The U.S. Food and Drug Administration (FDA) has announced that hand and body washes containing certain antibacterial ingredients can no longer be widely sold (the final rule can be found here, and the consumer update is here). Why have they been banned?

The Banned Antibacterial Ingredients

In high enough concentrations, antibacterial ingredients kill bacteria either by rupturing their membranes (their “skin”) or by interfering with how they work.

19 of these ingredients have been targeted:

• Cloflucarban
• Fluorosalan
• Hexachlorophene
• Hexylresorcinol
• Iodophors (Iodine-containing ingredients)
  • Iodine complex (ammonium ether sulfate and polyoxyethylene sorbitan monolaurate)
  • Iodine complex (phosphate ester of alkylaryloxy polyethylene glycol)
  • Nonylphenoxypoly (ethyleneoxy) ethanoliodine
  • Poloxamer-iodine complex
  • Povidone-iodine 5 to 10 percent
  • Undecoylium chloride iodine complex
• Methylbenzethonium chloride
• Phenol (greater than 1.5 percent)
• Phenol (less than 1.5 percent)
• Secondary amyltricresols
• Sodium oxychlorosene
• Tribromsalan
• Triclocarban
• Triclosan
• Triple dye

The most common ones in hand soap are triclosan and triclocarban. Any hand or body washes containing these ingredients will not be able to be sold in the US from September 2017.

Three other antibacterial ingredients are still being reviewed, but can still be used in soaps for the time being: benzalkonium chloride, benzethonium chloride, and chloroxylenol.

Why have antibacterial soaps been banned?

The key reason is: because they don’t work any better than non-antibacterial soaps to warrant the potential risks. While antibacterial soaps do tend to kill more bacteria, this hasn’t translated into tangible health benefits, like reduced rates of sickness. In the FDA’s regulatory terms, they’re no longer “generally recognised as safe AND effective (GRAS/GRAE)”.

The risks are:

Possible health effects from long-term, frequent exposure

Animal studies suggest that some antibacterial ingredients may contribute to health problems like hormonal disruption and skin cancer. A positive result in an animal study doesn’t automatically translate to humans, since there are fundamental differences between species – for example, chocolate is poisonous to dogs, and two paracetamol (acetaminophen) tablets will kill a cat. But it does signal that there could potentially be a problem, and more research is warranted (and is currently underway).

Contributing to antibiotic resistance

Antibiotics are a mainstay of modern medicine. However, a few bacteria have a natural immunity to antibiotics, and will survive and multiply. If this happens on a large enough scale, the bacteria will become resistant to that antibiotic, and you’ll need a new antibiotic. The scary thing is that antibiotic resistance is developing at a frightening speed – faster than the discovery and development of new antibiotics. Which means in the not-too-distant future, we may regress back to a scary time when skin infections were ~11% lethal.

Antiseptics aren’t antibiotics, but some studies have suggested that resistance to antiseptics is building in the same way, and that antiseptic-resistant bacteria are also antibiotic-resistant. This means that the widespread use of antiseptics could be contributing to the growth of superbugs that are resistant to common antibiotics.

Should I stop using all antibacterial products then?

Not necessarily. Note that the FDA has only banned them in hand soaps because the risks outweighed the benefits…and in hand soaps, the benefits are zero, because at the moment, the evidence shows that plain soap works just as well. Which means any risk is too much risk.

However, this decision was based on lack of evidence for effectiveness, and some evidence of potential harms. So if further evidence (clinical studies, for example) show that antibacterial soaps are effective, or that the health risks aren’t relevant for humans, the ban might be reversed. Unfortunately, science is often messy and inconclusive like that!

Note that these ingredients haven’t been banned in other consumer products that contain antibacterial ingredients like wipes, hand sanitisers, toothpastes or first-aid disinfectants, and they’re still allowed in healthcare settings (hospitals etc.). That’s because these situations are different, in terms of how the products are used and what the risks are – in wipes and sanitisers, the antibacterial ingredients stay on your skin for longer and would likely have a greater chance of killing the bacteria, while in healthcare settings, the bacteria present are often more harmful, and in some situations (e.g. open wounds, severely immunocompromised patients) small amounts of bacteria can be very dangerous. In these cases, the risks of antibacterial use are likely to be small compared to the benefits.

My personal approach is to avoid using antibacterial products unless necessary, such as if I have a cut that’s showing signs of infection; if I don’t have access to soap and water before eating, I’ll use an antibacterial hand rub containing alcohol as the active ingredient, since it’s impossible for bacteria to become resistant to alcohol, and its health effects are known and minimal. With emerging research on the microbiome indicating the importance of beneficial bacteria in our health, I’m becoming more wary of the “kill all the germs!” approach to staying well.