WASHINGTON - The federal government said Monday it has no evidence that antibacterial chemicals used in liquid soaps and washes help prevent the spread of germs, and it is reviewing research suggesting they may pose health risks.

Regulators at the Food and Drug Administration said they are revisiting the safety of chemicals such as triclosan in light of recent studies suggesting the substances can interfere with hormone levels and spur the growth of drug-resistant bacteria.

The government's preliminary ruling lends new support to outside researchers who have long argued that the chemicals are, at best, ineffective and at worst, a threat to public health.

"The FDA is finally making a judgment call here and asking industry to show us that these products are better than soap and water, and the data don't substantiate that," said Stuart Levy of Tufts University School of Medicine.

Under a proposed rule released Monday, the agency will require manufacturers to prove that antibacterial soaps and body washes are safe and more effective than plain soap and water. Products that are not shown to be safe and effective by late 2016 would have to be reformulated, relabeled, or removed from the market.

"I suspect there are a lot of consumers who assume that by using an antibacterial soap product they are protecting themselves from illness, protecting their families," said Sandra Kweder, deputy director in FDA's drug center. "But we don't have any evidence that that is really the case over simple soap and water."

The FDA proposal comes more than 40 years after the agency was first tasked with evaluating triclosan, triclocarban, and similar ingredients. Ultimately, the government agreed to publish its findings after a three-year legal battle with the Natural Resources Defense Council, an environmental group that accused the FDA of delaying action on triclosan. The chemical is found in an estimated 75 percent of antibacterial liquid soaps and body washes sold in the United States.

The Washington Post reported that the American Cleaning Institute, which represents the cleaning product industry, said Monday that it has provided the FDA with "a whole wealth of data" showing that antibacterial products are safe and more effectively than soap and water.