Antifouling biocides have been used for several hundred years to protect underwater parts of ships and offshore installations against infestations of algae, fungi, mussels, and other organisms. They help to preserve the structures and they do decrease fuel consumption on ships. They also help to keep pleasure boats operational that are only operated few days a month.
Antifouling biocides are toxicants meant to adversely affect target organisms. However, they do leach into the surrounding water and also affect non-target organisms.
In general, both heavy metal-based (Copper, Chromium, Zinc) systems and organic (carbon-based) systems (TBT, Irgarol, SeaNine) are used. Opposite to the heavy metal-based systems that will stay in the environment forever, organic biocides can over time be degraded and thus rendered harmless.
While in ancient times copper plating was used, in the 20th-century organic biocides such as TBT became popular. TBT was banned as it had detrimental (estrogenic) effects on mollusks at very low concentrations. TBT was succeeded by Irgarol and SeaNine-based systems. However, with the Biocidal Product Directive of the EU also antifoulings were regulated in a new framework. Consequently, Irgarol was disputed and is no longer legally on the market.
Currently, there are Copper and Zinc-based systems, Zinc and Copper Pyrithione and a series of other new organic compounds (Dichlofluanid, Tolylfluanid, Tralopyril, and Medetomidine) on the market.
This project focused on the presence, stability, and leaching of these “new” com-pounds, while omitting Copper or Zinc-based systems.