How air fresheners are made

The spray can in an air freshener was first a military design for dispensing insecticide.

stations: 5
things upstream: 48
raw sources: 21
steps from the ground: 7

The short version

An aerosol air freshener is a metal can holding a fragrance concentrate and a liquefied propellant gas under pressure. The can is filled, a valve is crimped onto its rim, and a pressing button opens the valve so the mix leaves as a fine mist. Other types use wicks, gels or heated plug-ins.

Blend the fragrance

Perfume oils are mixed with solvents and often with ingredients that bond or absorb odors. Some products add surfactants, preservatives or disinfectants.

Goes in
Perfume Ethanol
Fill the can

The concentrate goes into a can made of lacquered tinplate, steel with a layer of tin, or of aluminum for premium products.

Goes in
Tinplate
Crimp on the valve

A valve is crimped to the inside rim of the can. Its design determines the spray rate, and a spring closes it again when the button is released.
Charge with propellant

A propellant that is a gas at room temperature, but turns liquid under modest pressure, is forced in. Modern cans use mixtures of propane, butane and isobutane. Propellant filling machines must be installed outside the main production building, in a gas house.

Goes in
Propane
Fit the button

The actuator is fitted over the valve. Its nozzle controls the size of the droplets and how wide the spray spreads.

End of the lineAir freshener

Worth repeating

Air Wick launched in the United States in 1939 as a liquid that evaporated up a wick.
Commercial aerosol sprays arrived in 1948, from a military technology for dispensing insecticide.
CFC propellants were abandoned because they damaged the ozone layer, and the Montreal Protocol came into force in 1989.