CFC's are unreactive, non-flammable and non-toxic. They used to be used in fire extinguishers, as aerosol propellants, as coolant gas in fridges and as foam plastics to make insulation and packaging materials.
In the 1970's scientists discovered that CFC's were causing damage to the ozone layer. Their advantages couldn't outweigh the environmental problems they were causing, so they were banned.
Chemists have developed alternatives to CFC's, such as HCFC's(hydrochloroflourocarbons) and HFC's(hydroflourocarbons). These are less dangerous than CFC's so they're being used temporarily until safer products are developed.
Most aerosols now have been replaced by pump spray systems or use nitrogen as the propellant.
Many industrial fridges use ammonia or hydrocarbons as the coolant gas, and carbon dioxide is used to make foamed plastic.
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