Updated May 9, 2020
What is white dust?
What is white dust?
White dust is usually caused by mineral content in the water that goes into a humidifier. When the mist lands on furniture or other surfaces and dries, it can sometimes leave behind the dried mineral deposits, or “white dust”. For most people, the white dust is nothing to be concerned about; however, it could be problematic for some people with allergy, asthma or other lung/sinus health conditions.
Only two humidifiers produce white dust, ultrasonic and impeller portable humidifiers. The white dust they disperse is nothing more than a natural by-product of the minerals present in the water you fill your humidifier with. Ultrasonic and Impeller humidifiers produce humidity through a steaming process so when the water in the humidifier is heated, the water turns to vapor which is then is sprayed out of the humidifier in a mist form. Within this mist are dissolved minerals from the water itself. The minerals land on furniture, tables, counter-tops etc. creating the white dust you see.
Is white dust harmful?
The dust produced is not harmful in anyway and nothing to be concerned about. It can be cleaned off just as any other household dust would be, no special treatment needed. The hardness of your water will decide how heavy or light this layer of white dust will be (hard water is rich in minerals so the harder your water is the more dust you can expect to find).
How to get rid of white dust
Use Distilled Water To Fill Your Humidifier Tank. Using distilled instead of tap water to fill your humidifier will cut down on dust significantly. Distilled water has a very low mineral count and therefore will not produce white dust that hard tap water will.
Purchase a Demineralization Cartridge. A demineralization cartridge is specifically designed to trap the minerals before they become airborne into your home. (this will reduce or completely eliminate white dust).
Purchase a Warm or Cool Mist Humidifier. If your water is really hard and the dust is too much to handle, it may be a good idea to invest in a portable warm or cool mist humidifier. These humidifiers do not operate in the same fashion that Ultrasonic do and therefore will not disperse a layer of white dust. The only difference to keep a watch out for is the noise level. Ultrasonic humidifiers are known for being very quiet during operation, warm mist is still decently quiet, but cool mist is known for making quiet a bit of noise.