Biocides in antifouling paint formulations currently registered for use

Abstract

Antifouling paints incorporate biocides in their composition seeking to avoid or minimize the settlement and growing of undesirable fouling organisms. Therefore, biocides are released into the aquatic environments also affecting several non-target organisms and, thus, compromising ecosystems. Despite global efforts to investigate the environment occurrence and toxicity of biocides currently used in antifouling paints, the speci c active ingredients that have been used in commercial products are poorly known. Thus, the present study assessed the frequencies of occurrence and relative concentrations of biocides in antifouling paint formulations registered for marketing worldwide. The main data were obtained from databases of governmental agencies, business associations and safety data sheets from paint manufacturers around the world. Results pointed out for 25 active ingredients currently used as biocides, where up to six biocides have been simultaneously used in the examined formulations. Cuprous oxide, copper pyrithione, zinc pyrithione, zineb, DCOIT and cuprous thiocyanate were the most frequently ones, with mean relative concentrations of 35.9±12.8 %, 2.9±1.6 %, 4.0±5.3 %, 5.4±2.0 %, 1.9±1.9 % and 18.1±8.0 % (w/w) of respective biocide present in the antifouling paint formulations. Surprisingly, antifouling paints containing TBT as active ingredient are still being registered for commercialization nowadays. These results can be applied as a proxy of biocides that are possibly being used by antifouling systems and, consequently, released into the aquatic environment, which can help to prioritize the active ingredients that should be addressed in future studies.

Sustainability Evaluation of AquaSun Antifouling Coating Production

“…A recent comprehensive study on 1013 registered AF paints produced by 64 different manufacturers found that Cu 2 O with mean relative concentrations of 35.9% ± 12.8%, copper pyrithione, zinc pyrithione, zineb (zinc ethylenebis (dithiocarbamate)), DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) and cuprous thiocyanate at 18.1% ± 8.0% (w/w) are the most frequently biocide species used by marine coating manufacturers [23].…”

“…Furthermore, the aforementioned study [23] of Fillmann and co-workers surprisingly unveiled that regardless of the worldwide ban of tributyltin in 2008, TBT was still registered for use in 5 out of 1013 commercial paint formulations either as tributyltin oxide or as tributyltin methacrylate.…”

Characterization and Release Mechanisms of Aerogel-Encapsulated Biocide Crystals for Low-Loading and High-Utilization Antifouling Coatings

“…All samples were sonicated (Bandelin Sonorex, Buch & Holm) for 5 min before measurement. A size range interval was applied to the particle size distributions (after measurement) for obtaining the volume-weighted mean diameter D [4,3]…”

“…To obtain a broad-spectrum impact on biofouling species, cuprous oxide (Cu 2 O) is typically used in a combination with one or more approved organic booster biocides, such as zinc ethylene bisdithiocarbamate (Zineb), 4,5-dichloro-2-octyl-2 H -isothiazol-3-one (DCOIT), tralopyril, copper pyrithione (CuPT), zinc pyrithione (ZnPT), dichlofluanid, tolylfluanid, and/or medetomidine. 4 However, a major problem is the nonoptimal release rate control of the organic biocides. To obtain sufficient surface protection, a high biocide loading of the coating is required.…”

Rheological and shipbuilding steel adhesion properties of antifouling AquaSun coating

“…comprising marine biofouling, antifouling (AF) paints are applied to commercial and recreational vessels at 100,000 t/a yearly rate. 1,2 Over 3-5 years the AF coating applied to the vessel's hull releases all Cu + and booster biocides into seawater significantly impacting marine life including coastal macrofouling communities. 3,4 The leached biocides, indeed, are poorly biodegradable and therefore remain in marine sediments for a long time, harming the aquatic environment.…”