Probably depends on what’s in the water. Quoting the original research paper: > A phenomenon known as “white dust” is associated with filling ultrasonic humidi

Probably depends on what’s in the water. Quoting the original research paper: > A phenomenon known as “white dust” is associated with filling ultrasonic humidifiers with hard water; inhaling this white dust caused childhood lung injury (Daftary and Deterding, 2011)