Aerosol propellants are substances used to create pressure in aerosol containers, allowing the contents to be sprayed out in a fine mist. Commonly found in products like spray paint, deodorants, and hair sprays, these propellants help deliver the product evenly and efficiently. There are two main types of aerosol propellants: compressed gases and liquefied gases. Compressed gases, such as nitrogen or carbon dioxide, push the product out when the nozzle is pressed. Liquefied gases, like butane or propane, vaporize when released, creating pressure that forces the liquid product out of the can.