Ingredient dictionary

Isobutane

Isobutane is a light gas made only of carbon and hydrogen, used mainly as a propellant that pushes product out of an aerosol can. It is on the label of 41 products in our library. Checked against our library November 6, 2026.

What Isobutane does

Pushes product out of aerosol cans
Creates a fine, even spray
Evaporates quickly after spraying

Isobutane comes from petroleum and natural gas, and it is separated during refining and gas processing. It is a small molecule that is a gas at room temperature. Under pressure in a sealed can, it becomes a liquid. When the valve opens, it turns back into gas and pushes the product out as a fine spray.

Formulators like it because it is light, dries fast, and blends well with propane and n-butane. Blends let them tune spray force and mist size. Because it is flammable, it is used only in sealed aerosol cans, which should be kept away from heat and open flame.

Good for

Shoppers who like aerosol sprays for deodorant, dry shampoo, or makeup remover.

Frequently asked questions

Is isobutane safe for skin?

Isobutane is generally well tolerated in cosmetics. It is a gas that leaves the skin quickly, so it does not sit on skin like a cream. Like any product, though, it could bother very sensitive skin, so a patch test on a small area is a sensible first step.

Is isobutane the same as butane?

They are close relatives. Both are light gases made of carbon and hydrogen, but their atoms are arranged differently. Isobutane is a branched form, while n-butane is a straight chain. Formulators often blend them with propane to get the spray they want.