The solid particles that make up a fume are extremely fine, usually less than 1.0 micron. An example would be welding fumes. Mist A loose term applied to dispersion of liquid particles, many of which are large enough to be individually visible without visual aid. Most is formed when a finely divided liquid is suspended in the atmosphere. An example would be an oil mist found in a machine shop.
Most airborne hazards found on campus are either a dust or vapor.