R-134A belongs to a group of chemicals called hydrofluorocarbons (HFCs) and is also known as HFC-134A. Hydrofluorocarbons are used mainly as residential and automotive refrigerants. HFC-134A was developed to replace chlorofluorocarbon (CFC) refrigerants that contain chlorine, which damages the ozone layer.
HFC-134A replaced an older refrigerant, CFC-12 when CFCs were largely banned from use in 1987. HFC-134A does not damage the ozone layer like its CFC predecessors.
Auto air conditioners use HFC-134A as a refrigerant. Refrigerators and freezers can also use it as a refrigerant, and HFC-134A is also used in aerosol cans.
Though HFC-134A doesn't damage the ozone layer, it is not considered completely safe. The Global Development Resource Center considers HFC-134A a greenhouse gas that contributes to global warming.