1、 IMO/UNEP Guidelines on Oil Spill Dispersant Application including Environmental Considerations 1995 edition 0 International Maritime Organization London, 1995 First published in 1982 by the INTERNATIONAL MARITIME ORGANIZATION 4 Albert Embankment. London SE1 7SR Second edition 1995 Printed in the Un
2、ited Kingdom by the International Maritime Organization 4 6 8 10 9 7 5 ISBN 92801-1332-1 I IMO PUBLICATION I Sales number: IA575E The views expressed in this publication do not necessarily represent the decisions or the stated policies of the International Maritime Organization (IMO) and the United
3、Nations Environment Programme (UNEP), nor does mention of trade names or commercial processes constitute endorsement. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of 1MO and UNEP concerning the le
4、gal status of any State, Territory, city or area, or its authorities, or concerning the delimitation of their frontiers or boundaries. Copyright 0 1MO 1995 A11 rights reserved. No part of this publication may be produced, stored in a retrieval system or transmitted in anyform or by any means, electr
5、onic, electrostatic, magnetic tape, mechanical, photocopying or otherwise, without prior permission in writingfrom the International Maritime Organization. The IMO/UNEP Guidelines on Oil Spill Dispersant Application including Environmental Considerations provide up-to-date information on the use of
6、oil spill dispersants. They are intended primarily for use by Member Governments and other oil spill responders and should be read with the Manual on Oil Pollution, Section IV: Combating Oil Spills (IMO (1988). The present edition of these Guidelines supersedes the 1982 edition. France acted as “lea
7、d country” in preparing these guidelines. A first draft version of the text was presented to the thirty-fifth session of the Marine Environment Protection Committee (MEPC) of the International Maritime Organization (7-11 March 1994) by the Government of France, acting through the Centre de documenta
8、tion de recherche et dexperimentations sur les pollutions accidentelles des eaux (CEDRE). A workshop was subsequently held in Brest (France) on 9 - 11 May 1994, hosted by CEDRE, to review the text. The resulting document was considered at the thirty-sixth session of the MEPC (31 October to 4 Novembe
9、r 1994) by the OPRC Working Group. The Committee approved the document as amended for publication. The Committee expressed its appreciation to: w the Government of France and CEDRE for having taken the lead in revising these guidelines and for hosting the workshop to review the text; w the experts (
10、listed on page iv) who participated in the workshop and assisted in the preparation of the text; H The International Petroleum Industry Environmental Con- servation Association (IPIECA) for permission to use material from the report Dispersants and their Role in Oil Spill Response (IPIECA, 1993), on
11、 which section 3.3 is based; H the World Conservation Monitoring Centre for producing the sensitivity map for section 2.4.3; AEA Technology, CEDRE, Environment Canada, and IKU Petroleum Research for contributing figures and tables, thus making this publication available in its present form; and w al
12、l those who reviewed the text and provided comments. . 111 List of participants attending the workshop set to review the guidelines (Brest, France, 9-11 May 1994) Dr Jenifer Baker (IPIECA, UK) Mr David Bedborough (MPCU, UK) Mr Darko Domovic (REMPEC, Malta) Dr Mervin Fingas (Environment Canada, Canad
13、a) Dr Robert Fiocco (EXXON, USA) Mr Alun Lewis (IKU Petroleum Research, Norway) Ms Saara Lintu (IMO, UK) Dr Tim Lunel (AEA Technology, UK) Mr FranCois Merlin (CEDRE, France) Dr Daniel Owen (ITOPF, UK) Dr Gennady Semanov (CNIIMF, Russian Federation) Mr Jean Sparfel (CEDRE, France) iv Contents Chapter
14、 1 - General inuoduction . Chapter 2 - Planning for the use of dispersants 2.1 Introduction . 2.1.1 Risk assessment . . . . . 2.1.2 Sensitivity mappin . 2.1.3 Approval procedu . 2.2 Risk assessment process . 2.2.1 Dispersibility of o hysical properties . . . . . . . 2.2.2 Likely sizes of spil . . .
15、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2.1 Quantity of dispersant needed . 2.2.2.2 Methods of dispersant application . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 Net environ lysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4.1 lntrod
16、uction . 2.4.2 Factors to CO 2.4.3 Examples . dispersant planning . dispersant operations . . . 2.5 2.6 Requirements for as 2.7 The relevance of the short time window for . Compatibility with mechanical response methods . . . . . . . . . . . . . Chapter 3 - Decision-making at the time of the spill .
17、 3.1 The decision tree involving dispersant use . . . . . . . . . . . . . . . . . . . . . . 3.2 Outline of other spill response options . 3.2.1 Mechanical 3.2.2 In-situ burn der consideration) . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.3 Let oil come ashore and clean shoreline . 3.2.4 No
18、direct action 3.3 Toxicity aspects . . 3.4 3.4.1 Amenity and tourist resources . Suggestions for dispersant use in different habitats and with different reso 3.4.2 Birds . 3.4.3 Coral reefs . 3.4.4 Fish _ 3.4.5 Fish and shellfish ma 3.4.6 Gravel/cobble beaches . . . . . . . . , . . . . . . . . . . .
19、 . . . . 3.4.7 Industrial facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 3 3 3 3 3 4 4 5 5 5 6 6 7 8 9 11 12 15 15 17 17 18 18 18 18 20 22 22 22 22 23 23 23 V 3.4.8 3.4.9 Marine mammals . 3.4.11 Ponds used for aquaculture and salt production 3.4.12 Rocky shores
20、3.4.13 Salt-marshes. . . Mangroves . , . . . . . . . . . , . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.14 Sandy beaches . 3.4.15 Seagrass beds . . . , . . . . . . . . . . . . . . 3.4.16 Shellfish (intertidal) . . , . . . . . . . . . . . . . . . . . . . . 3.4.17 Shel
21、lfish (near-shore subtidal) . . . . . . Chapter 4 - Application 4.1 4.2 Application proced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Tactical procedure. . 4.5 4.5.1 4.5.2 General considerations on dispersant application at sea 4.4 Logistics for large Monitoring , _. . . .
22、 . . . . . . . . . . . Monitoring effectiveness . . . . . . , , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring environmental effects . . . . . . . . . . . . . . . . . . . . . . . . . Appendix 1 - General considerations on dispersants . . . . . . . 1 Definition 3 Nomencl
23、ature of currently availa 4 2 History of dispersants _ . 5 Dispersant dosages and applicatio 6 Facts about dispersants ._. . Composition of dispersants . . . . . . . Appendix 2 - The testing of dispersants 1 Effectiveness test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24、 . . . . . . . . . . . . . . . . . . . 2 Toxicity test . 3 Biodegradability tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix 3 - Fate of oil . Weathering . , . . . . . . . . , , . . . , . . . . . . . . , , . . . . . . . . . . . . . . .
25、. . . . Evaporation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dissolution of oil components . . . . . . . . . . . . . . . . . Sedimentation . . Natural dispersion . . . . Spreading . . . . . , . . . . . . . . . . . . . Drifting . . . . , , . . . . . . . .
26、. . . . . . . . 23 23 24 24 24 24 24 25 25 25 27 27 28 29 29 30 30 30 31 31 31 32 32 33 34 35 35 35 36 37 37 37 38 38 38 39 39 40 40 40 vi Appendix 4 . Examples of oil dispersibility and properties . Appendix 5 . Review of dispersant application methods . 1 Treatment from aircraft 1.1 Equipment adap
27、ted for helicopters . 1.2 Equipment adapted for fixed-wing aircraft 1.2.1 Single-engined aircraft . 1.2.2 Multi-engined aircraft . 2 Treatment from ships . 2.1 seawater 2.1.1 Treatment by means of an eductor . 2.1.2 Treatment using self-contained equipment 2.2 Treatment with concentrated dispersants
28、 applied undiluted . . 2.2.1 Treatment using air-blast sprayers . 2.2.2 Treatment using spray unit systems Treatment with concentrated dispersants pre-diluted in Appendix 6 . Dispersant application at sea: operational procedure 1 Area to be treated 2 Methods to be followed and those to be avoided 4
29、Shipboard dispersant application., 3 Aerial dispersant application . References . Further reading . 43 47 47 47 47 47 48 48 48 48 49 49 49 50 51 51 51 51 53 54 55 vii Chapter 1 General introduction This manual primarily describes the use of dispersants in oil spill response. Other response technique
30、s are referred to in order to provide background information. Natural or induced agitation of water causes dispersion of spilled oil into the water column. Dispersants are mixtures of surfactants in one or more solvents, specifically formulated to enhance the rate of this natural process (see append
31、ix 1). Their purpose is therefore to reduce the amount of oil coming ashore, by converting floating oil into small droplets dispersed in the water column. Dispersants are one of several operational methods for dealing with oil at sea. Others include: rn mechanical recovery of floating oil; rn leavin
32、g the oil to weather naturally at sea, but continuing to rn leaving the oil to come ashore, and then dealing with it as monitor its movement on the water; and appropriate. Further methods are still to be developed operationally. These include in-situ burning and the use of gelling and demulsifying p
33、roducts. This document deals with the use of dispersants at sea; it does not discuss their use in fresh/brackish water. Dispersants are not specifically designed to be used for shoreline clean-up operations; other products, called beach or rock cleaners, are better adapted for such an application. H
34、owever, in some countries, which experience shore tidal flushing, dispersants are also used for shoreline cleaning. The hydrocarbon-type dispersants used in the past have had adverse effects on the environment due to their toxicity. However, modern dispersants used today are significantly less toxic
35、 than the oils they disperse. One needs to define the place of dispersants in a general response to oil spills at sea. This is done by balancing the advantages and disadvantages and comparing these with other available response methods. Such a net environmental benefit analysis should consider all r
36、elevant environmental conditions and implications (see section 2.4). The possible detrimental effects of the use of dispersants might be offset by the gains that result from keeping other parts of the environment clear of oil. No single response option will be one hundred per cent effective for all
37、oils under all conditions: each has its limitations. 1 Chapter 1 - General introduction Some of the advantages and disadvantages of using dispersants in oil spill response are listed below: ADVANTAGES H In contrast to containment and recovery, dispersants can be used in stronger currents and greater
38、 sea states; H It is often the quickest response method; H By removing the oil from the surface it helps to stop the wind effect on the oil slicks move- ment that may otherwise push the surface slick towards the shoreline; contamination of sea birds and mammals; H It inhibits the formation of water-
39、in-oil emulsions (“choco- late mousse”); H It increases the surface area of oil that is available for natural degradation. H It reduces the possibility of D 1 SADVANTAGES H By introducing the oil into the water column, it may adversely affect some marine organisms which would not otherwise be reache
40、d by oil; achieved, effectiveness of other response methods on oil treated by dispersants may decrease; H Dispersants are not effective on all types of oil under all condi- tions; H If used on shore, it may increase the penetration of oil into the sediments; H It introduces an additional quantity of
41、 extraneous sub- stances into the marine envir- onment; H There is a limited time window when dispersants can be used. H If dispersion of oil is not The remainder of this publication is divided into three chapters. The first, on planning, deals with considerations on dispersant use that can be made
42、before a spill occurs. The second, on decision-making, explains how dispersant use should be considered at the time of a spill. The last chapter, on application, details the technical aspects of different application methods. 2 2.1 2.1 I 2.1.2 2.1.3 2.2 Chapter 2 Planning for the use of dispersants
43、Introduction Where dispersants are to be part of the response strategy, it is essential that the contingency plan gives a clear policy statement on their use, on the procedures in place for prior approval, and on resources available for a rapid response. When preparing the contingency plan, at whate
44、ver level (e.g. at a national or site-specific level), the following points should be considered. Risk assessment The Manual on Oil Pollution, Section 11: Contingency Planning provides guidelines for risk assessment. The assessment should determine: the type of oil likely to be spilled and whether d
45、ispersants will be an effective response option; the quantity of oil likely to be spilled, which will determine the quantity of dispersant required and the most suitable application method; and the location of the oil spill, which will also determine the most suitable application method given the ti
46、me needed to reach the spill. Sensitivity mapping It is necessary to determine the nature and distribution of the resources at risk from an oil spill, with particular reference to their sensitivity to dispersed oil. Sensitivity may be dependent on time of year. Approval procedures To facilitate a ra
47、pid response it is necessary for the designated authorities to have agreed at a national level before a spill the particular dispersants which can be used and the conditions for their use. This will probably require an agreed testing procedure for efficiency and toxicity (see appendix 2) and, where
48、possible, prior approval for the use of dispersants in certain areas. Regional contingency plans should be referred to; consultation with neighbouring countries should be under- taken where possible. Risk assessment process An essential part of risk assessment is the evaluation of potential spill sc
49、enarios. These should first identify the most likely cause of a spill at a particular location. Typical examples are: 3 Chapter 2 - Planningfor the use of dispersants blow-out at a production platform; tanker grounding or collision; and loading or discharging accident at a terminal. Each scenario will have different characteristics, such as the type of oil released, the size of the spill, the release rate and the location. Contrasting examples are a large and continuous release from a blow- out compared to a small and instantaneous release from a
