PART III
OUTLINE AND TEMPLATE FOR A NATIONAL POLICY ON THE
USE OF DISPERSANTS
Part III has been prepared with a view to assisting coastal States in the development of their
national policy on the use of dispersants. It has been developed as a template which can be
followed and adapted by the authorities in charge of the development/maintenance of the
national policy on the use of dispersants and can also be used for the implementation of
national or local contingency plan for dispersants.
PART IV
OPERATIONAL AND TECHNICAL SHEETS
Part IV is based on the publication entitled “Using dispersant to treat oil slicks at sea.
Airborne and shipborne treatment. Response manual
”
(CEDRE 2005). It provides a set of
practical technical sheets which point out the different operational issues when using
dispersants. It has been developed for operational users with a view to providing them with
the required knowledge for efficient dispersant application.
In order to keep the coastal States regularly informed of the current situation regarding the
use of dispersants, REMPEC shall update this document to include any new and significant
developments in the research field.
GUIDELINES FOR THE USE OF DISPERSANTS
FOR COMBATING OIL POLLUTION AT SEA
IN THE MEDITERRANEAN REGION
P A R T II
BASIC INFORMATION ON DISPERSANTS AND THEIR APPLICATION
TABLE OF CONTENTS
1.
Introduction.
2.
The Mediterranean Sea: Basic Considerations.
3.
General Notions on Dispersants.
3.1
Definition
3.2
History of dispersants
3.3
Nomenclature of dispersants
3.4
Composition of dispersants
4.
Use of Dispersants in Oil Spill Response Strategy.
5.
Factors Affecting Dispersant Action.
5.1
Type of oil
5.2
Contact dispersant/oil
5.3
Mixing
5.4
Weather conditions
6.
Physical characteristics of Dispersants.
6.1
Viscosity
6.2
Specific gravity
6.3
Pour point
6.4
Flash point
6.5
Stability / shelf-life
6.6
Others
7.
Environmental Effects.
7.1
Toxicity
7.2
Microbial degradation
7.3
Effects on seabirds and marine mammals
7.4
The use of dispersant on underwater oil releases (e.g; blow out)
8.
Net Environmental Benefit Analysis.
9.
Testing, Assessment and Selection of Dispersants.
9.1
Effectiveness tests
9.2
Toxicity tests
9.3
Biodegradability tests
9.4
Other tests
10. Dosages and Application Rates of Dispersants.
11. Dispersant Application Systems.
11.1
Aircraft mounted spraying systems
11.1.1 Airplanes
11.1.2 Helicopters
11.2
Boat-mounted spraying systems
11.2.1 Systems for spraying conventional dispersants
11.2.2 Systems for spraying diluted dispersants
11.2.3 Systems for spraying neat dispersants
11.3
Portable
units for individual use
12. Logistic Requirements for Efficient Use of Dispersants.
13. Storage of Dispersants.
13.1
Storage
13.2
Ageing
13.3
Disposal of aged stockpiles
Bibliography.
LIST OF FIGURES
Figure 1: Map of the Mediterranean Sea
.......................................................................................... 2
Figure 2: Slicks being dispersed by a helicopter
............................................................................. 3
Figure 3: Plume of dispersed oil at sea
............................................................................................ 4
Figure 4: Dispersant stockpile in drums
............................................................................................ 5
Figure 5: Aerial dispersant application with a DC3 aircraft from the UK authorities
................. 8
Figure 6: Spotter aircraft of the British Maritime Coastguard
........................................................ 9
Figure 7: Weathered oil emulsion which dispersion remains uncertain
..................................... 10
Figure 8: Ship applying dispersant
.................................................................................................. 11
Figure 9: Samples of dispersant during quality control in the laboratory
................................... 13
Figure 10: Toxicity tests with shrimps conducted on dispersed oil in UK
.................................. 14
Figure 11: The Sea Empress incident (UK)
................................................................................... 16
Figure 12: Assessment of the impact of dispersed oil on fish
.................................................... 16
Figure 13: Under water blowout in ultradeep environment, Deep Water Horizon incident
.... 19
Figure 14: Field experiment conducted on mangrove with dispersed oil
................................. 20
Figure 15: the Labofina / WSL test apparatus
............................................................................... 22
Figure 16: The IFP / flow through test apparatus
......................................................................... 23
Figure 17: The swirling flask test method
...................................................................................... 23
Figure 18: The MNS test apparatus
................................................................................................ 23
Figure 19: The British testing equipment for assessing the toxicity
........................................... 25
Figure 20: Ship mounted modern application spraying equipment
............................................ 26
Figure 21: Crop spraying aircraft
..................................................................................................... 27
Figure 22: Spraying multi-engine aircraft during Deep Water Incident
...................................... 28
Figure 23: POD spraying aircraft
.................................................................................................... 28
Figure 24: Large Self Contained spraying system
....................................................................... 29
Figure 25: Fixed spraying systems for helicopter
.......................................................................... 29
Figure 26: Helicopter equipped with independent spraying bucket
............................................ 29
Figure 27: Conventional dispersant spraying system for boat
.................................................... 30
Figure 28: Application of dispersant pre-diluted into sea water
.................................................. 31
Figure 29: Neat Concentrate dispersant spraying system for boat
............................................ 32
Figure 30: Dropping zone, arranged on the coast
........................................................................ 33
LIST OF TABLES
Table 1 : Basic considerations for the Mediterranean sea
............................................................. 2
Table 2: Dispersants classification
.................................................................................................... 4
Table 3: Composition of conventional and concentrate dispersants
............................................ 5
Table 4: Typical compounds used in dispersant formulations
...................................................... 6
Table 5: Dipersant typical viscosity range
...................................................................................... 12
Table 6: Data from the Sea Empress incident
............................................................................... 15
Table 7: Effectiveness tests parameters
........................................................................................ 22