Ionic technology hitting consumers from head to toe

Whether you're cruising through a drug store or surfing TV channels, you can't help but notice claims about ions. There are ionic hair dryers. Ionic air purifiers. Ionic foot pads. Even ionic clothes hangers.

It sure sounds impressive. But if it's been a while since you've had a chemistry class, you might also wonder what it all means, and whether it's worth the money.

At the risk of inducing a junior high flashback, the science is pretty simple: An ion is an atom or molecule that has either lost or gained one or more electrons after interaction with another positively or negatively charged particle. This occurs in a process called ionization and results in a free electron, with a negative charge, getting knocked off an atom or molecule.

So what does that do for your frizzy hair or dirty air?

In ionic hair dryers, these free electrons or negative ions break up water molecules so that hair can dry faster, according to manufacturers. They also leave behind some of the water particles — leaving the hair more hydrated and less likely to tangle and frizz.

Ionic air purifiers work roughly the same way, with negative ions attaching to smoke and dust particles that are, in turn, attracted to positively charged plates and filters.

How well that works is the matter of some debate.

The Good Housekeeping Institute, which tests hair products, found that ionic hair dryers did add sheen to hair, but weren't any faster — some cut drying time, but others extended it.

And ionic air purifiers create ozone as an unwanted byproduct when ionizing the air, according to Bob Markovich, home and yard editor for Consumer Reports magazine.

"It sounds very impressive, 'ionic' and 'charged particles,'" Markovich said. "But how much ozone do they produce?"

Popular air purifiers on the market produce ozone below the 50 parts per billion threshold set for medical devices, but there are no mandatory ozone standards set for them, Markovich said. The 50 ppb limit has been under scrutiny by the scientific community and some believe the benchmark should be set even lower, he said.

He suggested some simple tips to keep your air clean before buying an air cleaner: banning indoor smoking, using an outdoor venting fan in the bathroom and kitchen, keeping pets out of the bedroom and opening the windows as much as possible.

Another ionic-based product line consists of the ionic foot baths or foot pads that claim to remove heavy metals and other toxins from the body by sucking them out of your feet. The pads are sold on infomercials and through mainstream retailers including Avon.

There has been no scientific study to evaluate the claims. But Dr. Stephen Barrett, a retired psychiatrist who operates the Web site Quackwatch.org, said the concept that toxins can be removed through the feet simply is not valid.

"The skin doesn't do much in the way of excreting, just water and a little salt. It's not a detoxifying organ," Barrett said. "Products the body wants to get rid of get detoxified by the liver and excreted by the kidneys."

No mainstream practitioners use the devices, and advocates of the devices have yet to provide evidence that toxins are actually being removed through the feet, Barrett said.

"The whole thing doesn't make any sense," he said.

As for that hanger that uses ionic technology to get rid of smoke odor? We haven't been able to find one — but a little odor-neutralizing spray could do the same thing, no chemistry lessons required.