Chlorofluorocarbons (CFCs), which were discovered as early as in 1930 by Thomas Midgley, find a variety of industrial applications. They have four basic uses: (i) Refrigerants, (ii) Foam blowing agents, (iii) Cleaning agents and (iv) Propellants. As refrigerants, CFCs are used in freezers, refrigerators and in air conditioning units in automobiles and buildings. As blowing agents CFCs are used in making both rigid foam which appears in items such as foam ice chests and fast-food hamburger boxes, and flexible foam used in furniture cushions and foam pillows. As cleaning agents they wash hundreds of products in electronic and other industries ranging from computer chips to artificial hip joints. In addition to their application as propellants, these are also used in aerosol sprays. CFCs are also used in fire extinguishing units and urethane shoe soles.