number. Are the levels high enough to be a risk to human health? Can they influence gene expression? Perhaps the biggest question: is their ubiquitous use contributing to antibiotic resistance?
There is not enough data out there to answer these questions, and while there may not be significant evidence to show that triclosan is harming the environment or causing antibiotic resistance, it is possible. Thus, the recent decision reflects a conservative choice: if there are not many perceivable benefits from the use of triclosan, it is better to remove it than to risk it causing harm.