Many long-term readers of Marine Business News will know we pride ourselves on a number of things, one of them is sharing news and information with the recreational marine industry to help improve knowledge and understanding.
To support that, we reach out to subject matter experts wherever possible.
We’re also proud of the breadth and diversity of our readership. One such reader is the respected Tom Bischoff, Director of Safety, Quality Assurance & Global Regulatory Affairs for American Chemet Corporation in the USA.
Tom recently sent us a note in response to a story we published a few weeks ago by Hans Buitelaar, titled “Prevent fouling without poison.”
Tom had some thoughts on the article and was kind enough to share them with us. Here’s what he had to say.
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I am writing today in response to the claims that copper-based antifouling coating are harmful. As I will provide evidence for in the paragraphs to follow, copper-based antifouling coatings are safe for use in all registered applications.
Antifouling coatings are engineered to target fouling organisms at the hull surface, with copper-based options remaining the most effective, environmentally friendly, and widely approved. The Biocidal Products Regulation defines biocides as agents for controlling harmful organisms, not mere “poisons,” and only products proven safe and effective are authorized for use. Copper is a naturally occurring ubiquitous micronutrient and necessary to nearly all plants and animals. Copper from copper-based coatings becomes non-toxic and non-bioavailable shortly after leaching, and these coatings have been approved by regulatory agencies in their area of use. References to California and Washington State in the original article are incomplete, as regulatory agencies now evaluate overall ecological health and have found no feasible, safer alternatives to copper-based coatings, while raising concerns about data limitations and composition of alternatives. The article’s recommendation to eliminate all harmful components overlooks the primary goal of antifouling: to prevent fouling and the spread of invasive species.
Below are details that further explain my message above.
I wanted to point out some facts regarding antifouling coatings. Antifouling coatings, whether biocidal or biocide-free, are specifically designed to prevent fouling near the hull surface, within the microlayer of the surface, targeting specific fouling organisms. Studies have shown that the copper that leaches from copper-based coatings binds to other organic ligands almost immediately when away from the hull surface, rendering it non-bioavailable and non-toxic. Specific to copper-based biocidal coatings, each one has been approved by regulatory agencies in their area of use, and whenever a complete scientific risk assessment has been conducted, the use of copper has been approved.
The Biocidal Products Regulation defines a biocidal product as ” any substance or mixture, in the form in which it is supplied to the user, consisting of, containing or generating one or more active substances, with the intention of destroying, deterring, rendering harmless, preventing the action of, or otherwise exerting a controlling effect on, any harmful organism by any means other than mere physical or mechanical action”. To infer that the term biocide is synonymous with “poison” is not correct. Biocidal products are regulated and only those that demonstrate efficacy AND pass a rigorous environmental and health risk assessment are placed onto the market. Cuprous Oxide is one of the few active ingredients that has been approved for use.
The references to Washington State and California are incomplete.
California: While there are studies that show elevated concentrations of copper in California marinas, there are also studies that show there is nearly no toxicity, due to the mechanisms described above. In discussions with the Regional Water Boards, they are starting to evaluate the marinas from an ecological health standpoint as opposed to strictly looking at copper concentration, recognizing that elevated copper concentrations do not necessarily equate to toxicity.
Washington: In the 2024 report, not only did the report find that there were no “safer and effective alternatives to copper-based antifouling paints are feasible, reasonable, and readily available” but also highlights several concerns they found with non-copper biocides and non-biocidal products. Concerns regarded lacking sufficient data about the composition and possible releases from these products (PFAS, etc.). To not include this information in the article misrepresents the findings from the report. Additionally, many of the non-biocidal alternatives are only available for commercial vessels, not for recreational boating.
The article states the best way to provide fouling protection is to include no harmful components. However, this opinion is shortsighted as it doesn’t incorporate the main goals of antifouling solutions, which is to prevent fouling and transfer of invasive species. Copper-based antifouling solutions have proven to be the most effective at preventing fouling in a wide range of environments and use patterns, as evidenced by their continued dominance of the market. While alternative antifouling systems are on the market, there are drawbacks to each one of them including durability, difficulty or cost of application, and concerns with the chemical makeup of the coating (silicon oils, PFAS, microplastics, etc.).
The best way to provide fouling protection is to use an antifouling system that is efficacious and passes a health and environmental risk assessment.
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We thank Tom for reading Marine Business News and his time to respond. For those of you interested, and I know there are quite a few, read his full report visit the Marine Business News Resources page or click on the banner below to go directly to the report.
For more information about American Chemet Corporation, visit their website HERE
Click here to read the report
Tom Bischoff, Director of Safety, Quality Assurance & Global Regulatory Affairs for American Chemet Corporation
Tom Bischoff, P.E. is the Director of Quality Assurance, Safety, and Global Regulatory Affairs at American Chemet Corporation and is a registered Professional Chemical Engineer. In his role at American Chemet, Tom manages the manufacturing site’s safety, environmental, sustainability, and quality programs as well as the regulatory compliance team.
About American Chemet Corporation
American Chemet Corporation was founded in 1946 and is a privately owned company located in East Helena, Montana. Chemet is a leading manufacturer of copper based chemicals and powders. Its current product line includes cuprous oxide, cupric oxide, basic copper carbonate, and copper powder.
