A 2009 study by scientists at the Environmental Protection Agency showed that triclosan decreases levels of testosterone and sperm production in male rats. Female rats exposed to triclosan showed signs of early puberty and altered levels of estrogen and thyroid hormones.
And 2010 study by University of Florida researchers found that triclosan interfered with the transfer of estrogen to growing fetuses in pregnant sheep. Estrogen is important in both male and female development because it promotes growth of organs like the lungs and liver.
Sansoni, the soap and detergent industry spokesman, says those animal studies can't be applied to humans and "make exaggerated claims about the damaging effects" of triclosan.
But safety concerns over triclosan don't just involve rats and other animals. Some experts argue that routine use of anti-bacterial chemicals like triclosan is contributing to a surge in drug-resistant germs, or superbugs, that are immune to antibiotics. Few studies have attempted to track antibiotic resistance in the real world. But laboratory studies have shown that antibiotic-resistant strains of E. coli and other bacteria can grow in cultures with high levels of triclosan.
As a result of the growing concerns, some leading medical societies, hospitals and companies have abandoned the chemical.
Kaiser Permanente pulled triclosan from its 37 hospitals across the country in 2010, switching to traditional soaps and alcohol-based hand sanitizers. Kathy Gerwig, Kaiser Permanente's vice president for workplace safety, said the hospital chain decided to phase out triclosan as part of its "precautionary approach" to safety issues.
"If there is credible evidence that a product we're using might have some disadvantages from a health or environmental standpoint, then it's our obligation to look for a safer alternative," Gerwig said.
Johnson & Johnson also has pledged to remove triclosan from all its baby products, including No More Tears shampoo, by the end of this year. The company said it will remove the chemical from all adult toiletries by the end of 2015.
"We want people to have complete peace of mind when they use our products," said Susan Nettesheim, vice president of product stewardship, when the company made the announcement last summer.
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