Makers of antibacterial soaps will have to demonstrate their products are safe for daily use and better than plain old soap and water, federal health authorities said Monday.
Millions of Americans use antibacterial hand soaps and body-washes, and about 75 percent of these products contain the antimicrobial ingredients triclosan or triclocarban.
But there's no evidence that these ingredients are more effective than conventional soaps, and may even be harmful, according to the U.S. Food and Drug Administration.
The agency proposed a new ruling on the products Monday and asked manufacturers for evidence that the compounds are safe and effective. It's the first time authorities have asked for proof of the products' safety in the four decades they've been on the market. The proposed rule doesn't apply to hand sanitizers.
Data already suggest that long-term use of triclosan, which is added to liquid products, and triclocarban, added to bar soaps, may raise the risk of drug resistance and artificial hormone exposure.
Both compounds may act as estrogens, altering hormone activity in the body, studies have suggested. The key hook enticing consumers has been the germ-killing effects. "In my opinion, that is nothing more than marketing," Dr. Bruce Hirsch, of North Shore University Hospital in Manhasset, said Monday.
"These products may be contributors to drug resistance because they kill bacteria, but they do so very slowly, more slowly than soaps, which contain detergent," Hirsch said.
Detergents clean greasy hands by breaking apart oils at the molecular level -- and they kill bacteria similarly by disrupting their cell walls, which are largely made up of fats, he said.
Exposure to antimicrobial agents, however, provides ample opportunities for bacteria to develop the genetic capacity to repel the compounds.
"We know if we expose certain bacteria to ampicillin," an antibiotic in the penicillin family, Hirsch said, "the genes for resistance to other antibiotics can become more numerous, even when those other drugs are nowhere in the picture."
The FDA's proposed rule ultimately could limit the antibacterial products on the market.
Dr. Luz Fonacier, of Winthrop-University Hospital in Mineola, said triclosan and triclocarban have been shown to have wide-ranging effects throughout the environment, persisting in waterways. "There is no proof that these soaps have an advantage over regular soap and water," Fonacier said, "yet their potential for harm is greater than their potential for good."
While the two compounds are being analyzed, the FDA is asking consumers to use products cautiously. "Washing with plain soap and running water is one of the most important steps consumers can take to avoid getting sick and to prevent spreading germs to others," Dr. Sandra Kweder, an FDA deputy director, said Monday.