Frequently Asked Questions
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Q13.
Is copper a heavy metal?
What are the various types of copper and copper containing systems in antifoulings?
Is there any existing legislation regarding copper in antifoulings?
Is there any planned legislation regarding copper in antifoulings?
What level of copper (%) is used in today’s TBT-containing coatings?
What level of copper (%) is used in today’s TBT-free antifoulings?
If copper and copper containing ingredients were banned from today’s TBT-free antifoulings what would be the effect on the coatings industry?
Can there be a totally copper-free antifouling?
If it’s possible to develop a totally copper-free antifouling, are there such coatings available, or being developed?
What would be the level of in-service performance from a copper-free antifouling?
Is IMO looking to ban the use of copper in antifoulings, both in the short-term and long-term?
What are organic co-biocides and what role does copper play in them?
Q1. Is there a problem with copper in antifoulings?
A. Antifouling paints are formulated to release copper at a controlled rate. This rate will ensure that organisms are inhibited from attaching to the protected surface, but that the copper will be deactivated as it moves away from that surface. Used in this way copper in antifoulings does not result in environmental toxicity.
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Q2. Is copper a heavy metal?
A. Yes - any metal element with density >5 is defined as a “heavy metal”. Thus about 60 elements are defined as “heavy metals”. These elements include not only metals such as Arsenic, but also Iron and Gold.
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Q3. What are the various types of copper and copper containing systems in antifoulings?
A. Copper can be incorporated as active ingredient in antifouling paints as copper powder, cuprous oxide or cuprous thiocyanate. These different forms are used to give the paint different properties for use on different substrates or in different circumstances. From the antifouling performance point of view, and from the effect on the environment the difference in the forms is not important.
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Q4. Is there any existing legislation regarding copper in antifoulings?
A. There are some locations, notably in Holland and Sweden where special local environmental conditions, unique to those areas, have caused restrictions to be placed on the use of copper in antifoulings.
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Q5. Is there any planned legislation regarding copper in antifoulings?
A. No international or national body has announced any further plans to legislate in relation to copper in antifoulings.
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Q6. What level of copper (%) is used in today’s TBT-containing coatings?
A. In the range 20-50 %.
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Q7. What level of copper (%) is used in today’s TBT-free antifoulings?
A. In the range 20-50 %.
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Q8. If copper and copper containing ingredients were banned from today’s TBT-free antifoulings what would be the effect on the coatings industry?
A. All known efficacious and economic antifoulings acceptable for use in the environment for general use have copper as an active ingredient. Without copper the coatings industry would not be able to supply the marine and pleasure boat industry with products necessary to maintain clean hulls. This would result in higher fuel costs, and ultimately hazard due to loss of manoeuvrability. It would also result in the hazard of transfer of potentially invasive species from one habitat to another.
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Q9. Can there be a totally copper-free antifouling?
A. Yes
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Q10. If it’s possible to develop a totally copper-free antifouling, are there such coatings available, or being developed?
A. Yes - the most common are termed “foul release” coatings. These do not stop organisms from settling on their surface, but release them relatively easily.
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Q11. What would be the level of in-service performance from a copper-free antifouling?
A. “Foul release” coatings are effective, but only on vessels that move fast through the water, and do not stand still for long. This is generally estimated to be about 10% of the world’s tonnage and a much smaller fraction of the number of vessels in the world.
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Q12. Is IMO looking to ban the use of copper in antifoulings, both in the short-term and long-term?
A. IMO has just introduced a treaty to ban TBT, which it was generally agreed should be banned 7 years ago. Incorporated within this treaty is a mechanism for IMO to consider control of use of other substances in antifoulings, in a less protracted manner. To date there is no proposal to control any substance other than TBT.
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Q13. What are organic co-biocides and what role does copper play in them?
A. The effectiveness of an antifouling, in particular against soft fouling organisms can be greatly enhanced by the use of co- biocides. These permit reductions in the copper content in the coating as well as improved performance.
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