To reduce the possibility of health hazards from dirty room humidifiers, the staff of the Consumer Product Safety Commission recommends that you take the following precautions:
- Do not allow film and scale to develop in your humidifier. Change the water in your room humidifier daily. Empty the tank before you fill it.
- Use distilled or demineralized water in your room humidifier to reduce the buildup of scale and the release of dust. Do not use tap water because it contains more minerals.
- Use demineralization cartridges or filters if supplied or recommended for use with your humidifier.
- Drain and clean the tank of your room humidifier before you store it. Clean it after summer storage. Remove dust on the outside of your unit.
- Clean your room humidifier well and often during the heating season.
- Maintain the relative humidity in your home between 30% and 50% if possible. Humidity levels above 60% may allow moisture to build up indoors and condense on surfaces, where bacteria and fungi can settle and grow. You can measure humidity with an instrument called a hygrometer, available at your local hardware store.