Use of Copper-Based Antifouling Paint – A U.S. Regulatory Update

By Neal Blossom, Frank Szafranski, AkzoNobel Yacht, Aggie Lotz

The efficacy of the active biocide ingredients used in antifouling bottom .paint to contain and impede the growth of biofouling on boat hulls is of global economic concern, given that costs associated with mitigating the damage caused by invasive species are escalating, especially in coastal waters where fouling nutrients are concentrated. The efficacy of an antifouling coating depends on site-specific fouling pressure where the vessel operates, which biocide(s) are used in the formulation, and the biocidal release rate from the painted surface to the ambient water.

Coatings formulated with cuprous oxide have been around for at least 100 years, and are applied to an estimated 90% of the world’s vessels whose hulls are protected with biofouling control coatings. Historically, copper has been repeatedly challenged and subsequently reviewed for its risk and effectiveness, and is arguably the most researched substance for toxicity in the marine environment.