Emissions from copper-based paints have become a growing problem over that last decade. Copper is the most common biocide in industrial paints, specifically used in the marine industry. A high content of copper is more effective in the prevention of growth of fouling organisms such as mussels, clams and barnacles to attach to boats, and other aquatic vessels. Unfortunately, copper-based paints have been found to be toxic and harmful for water quality, marine life, aquatic plants and underwater ecosystems. Heavy metals emitted off the paint do not degrade within the ocean, therefore runoff from shipyards and harbors contaminates waterways.
As much as 40% of copper inputs into the Baltic Sea come from traditional antifouling paints on ships, vessels and leisure boats. This statistic can be reduced and prevented by industries switching the more sustainably friendly biocide free silicone-based paint.
“As the Baltic Sea is an inland sea, it takes 25-30 years for the water to be exchanged. This means that the heavy metal remains for a very long time. It is therefore important to be aware of the substances we release.” - Maria Lagerström, researcher in the unit of Maritime Environmental Studies at the Chalmers University of Technology.
Silicone-based paints are a great alternative for the aquatic shipping sector. Produced from silicon oxide extracted from sand, this paint was found to be less harmful than traditional antifouling paint. The usage of silicone-based paints are high in the tire manufacturing industry but has increased interest in the shipping sector. Back in 2009, the usage was 1% but grew to 10% by 2014. It may not seem like a huge increase but for industries that prefer to use the original products, this is a noteworthy step forward.
It would be smart for the shipping industry to jump on board with the production of silicone-based vessels. The use would increase the efficiency of the vessels, taking form as less fuel consumption, faster speed, higher waterproof surfaces and increased resistance of harsh weather conditions. Not to mention silicone-based paints do not release damaging chemicals into the ocean.
In multiple studies conducted by researchers at Chalmers University of Technology, the University of Gothenburg and the Swedish Environmental Institute IVL, it was found that traditional antifouling copper paints continuously leach heavy metals, chemicals and toxins into the water, while the alternative silicone paint prevents fouling just by it’s slippery smooth textured surface.
One specific study produced in the scientific paper’s collection of ecotoxicological studies, showed that some silicone-based paints contain a high fluorine content, or PFAS, meaning that the substances are resistant to biodegradation in the environment due to strong chains linked of carbon and fluorine atoms. PFAS are typically found in the aerospace, automotive, electronic and construction industries. Fortunately the silicone-based paint tested in the study was fluorine free.
The main takeaways from these studies is that the shipping industry needs to make quicker adjustments to the products they use – taking into account the current and future state of the ocean, its inhabitants and the ecosystem's effect on the rest of mankind.