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Le Lann - Chemical dispersion as an oil pollution response - French approach 
be sufficient to generate dispersion of the oil, while the efficiency of the mechanical recovery 
would be maximal. 
Once all these points examined, if the decision to use chemical dispersants is taken, then 
one must proceed to implementation. 
Implementation of the decision, availability of qualified dispersants and spraying plat 
forms 
Once the decision to treat an oil slick with chemical dispersants has been made, it is neces 
sary to proceed quickly with the implementation of the decision, because the time slot during 
which hydrocarbons can be chemically dispersed is limited. In addition, as time elapses, 
even while remaining within the time slot, the efficiency of chemical dispersion decreases. 
For an effective action, it is essential to have a quick access to qualified chemical disper 
sants from stockpiles and to the platforms for spraying the product, whether ships or aircraft. 
This can be achieved by implementing dispersant stockpiles at national level and by equip 
ping ships for the application of dispersants. Fitting aircraft for this purpose is not impossible 
but is much more complicated because of aeronautical constraints. 
Another solution is to rely, via partnership agreements or trade agreements, on structures 
able to provide the service very quickly. The British company OSRL offers this type of service 
and can provide equipped aircraft and dispersants from its own stocks within 24 hours from 
initial call. The European Maritime Safety Agency is currently setting up a dispersant spray 
ing capability on its oil spill response stand-by vessels. It seems to be currently studying the 
possibility to set up chemical dispersant stockpiles to be made available to Member States in 
case of necessity. A consultation was launched recently for the procurement of chemical 
dispersants by the Agency. 
Conclusion 
The process used in France for the selection of qualified chemical dispersants and for mak 
ing decision on the operational use of dispersants can inspire processes in other countries. 
The first point is to define the criteria for qualification of products for use in areas under na 
tional jurisdiction. To do this, it is necessary to select an efficiency test from the existing ones 
and set the efficiency threshold beyond which the dispersant would be acceptable. An ac 
ceptable level of toxicity shall also be defined and the corresponding test shall be selected, 
keeping in mind that the OSPAR tests have a wide international recognition. Once some dis 
persants have been qualified, it is necessary either to constitute a national stockpile or to 
implement any other solution that would enable use of the products from a partner’s stock. 
The difficulty of conducting a full cost - benefit analysis in real time during an accident makes 
it necessary to define a simple process for decision making in emergency situations. The 
principle to keep in mind is that this process shall ensure that hydrocarbon concentration in 
the water column remains below a value for which no significant and lasting toxicity to marine 
species is observed. A concentration of 10 ppm seems to be reasonable. Any solution meet 
ing this basic requirement and relying only on readily available data for decision making is 
acceptable. 
Finally, it is important to consider the implementation phase of pollution response through the 
use of chemical dispersants. It is necessary to provide quick and easy access to platforms 
for the application of dispersants on oil spills at sea. Public service vessels may be fairly 
simply equipped, but if product spraying from aircraft is necessary, it seems preferable to rely 
on a service provider.