First published in 2005 by Marine Environmental Emergency Preparedness and Response Regional Activity Centre the Northwest Pacific Action Plan (NOWPAP MERRAC) Established at /MOERI P.O.Box 23, Yuseong, Daejeon 305-600 Republic of Korea Copyright © NOWPAP MERRAC 2005 All rights reserved. No part of this publication may, for sales purposes, be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, electrostatic, magnetic tape, mechanical, photocopying or otherwise, without prior permission in writing from the NOWPAP MERRAC. For bibliographical purposes this document may be cited as: MERRAC Technical Report No. 3, Guideline for the Use of Dispersants, NOWPAP MERRAC, 2005. Foreword MERRAC, the Marine Environmental Emergency Preparedness and Response Regional Activity Centre, is one of four Regional Activity Centres of the Northwest Pacific Action Plan (NOWPAP) which was adopted in 1994 as a Regional Seas Programme of the United Nations Environment Programme (UNEP) by the People’s Republic of China, Japan, Republic of Korea, and Russian Federation. MERRAC is responsible for regional co-operation on marine pollution preparedness and response in the region. With technical support from the International Maritime Organization (IMO), MERRAC is currently functioning as secretariat for the NOWPAP MERRAC Focal Points Meeting, Expert Meeting, Competent National Authorities Meeting for NOWPAP Regional Oil Spill Contingency Plan (CNA meeting). The Centre also carries out other special activities including the management of a regional information system, organization of training and exercise, capacity building, co-ordination of research and development on the technical aspects of oil spills. As one of main outcomes of MERRAC activities, the NOWPAP Regional Oil Spill Contingency Plan (the Plan) and its relevant Memorandum of Understanding (MoU) have been developed and officially come into effect as being signed by all NOWPAP Members. The purpose of the Plan is to provide an operational mechanism for mutual assistance through which the Member States will co-operate during major marine oil pollution incidents in the region. In order to provide practical and technical guidelines to promptly and effectively respond to major oil spill accidents within the framework of the Plan, the 5th MERRAC Focal Points Meeting (MERRAC, Daejeon, 20-24 May 2002) especially agreed to carry out the series of MERRAC specific projects related to oil spill prediction model, sensitivity mapping, oil dispersant, shoreline cleanup, etc. i The documents have been prepared by the Experts Groups, whose members have been officially nominated by the NOWPAP Members and has a profound professionalism in the relevant fields. The 8th NOWPAP MERRAC Focal Points Meeting (MERRAC, Daejeon, 24-27 May 2005) finally reviewed the drafts and then approved to publish them as MERRAC Technical Report series. This technical reports are described the current situation of the relevant subjects and future actions of MERRAC related to relevant subjects. A series of the MERRAC Special Reports to be published in 2005 are as follows: . Sensitivity Mapping . Guideline for Shoreline Clean-up . Guideline for the Use of Dispersants As Director of MERRAC, I would like to thank the MERRAC Focal Points and all experts of the Expert Groups for their support and contributions to finalizing the MERRAC Technical Reports. Chang-Gu Kang Director of MERRAC, November 2005 ii CONTENT Chapter 1. Introduction ·············································································· 1 Chapter 2. Function and Chemical Composition of Oil Spill Dispersants ·············································································· 2 Chapter 3. History ······················································································· 4 Chapter 4. The Role of NEBA ··································································· 7 Chapter 5. Developing List of Approved Dispersants ························ 9 Chapter 6. Policy of Dispersant Application by NOWPAP Countries ················································································· 10 6.1 Laws, Regulations and Guidelines Applied to Use of Dispersants in NOWPAP Countries ········································································· 10 6.2 Specific of Dispersant Application by NOWPAP Member States ······ 10 Chapter 7. Dispersant Application Techniques ·································· 21 7.1 General Recommendations ································································· 21 7.2 Dispersant-oil Ratio ··········································································· 21 7.3 Safety Precautions in Dispersant Application ····································· 22 7.4 Techniques for Applying Dispersants to an Oil Slick ························· 23 7.4.1 Boat Treatment ········································································· 23 7.4.2 Aerial Treatment ······································································ 25 7.5 Strategic Recommendations for Dispersant Application ····················· 27 7.6 Tactic Recommendations for Dispersant Application ························· 27 7.7 Water and Weather Considerations in Dispersant Application ············ 29 7.8 Monitoring the Effectiveness of Dispersant Application ···················· 30 7.9 Monitoring Environmental Effects ····················································· 30 Chapter 8. Discussion of the Future Works on Dispersant Application Issues ································································· 31 8.1 Results of 7th NOWPAP MERRAC Focal Points Meeting ················· 31 8.2 Results of 2004 NOWPAP MERRAC Expert Meeting and 8th NOWPAP MERRAC Focal Points Meeting ······································· 32 Chapter 9. Conclusions and Recommendations ································ 34 iii Chapter 10. Summary ··············································································· 35 References ·································································································· 36 Annex A. List of National Experts of the Expert Group for NOWPAP Regional Guidelines on Use of Oil Spill Dispersants ··············································································· 40 Annex B. List of Oil Spill Dispersants Approved by NOWPAP Member States ·········································································· 42 Annex C. List of Oil Spill Dispersants Application Technique of NOWPAP Member States ······················································· 48 Annex D. NOWPAP Guidelines on Oil Spill Dispersant Application ················································································ 58 iv Chapter 1 Introduction Over the past few years, the use of dispersants has become an increasingly common method to combat oil spills at seas. The reason for this is in part because new approach of their application and in part because current mechanical methods have definite limitations. This has led to a change in attitudes both nationally and internationally. Several countries have expressed positive attitudes towards dispersants and have therefore softened their views on the use of such products. This report aims to give an overview of the international usage of dispersants as a base for development of NOWPAP Guidelines on Oil Spill Dispersant that can be use during the joint response operation within the framework of NOWPAP Regional Oil Spill Contingency Plan. Based on an analyse of NOWPAP member States’ dispersants use polices and IMO Guidelines, the NOWPAP Guideline (Annex D) was prepared by experts from the People’s Republic of China, Japan, Republic of Korea and the Russian Federation as a lead country (Annex A). 1 Chapter 2 Function and Chemical Composition of Oil Spill Dispersants When oil is introduced into a water environment, the spill will spread horizontally on the water surface. Spreading varies with surface tension at the border between the oil and water. The higher the oil surface tension (and therefore the surface tension between the oil and water), the less the oil spreads. The function of an oil spill dispersant is to greatly reduce interfacial surface tension and enhance the rate of transfer of spilled oil from the water surface into the water column. Effective application of dispersant to oil that is dispersible will achieve this result. The main concerns about dispersant use are that the temporary increase in oil concentration and the potential for higher concentrations of toxic water-soluble oil components will cause environmental damage. Dispersion is the conversion of spilled oil from a coherent slick floating on the surface of the sea into very small oil droplets, estimated as about 70 pm in diameter or less (Lunel, 1993), by the prevailing wave energy. These oil droplets are nearly neutrally buoyant due to their small size, and they remain dispersed into the water column until the majority of the oil is eventually biodegraded. The rate of dispersion depends on the oil’s properties, principally viscosity, and the prevailing wave energy. Low viscosity oils disperse faster than higher viscosity oils and dispersion is faster in rough seas than in calm conditions. Dispersion occurs naturally and can proceed at a rapid rate in rough conditions with some low viscosity oils, such as No. 2 heating oil (North Cape incident (OSIR, 1996)), or Gullfaks crude oil (Bruer incident (Harris, 1995)). The effective use of dispersants allows the