Antifouling - Copper not so bad after all?

by IBI News/Bob Greenwood on 19 Nov 2006 New scientific research has cast doubt on the widely-held belief that copper-based antifoulings are a serious risk to marine organisms. The findings of new tests carried out by UK-government agency CEFAS (Centre for Environment, Fisheries and Aquaculture) on behalf of CEAP (the Copper Antifouling Environmental Programme which is supported by copper producers) were released on November 15 at METS.
According to CEFAS science director Dr Mike Waldock, who presented his group's findings, even though copper has been used as an effective means of keeping boat hulls clear of the marine growth that impairs performance, 'there's an enormous science base, but the fundamental issues haven't been addressed.'

Dr Waldock told IBI: 'Some regulations are loaded in the wrong direction. For example, California is minded to ban copper, but (the regulators) haven't got the risk assessment right.'

He added: 'In the past the measured total units of copper dissolved in water had been shown to be harmful to life, but a previously unknown ratio of copper gets bound up in complexing agents.' These agents render what turns out to be about 80 per cent of the total amount of copper present virtually harmless, he explained. It's only the remaining 20 per cent of labile (unstable copper) that is injurious.
'Previously tests were done in clean sea water, when all the copper types were measured. It was like looking at apples and oranges and coming up with a risk assessment,' said Dr Waldock.

Field tests were carried out under varying conditions by CEFA at four locations around the coast of the UK, including the Hamble river, which with 5,000 boats moored has one of the highest boating densities in the world. They were corroborated by parallel tests in Finland that produced near-identical results.
CEAP has since presented the CEFAS findings to a French inquiry body which is expected to produce a report perhaps late next year that could influence the EC Commission in its framing of a new Biocidal Products Directive (EU).

Duncan Norman concluded: 'We wouldn't give copper an entirely clean bill of health, but its far less harmful than was previously thought. The message is: 'use sensibly'.'