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CQD Journal for the Maritime Environment Industry |
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FROM THE EDITOR |
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This November the General Assembly of IMO will be debating the phase out of tributyltin (TBT) in
vessel hull paint. CQD has been doing a short series of articles on this explosive issue. Although it appears extensive, the long term effects on the shipping industry and environment warrant in-depth analysis. Deep
thanks go to Mary Sue Brancato and Michael Champ for their expert advice and editorial assistance. They both provide extremely valuable insight into this pressing problem. Contact Mary Sue Brancato at Contact Michael Champ at Hope you find this enlightening! |
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Chris Swanson Editor |
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for use on over 70% of the world's ocean-going fleet because of cost-effective performance may soon
be phased out. Last November the Marine Environment Protection Committee (MEPC) of the International Maritime Organization (IMO) voted in favor of a worldwide ban on antifouling boat bottom paints
containing tributyltin. Justifications for MEPC recommending a total ban were partially based upon data presenting TBT as extremely toxic and claims that safer alternatives were available. |
TBT paints and alternatives work to keep barnacles and other fouling organisms off of ships' hulls. photo courtesy of John Lewis |
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Over 200 of the world's top scientists met recently in Melbourne, Australia at the
International Congress on Marine Corrosion and Fouling. Experts from industry, academia, and government in the field of biofouling and marine coatings discussed and debated antifouling technologies particularly the TBT
issue. Evidence related to the MEPC proposed ban was presented and discussed at the Symposium.Experts spoke on topics such as: fouling control in the 20th century, ship hull fouling and invasive species, regulating TBT paint,
novel approaches to preventing fouling, economics and many more. Among the speakers was Dr. Michael Champ (co-editor of Organotin: Environmental Fate and Effects,
published by Chapman & Hall, 667 pages, Oxford, UK). As a senior Science Advisor at EPA, Champ helped write the US Organotin regulations in the mid 80's. He feels the information reported and the peer review comments from Melbourne were much more pertinent |
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to the regulatory debate than the papers submitted to MEPC (42). In addition, several
overview papers at Melbourne questioned most of the science being used to ban TBT. Few of the experts attending the Conference reviewed the data submitted to MEPC or IMO. Champ observed that MEPC
passed over an independent peer review by the scientific community.
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Presentations in Australia Scientists at the Melbourne Congress debated many issues, yet one of the hottest was alternatives to TBT based paint. Alternatives currently being
tested were outlined including copper based paints, silicone based paints, ship vs. lab evaluations of foul release coatings and cost analysis of TBT vs. alternative paints. Dr. Champ (ATRP Corp.) was invited to Melbourne to
present a concept for the creation of an international Marine Coatings Board (MCB). The Board's goal is to independently review and test TBT alternative products and services. MCB will act as an independent or neutral
third party generating information for all countries in a single data set. Champ feels the Board can save interested parties millions of dollars on each paint technology. TBT competing alternatives have not been fully
tested and compared to determine their respective pros and cons in various controlled environments and operating conditions. Existing reports do not address all the factors and trade-offs that should go into comprehensive,
balanced decisions affecting the availability and use of antifouling coatings. Although many technologies show promise, answers are a long way away. Another expert who spoke in Melbourne was Mary Sue Brancato of Parametrix,
Inc. A recognized expert on the organotin biocide issue, her work with Parametrix has been reported in numerous science journals including Environmental Science & Technology (ES&T). Brancato agrees there is not
enough data on alternative paints, and the data collected has not been objectively reviewed or reported, nor made available to the public. In addition, she says "indirect environmental effects need to be evaluated with
respect to alternatives including increased fuel usage, introductions of invasive species and economics." In a biofouling paint, the effective ingredient is the biocide or the booster biocide, This is the chemical or other
substance that retards growth of marine organisms on the hull. TBT, copper and silicone are prime ingredients in some booster-biocides. In the case of many TBT alternatives, testing has been performed on the biocide but not
on the booster-biocide paint complex. Brancato insists regulators must look at the entire formulation, not just the biocide. The biocide itself may appear safe, yet the biocide-booster paint complex may present risks.
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Alternative Paints in the United States Alternative antifouling coatings are available in the US. However, Champ and others point out Ecoloflex and other commercially available
alternatives do not meet US EPA air emission restrictions such as volatile organic carbon (VOCs). Manufacturers have stated they can reformulate to meet US emission standards, but a reformulation could create a drastic change
in the properties of the paint. Reformulating may mean research performed over the past three years at great expense will not be valid for a new "US Approved" version. Paint manufacturers who would pay these research costs would
then have to justify the expense of reformulation and associated testing against the potential "US only" market. US vessels represent less then 2% of the world's ocean-going merchant fleet (MARAD, 1997).
Competing nations do not have the strict air emissions standards of the US and would not require reformulated paint. Such expenses would certainly make the US version more expensive.
US shipyards, which rely on foreign vessels for repair business, would be at a severe disadvantage. Shipowners already faced with higher costs related to non-TBT paint will certainly stay
away if US shipyards can only use paint costing even more. |
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Is a Worldwide ban justified? No one seems to doubt alternative antifouling paint will cost more. The most conservative estimates are at least two times as much. If the
shipping industry, consumer or taxpayer is to absorb these costs there must be a valid reason Are TBT levels continuing to increase worldwide? Does current research show TBT is causing detrimental harm to a greater
number of affected species (whelks) or any new species? Brancato believes the current limitations in place are effective and working. She points to separate studies performed by the US EPA, US Navy, NOAA NS&T and others
showing declining environmental risks in US, European and Japanese waters. Since TBT was banned for use on vessels under 25 meters in 1988, median TBT concentrations have dropped below the US EPA water quality criteria in
almost all areas. These studies indicate the primary source for TBT introduction, pleasure craft, has been eliminated. There are a few studies monitoring the presence of TBT in tissue from marine mammals such as
dolphins. Reports from such studies hint that TBT is as potentially dangerous as PCB'c for marine mammals. Brancato notes there is no evidence showing TBT causes harm to marine mammals. The mere presence of a
chemical in an organism does not mean that chemical caused or contributed to the animal's mortality. "You can't just look at the tissue," she says. "You need to establish cause and effect via a risk assessment from exposure
through diets, the most likely source." Brancato recently performed such a study; testing the risks of sea otters accumulating TBT by consuming bivalves in high TBT areas. The study found sea otters foraging in
coastal waters (99% of the US population) are not at risk from dietary TBT exposure. Studies show TBT risks are declining and the 25 meter ban is working. Why then is the MEPC of IMO now suggesting a complete ban on TBT?
Dr. Champ and other attendees concluded the science presented to the MEPC's working group should not have been acceptable since it was not peer reviewed. MEPC delegates were given and possibly influenced by papers from groups
with vested interests in a TBT ban. Peer reviewed science was not given equal presentation. Brancato notes certain papers submitted to MEPC, alluding to the dangers of TBT, cite old data from pre-TBT
limitations. Even peer reviewed scientific literature can report incorrect analysis and conclusions as noted in comments to ES&T (Volume 31, No. 10). Such information when presented to a group such as MEPC is
incorrect and could lead to a wrong decision for the environment. The International Congress in Melbourne aired many varied views on TBT and alternatives, pro and con. Before IMO's General Assembly votes on a global TBT-ban
this November, documents from the Melbourne Conference and elsewhere should be critically reviewed. These papers detail a broader "science based" picture on TBT than those presented to the MEPC. |
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Marine Coatings Board The Marine Coatings Board (MCB) is proposed as an independent, open, integrated, systems-based process to facilitate characterization and evaluation of
antifouling systems (see Marine Pollution Bulletin, Volume 38(4):240-247). The function of the MCB is to generate standardized and consistent data so that regulations and industry can balance the environmental effects of a
particular coating against others. The MCB project can reshape the global debate and decision criteria for marine antifouling coatings. Currently regulators have focused on a few specific adverse environmental
effects. The MCB will change focus to a comprehensive consideration of all relevant factors and effects. The shipping industry acknowledges the importance of a global consideration of antifoulants' effects on the
environment. The MCB will review more complete performance, cost and effects data. Relevant environmental conditions for representative vessel-types will be used to validate and characterize products. The ultimate
goal is to facilitate coatings decisions for everyone. For further information e-mail Michael Champ at ATRP Corp. - |
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Costs Analysis of TBT vs. Tin-free alternative A vital source of information for all shippers is the report published by Princeton Economic Research, Inc. and Parametrix, Inc. - Cost
Analysis of TBT Self-Polishing Copolymer Paints and Tin-free Alternatives for Use on Deep-Sea Vessels written by N. Damodaran, J. Toll, M. Pendleton, C. Mulligan, D. DeForest, M. Kluck & J. Felmy, November 1998. To
get a copy of this and other vital information on TBT and alternatives see |
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CQD Journal for the Maritime Environment Industry is published by E.M. Miller Associates, Inc., Florham Park, NJ. www.CQDJournal.com All rights reserved. Copyright 1999. |
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This page last updated by Miller Associates: Thursday, June 05, 2003 |
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