Concerns have swirled around the popular antibacterial chemical triclosan for years, linking it to health implications such as impaired thyroid function and liver toxicity. And more studies keep adding to the concerns.
The U.S. Food and Drug Administration (FDA) banned triclosan in antiseptic wash products like liquid hand soap, effective September 2017, but according to the Environmental Working Group, it's still found in many household products, including many dishwashing detergents, deodorants and "antibacterial" products like cutting boards and food containers. EWG notes that wastewater treatment does not remove all of the chemical, so triclosan ends up in lakes, rivers and water sources, making it ubiquitous in the environment as well. That's why concerned people have limited their exposure to the chemical over years by choosing products carefully, especially when washing their hands.
Here's a look at just some of the research that has linked triclosan to health concerns.
Women and osteoporosis
A study published in The Journal of Clinical Endocrinology & Metabolism suggests that women exposed to triclosan may be more likely to develop osteoporosis than women who aren't exposed to the chemical.
For the study, researchers analyzed data on 1,848 women in the U.S. and found that those with the highest levels of triclosan in their urine were nearly 2.5 times as likely to have osteoporosis as the women who had the lowest levels of triclosan in their bodies.
The evidence was stronger in postmenopausal women than in premenopausal women, according to the researchers, who say more studies are needed to validated their findings.
Triclosan and muscle function
In an earlier study, researchers at the University of California Davis concluded that triclosan may hinder muscle function in both animals and humans. The study, published in the Proceedings of the National Academy of Sciences, looked at the effects of triclosan in humans and found that it impairs human muscle contractions at the cellular level. Exposure to triclosan disrupted the cell communication that is necessary for muscles to function properly. This caused failure in both the heart and skeletal muscle cells.
Researchers also evaluated triclosan's effect on fish and mice and found that it inhibited normal muscle functioning in both. In the mice, triclosan exposure reduced proper heart function by as much as 25% while grip strength was reduced by as much as 18%. For the fish, minnows were exposed to concentrations of triclosan similar to those found in the wild for seven days. After exposure, the minnows were significantly worse swimmers than those who were not exposed to the chemical and were also less efficient in swimming tests that evaluated their proficiency at evading a predator.
The study's authors argue that the pervasiveness of triclosan adds to the concern about its health implications. "These findings provide strong evidence that the chemical is of concern to both human and environmental health," noted the study's lead author, Isaac Pessah.
Earlier research has suggested that triclosan may interfere with the thyroid and impact thyroid function. Although one study found that toothpaste containing the chemical had no negligible impact on the thyroid, other research found that the chemical is an endocrine disrupter in various species. For example, the chemical has been found to cause cancerous tumors in rats.
Although triclosan can be worrisome, there is some good news.
"Luckily, triclosan is rapidly excreted from the body after exposure, so in theory, it should be possible to reduce the amount of it we have on our bodies by avoiding continuous exposure," Luz Claudio, an environmental medicine and public health researcher at the Icahn School of Medicine at Mount Sinai in New York City, told the Associated Press.
"People who are concerned can avoid products that contain triclosan by reading the labels."
Want to limit your family's exposure to triclosan? MNN's Matt Hickman has some great tips in his post on getting triclosan out of your home.
Editor's note: This story has been updated with new information since it was published in August 2012.