Triclosan is a synthetic compound used in many personal care products labeled as antibacterial. It's been in use for more than 40 years so many people, including product safety regulators, consider it safe to use. Various studies, however, suggest otherwise.

One study found triclosan in the nasal passages of 41% of 90 healthy adults. In addition, the nasal passages of this 41% were more likely to be host to a colony of an illness-causing bacteria: Staphylococcus aureus.

The presence of triclosan and the Staph bacteria may not cause harm in most healthy adults but it might be of concern to expectant mothers. Bacteria in the mouth that cause infection and tooth decay can work their way down into the placenta, where the baby is exposed to them.

This ability of bacteria to go from mouth to placenta is one reason why oral hygiene is critically important during pregnancy; infections in the mother's mouth can promote adverse outcomes for the pregnancy and the baby. The nose is connected to the mouth, making it possible for nasal infections to reach the placenta, too.

About 30% of all people have Staph colonies in the nose and throat. When colonization advances to infection, illness occurs. These Staph-based illnesses can be minor abscesses but they can be life-threatening cases of endocarditis and bacteremia, too. At particular risk of Staph infection are diabetics with foot ulcers and people who develop an infection at the site of surgery. In the United States in 2005, approximately 19,000 people died from illness caused by Staph infections.

In addition to fostering the growth of Staph colonies in the nose, triclosan is known to disrupt the endocrine system, especially the estrogen and androgen receptors. It also weakens the muscles of the heart and skeletal system.

Many antibacterial personal care products in the home contain triclosan. Soaps, shampoos, and toothpaste often contain it, even the brands marketed to children. Some clothing is treated with triclosan as are some of the products used to make kitchen countertops. Commonly used medical equipment, such as sutures and catheters, may contain triclosan. Some patients are given a triclosan bath to rid the body of Staph germs before surgery.

Dr. Blaise Boles, of the University of Michigan, led the study of triclosan and nasal bacterial colonization. In addition to finding proliferation of the Staph bacteria in the noses of study subjects who also had triclosan in their noses, the researchers discovered that triclosan attaches itself to host proteins (nasal tissue, for example), which induces the Staph bacteria to bind to the proteins, too. Triclosan also showed significant attachment properties on glass and plastic surfaces.


  1. Boles, Blaise R., et al. "Triclosan Promotes Staphylococcus aureus Nasal Colonization." mBio. American Society for Microbiology. Apr 8, 2014. Web. Apr 20, 2014.
  2. "Triclosan (products list)." Household Products Database. US Department of Health & Human Services / National Institutes of Health. Dec 2013. Web. Apr 20, 2014.