(1) A rocket fuel.(2) A compressed gas used to expel the contents of containers in the form of aerosols. Chlorofluorocarbons were once widely used because of their nonflammability. The strong possibility that they contribute to depletion of the ozone layer of the upper atmosphere has resulted in prohibition of their use for this purpose. Other propellants used are hydrocarbon gases, such as butane and propane, carbon dioxide, and nitrous oxide. The materials dispersed include insecticides, shaving cream, whipping cream, and cosmetic preparations. See Ozone (note).