So, we all know what an aerosol product can do, let’s see how it works.
Aerosols rely on a basic principle of physics: a gas under enough pressure will turn into a liquid, and when that pressure is relieved will expand and turn back into a gas. That process is called vaporization. An aerosol can is kept closed by the stem gasket, which seals the opening under the button.
This gasket is kept in place by a spring inside the housing. When the button is pressed, it pushes the valve stem down against the spring, relieving the pressure that keeps the gasket sealed. When the seal opens, the higher pressure inside the can pushes the product up through the dip tube and out the valve.
A controlled amount of propellant in the product vaporizes as it leaves the can, creating a spray or foam. A small amount of liquefied gas propellant still in the container also vaporizes, keeping the pressure constant.
The combination of product and propellant is finely tuned to produce just the right concentration, spray pattern and particle size to make the product most effective.