How Humidifier Residue Can Make You Sick

Home humidifier sitting on a floor and plugged into wall

Bart Everson / Flickr / CC BY 2.0

Dry air can cause a range of health issues, including nosebleeds, dry skin, dehydration, and cracked lips. One standard measure to combat dry air is to use a home humidifier, which puts much-needed moisture back into the air. However, sometimes a humidifier can do more harm than good. Health issues that can arise from a humidifier include allergies, asthma flair-ups, coughs, flu-like symptoms, and lung and sinus infections. These tips might help you figure out whether your humidifier is making you sick.

  • 01 of 06

    How Humidifiers Can Cause Health Issues

    Health issues from a humidifier almost always occur because it contains bacteria or mold. It's easy to understand how this can happen. The nature of a humidifier is to hold standing water, evaporate it through a system of damp wicks, and blow out that moistened air.

    That's all well and good if the water being evaporated is sterile. But the water reservoir is just the kind of damp environment that promotes mold and bacteria growth. And once your humidifier is infected, your appliance has become a distribution system for pathogens. As germs and mold spores are blown into the air, they hunt for new moist, warm places to take up residence—often your lungs or sinus cavities.

    Fortunately, it's fairly easy to prevent your humidifier from becoming a petri dish: Just clean it regularly. If you use a humidifier daily, a cleaning routine repeated every three days should keep your air healthy.

  • 02 of 06

    Cleaning a Humidifier Base

    You always should follow your humidifier's specific cleaning instructions. But there are some general guidelines that apply to many standard machines. To deep clean your humidifier, first disinfect its base using 3 percent hydrogen peroxide or white distilled vinegar. Here's what to do:

    1. Unplug the humidifier unit.
    2. Remove the unit's water tank and filter.
    3. Pour a generous amount of hydrogen peroxide or white distilled vinegar into the base of the humidifier.
    4. Use a clean toothbrush to scrub away film and mineral buildup.
    5. Let the liquid sit in the humidifier’s base for at least 10 to 30 minutes, and then pour out the liquid.
    6. Rinse by adding and swishing fresh water in the base. If any mineral residue is left, repeat the entire process.
    7. When the base is clean, let it air dry.
  • 03 of 06

    Cleaning the Wick

    Cool-mist humidifiers don't have an evaporative wick, but most larger floor models operate by a wicking pad that soaks up water to facilitate its evaporation. This wick can either be a flat or cylindrical pad that fits around a rotating drum.

    Whatever type of wick you have, remove it from the humidifier each time you clean it, and thoroughly rinse it in clear water. Don't use any cleaning solutions on the wick. If the wick has become caked with white mineral deposits, replace it with a fresh wick pad.

  • 04 of 06

    Cleaning the Tank

    A humidifier's water tank is also a haven for bacteria and mold and must be cleaned regularly.

    1. Mix a solution of four parts water to one part hydrogen peroxide (3 percent) in the tank.
    2. Allow the solution to remain in the tank for at least 30 minutes. Then, empty the tank.
    3. Rinse thoroughly with clean water, and let the tank air dry.

    To prevent bacteria and mold growth, replace the water in your tank daily, and repeat the cleaning process at least weekly.

    Continue to 5 of 6 below.
  • 05 of 06

    Is a Clean Humidifier Still Making You Sick?

    If your humidifier is still aggravating your sinuses and throat even after it has been thoroughly and regularly cleaned, it might be time to stop using tap water and switch to distilled water.

    Tap water contains minerals and contaminants that can encourage bacteria growth. These minerals are especially prevalent if you have hard water. They're what cause the white dust that's left behind in the tank and on the wick after the water evaporates. On the other hand, distilled water is produced by an evaporation process that captures only the water molecules and leaves behind any mineral deposits.

    Over time, there can be such a buildup of mineral deposits that a portable humidifier can no longer work efficiently. When this happens, it's likely time to buy a new humidifier. Plus, if there is a noticeable buildup of mineral deposits, a buildup of bacteria is almost certainly present, as well. Consider switching to an antimicrobial humidifier. These units can purify stored water, so they produce a cleaner and healthier mist.

  • 06 of 06

    Remember the Whole-House Humidifier

    If your HVAC system has a built-in humidifier feature, its components need to be cleaned and maintained regularly, just like with a portable humidifier. Otherwise, it also can cause health issues for you, which could potentially be more severe because it pumps the air throughout your entire home. Follow the instructions for your system on how to clean and maintain it.