Aerosol

Suspensions in gas, of tiny drops of liquid, or tiny particles of solids, are called aerosols.

Dangerous aerosols in industry

Some solids, suspended in air, can be dangerously explosive. Suspended coal dust in mines, or suspended flour or grain dust, in flour mills and grain elevators, can be dangerously explosive.

(PD) Photo: United States Department of Labor
Fire following a dust explosion that occurred in North Carolina plant that made rubber products for the pharmaceutical industry.

Consumer products delivered as aerosols

Some modern consumer products, like paint, hair-spray, whipping cream, or penetrating lubricants, are applied as aersols. Products delivered as aerosols are typically distributed in pressurized cans, where the liquid to be delivered is pressurized by a gas called a "propellant". Air is rarely used as a propellant. Nitrous Oxide (laughing gas) is used as a propellant for edible products, like whipping cream. Some other products use light hydrocarbon gases, like butane or propane, which can pose a fire risk. In the late twentieth century chlorinated fluorocarbans were a commonly used propellant; but they are no longer used because it was found the expelled propellant was very damaging to the atmosphere's ozone layer.