Manual for Refrigeration Servicing Technicians - UNEP - Division of ...

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Environmental Impact
Exposure to increased UV-B radiation could also suppress the body’s
immune system.
Immunosuppression by UV-B occurs irrespective of human skin
pigmentation. Such effects could exacerbate the poor health
situations of many developing countries.
Increased UV-B radiation could also cause decreased crop yields
and damage to forests. It could affect ocean life causing damage to
aquatic organisms, parts of the marine food web, which may lead
to a decrease in fish higher up the food chain. Materials used in
buildings, paints, packaging and countless other substances could
be rapidly degraded by increased UV-B.
Depletion of stratospheric ozone could aggravate the
photochemical pollution in the troposphere resulting in an increase
of ozone at the surface of the earth where it is not wanted. Earth
and inhabitants, therefore, have an enormous stake in preserving
the fragile ozone layer shield.
Global consensus supports the theory that chlorine and bromine
containing man-made chemicals emitted into the atmosphere are
responsible for the depletion of ozone in the stratosphere. The
larger part of these compounds, called ODS, consists of CFCs,
HCFCs and halons (used as fire extinguishing agents), which are
most effective in ozone depletion. CFCs have been used for years
as refrigerants, solvents or blowing agents. ODS are classified
considering how harmful they are for the ozone layer using a
parameter called ozone depleting potential (ODP).
ODP is a relative index indicating the extent to which a chemical
product may cause ozone depletion. The reference level of 1 is the
potential of R11 and R12 to cause ozone depletion. If a product
has an ODP of 0.5, a given weight of the product in the atmosphere
would, in time, destroy half the amount of ozone that the same
weight of R11 would destroy. ODP is calculated from mathematical
models which take into account factors such as the stability of the
product, the rate of diffusion, the quantity of depleting atoms per
molecule and the effect of ultraviolet light and other radiation on the
molecules.
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