Synthetic chemical, which is odourless,
nontoxic, nonflammable, and chemically inert.
CFCs are used as propellants in aerosol cans,
refrigerants in refrigerators and air
conditioners, in the manufacture of foam
boxes for take-away food cartons, and as
cleaning substances in the electronics
industry. They are partly responsible for the
destruction of the ozone layer. In June 1990
representatives of 93 nations, including the
UK and the USA, agreed to phase out
production of CFCs and other ozone-depleting
chemicals by the end of the 20th century.
When CFCs are released into the atmosphere,
they drift up slowly into the stratosphere,
where, under the influence of ultraviolet
radiation from the Sun, they break down into
chlorine atoms which destroy the ozone layer
and allow harmful radiation from the Sun to
reach the Earth's surface. CFCs can remain in
the atmosphere for more than 100 years.
Replacements for CFCs are being developed,
and research into safe methods of destroying
existing CFCs is being carried out.