text: HFCs were developed in the 1990s to substitute for substances such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). As these substances were found to deplete the ozone layer, the Montreal Protocol began to lay down provisions for them to be phased-out globally after the agreement was ratified in 1987. 
  PFCs and SF were already in use prior to the Montreal Protocol.
  NF use has grown since the 1990s along with the rapid expansion of the microelectronics fabrication industry.