Antibacterial Soap: Safe Suds or Snake Oil?
It seems like every time you go to wash your hands these days, the soap is “antibacterial.” And it’s not just soap: There’s antibacterial dishwashing liquid, hand lotion, shaving cream, trash bags, toothpaste, deodorants, cutting boards, bedding, sandals, toys, socks, sports clothing … almost everything we put on or near our skin.
I’m suspicious of antibacterial soaps, because it seems that nuking all the bacteria around you might lower your resistance to the really bad bugs. But that’s just my hunch. So I decided to find out whether the antibacterial stuff works any better than regular, chemical-free soap -- or whether it’s just a marketing scam.
What I discovered is even more disturbing. It turns out that most antibacterial soaps are actually worse than useless: they’re an outright threat to our health and environment.
The active ingredient in most antibacterial soaps, listed on the label, is triclosan, which is indeed ubiquitous. Triclosan appears in more than half of all hand soaps sold in the United States, and over $1 billion worth of products per year. Because we absorb it into our skin (or via our mouths, with toothpaste and mouthwash), and it accumulates in our bodies, the Centers for Disease Control and Prevention has reported that it shows up in the urine of three-quarters of the population over the age of five; it also appears in breast milk and umbilical cord blood. More than a million pounds of triclosan are produced annually in the U.S.
Can all that triclosan be good for you? The FDA, which regulates the chemical in personal products, says it is “not currently known to be hazardous to humans.” But it hedges that statement: “several scientific studies have come out since the last time FDA reviewed this ingredient that merit further review.” That’s not surprising, since the last time the agency reviewed triclosan in antibacterial products was 38 years ago, and it has yet to make a decision about whether the chemical should stay on the market. The FDA has declined to act despite scores of studies, the vast majority of which raise concerns about triclosan’s potential ill health effects.
Meanwhile, as the FDA continues its glacial review process, several elected officials, consumer and environmental groups (including the Natural Resources Defense Council, which publishes OnEarth), and even the American Medical Association -- all of whom have reviewed the studies -- are insisting that the FDA finally regulate triclosan, because those studies show it to be not only useless, but risky.
Take even a casual look at some of the studies the FDA is supposedly reviewing, and it’s clear that triclosan is hazardous. Animal studies have shown that triclosan alters hormone levels -- lowering levels of thyroid and testosterone in lab rats, as BPA in plastics does. Although scientists still don’t know exactly how triclosan affects human hormones, endocrine disruptors in general can cause early-onset puberty, reduced fertility, obesity, and cancer. Another recent study on mice shows that triclosan impairs the functioning of their muscles.
Triclosan behaves like a very potent drug, says UC Davis molecular biologist Isaac Pessah, who did those mice and fish studies. The structure of the triclosan molecule is similar to other compounds not found in the environment that can affect muscle contraction, so his research team decided to see whether triclosan had the same effect. After they found that triclosan slowed down human heart muscle cells and fibers, they tried it on mice, giving them doses comparable to the levels people get in consumer products. The result: Mice given a single dose of triclosan experienced a 25 percent reduction in heart function, and an 18 percent reduction in grip strength for an hour. The researchers also exposed fathead minnows (which are frequently used in pollution studies because of their high sensitivity) to triclosan and found a marked reduction in their swimming activity after they had been exposed to the chemical for a week.
Pessah believes the chemical could cause muscle problems in people, too, and would be particularly dangerous to those with heart conditions or other muscle disorders. “If you already had muscle impairment, a small decline in cardiac output would be devastating,” Pessah says. He hopes his findings will spur epidemiological studies to see if people who have been exposed to triclosan during their daily lives suffer more muscle impairment than people who have less exposure.
So given all that, should triclosan be banned? Pessah said the chemical might have some useful niches as a prescription drug, targeting some bacteria as an antibiotic, but he doesn’t think it should be sold over-the-counter. “You don’t put Prozac in virtually every product you use, including your cosmetics and underarm deodorant,” he says. “Here’s a compound that’s very biologically active, and could be useful in some prescription situations, yet it’s being manufactured in millions of pounds, ending up everywhere.”
Other researchers have shown that exposure to triclosan is indeed taking its toll on people. In 2011, epidemiologists at the University of Michigan School of Public Health found that the more triclosan researchers detected in children’s urine, the more likely they were to have allergies. In 2012, Johns Hopkins immunologist Jessica Savage found that triclosan levels were also correlated with food allergies -- to peanuts, shrimp and dairy -- particularly among boys. The researchers speculated that it was the antimicrobial qualities of the chemical that altered people’s immune responses -- if you don’t get exposed to bacteria because you’re killing off all the good and bad ones, your system doesn’t know which ones to fight off and so goes into overdrive against any invaders.
Triclosan was initially developed as a surgical scrub in the 1960s by Ciba, which is now part of the German chemical giant BASF. Ironically, it has proven to be most deadly in hospitals. Triclosan is a biocide and kills certain bacteria, including healthy flora, but it lets other harmful bacteria flourish. One of the bugs triclosan doesn’t kill is pseudomonas, a major cause of hospital-acquired infections. In some cases, fatal outbreaks of the disease have been traced back to the hospital triclosan soap dispenser. Kaiser Permanente was the first large hospital chain to stop using triclosan.
The American Medical Association has also raised a red flag about triclosan, concerned that it causes antibiotic resistance: the germs that survive triclosan become stronger, making it harder to treat common infections with our current arsenal of antibiotics. When bugs like e. coli, staph, and salmonella are exposed to triclosan, they develop a cross-resistance to other antibiotics that work by a similar mechanism. In 2000, the AMA issued a statement recommending that triclosan and other antimicrobials “should be discontinued” in consumer products. It also urged the FDA to finish the process of banning triclosan in consumer products. That was a dozen years ago.
The risks associated with antibacterial soaps are certainly enough to give one pause. But are there benefits that outweigh the fact that most of us are carrying a load of triclosan in our bodies?
The American Cleaning Institute, which represents the $30 billion U.S. cleaning products industry, makes the case that antibacterial soaps are important to public health, stating on its website that antibacterial personal care products provide “an extra measure of protection for both consumers at home and doctors and nurses in hospitals seeking to prevent the spread of germs.” The implication is that soap and water aren’t enough to get rid of disease-causing germs and to protect public health, so responsible consumers should use triclosan. Many consumers have indeed bought this notion that if clean is good, cleaner is better -- a claim that producers of triclosan products can continue to make as long as they are unregulated by the FDA.
But scientists say that’s just a marketing ploy. “The whole concept is bunk,” says Allison Aiello, a University of Michigan epidemiologist who analyzed 27 studies of triclosan and its impact on preventing illness that have been conducted while the FDA has been making up its mind about the chemical. First off, “germs” is a catch-all term for bacteria and viruses, and triclosan doesn’t touch viruses. Second, it doesn’t fight bacteria any better than when you wash your hands -- no matter what the cleaning institute claims. “Triclosan doesn’t provide any benefit above and beyond soap,” Aiello says. “This is a case where the risk outweighs the benefit.” The only people who disagree with her are the ones making or marketing the stuff.
To explain why triclosan doesn’t work any better than soap, Aiello described what happens when we wash our hands. First, just the friction of rubbing your hands under water makes most of the bacteria on them slide into the sink (that’s why it’s better, in a pinch, to rinse your hands with water when there’s no soap). More important than what soap you use is how long you spend washing your hands -- at least 15 seconds. Soap, innocent of toxic chemicals, works very elegantly: It doesn’t kill germs, but attaches to them and carries them away. Soap molecules have a head and tail, like sperm, but even smaller. The tail attaches to organic materials -- oil, viruses, bacteria, fungi, dead skin -- while the head keeps it afloat in the water. Together, soap molecules surround the materials they’ve attached to, making an impenetrable barrier while escorting the dirty stuff down the drain. Triclosan may kill some of those bacteria (again, not the viruses), but Aiello says, there’s no point, since the bacteria is already on its way down the sink.
Brian Sansoni, spokesman for the American Cleaning Institute, disagrees. He calls concerns about triclosan “overblown accusations,” and was quoted in ICIS.com, a trade news service for the chemical industry, saying that the notion that triclosan increases bacteria resistance was a “suburban myth” (the AMA, apparently, has offices in the suburbs). He points to a handful of studies that show that triclosan is more effective than plain soap and water in killing germs; most of these studies, however, were sponsored by the institute or Dial soap, makers of the best-selling triclosan product.
I called Rutgers University microbiologist Don Schaffner, who published analyses of many of the studies on triclosan that were funded by the institute and appear on its website. He said that while triclosan does kill more of some bacteria than soap, that difference was “small,” and appeared in studies where there were “artificially high” levels of microorganisms on the skin. In one study he looked at, for instance, participants dipped their hands in Shigell and E. coli and then handled melon balls right afterward. These were not real-world situations, but scenarios where participants slathered themselves with the exact same bacteria that triclosan kills, so it’s no wonder the triclosan came out ahead.
“No one is dunking their hands in an E. coli broth before handling food,” says Sarah Janssen, a physician and senior scientist with NRDC, which joined other environmental groups last year in suing the FDA to rule on restricting the use of triclosan. Many studies, as well as meta-studies that have looked at the results of other research papers, have examined infection rates in populations of people who used a triclosan soap and plain soap and have shown no difference. “In the real world,” she says, “plain soap was just as effective as triclosan soap at preventing infection.” Using triclosan soap, she says is “an unnecessary exposure to an unsafe chemical.”
Which brings us to the obvious question: Why, with so many people urging that triclosan be regulated, hasn’t the FDA banned triclosan? “The FDA has sat on its decision on triclosan forever,” says Janssen. The FDA first proposed a regulation that would remove triclosan from over-the-counter use in 1974, but declared that the data were insufficient to make a final classification. “There’s a loophole in the FDA regulations that allows anyone to manufacture and distribute these products,” says Janssen. If the FDA finalized its decision, $1 billion worth of antibacterial products -- 76 percent of liquid soaps by one measure -- would have to come off the market. “There’s a big financial incentive not to finalize the decision,” Janssen says. (OnEarth exposes other laxes in FDA oversight in the Winter 2013 cover story, "The FDA is Out to Lunch.")
The FDA’s decision-making process on over-the-counter drugs is the opposite of the precautionary principle, which holds that if something is suspected of causing harm to individuals or the environment, the burden of proof is on the manufacturer to show that it is safe. “They want very specific, complete evidence of harm,” says Alison Aiello, who has conducted metastudies on triclosan and who sat on the advisory panel in 2005 FDA hearings which concluded that there was no evidence that antibacterial soaps work better than regular soap and water, “yet it doesn’t seem anyone is weighing the fact that there’s no benefit whatsoever.”
When I called the FDA to ask what was going on, spokesperson Stephanie Yao commented, “Rulemaking takes time.” When I mentioned that 38 years seemed like a lot of time, she replied in an email, “We are committed to completing our review and communicating our findings as soon as possible,” but was not specific about when.
There may be some movement toward getting rid of triclosan, though. Nichelle Harriott, a staff scientist with Beyond Pesticides, a Washington, D.C.-based science and policy non-profit group that focuses on reducing toxic pesticide use, says the FDA may be waiting for the EPA, which regulates the chemical in the environment, to weigh in on triclosan before finalizing its decision. Harriott predicts that given the new health and environmental studies on triclosan, “we’re going to see triclosan phased out.”
Every few years, the EPA has to review chemicals that are used as pesticides; triclosan was first registered as a pesticide in 1969. Aside from consumer products, triclosan is used in agriculture to stop the growth of bacteria, fungi, and mildew. It also has industrial uses, preventing bacterial growth in such products as fire hoses, conveyor belts, and ice-making equipment, and as a preservative in many fabrics, plastics (toys, toothbrushes), floor waxes, carpeting, and a wide variety of products. The EPA last assessed triclosan in 2008, but is updating its assessment, it says, based on recent data on the thyroid and estrogen effects of the chemical.
Aside from the potential health risks of triclosan, there are plenty of other environmental hazards. Because consumers wash so much triclosan down the drain, it gets diffused throughout the environment. It’s one of the most frequently detected chemicals in streams and has even shown up in wild bottlenose dolphins. Triclosan is found in high concentrations in treated sewage sludge, called biosolids, which are often used as fertilizer in agricultural fields. Sarah Janssen says that once in the soil, the triclosan gets absorbed into the roots of the plants we eat. “Consumer product use is resulting in contamination of the food chain, which gives us a double dose of exposure.”
While the EPA and FDA have done nothing to restrict triclosan, there has been enough pressure by environmental and medical groups that some manufacturers have voluntarily stopped using the chemical.
Johnson & Johnson has removed triclosan from all its personal care products. Spokesperson Peggy Ballman says that even though the ingredients are “safe by scientific standards,” questions about its environmental impact have been raised, so the company decided to phase triclosan out to give consumers “peace of mind.” No more tears. Colgate-Palmolive has removed it from some of its dish and hand soaps, but kept the chemical in its toothpaste, which is FDA-approved for treating gingivitis (the only use of triclosan that is fully approved by the FDA, even though the triclosan is in toothpaste that everyone uses, whether or not they have gum disease).
Kaiser Permanente, a Bay Area-based nonprofit hospital system with hospitals in nine states and over 9 million health plan subscribers, has also banned triclosan. Kathy Gerwig, Vice President for Workplace Safety and Environmental Stewardship, says the organization was convinced that triclosan was no more effective than soap and water, and they were concerned about the bigger health care picture. “When we look at how we prevent disease, it’s not just preventing colds and flu, but longer-term diseases that might be a result of health hazards that are caused by chemicals found in products and the environment,” she says, pointing to the studies on the chemical’s effect on immune functioning, allergies, and hormones. “Where credible evidence exists for us to think there is a problem with a chemical or product, we consider it our obligation to use a safer alternative.”
The credible evidence that there’s a problem with triclosan clearly does exist -- so much so that large corporations and hospital chains are moving away from its use. But that’s no thanks to the agency charged with taking care of our health. Perhaps an even bigger problem is that the FDA has taken nearly four decades to review ample evidence that triclosan is harmful; it may only finally regulate it after all the companies in the $750 million hand soap market have a chance to substitute it -- perhaps with something equally ineffective, or hazardous, which will take another lifetime to regulate.
Fortunately, for consumers, it’s a simple matter to avoid the chemical by checking labels, since triclosan is always listed, and buy soap instead (or alcohol-based hand sanitizers). Eating organic foods that haven’t been slathered with triclosan-infused fertilizer is also a good move. The FDA clearly isn’t going to protect us from triclosan; the only thing concerned consumers can do is wash their hands of the stuff.