How the First Aerosol Spray Can Works

A 1941 invention by Lyle Goodhue and William Sullivan that created the modern aerosol spray can by using a liquefied gas to propel liquid contents.

What it covers

The patent describes a pressurized container that uses a liquefied gas propellant to force a liquid product out through a nozzle. When the valve is opened, the difference in pressure between the inside of the can and the outside causes the liquid and propellant mixture to rush out. As the propellant evaporates, it breaks the liquid into a fine mist or aerosol. This mechanism allowed for the portable, self-contained spraying of insecticides, which was the original intended use during World War II.

What it doesn't cover

• —Does not cover non-pressurized pump-action spray bottles.
• —Does not cover systems that use mechanical air pumps instead of liquefied gas propellants.
• —Does not cover the chemical composition of the liquid being sprayed.

The clever bit

The inventors realized that by using a propellant that is liquid under pressure but turns to gas upon release, they could maintain a constant pressure inside the can until the very last drop was used.

Why it matters

This invention fundamentally changed how we apply everything from hairspray and deodorant to spray paint and cooking oil. It enabled the mass-market convenience of the aerosol industry, which became a staple of 20th-century consumer goods.

Real-world examples

• 1.Hairspray cans
• 2.Aerosol whipped cream
• 3.Spray paint cans
• 4.Air freshener sprays
• 5.Insecticide spray cans