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. There are ways to reduce or eliminate white dust output from a humidifier. The first is to use distilled water that does not contain any mineral content. Another method is to use Stadler Form’s Zero Calc Descaler, which helps pull ionic particles that cause white dust out of the water when the humidifier is operating.