Organic compounds made up of atoms of carbon, chlorine, and fluorine. An example is Freon-12 (CCl2F2), used as a refrigerant in refrigerators and air conditioners and in making plastics such as Styrofoam. Gaseous CFCs can deplete the ozone layer when they slowly rise into the stratosphere and their chlorine atoms react with ozone molecules. Also used Freons chromosome Grouping of various genes and associated proteins in plant and animal cells that carry certain types of genetic information. See genes.