Tips on safely and properly using a room humidifier

WASHINGTON - The temperatures outside are dropping, and that means a lot of people are cranking up the heat inside.

But that heated air is mighty dry, and can result in irritated noses, throats and eyes, not to mention all that itchy skin.

Portable room humidifiers can help put the moisture back in. However, there is one big caveat: They must be thoroughly cleaned on a regular basis.

Dr. Assil Saleh with Foxhall Internists in D.C. says a poorly maintained humidifier can become a breeding ground for bacteria and mold.

"You want to make sure they are clean," she says, "because you don't want to be propagating an infection, particularly if you are using it in a baby's bedroom, or an elderly person with a compromised immune system."

She says just putting in fresh water, even if it is distilled, is not nearly good enough. Saleh says maintenance tips can be found in the instruction manual, and it is important to follow them closely.

It doesn't matter if the humidifier is a vaporizer that spews steam into the air, or if it produces a cool mist. All carry the same germ risk. And all need to be used with care.

"I think there is a potential benefit to them," Saleh says, "but if you are to use them, definitely clean them regularly and be careful with them."

The Consumer Product Safety Commission recommends changing the water daily and be sure to completely empty the tank before refilling. Unplug the unit before cleaning, and use the cleaning method suggested by the manufacturer, being careful to rinse the tank of any traces of chlorine bleach or other disinfectants that may be used.

The CPSC also suggests keeping home humidity levels between 30 and 50 percent. Higher levels can allow moisture to build up indoors in places where bacteria and fungus can grow.