Albert E. Fischli, IUPAC-President
(IUPAC Secretariat, 2-3 Pound Way, Cowley, Oxford OX4 3YF, UK)
A crusade is ongoing against element 17
in the periodic table, i.e. chlorine, one of the most abundant on earth.
It is blamed, amongst other things, to be responsible for the depletion
of the ozone layer, bioaccumulation of chlorinated compounds such as DDT
or PCB's in animals and for the formation of dioxins in urban waste incineration.
Due to socio-economic implications the issue
has gone too early beyond the borders of the scientific community, before
facts have been proven and evaluated. As a result, it has been treated
in inappropriate and emotional ways even affecting scientific ethics in
Therefore, the International Union of Pure
and Applied Chemistry (IUPAC), conscious of its responsibilities in this
area, has decided to publish this White Book with the collaboration of
outstanding worldwide renowned scientific specialists from North-America,
Europe and Japan in order to inform the public and the decision makers
as well as the scientific community in an objective, open and unbiased
way on the up-to-date scientific knowledge.
In doing so IUPAC is following its philosophy
to make independent judgments on important issues that are touchy or sensitive
to the general public, governments and industry. IUPAC is not acting as
a judge, but would like to critically evaluate the various factors for
and against a particular issue.
The occurrence of chlorine in nature and
also in living organisms, either as inorganic compounds or as numerous
and very diversified natural "organo-chlorines" does not make
any doubt any more (T. GRAEDEL and W.C. KEENE, G.W. GRIBBLE).
The availability of the raw material, salt,
the development of convenient production technologies and the chemical
properties of chlorine have generated a blooming tree of applications
in such different fields as the pulp and paper industry (K. SOLOMON),
the disinfection of water (H. GALAL-GORCHEV) but mainly in organic synthesis
leading to a host of useful products, for example, polymers, pharmaceuticals,
pesticides, dyes and pigments (J. FAUVARQUE).
It is quite clear that chemists have not
always been aware beforehand of all the possible consequences of having
manufactured new molecules, be they chlorinated or not. Chemicals emitted
voluntarily or inadvertently in the environment are distributed there
according to a complex set of physico-chemical properties (J. MIYAMOTO, K. BALLSCHMITER).
Volatile compounds such as aliphatic chlorinated
and chlorofluorinated hydrocarbons find their way to the "atmospheric
compartments". Long-lived members of this family are even able to
reach the stratosphere where they have been shown to produce detrimental
effects to the global environment (M. MOLINA).
The substitution of these so-called CFC's
by new shorter-lived molecules has probably been the best example of a
sound scientific approach to solving environmental problems. A host of
scientific studies has shown that short-lived chlorinated aliphatic compounds
make only minor or even insignificant contributions to environmental problems
such as stratospheric ozone depletion, global warming, "photochemical
smog", "acid rain" or chloride levels in precipitations
(J.A. FRANKLIN and H.W. SIDEBOTTOM).
Are organo-chlorines harmless or harmful
? The question seems as irrelevant as asking if natural compounds are
harmless and anthropogenic ones toxic.
Ecotoxicity (K. BALLSCHMITER) and toxicity
(A. HANBERG) as any other "chemical" property of any compound
depends on the structure of its molecule; chlorinated or otherwise halogenated
compounds do not escape this rule. Therefore, an undifferentiated ban
of whole classes of chemical compounds has to be qualified as unscientific.
Even in apparently "homogeneous"
families such as the dioxins, toxicity varies considerably with the position
and the number of substituents (Ch. RAPPE). There is thus no scientific
foundation to the amalgamation of all chlorinated compounds as a group
showing special toxic and ecotoxic properties, no more than one should
consider organo-oxygens or organo-nitrogens as a whole as harmful because
highly toxic warfare agents as sarin or tabun contain these atoms in their
This obviously doesn't mean that organo-chlorine
waste, as any sort of waste, has not to be managed. The problem has been
tackled and technical solutions have been developed to reduce byproducts
formation by improving the production processes, to destroy and/or valorise
the remaining production wastes (R. PAPP). This has now to be generalized
in the most economic and environmentally friendly ways. In some cases,
post-use recycling is being developed and starts to be generalized as
for the recycling of PVC for which "second life" applications
have been found (G. MENGES).
In conclusion, I would like to add a few
words formulated by the Nobel laureate Prof. Lord George Porter earlier
on. "There is no way that humans can foresee all the consequences
of their actions, .... The only sure foundation for security in this technological
world is to have a science base which is continually asking whatever questions
seem interesting and is always there to advise and to act when the need
It is the responsibility of the scientific
community to develop this science base, of the media to help them to
inform the public in an understandable and unbiased way, of the public
authority to take the relevant decisions on the bases of sound science
and not on emotional reactions and of industry to act responsibly, endorsing
product stewardship and responsible care. This is true for chlorine
and its chemistry as well as it is for all human activities.