There's no data to prove that, he says, and manufacturers concede he is correct. Such studies, they say, are impractical due to expense and the multitude of variables associated with illness.
Ordinary soap and warm water are probably good enough at controlling bacteria for most people, Katona says. (He uses "whatever soap my wife buys.")
"By washing with warm water and [any] soap, you get rid of almost all bacteria," he says. Extending hand-washing time--from a slipshod 10 seconds to a more ideal 30--can help too.
But the antibacterial soaps "may have a role in certain cases--in someone who has skin disease or diabetes," Katona says.
Some dermatologists recommend antibacterial soaps for the control of acne and other skin conditions. And it can be helpful in children with chicken pox, adds Dr. Kenneth Saul, a Thousand Oaks pediatrician, "because there is a high incidence of secondary skin infections." Otherwise, he doesn't particularly endorse antibacterial soap use "unless children are having a history of skin infections" or if siblings have a skin problem.
This antibacterial boon might be as rooted in the psyche as in the sink. Anxiety about epidemics--from AIDS to the Ebola hemorrhagic fever outbreak in Zaire--might be feeding the germ-killing fervor. Never mind that the culprits, in both AIDS and Ebola, are viruses and soap won't make a difference.
Still, germ-killing translates to control, at least in some people's minds.
The burgeoning health concerns of the aging baby boomer population might also be boosting antibacterial soap sales, says Dennis Rook, USC assistant professor of marketing, who specializes in the psychosocial dimensions of consumer behavior. "We're probably a little more hypochondriacal than we used to be."