19th International Congress on Marine Corrosion and Fouling

Regulatory Issues Associated with the Development and Use of Biocide-(DCOIT)- Containing Rubber

Thomas S. Ramotowski

NUWC Division Newport, Newport, RI, 02841, USA

June 26, 2018 Melbourne, Florida, USA

UNCLASSIFIED – Distribution Statement A – Approved for Public Release; Distribution is Unlimited Topics

• Background > DCOIT Biocide in Rubber • FIFRA > Legal Definitions and Requirements • The Regulatory Approval Process > Modify Existing Label or Register a “Treated Article” > DCOIT “Blooming” from the Rubber > ASTM D-6903 • Final Approval from US-EPA • Summary and Acknowledgements Protecting Elastomers from Marine Biofouling: Problems & Opportunities

The options: paint/coat or include a biocide

Paints/coatings typically do not work well on rubbery substrates.

Differences in modulus lead to cracking and peeling.

There are adhesion and abrasion issues.

Biocide-based paints and coatings only work for short periods of time due to limited biocide storage capacity (thickness based reservoir effect). DCOIT: An Environmentally Friendly Marine Biocide

Starting in 2013, NUWC Newport had been working to determine whether DCOIT, a heavy metal free, isothiazolinone-based biocide that breaks down rapidly once released into the marine environment, could be used to protect critical elastomer-based parts from marine biofouling.

Rohm & Haas (now part of Dow Chemical) was awarded a Green Chemistry Prize by the US-EPA in 1996 for the development of DCOIT.

Half-life in seawater/sediment: DCOIT = one hour/one day TBTO = nine days/six-nine months

Bioaccumulation factors: DCOIT = essentially none TBTO = 10,000x 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Max. Allowable Env. Conc. DCOIT = 0.63 ppb a.k.a. Vinyzene-Max, Kathon-287T and TBTO = 0.002 ppb DCOIT, a heavy-metal free marine biocide made by the Dow Chemical Company4 Static Testing of Rubber Panels Containing DCOIT

1% 6% 3% 0%

Neoprene test panels after 14 months exposure, FIT, Melbourne, Florida 6%

EPDM Rubber test panel after 44 months of exposure Narragansett Bay, Rhode Island

EPDM Rubber test panels after 24 months exposure, FIT, Melbourne, Florida Conathane EN-7 Polyurethane Test Panels Containing DCOIT

12 months, TMSI, Singapore 14 months, FIT, Melbourne, Florida, USA

0% 3% 6% 0% 3% 6%

12 months, Pearl Harbor, Hawaii, USA

0% 3% 6% VM Release Rate versus Time Plot

• Smaller (slower) D shows more severe changes in VM release rate to the water – a “D” of that magnitude cannot replenish the rubber/water interface fast enough to balance VM loss to the water. • Dow suggests a level of 3.0 μg/cm2-day is the minimum release rate needed to protect a surface from biofouling. That value could be used to estimate useful service life for a VM Red curve = fixed D; blue curve = 4x fixed D protected article. Rubber thickness = 0.25”.

7 FIFRA

Even though the intended targets of marine biocides are not insects, fungi or rodents, such materials are regulated in the USA under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) FIFRA Background

● FIFRA dates back to the Federal Insecticide Act of 1910.

● Originally enacted in 1947, codified under 7 USC chapter 6 § 136 et cet.

● Originally enforced by the Department of Agiculture, but in 1972 the enforcing agency was changed to the Environmental Protection Agency (EPA) with a change in emphasis to protect the environment and public health.

● Under FIFRA, the US-EPA has the authority to regulate the marketing of economic poisons in the USA. It can enter into cooperative agreements with States to cooperate in the enforcement of FIFRA. FIFRA: Legal Requirements

● FIFRA: Established the registration requirement for all pesticides only after a period of data collection to determine: > effectiveness (for intended use) > appropriate dosage > hazards ● Pesticide label holds users responsible for proper usage. If restrictions are ignored, users are liable for any regulatory consequences. FIFRA: What Is a “Pest”?

● FIFRA: A “pest” is any insect, rodent, nematode, fungus, weed or any other form of terrestrial or aquatic plant or animal life or virus, bacterium or other micro-organism. > Does not apply to the last three examples when present in/on living people or animals. FIFRA: What Is a “Pesticide”?

● FIFRA: A “pesticide” is any substance or mixture of substances intended for preventing, destroying, expelling or mitigating any pest. > To obtain regulatory approval, applicant needs to prove the active ingredient(s) will not cause unreasonable adverse effects on human health and/or the environment. FIFRA: The Difference between R&D and Production

● FIFRA: No individual may sell, use, or distribute a pesticide not registered with the US-EPA. ● One major exception: Experimental Use/Testing. ● If the pesticide is not registered, then it must be provided gratis for experimental use/testing. ● Once the use changes from R&D to production, the pesticide may be sold, but formal registration is required. The EPA Options

By late 2014, testing had shown that DCOIT could protect rubbery substrates from marine biofouling for significant lengths of time. The Navy use switched from R&D to production. That meant we would have to get regulatory approval from the US-EPA. EPA Options ● Modify an existing label (there were several because of Rohm & Haas/Dow merger – e.g., “Vinyzene Max”; “Kathon 287T”; “Sea-Nine”) > No existing label had > 0.2% DCOIT content; we needed up to 6% > Easiest/fastest way to get approved because existing data from Dow could be used. > Requires cooperation/help from Dow Chemical ● View the DCOIT-containing rubber as a “treated article” > Onus is on the Navy to provide required data > Takes more time/could require additional testing The EPA’s Concern About DCOIT “Blooming” from the Rubber

Both US-EPA and Dow Chemical were concerned about reports of the DCOIT biocide “blooming” from the rubber substrate the Navy was using. DCOIT “Blooming” (Continued)

Sampling rubber boots for DCOIT FT-IR spectrum of DCOIT biocide ● FT-IR sampling of several old, large panels indicated the white material on their surfaces was DCOIT biocide.

● Extensive sampling of Navy sensor rubber boots containing 6% DCOIT by weight revealed no detectable trace of DCOIT biocide on their surfaces.

● Large panels were the first ones ever made with DCOIT – 12% by weight. > exceeded solubility limit, hence blooming behavior > 6% by weight or less of DCOIT is below solubility limit = no bloom Rotating Cylinder Release Rate Data (ASTM D-6903) for Biocides in Rubber

ASTM D-6903 method (developed for AF paints) had to be modified for our rubber samples. Thin sheets of treated rubber were cut and glued to the rotating cylinder. US-EPA Registration Approval

On June 26, 2017, the US-EPA approved the Dow/Navy requested label change for Vinyzene Max. US-EPA Registration Approval (Continued)

This covers Federal requirements…now we need to satisfy State requirements! Summary and Acknowledgements

● Marine biocides are regulated under FIFRA – the Federal Insecticide, Fungicide and Rodenticide Act – by the US-EPA > It does not matter if – - the federal Government paid for the R&D - the R&D was carried out by U.S. Government scientists and engineers at a U.S. Government facility for a U.S. Government need. ● An appropriate label must be developed for the biocide > an existing label can be changed/updated > approval as a “treated article” > needed once biocide transitions from R&D to production ● Need to show effectiveness, dosage, and document hazards ● US Navy now has proper US-EPA registration for use of DCOIT biocide in polymers up to 6% by weight; working on State specific approvals.

Special thanks to: Elizabeth Haslbeck (NSWC Carderock) David Laganella and Joanne Ryder (Dow Chemical Co.) David Mercier, esquire (NUWC-NPT) Questions?