How does UNEP freeze CFC?

The developed and developing countries are cutting down the use of CFC to a great extent. They are also finding alternatives to CFCs that are environmentally not harmful and replacing the use of CFC with such chemicals.

In addition efforts are also on to prevent illegal traffic, new
ozone-depleting substances entering the market, exemptions for
the use of controlled substances as process agents in the
chemicals industry, and other technical matters.

Under the 1987 Montreal Protocol, governments have agreed to
phase out chemicals that destroy stratospheric ozone, which is
essential for shielding humans, plants, and animals from the
damaging effects of ultraviolet light. Scientists predict that
the ozone layer will start to recover in the near future and will
fully recover some time in the 21st century -- but only if the
Protocol continues to be vigorously enforced.