Tips for keeping your humidifier clean

To keep your humidifier free of harmful bacteria and mold, always follow the cleaning instructions that came with it. Don't add anything to the water and don't use disinfectants that aren't approved.

These tips for portable humidifiers also can help:

• Use distilled or demineralized water. Tap water contains minerals that can allow bacteria to grow inside the humidifier. When released into the air, these minerals often look like white dust on your furniture. You also might breathe in some minerals that are spread into the air. Distilled or demineralized water has fewer minerals than tap water has. Also, use demineralization cartridges or filters if the maker of the humidifier suggests doing so.

  Change humidifier water often too. Don't let film or other types of buildup form inside a humidifier. Unplug the device first. Then empty the water tank, dry the inside surfaces and refill it with clean water. Do this every day if you can. These steps are very important if you use a cool-mist or ultrasonic humidifier.

• Clean humidifiers every three days. Unplug the humidifier before you clean it. Remove any mineral buildup or film from the tank or other parts of the humidifier with a 3% hydrogen peroxide solution. You can buy this at a pharmacy. Some humidifier makers suggest you use chlorine bleach or other disinfectants.

  Always rinse the tank after cleaning. This can keep harmful chemicals from getting in the air. If they become airborne, you might breathe them in.

• Change humidifier filters. If the humidifier has a filter, change it at least as often as the device maker suggests. Swap it out more often if it's dirty. Also, change the filter in your central air conditioning and heating system on a regular basis.
• Keep the area around humidifiers dry. Things nearby could get damp or wet, including windows, carpet, drapes or tablecloths. If that happens, turn the humidifier down or use it less often.
• Prepare humidifiers for storage. Drain and clean humidifiers before you store them. Clean them again when you take them out of storage for use. Throw away all used cartridges, cassettes or filters.
• Follow instructions for central humidifiers. If you have a humidifier built into your central heating and cooling system, read the instruction manual. Or ask a heating and cooling repairperson how to keep the unit in good shape.
• Think about replacing old humidifiers. Over time, humidifiers can build up material that is hard or impossible to remove. This buildup also can make bacteria more likely to grow.