Substances commonly dispensed by the aerosol process include resins, paints, waxes, and cosmetics. Chlorofluorocarbons (fluorocarbons), hydrocarbons, and carbon dioxide are used as propellants. The use of fluorocarbons is being questioned because the possibility exists that when they reach the stratosphere they are subject
to attack by ultraviolet radiation, which frees their chlorine atoms, which in turn react with the ozone and thus deplete the protective ozone layer. The use of carbon dioxide as a propellant has been limited because of problems in filling aerosol cans on a mass production basis. Aerothene MM, of Dow Chemical, is a methylene chloride that has properties needed for the efiicient functioning of carbon dioxide and hydrocarbon propellants in cosmetic aerosol applications. In noncosmetic aerosol applications,such as paints and insecticides, hydrocarbons claim 45% of the market. Principal objection to their use for cosmetic aerosols has been their flammability.