Resources
History of the Aerosol
The first use for an aerosol package arose during World War II, but the idea of using low-pressure liquefied gas to atomize droplets of liquid in the air was developed in 1924. Canisters filled with insecticide and propellants were used to protect U.S. servicemen from insects carrying diseases such as malaria. Shortly after the war, Robert Abplanalp, founder of Precision Valve Corporation (PVC), invented the first mass-produced aerosol valve. The patent was filed in September 1949 and was issued on March 17, 1953. From that invention, the aerosol industry quickly developed in the United States and around the world.
How an Aerosol Works
The aerosol package is a self-contained dispensing system with three main elements:
1. Active Ingredients (soap or disinfectant, etc.)
2. Inert or Inactive ingredients (water)
3. Propellant
The propellant is a gaseous compound which pushes the product out of the container and produces a spray or foam. In most cases, the propellant also acts as a solvent to keep the product at the proper strength. In the United States, the most common propellants are naturally occurring hydrocarbons. A few products, about 10% of today’s aerosols, use compressed gases like carbon dioxide and nitrous oxide as propellants.
The final element is the container, which is usually a steel or aluminum can. The leak-proof can protects the product from contamination and evaporation.
All of these pieces work together based on simple scientific principles. An aerosol package is an air-tight, pressurized container. Pressing the actuator button opens the valve. Since the pressure outside the can is less that the pressure inside, the propellant expands, pushing the product up the dip tube and out through the valve. This system allows the product to be applied in a variety of ways; in a fine mist, a metered spray delivering just the right amount, foam, or even a long distance spray.
Safety and Disposal
Like most household or personal care products, aerosols are not hazardous when handled and disposed of properly. Reading and following the instructions printed on the label will ensure proper and safe use. The label instructions are there for your protection.
The best way to dispose of an empty aerosol container is to recycle it. Aerosol cans are made of steel and aluminum and can be recycled like any other empty steel cans. A growing number of communities accept empty aerosol cans together with other metal containers. Check with your local recycling coordinator, however, before putting any material in your recycling bin. Be sure the can is empty before placing the container in the trash with your other solid waste if recycling is not available.
Informational Links
Aerosol Information
http://www.spraytechnology.com/links.htm
http://www.nationalaerosol.com/
Aerosol Gas Houses
http://www.gsi-manu.com
Aerosol Valves
http://www.epspray.com/e/technologie.htm
http://www.precision-valve.com/
