Scientists' consensus: Be wary of antimicrobials

June 20, 2017
soapy hands in sink
The Food and Drug Administration has banned companies from marketing consumer antiseptic wash products containing one or more of 19 ingredients, including triclosan and triclocarban.

What some consumers don’t know about antimicrobials could not only lead them to spend money needlessly but also could affect everything from their reproductive health to their susceptibility to allergens to the wellbeing of the environment. 

That’s the conclusion of more than 200 scientists who have signed a consensus statement released today. Research physiologist Patricia Fair at the Medical University of South Carolina was one of 16 people who co-authored the statement, which warns of the potential risks associated with triclosan and triclocarban. 

“Those chemicals are in personal care products, cosmetics, plastic household cutting boards, baby products, toys, building products, textiles and shower curtains. It just goes on and on,” Fair said.

The Florence Statement on triclosan and triclocarban was introduced at a symposium on organic pollutants in Florence, Italy. It summarizes research showing the chemicals are for the most part ineffective and may be harmful, Fair said. She called them possible endocrine disruptors, which means they may interfere with naturally-produced hormones.

“The consensus was basically that these two antimicrobials, triclosan and triclocarban, are in about 2,000 products,” Fair said. “They’re persistent, they interfere with hormone actions, they bio-accumulate in the environment and their use should be reduced unless they are medically or clinically necessary.”

Consensus statement: Recommendations about antimicrobials

The statement calls for the international community to limit the use of the chemicals and examine other antimicrobials as well and makes four recommendations:

  • Avoid using antimicrobial chemicals unless there is a health benefit and evidence that they’re safe.

  • When there is a need for antimicrobial chemicals, choose safe alternatives to triclosan and triclocarban.

  • All products containing antimicrobials should be labeled, even if they don’t make health claims.

  • The safety of antimicrobials and the changes they cause should be evaluated over the long term.

Last year, the Food and Drug Administration issued a rule banning companies from marketing consumer antiseptic wash products containing one or more of 19 ingredients, including triclosan and triclocarban, which were the most commonly used antimicrobial chemicals. “After studying it for 40 years, they ruled and agreed with all the studies that show there’s no benefit or necessary safety data for having these chemicals in hand soap and body wash,” Fair said. “It’s not more effective than plain soap and water.”

But Fair said the ban doesn’t go far enough, and consumers should be aware that triclosan and triclocarban are still in some products. For example, the nonprofit Environmental Working Group, which focuses on environmental health, reports that triclosan may be in dish soap, deodorant, toothpaste, mattresses, plastic food containers and shoe insoles. 

Concerns about triclosan and triclocarban

Fair, a research professor in the Department of Public Health Sciences at MUSC, cited several concerns about triclosan and triclocarban. 

  • The chemicals may interfere with estrogen and androgen systems, even at relatively low levels. 

  • Rodent studies show they reduce testosterone, follicle stimulating hormones, sperm production and can lead to implantation failure. 

  • A couple of human studies showed decreased gestation age at birth and lower head circumference at birth in boys.

  • They appear to disrupt thyroid function in lab research and may cause increased sensitivity to allergens. 

Fair’s own research shows the chemicals have a broad impact. “One of our studies was the first to report the detection of these compounds in dolphins in Charleston and Florida in blood samples,” she said. 

“It’s so widespread, and over a million pounds is just flushed down the wastewater. Obviously, whatever we’re using in consumer products, all of that goes down the drain and out in the environment, and it’s highly toxic to aquatic life. It’s been detected in 58 percent of American rivers and detected in 75 percent of Americans. It’s pretty pervasive.”

She said the issue is exposure over time. “One of the first uses was in toothpaste. Since then it’s just besieged every consumer product. It’s used so much 24/7. You’re just getting multiple exposures, and it never ceases.”

Fair has long had an interest in the impact of the environment on health, including the immune system. Her most recent published study, appearing in the scientific journal PLOS ONE, found that the immune systems of dolphins in the wild were activated more chronically than those of dolphins in captivity. She said the wild dolphins are probably coming across more pathogens, parasites and pollutants, including triclosan.

“I think we were able to show that the environment is a real driver of immune responses. You want a normal immune system. The question is, how do you define normal? At what point is the tipping point to be overstimulated? Do we want a chronic stimulation of our immune system that isn’t in our best interest? That can lead to inflammatory responses, autoimmune diseases,” she said.

Message for consumers

“I always try to bring a balanced message that we live in a modern world with microbes, and you want your immune system to function and to ward off these pathogens. At the same time, if it becomes overstimulated, that can also have a negative effect on an animal or human."

That balanced message applies to the use of consumer products as well, she said. “A lot of people think, ‘Oh, antimicrobial, that’s great. I want to kill germs.’ But you can’t kill them all. Not all of them are bad. And you know the hygiene theory that children need to be exposed to some bacteria to strengthen their immune systems.”

When it comes to antimicrobials, she said it’s important to make sure the public knows what scientists have found. “We want to make consumers very aware. I think that’s an important message to get out. People need to take individual responsibility. A lot of confidence is given to the idea that the government must have OK’d these chemicals, so that means they won’t cause any harm, and it’s safe to use them. That’s a misconception,” she said.

“So many chemicals and so little data. These chemicals in the products simply aren’t necessary, and the risks far outweigh any potential benefits. I think that’s the take home message.”

About the Author

Helen Adams