Aerosol deodorant. A woman using an aerosol underarm spray deodorant. Deodorants usually contain an anti-perspirant which prevents sweat from reaching the surface of the skin where it is decomposed by bacteria causing body odour. Chlorofluorocarbons (CFC's) found in many aerosols are being replaced by hydrofluoroalkanes (HFA's) to reduce damage to the earth's ozone layer.