It is now well known that man-made chlorofluorocarbons (CFCs) have caused thinning of the earth’s ozone layer.1 CFCs are no longer used in aerosol products as a propellant. Since the Montreal Protocol – a 1987 voluntary international treaty for the elimination of CFCs from aerosols – the use of CFCs in aerosols has been completely phased out across the world.CFCs in aerosols have now been replaced with liquefied gas to act as a propellant – usually butane or propane. Some aerosols are propelled by compressed gases such as carbon dioxide. Aerosol antiperspirants and deodorants no longer contain propellants that damage the ozone layer.
What is the ozone layer?
Ozone is a gas that occurs naturally in the earth’s atmosphere and is concentrated primarily in the ozone layer, which is located 10-40 km above the earth’s surface, in the stratosphere. The ozone layer serves an important function in preventing harmful ultraviolet-B (UV-B) radiation from the sun entering the lower atmosphere and reaching the Earth's surface.
References- The Office of Oceanic and Atmospheric Research. The Ozone Layer. http://www.oar.noaa.gov/climate/t_ozonelayer.html (Last accessed 21.12.12)