The chemical triclosan has been a popular ingredient in many household cleaning products despite the fact that its supposed antibacterial properties have not been proved. Making a questionable claim is one thing; promoting an ingredient that also might have harmful side effects is quite another.

Triclosan is found in so many products ranging from soap to toothpaste to cutting boards that a survey by the Centers for Disease Control and Prevention found traces of the chemical in the urine of 3 in 4 people older than five.

That’s a pretty heavy concentration for a chemical that might pose hormonal problems, make bacteria more resistant to antibiotics and pose an environmental hazard. That’s why both the FDA and the Environmental Protection Agency are studying its effects. In April 2010, the FDA announced that “in light of animal studies raising questions about triclosan’s safety, the agency is engaged in an ongoing scientific review to incorporate the most up-to-date data and information into the regulations that govern consumer products containing triclosan. … For some consumer products, there is clear evidence that triclosan provides a benefit. For other consumer products, FDA has not received evidence that the triclosan provides an extra benefit to health. At this time, the agency does not have evidence that triclosan in antibacterial soaps and body washes provides any benefit over washing with regular soap and water.”