Alternatives to CFCs

Monitoring and Management‎ > ‎4. The Atmosphere‎ > ‎

Present information from secondary sources to identify alternative chemicals used to replace CFCs and evaluate the effectiveness of their use as a replacement for CFCs

  • Hydrochlorofluorocarbon (HCFC): A haloalkane containing hydrogen, chlorine and fluorine atoms.
  • HCFCs were the first substances used as replacements for CFCs.
  • The carbon-hydrogen (C-H) bonds in HCFCs are susceptible to attack by reactive radicals and atoms in the troposphere, and are therefore decomposed there to a significant extent.
  • However, they still diffuse into the stratosphere and cause significant ozone destruction.
  • Hydrofluorocarbon (HFC): A haloalkane containing hydrogen and fluorine atoms.
  • HFCs are now widely used as replacements for CFCs.
  • They contain carbon-hydrogen (C-H) bonds that cause them to undergo some decomposition in the troposphere, and contain no carbon-chlorine (C-Cl) bonds that would form chlorine free radicals in the stratosphere.
  • Thus, the ozone-destroying capacity of HFCs is zero.
  • The most widely used HFC is 1,1,1,2-tetrafluoroethane, which is used primarily in refrigeration and air conditioning.
  • It is more expensive and less efficient than the CFCs it replaces.
  • Hydrocarbon: A compound containing only hydrogen and carbon.
  • Hydrocarbons have replaced CFCs as propellants in spray cans.