A review.This article discusses the aerosol technol. which may be defined as involving the development, preparation, manufacture, and testing of products that depend on the power of a liquefied or compressed gas to expel the contents from a container.The propellant, said to be the heart of an aerosol system, maintains a suitable pressure within the container and expels the product once the valve is opened.Propellants may be either a liquefied halocarbon, hydrocarbon, or halocarbon-hydrocarbon blend, or a compressed gas such as carbon dioxide, nitrogen, or nitrous oxide.