American Coatings Association

California Assemblywoman Toni Atkins (D-78) on Feb. 15, introduced AB 425, legislation related to copper-based antifouling coatings. The use of copper in antifouling paints has been targeted by many groups as contributing to adverse water conditions in certain California marinas.

The bill’s language proposes that no later than Feb. 1, 2014, California’s Department of Pesticide Regulation (DPR) shall evaluate whether to register copper-based antifouling paint, and make recommendations for appropriate mitigation measures that may be implemented to address the protections of aquatic environments from the effects of exposure to that paint if it is registered as a pesticide. As part of that evaluation, the department shall determine a leach rate for copper-based antifouling paint used on recreational vessels.

Existing California law requires every manufacturer of, importer of, or dealer in any pesticide, except a person that sells any pesticide that has been registered by the manufacturer or wholesaler, to obtain a certificate of registration from DPR before the pesticide is offered for sale. California SB 623, introduced in a prior legislative session and deferred in June 2012, proposed to ban the use of copper in antifouling paint for use on pleasure craft.

ACA and its Antifouling Workgroup (AFWG), working with ACA’s California Paint Council successfully advocated against SB 623. The proposed measure mandated the outright ban of these coatings for recreational vessels after 2019, if the low-leach rate coatings did not appear to be reducing copper in marinas using Total Maximum Daily Loads (TMDL) for copper that must be met by 2022. It would also require manufacturers to use the least toxic alternative when replacing the copper in marine antifouling paint, even though such alternatives are not defined, and have not been proven as effective or as safe as the current copper-containing coatings. ACA’s efforts were successful in staving off a ban and deferring the legislation until now.

The legislation’s sponsor dropped the bill after ACA submitted a letter underscoring new evidence which could change how copper impaired waters are defined. Specifically, the letter referenced EPA’s review of the Biotic Ligand Model (BLM) for marine waters and DPR’s reevaluation of copper as an approved biocide in antifouling paints. ACA believes that EPA’s BLM may well show that the copper threat to waters has been overstated. The BLM is a much more recent method of calculating metal toxicity using 10 water chemistry parameters.

ACA and its AFWG contend that antifouling paints release copper at a restricted rate and that excessive underwater hull cleaning practices contribute a high percentage of the release of copper into marinas. Further, modern antifouling copper-based coatings are designed to be effective without frequent cleaning and cleaning schedules should follow manufacturers’ recommendations.

In March 2011, members of the AFWG, and other affected registrants, received a data request from the California Department of Pesticides Regulation (DPR) titled, “Clarification of Leach Rate Determination, Notice of Additional Data Requirements and Meeting Regarding the Reevaluation of Copper Based Anti-fouling Paint Pesticides.” The data requirement called for, among other things, a protocol to accurately determine the impact underwater hull cleaning has on overall copper release from antifouling paint.

ACA’s AFWG developed and submitted, in June 2012, the “In Water Hull Cleaning and Passive Leaching Study Protocol” to DPR and coordinated the funding of the study amongst copper suppliers and copper-based antifouling registrants in California. The purpose of this study is to ascertain the effect of underwater hull cleaning methods on various types of anti-fouling paints and to quantify the amount of copper that enters the water column from passive leaching. The study will test the most contemporary anti-fouling paints used in Shelter Island Yacht basin. This includes ablative coatings, which were not properly addressed in prior studies. ACA contracted with the Space and Naval Warfare Systems Command, a subgroup of the U.S. Navy, and Scripps Institution of Oceanography and appointed a study overseer to visit the site and ensure adherence to the protocol. The study commenced on Aug. 13, 2012, and a final report of the results is expected in the spring of 2013. It will be published in the Journal of Biofouling and DPR will use the results of the study to inform the development of mitigation strategies.

The results of the study and the mitigation strategies developed by DPR will not just determine the course for anti-fouling coatings in California, but will have global implications.

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