Emissions from copper-based antifouling paints are a well-known environmental problem. As much as 40 percent of copper inputs to the Baltic Sea come from antifouling paints on ships and leisure boats. According to a new study from Chalmers University of Technology, Sweden, this is completely unnecessary. When the researchers compared copper-based antifouling paint with biocide-free silicone-based paint, they found that the environmentally friendly alternative was best at keeping the fouling at bay. "This means that we now have a great opportunity to drastically reduce the release of the heavy metal into our sensitive sea. This is the first independent scientific study to show that silicone paint is more effective than copper-based paint in the Baltic Sea region," says Maria Lagerström, researcher in marine environmental science at Chalmers.
Environmentally friendly paints are rarely used
Effective even over a longer period of time
- The scientific paper 'Are silicone foul-release coatings a viable and environmentally sustainable alternative to biocidal antifouling coatings in the Baltic Sea region?' has been published in the journal Marine Pollution Bulletin.
- The study is led by Maria Lagerström, Anna-Lisa Wrange, Dinis Reis Oliveira, Lena Granhag, Ann I. Larsson and Erik Ytreberg. The researchers are based at Chalmers University of Technology, the University of Gothenburg and the Swedish Environmental Institute IVL.
- Traditional antifouling paints inhibit fouling by continuously leaching copper and/or other toxic substances that are poisonous to marine organisms. For silicone paints, it is instead its smooth surface properties that make it difficult for fouling to stick to the hull. The paints are also self-cleaning, which means that any fouling that has managed to stick is removed as the hull moves through the water.
- Silicone paint is based on the substance silicone, which is produced using silicone oxide extracted from sand. The scientific paper's collection of ecotoxicological studies shows that silicone paints are significantly less harmful to the environment than copper paints. But some silicone paints contain highly fluorinated substances, known as PFAS, which are very resistant to biodegradation in the environment. However, the silicone paint tested in the study was fluorine-free.
- The research was funded primarily by the Swedish Transport Administration, within the framework of the Lighthouse Swedish Maritime Competence Centre and the Sustainable Shipping project.