"Triclosan is one of the most reviewed and researched ingredients used in consumer and health care products," says Brian Sansoni, a spokesman for the group, whose members include Colgate-Palmolive and Henkel Consumer Goods Inc., maker of Dial soap.
While it can take years for the government to make rules, members of Congress say there is little precedent for the FDA's four-decade review of triclosan.
"When FDA first started evaluating the rules governing triclosan's use, Richard Nixon was still president," said Rep. Edward Markey, D-Mass, who asked the FDA to take a closer look at triclosan in 2010 after the European Union banned the chemical from products that come into contact with food.
"Science has evolved and so should FDA's regulations guiding the use of this chemical in consumer products," he says.
U.S. scientists agree that the FDA's review is overdue. The Endocrine Society, a group of doctors and scientists who specialize in the hormone system, flagged triclosan four years ago as an ingredient that alters levels of thyroid hormones and reproductive hormones like testosterone and estrogen.
"I think the FDA is behind the curb," said Dr. Andrea Gore of the University of Texas at Austin, who was the lead author of the Endocrine Society's statement on hormone disrupting chemicals. "At what point do you draw a line and say we need to take this out of products that are being applied to our skin? What is enough evidence?"
Some Americans are shocked that the FDA has taken so long. Mallory Smith is troubled to learn that the government has never confirmed the safety antibacterial soap's key ingredient.
Smith, who works for the federal government, says she keeps antibacterial soap in the kitchen to clean her hands after she's handled raw meat.
"As a regular consumer I rely on the government to identify products that are safe for me to use," Smith said. "If something is brought to their attention they should look into it, and ban the chemical if necessary."
Others are less surprised by the government's multi-decade review. "It sounds like a typical government agency to me: totally unproductive," said David Fisher, who sells restaurant equipment in Arizona.
Ironically, triclosan first became widely used because it was considered safer than an older antibacterial ingredient, hexachlorophene. That chemical was banned from household items in 1972 after FDA scientists discovered that toxic levels could be absorbed through the skin. Several infant deaths in France were connected to baby powder that contained unsafe levels of the chemical, due to a manufacturing error.
Triclosan was initially used in hospitals in the 1970s as a scrub for surgeons preparing to perform an operation. It was also used to coat the surfaces of catheters, stitches and other surgical instruments.
Beginning in the 1990s, triclosan began making its way into hundreds of anti-bacterial consumer goods, ranging from soap to socks to lunchboxes. The growth has in part been fueled by Americans who believe that anti-bacterial ingredients provide an added level of protection against germs.
As the use of triclosan has expanded, more scientists have questioned its effectiveness. In 2007, researchers at the University of Michigan and other universities compiled data from 30 studies looking at the use of antibacterial soaps. The results showed soaps with triclosan were no more effective at preventing illness or reducing bacteria on the hands than plain soap.
Other studies have shown that longer hand-washing improves results far more than adding antibacterial ingredients. The Centers for Disease Control recommends washing hands at least 20 seconds. The CDC also recommends using hand sanitizer — most of which use alcohol or ethanol to kill germs, not chemicals like triclosan — if soap and water are not available.
Troclosan's safety also has become a growing concern in recent years. To date, nearly all of the research on triclosan's health impact comes from animal studies —which are not necessarily applicable to humans — but the findings still have researchers concerned.