Image caption Scientists warn antibacterial products may create resistance to antibiotics in humans

The US health regulator has warned that antibacterial chemicals in soaps and body washes may pose health risks.

The Food and Drug Administration (FDA) called for a safety review of such products.

It proposed a rule requiring manufacturers to prove such soaps are safe and more effective against infection than plain soap and water.

Recent studies indicate an ingredient in such products could scramble hormone levels and boost drug-proof bacteria.

The proposal rule does not apply to alcohol-based hand sanitizers and products used in healthcare settings.

Manufacturers have until the end of 2014 to submit the results of clinical trials on their products, the FDA said. The new regulations would be finalised in 2016.

'Unanticipated hormonal effects'

"New data suggest that the risks associated with long-term, daily use of antibacterial soaps may outweigh the benefits," Colleen Rogers, an FDA microbiologist, wrote in a statement on Monday.

Certain ingredients in such products - such as triclosan in liquid soaps and triclocarban in bar soaps - may contribute to bacterial resistance to antibiotics, the agency added.

Such products may also have "unanticipated hormonal effects that are of concern", according to the statement.

Recent studies of such chemicals on animals have shown they may alter hormones, the FDA said, but such results have not yet been proven in humans.

"Because so many consumers use them, FDA believes that there should be clearly demonstrated benefits to balance any potential risks," the statement added.

If the FDA's proposed rule is finalised, companies would be required to provide data to support their product's health claims.

If they cannot, the products would be reformulated or relabelled in order to remain on the market.

In March, a federal appeals court approved a lawsuit by the non-profit Natural Resources Defense Council, aimed at forcing the FDA to review the health impacts of triclosan.