An aerosol is a suspension of very small particles of solid or liquid dispersed in a gas medium. Solid particles may be either inorganic or organic materials. Smoke, smog, fog and mists are all aerosols. Airborne pollutants and pollens that bother asthma sufferers are often contained in aerosols. Aerosols are also of concern with regard to contamination of sensitive electrical components. The term aerosol is also used to describe self-contained pressurized spray systems used to dispense various solid, liquid, and gas products. Aerosol products have four key components: a package which is capable of containing relatively high pressures; a valve which seals the can and controls dispensing; a gaseous propellant which forces the contents out of the can, and the active ingredients make the formula functional.

The first aerosol products were created during the early years of World War II to deliver pesticides. Over the last 40 years, aerosols...