History
The
ethylenebisdithiocarbamates were rediscovered in 1945
when Dimond et al. (2) reported a “new water soluble
protectant fungicide.” The parent compound, disodium
ethylenebisdithiocarbamate, was highly soluble in water
and was unstable in air, and it might have been only
a laboratory curiosity and remained unnoticed but for
the applications developed by Heuberger and Manns (3),
who stabilized it by converting it into zinc salt by the
addition of zinc sulfate–lime mixture. This was followed
by the introduction of zineb as fungicide by the Rohm and
Haas Company, USA. The same phenomenon was later
confirmed by Barratt and Horsfall (4), who attributed
the stabilizing effect as due to zinc salt formation.
From the numerous compounds suggested by Hester (5),
only disodium ethylenebisdithiocarbamate and its zinc
and manganese salts are largely accepted for practical
application. Research on these dithiocarbamates led to
some promising variants.
Uses
Ethylenebisdithiocarbamates have strong metal binding
capacity and act as inhibitors of enzymes. They
have a profound effect on biological systems, and so
they are widely used in medicine and in agriculture
as fungicides (6). Their residues on food and fodder are
hazardous and may potentially cause chronic damage to
health, because humans consume these items as a part
of their normal dietary intake and ethylenebisdithiocarbamates
are widely used as fungicides. Therefore, their
residues must be closely checked because their persistent,
as well as cumulative, action may be harmful. Some of
the most-used ethylenebisdithiocarbamate fungicides are
nabam [disodium ethylenebis (dithiocarbamate)], mancozeb
[manganese/zinc ethylenebis (dithiocarbamate)],
and maneb [manganese ethylenebis (dithiocarbamate)].
