After a long day out, shaking hands, wiping your child’s face, or even just touching that convenience store door knob, scrubbing away the grime with bacteria-bashing soap seems like a great idea, right? Unfortunately for you, those around you, and the environment, new data has surfaced showing that these cleansers actually do more harm than good.
Researchers are reporting that certain antibacterial chemicals found in soaps, mainly triclosan and triclocarban, actually increase the risk of infections, change the microbiomes in the gut, and can spur bacteria evolution to become resistant to prescription antibiotics. All the while, proof of antibacterial soap benefits are slim.
There are specific but few circumstances where those antimicrobials can be useful. Mainly in prolonged washes. For instance, when surgeons scrub down for minutes at a time before surgery, or for a hospital patient that can’t scrub with soap but can soak in a chemical bath. Most people only wash their hands for only a couple seconds. This doesn’t really destroy any microbial bacteria at all.
The Food and Drug Administration hasn’t over looked these facts either. The agency has deemed the chemicals safe, but they are revisiting claims that the chemicals make soaps and other products better. The FDA has asked companies to show evidence of the benefits of antibacterial soap, to discover a ruling. But this could make the $5.5 billion soap market ditch these chemicals all together.
Soap and the Triclosan Scandal
Until these rulings are made, researchers continue to find more disheartening evidence pertaining to these chemicals, particularly triclosan. The antimicrobial is used in medical equipment to cosmetics, and easily enters the body via ingestion or skin absorption. It can be found in human blood, breast milk, and even mucus.
In 2014 a study led by a microbiologist by the name of Blaise Boles of the University of Michigan in Ann Arbor, tested 90 adults and 41% (37 people) had triclosan-laced boogers. Antimicrobial-mucus can ironically double your odds of having bacteria in your nose.
In rats exposed to triclosan, Dr. Boles and his colleagues found that triclosan exposure made it more difficult, not less, for the rodents to fend off Staph invasions. Triclosan seems to make the bacteria “stickier”—better able to adhere to proteins and surfaces. That stickiness could be why Staph is so good at hunkering down in the schnoz, setting the stage for future infections.
Other researchers have been looking at how triclosan and other antimicrobials may alter microbial communities further down from the nose—in the gut.
Flush with Chemicals
While researchers continue to work out what antimicrobials do while they’re in people’s bodies, Dr. McNamara of Marquette University focuses on what the chemicals do once people pee them out or wash them down the drain. McNamara and his colleagues have been tracking both triclosan and triclocarban in wastewater treatment plants, where both chemicals can accumulate.
In a 2014 study, McNamara’s research team found that triclosan messed with the microbial communities that break down sewage, in some cases sabotaging their ability to digest the sludge. The chemical also caused a spike in the presence of a gene called mexB in the sewage microbes. This gene codes for a pump that allows bacteria to simply kick out triclosan before it can kill them off. This pump, McNamara hypothesizes, also spits out common prescription antibiotics, such as ciprofloxacin. In experiments, bacteria with mexB were resistant to antibiotics, too.
In a January study, McNamara, his graduate student Daniel Carey, and colleagues found that triclocarban had the same effect as triclosan—it also disrupts the microbial communities that digest sewage and spurs bacteria to become resistant to drugs.
From wastewater treatment plants, these superbugs can leak out into waterways, wildlife, and potentially back to people, McNamara told Ars.
While some experts are hopeful that actions by the FDA and state regulators may nix the use of these chemicals in commercial products, McNamara thinks consumer choices may be the most powerful way to reduce use of the chemicals. People could use regular soap or ethanol-based sanitizers and have effective, less risky cleansers, he said. “There’s a way that we can still keep our hygiene without having these extra chemicals.”