Members Handbook 20023 - ITOPF

oil into the sea. The oil is broken down
into tiny droplets which are dispersed
into the water column, where they are
diluted by currents and eventually break
down naturally.
© CEDRE
In-situ Burning
Because of the logistical difficulties of
picking up oil from the sea surface and
storing it prior to final disposal on land,
an alternative approach involves
concentrating the oil in special fireproof
booms and setting it alight. In practice,
this technique is unlikely to be viable in
most ship-source spills, due to the
difficulty of collecting and maintaining
sufficient thickness of oil to burn. As the
most flammable components of the
spilled oil evaporate quickly, ignition can
also be difficult. Residues from burning
may sink, with potential long-term effects
on sea bed ecology and fisheries. Close
to the shore or the source of the spill,
there may be health and safety concerns
as a result of the risk of the fire spreading
out of control or atmospheric fall-out
from the smoke plume.
Dispersants
Dispersant chemicals work by
enhancing the natural dispersion of the
Dispersants can be sprayed from boats,
planes and helicopters. With good
operational support, large quantities of
oil spread over a wide area can be
treated quickly and effectively. For
maximum effectiveness, dispersants
need to be applied to oil before it has
become viscous through evaporation or
formed an emulsion. Some types of oil
such as heavy fuel oil and viscous crude
are less amenable to dispersion from the
outset.
The controlled use of dispersants can
reduce the overall impact of an oil spill
on environmental and economic
resources. However, since their use
results in the oil being transferred from
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