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Oil Spill Dispersants

The National Plan to Combat Pollution of the Sea by Oil and Other Noxious and Hazardous Substances

Guidelines for Acceptance

(Taken from the last Tender documentation for the purchase of Oil Spill Dispersants for Australian Maritime Safety Authority )

Contact for inquiries and changes

If you have any questions regarding this document, please email: Environment Protection Response

1. Scope

1.1 This specification covers the Australian Maritime Safety Authority's requirement for X tonnes of oil dispersant concentrate.

2. Applicable Documents

2.1 Reference is necessary to the latest issue (unless otherwise stated) of the following documents which form a part of this specification to the extent specified herein:

i. Australian Standard AS 1792 - 1976 "Method For Determining The Biodegradability Of Surfactants"
ii. Australian Standards AS 3900 (ISO 9000) series of Quality Assurance Standards
iii. Federal Office Of Road Safety - "Australian Code For The Transport Of Dangerous Goods By Road And Rail"
iv. International Maritime Organization - "International Maritime Dangerous Goods Code"
v. International Air Transport Association - "Dangerous Goods Regulations"
vi. Worksafe Australia - "Guidance Note For The Labelling Of Workplace Substances"
vii. Worksafe Australia - "Guidance Note For The Completion Of A Material Safety Data Sheet"

3. Definitions

3.1 For the purpose of this specification, the following definitions apply:

i. AMSA - The Australian Maritime Safety Authority.
ii. Approved Dispersant - A dispersant which has been tested for toxicity and dispersal efficiency and which, having met acceptable toxicity and efficiency criteria, is suitable for use in Australian waters.
iii. Batch - A quantity of some commodity made in one operation or lot
iv. Cloud Point - The temperature at which solid substances begin to separate from solution.
v. Dispersant - Chemicals which reduce the surface tension between oil and water, and thereby facilitate the breakup and dispersal of the oil in the form of finely divided droplets throughout the water column.
vi. Dispersant Efficiency - The ratio expressed as a percentage of the volume of oil dispersed to the total volume of oil treated with dispersant.
vii. Flash Point - The temperature at which a liquid gives off sufficient vapour to flash in the presence of a naked flame.
viii. Shall and Should - shall is mandatory, should is desirable or advisory.
ix. Surfactant - Surface Active Substance -A substance which has the effect of altering the interfacial tension between oil and water.
x. The Authority - AMSA

4. Requirement

4.1 General- The requirement is for an approved dispersant concentrate for the dispersal of oil at sea. The dispersant shall be in the form of a liquid and the material offered against this specification shall, under normal operating conditions, contain no solid material, no suspended matter and no additional liquid phases. It should be non-corrosive to the storage containers and should not contain substances that are normally considered to be toxic to humans.

4.2 Prohibited Ingredients - The dispersant shall not contain benzene, carbon tetrachloride, or other chlorinated hydrocarbons, phenol, cresols, caustic alkali, or free mineral acid.

4.3 Aromatic Hydrocarbons - If hydrocarbon solvents are used in the manufacture of the dispersant, they shall be low in aromatic hydrocarbons, with an upper limit of three percent total aromatic hydrocarbons as determined by Gas Chromatography/Flame Ionisation Detection, Infra Red Spectroscopy or Fluorescence Detection.

4.4 Stability - The surfactants shall be wholly soluble in the solvent and shall remain uniformly distributed at all temperatures from -10c to +50c.

4.5 Physical Properties

4.5.1 Flashpoint- Tenderer shall advise the flashpoint of the tendered dispersant, as determined by the Pensky Marten closed cup method (ASTM D93, IP 34, BS 2834).

4.5.2 Cloud Point - The cloud point of the dispersant as determined by methods (IP 219 or ASTM D2500) shall not be more than -5C. The dispersant shall not separate into layers at temperatures greater than -10C.

4.5.3 Viscosity - The dispersant viscosity at 0c shall not be more than 250 centistokes (2.5 10-4m2s-2) at a shear rate of 103s-1.

4.6 Ecotoxicity

4.6.1 Toxicity- It is a mandatory requirement that each dispersant tendered against this specification shall have been tested for marine toxicity. The testing shall involve two temperate and two tropical marine fauna species, with the object of determining the dispersants 96 hour LC50 and to establish incipient lethal limits. The testing shall be carried out at a recognised and accredited testing laboratory and the tenderer shall forward a copy of the test results with the offer. A brief description of the required testing protocol is given at annex "A". This protocol is currently under review, but remains in effect for the interim. A candidate product previously accepted under the requirements of this document will not be required to be tested under the revised protocol, providing the formulation remains the same. However, new products will be required to be tested at supplier/tenderers cost.

4.6.2 Toxicity Limit - The dispersant as tested under the current protocol shall have a 96 hour LC50 value on the order of magnitude of 10 mg/litre (ppm) as derived from the 96 hour semi static exposure regime.

4.6.3 Biodegradability -The surfactant shall be biologically soft as determined by the procedures specified in AS 1792 - 1976.

4.7 Operational

4.7.1 Efficiency Testing - It is a mandatory requirement that each dispersant tendered against this specification shall have been tested for dispersal efficiency. For the purposes of this specification, the "Mackay Dispersant Performance Test" is the only efficiency test acceptable to AMSA. See annex "B" for a description of this test.

4.7.2 Efficiency- The dispersant shall be more than 75% efficient at an application ratio of 20:1, ie. twenty parts oil( light Arabian crude which has been artificially weathered), to one part dispersant, when tested by the Mackay dispersant performance test.

4.7.3 Test Report - The efficiency testing shall be performed by a recognised and accredited testing laboratory and the tenderer shall forward a copy of the test report with the tender.

4.8 Storage

4.8.1 Storage Requirements -The tenderer shall advise in their offer the storage requirements for the tendered product. This advice shall also include information as to whether or not there are special conditions or legislative requirements (eg. Australian Standard 1940 "The Storage And Handling Of Flammable And Combustible Liquids"), applicable to storage of the tendered dispersant.

4.8.2 Stability in Storage- In storage the dispersant shall not separate, gel or solidify.

Storage Life - The dispersant when stored according to the manufacturer's recommendations, in the original sealed containers, with ambient temperatures ranging between -10c and +50c, should have a storage life of not less than ten (10) years.

4.8.3 Maintenance in Storage - The tenderer shall advise if any maintenance procedures are recommended or are required in order to achieve the desired storage life of not less than ten (10) years.

4.9 Packaging

4.9.1 Container Volume - The tenderer shall tender for the supply of the specified dispersant in:

i. 200 litre drums, and;
ii. 1 000 litre intermediate bulk containers (IBC).

4.9.2 Storage Life - The drums and IBCs shall provide safe sound storage for the dispersant for a minimum storage period of not less than ten (10) years. See clause 7.6.

4.9.3 Transport Codes- The tendered containers shall be suitable for the transport of the dispersant by all transport modes (land, air and sea) and shall therefore meet the packaging requirements of the following transportation codes:

i. Australian Code For The Transport Of Dangerous Goods By Road And Rail.
ii. International Maritime Dangerous Goods Code
iii. International Air Transport Dangerous Goods Code

4.9.4 Corrosion Resistance - The containers shall be suitable for use in a marine environment and should not be degraded by exposure to temperatures in the range of - 30c to + 50c, humidity up to 100% and high levels of UV radiation.

4.9.5 Batch Numbers - The dispersant's batch number and year of manufacture shall be clearly marked on the side of each container.

4.9.6 Labelling - The dispersant containers shall be labelled in accordance with the requirements of the "Worksafe Guidance Note For The Labelling Of Workplace Substances [NOHSC:3013(1991)]". The label shall be in the specified format and shall provide all the information required by the guidance note. The label shall be weatherproof, UV stable, not effected by dispersant and truly permanent.

4.10 Material Safety Data Sheet

4.10.1 Material Safety Data Sheet - it is a mandatory requirement that a material safety data sheet (MSDS) be submitted with each tender. The MSDS shall be the latest issue for the tendered product.

4.10.2 Format- The format is flexible however it is desirable that it should conform to that shown in Appendix 3 Sample Form of the "Worksafe Guidance Note For Completion Of A Material Safety Data Sheet [NOHHSC:3001(1991)] "

4.10.3 Information - The MSDS should be complete in all detail and shall provide as a minimum all the information listed as core entries in Appendix 6 - "Material Safety Data Sheet Checklist", of the guidance note.

4.11 Test Certificates

4.11.1 Test Certificates- Information regarding the physical, chemical and toxic properties, and efficiency of the tendered product shall be provided in the form of test certificates issued by recognised and accredited testing laboratories.

5. Quality Assurance

5.1 The tenderer shall use an inspection system conforming to the AS 3900 (ISO 9000) series of quality standards which shall ensure that the dispersants offered to the Authority for acceptance conforms to the specified requirements. The inspection system shall be documented and available for review.

5.2 The dispersant manufacturer shall use a quality control system conforming to the AS 3900 (ISO 9000) series of quality standards which will ensure that each batch of dispersant delivered is the same formulation and quality as that tendered and that which has been subjected to the specified testing protocols.

5.3 AMSA reserves the right to take samples of dispersant for examination and or testing to ensure that supplies conform to the requirements of this specification.

5.4 AMSA reserves the right to reject any dispersant supplies which fail to meet the requirements of this specification.

5.6 Acceptance of the dispersant shall be subject to agreement by the Inspecting Officer that the quality requirements of this specification have been met.

6. Tender Assessment Criteria

6.1 Evaluation of offers will be based on the following criteria which is listed in priority order

i. Compliance with this specification
ii. Efficiency and toxicity
iii. Storage requirements, eg. flammable store
iv. Cost

6.2 Quality Assurance Standards- Tenderers who do not meet the quality requirements as stated in 5.1 and 5.2 will not be necessarily eliminated in the evaluation process. Tenderers in this category should supply, with their offer, full details of their current quality system including plans for its development and implementation.

7. Notes

7.1 Variations- The tenderer shall state specifically whether or not the dispersant offered complies with each and every paragraph of this specification and shall clearly indicate any deviation(s) therefrom.

7.2 Delivery - The tenderer shall advise when delivery of the tendered dispersants can be made.

7.3 Transport Requirements - The tenderer shall advise of the requirements to transport the tendered product in compliance with the following transportation codes.

i. Australian Code For The Transport Of Dangerous Goods By Road And Rail.
ii. International Maritime Dangerous Goods Code
iii. International Air Transport Dangerous Goods Code

7.5 Delivery Costs - The tenderer shall advise in the offer details of the costs to transport the dispersant to:

Adelaide	South Australia	10 tonnes
Thursday Is	Queensland	12 tonnes
Townsville	Queensland	4 tonnes
Mackay	Queensland	10 tonnes
Brisbane	Queensland	6 tonnes

7.6 Dispersant Containers - AMSA has held dispersant concentrates in storage for more than ten years. The 200 litre containers are either high density polyethylene or polysteel (steel container with a polyethylene liner) drums. Some of the polysteel containers have failed after four or five years. The failures have occurred when the polyethylene liner ruptures allowing the dispersant to escape through a breather hole in the bottom of the steel drum. Failures have not occurred in the high density polyethylene containers. The problem appears to be with the different quality of polyethylene used in the two types of container. For this reason it is recommended that tenderers should seek advice from both the container manufacturer and the drum material supplier or manufacturer. In the case of polyethylene these would be ICI, Hoest, BP et al

Annex A

Testing Oil Dispersants For Toxicity

1. Test Species

Temperate

a. Aldrichetta forsteri (juvenile) -yellow-eyed mullet (fish)
b. Allorchestes compressa -estuarine amphipod (crustacean)
c. Atherinosoma microstoma -smallmouth hardyhead (small estuarine fish)
d. Macrobranchium intermedius - ghost shrimp (estuarine crustacean)
e. Platynympha longicaudata - estuarine isopod (crustacean).

(Or reasonable alternative species which (1) are common and representative of a typical temperate marine community, (2) are available throughout the year and readily collectable from the field, (3) are of an appropriate size, and (4) are adaptable to laboratory conditions).

Tropical

a. Liza vaigiensis - a species of tropical reef mullet (fish)
b. Penaeus monodon - a banana prawn (crustacean).

(Or reasonable alternative species which (1) are common and representative of a typical tropical marine community, (2) are available throughout the year and readily collectable from the field, (3) are of an appropriate size, and (4) are adaptable to laboratory conditions).

2. Test Method

Tests are to be semi static tests involving daily renewal of test solutions. They should conform to the normal requirements of bioassay procedures and in particular there should be:

a. At least one control chamber and six test chambers each having a different concentration of the test dispersant.
b. Full randomisation of chambers and animals.
c. Test chambers are to be gently aerated to prevent stratification of test media. At least ten animals per test chamber but the biomass should not exceed one gram per litre and the dissolved oxygen should not fall below four milligrams per litre in twenty four hours.

Test data should be reported as toxicity response curves showing the LT value at each concentration tested. 96 LC50 values shall be determined from the response curves and incipient LC values should be determined if possible.

In order to determine LT50 value for the lower concentrations, it may be necessary to extend the text period beyond the basic 96 LC50 test up to and for no more than seven days. During the extended period, daily animal observations, feeding and medium changes should be carried out for each of the concentrations requiring extension as well as for the control.

Full details of the test animals, acclimation procedures, test conditions and derivation of results should be reported. Dispersant concentrations should be reported as nominal (added) values, because the qualification of exposure concentrations would require detailed surfactant analyses beyond the scope of most laboratories.

The salinity should be 35 0/00 in all tests. The temperature for tropical tests should be 30C 3 and 15C 3 for temperate tests.

Annex B

Mackay Dispersant Performance Test

Introduction

The Mackay dispersant performance test is used to determine :-

a. How well various chemical dispersants work on various types of oil under given energy conditions, water salinities and temperatures.
b. The relative performance of different chemical dispersants under the same conditions.

In the Mackay test a circulating air current imparts energy to the water surface in the test chamber. This method of generating turbulence is believed to simulate ocean conditions more accurately than do shaking, stirring or pumping methods. This method does not attempt to simulate subsurface ocean hydrodynamics. The focus is on approximating the mixing at the surface, since this is where oil dispersal occurs.

Outline of the procedure

The equipment and procedures described are those developed by Dr Donald Mackay of the University of Toronto.

The Mackay method of testing oil dispersants allows for the variation of air and water temperatures, mixing energy, water salinity and dispersant to oil ratios.

The Mackay tester, figure 1, consists of a cylindrical glass vessel with an internal diameter of 300mm and a height of 300mm. The vessel is covered with a plexiglass lid which is fitted with a gasket to provide a good seal between the lid and vessel. Lugs on the lid ensure that it is located concentrically on the vessel.

In the lid are:

a. air inlet and outlet tubes
b. ports through which oil and dispersant are introduced into the test chamber
c. glass sampling tube
d. oil containment ring and rod

The containment ring prevents uncontrolled spreading of oil over the water surface inside the test vessel prior to the introduction of the dispersant under test.

The test vessel is positioned in another vessel in which temperature controlled water is circulated. Temperature controlled airflow from a variable flow airpump is circulated through the test vessel. Six litres of synthetic seawater or fresh filtered seawater (adjusted) to a specified salinity is used in the test. The volume of oil used is 10ml.

When the seawater temperature in the test vessel has stabilised to within 1C of that specified, air is circulated through at the required velocity. When the air temperature is within 1C of that specified and wave motion in the vessel is established and stable, 10ml of the test oil is introduced into the vessel and released in the containment ring. The desired amount of dispersant under test is applied to the oil surface and is allowed to penetrate through the oil film for 1.0 minutes. The containment ring is then lifted and dipped into the water two or three times to dislodge as much adhering oil as possible. After ten minutes the airflow is stopped and a 500ml sample of the oil, dispersant and water mixture is taken through the sample tube the inlet of which is positioned 45mm above the bottom of the test vessel. The first 50ml is discarded and the balance retained as the test sample. After a further five minutes a second 500ml sample is taken and the first 50ml is discarded as before.

The samples are treated with dichloromethane (CH2Cl2.), and filtered through anhydrous sodium sulphate ( Na2SO2.). The concentration of oil in the sample(s) is determined by UV-spectrophotometer. The values obtained are compared to a calibration curve. 100% effectiveness corresponds to an ideal situation where all of the oil has been dispersed into the water column.

The shearing and mixing forces necessary to break up the dispersant treated oil and drive it into the water column in finely divided droplets are generated by the wind driven wave action created by the flow of air over the water's surface. To give a quantitative measurement of the mixing energy, and to correlate the energy level to sea state, oxygen transfer coefficients are determined. Oxygen transfer coefficients are, in the main, dependent on the amount of air flow immediately over the water's surface. Determination of oxygen transfer coefficients are done by first deoxygenating the water to about 10% saturation. This is achieved by either bubbling nitrogen through the water or by the addition of a small amount of a saturated solution of sodium sulphite (Na2SO3). An airflow of the desired velocity is circulated through the chamber. Using a dissolved oxygen meter, oxygen concentrations are plotted as a function of time. This is done for all desired energy levels.

Mackay has suggested that there is a correlation between turbulence levels in the test vessel and sea conditions (Mackay et al, 1980). This makes it possible to perform laboratory tests at approximately desired sea states. It is pointed out, however, that an exact simulation of environmental conditions in any laboratory is virtually impossible.

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last updated: 19 October 2006