There are various systems without biocides available that can serve as alternatives for antifouling paints on pleasure boats to prevent the growth of algae and shellfish on the hull. These systems include hard ‘foul release coatings’, other hard coatings, films with flexible plastic fibres that act as spines and systems based on ultra sound. RIVM has drawn up an overview of current and future possibilities for preventing the fouling of the surfaces of pleasure boats under the waterline.
A number of systems are expected to have considerably less impact on the environment than those now in use. Some promising antifouling systems are still in the research phase, such as systems that use ultraviolet light or natural, readily degradable biocides that stay in the coating.
The Dutch government is committed to encouraging boat owners to switch to the use of antifouling systems that are safer and have less environmental impact. The overview by RIVM contributes to that. RIVM also puts forward suggestions for promoting the use of these cleaner antifouling systems.
Copper and zinc
Existing antifouling paints are often ‘self-polishing paints’ which contain copper as a biocide and zinc as a co-formulant: the paints wear during sailing, gradually releasing these substances. As a result, heavy metals end up in the water and impact the environment.
RIVM recommends examining the legal possibilities for reducing the use of antifouling systems that contain biocides and self-polishing paints. It should be clearer for consumers how well or badly existing possibilities score in the field of antifouling performance, safety and environmental impact. It is also desirable to develop a standardised test that can be used to determine the efficacy of antifouling systems under different conditions.