The most effective anti-fouling environmentally friendly paint on boats

Emissions from copper-based anti-rust paint are a well-known environmental problem. Up to 40% of the copper input to the Baltic Sea comes from antifouling paint on ships and recreational boats.

This is completely unnecessary, according to a new study from Chalmers University of Technology, Sweden. When the researchers compared copper-based antifouling paint with germ-free silicone-based paint, they found that the eco-friendly alternative was the best at preventing fouling.

“This means we now have a great opportunity to dramatically reduce the release heavy metal into our sensitive waters. “This is the first independent scientific study to show that silicone paints are more effective than copper-based paints in the Baltic Sea,” said Maria Lagerström, marine environmental science researcher at Chalmers.

Together with colleagues at the University of Gothenburg, the Swedish Environment Institute IVL and Chalmers, Maria Lagerström investigated whether biocide-free silicone paints on the hulls of ships and recreational boats were a viable alternative to copper bottom paint to prevent staining or not.

The study was carried out over a year at three sites in the Baltic Sea and Skagerrak and the results have been published in the journal Science. Sea pollution bulletin.

Environmentally friendly paint is rarely used

The use of copper in antifouling paint is a known and widespread environmental problem for aquatic plant and creatures of the Baltic Sea. Heavy metals do not degrade in the environment and as a result, water, sediment and soil in marinas, ports and shipyards are often contaminated and exceed the environmental guideline values ​​for copper. An earlier study from Chalmers shows that antifouling paints account for 40% of the total Baltic Sea copper input.

“Since the Baltic Sea is an inland sea, it takes 25–30 years to exchange water. This means that heavy metals persist for a very long time. Therefore, it is important to be aware of these substances. that we emit,” said Maria Lagerström.

Despite the negative impact of heavy metals on Marine environment, the antifouling paint market for ships and recreational boats is completely dominated by copper-based paints. The market share of silicone coatings for the shipping industry was 1% in 2009 and increased to 10% in 2014.

For recreational boating, the proportion of boats painted with silicone paint is estimated to be significantly lower. And while there are more eco-friendly options on the market, change seems hard to come by.

“Both the shipbuilding industry and the recreational boating sector have one thing in common: they are very traditional. People like to use products they are used to and they are also skeptical about whether alternatives are available. non-toxic really effective or not,” he said. Maria Lagerstrom.

Effective even for a longer period of time

Although the study on different antifouling paints was completed after twelve months, the results persisted over time.

“We actually left our test panels at one of the test sites. These panels have now been under the surface for more than two years. We can see that the silicone coating is still performing well and more importantly works better than copper layer paint“, said Maria Lagerström.