Triclosan has been shown to disrupt hormones and muscle function, environmental groups say

The U.S. Food and Drug Administration (FDA) on Friday issued a rule banning antibacterials in soap, which the agency said were no more effective than simple soap and much more harmful for the environment and consumer health.

The FDA gave companies a year to remove chemicals such as triclosan and triclocarban from their products or take them off the shelves entirely, and an additional year to get rid of ingredients like benzalkonium chloride, which are less commonly used.

"Consumers may think antibacterial washes are more effective at preventing the spread of germs, but we have no scientific evidence that they are any better than plain soap and water," Janet Woodcock, M.D., director of the FDA's Center for Drug Evaluation and Research (CDER), said in a statement. "In fact, some data suggests that antibacterial ingredients may do more harm than good over the long-term."

As environmental and public health groups have noted, triclosan has been shown to disrupt hormones and muscle function. And although the chemical kills bacteria by breaking open their cell walls, the process takes up to nine hours—so it is ineffective when simply washing hands.