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August 27, 2004

Public Information and Records Integrity Branch (PIRIB) (7502C)

Office of Pesticide Programs (OPP)

Environmental Protection Agency

1200 Pennsylvania Ave., NW.

Washington, DC 20460--0001

Tony Kish

Antimicrobials Division

Office of Pesticide Programs

Environmental Protection Agency, Mail Code 7510C

1200 Pennsylvania Avenue, NW.

Washington, DC 20460-0001

Dear PIRIB and Mr. Kish:

**Subject: Preliminary Risk Assessment for Zinc Pyrithione (Docket No.
OPP--2004--0147)**

This letter focuses on the marine antifouling paint use of zinc
pyrithione. Due to water quality concerns, use of the most common marine
antifouling paint biocides---copper oxides---may be restricted in
certain geographic areas. This letter requests that U.S. EPA ensure that
the reregistration process anticipates and avoids water quality impacts
from zinc pyrithione that may result from the transition away from
copper-based marine antifouling paints.

The San Francisco Bay Regional Water Quality Control Board (Water Board)
is responsible for maintaining water quality in the San Francisco Bay
Area to protect beneficial uses of surface and ground waters. Numerous
scientific studies have demonstrated that use of some pesticides
registered in accordance with Federal Insecticide, Fungicide, and
Rodenticide Act requirements has adverse effects on aquatic species. As
a result of discharges of pesticides registered for use by the
U.S. Environmental Protection Agency (U.S. EPA), we, the Water Board,
have found many waters within our jurisdiction are not fully supporting
designated beneficial uses. Therefore, we placed these water bodies on a
list of impaired waters as required by Clean Water Act §303(d). The
Clean Water Act further requires us to prepare resource-intensive total
maximum daily loads (TMDLs) for these listed waters. We then must
mandate expensive programs to implement the TMDLs to restore the
beneficial uses of pesticide-impaired waters. Through this process, we
have recognized that it is far more effective and efficient to prevent
the impairment from occurring in the first place and that the U.S. EPA
has a central role to play in such efforts to minimize the potential for
registered pesticides to impair surface water quality.

Zinc pyrithione is very highly toxic to aquatic life. A versatile
biocide, zinc pyrithione is incorporated in a variety of solid and
liquid products like paints, sponges, sealants, and foam. U.S. EPA
recently approved zinc pyrithione for use in marine antifouling
coatings. Due to concerns about the environmental impacts of this toxic
biocide, the marine antifouling paint use is approved only until
June 30, 2005, pending further U.S. EPA review.

Our concern regarding zinc pyrithione relates to its marine antifouling
paint use. Previous marine antifouling paint biocides have impaired the
beneficial uses of the nation's surface waters. Historically, the
biocide tributyltin was commonly used in marine antifouling coatings.
Tributyltin is highly toxic to aquatic life. Its use on recreational
boats was phased out in the late 1980s, when U.S. EPA restricted use of
tributyltin-based antifoulants to ships longer than 25 meters.
Copper-based biocides---long used on recreational boats---became the
primary antifouling coating option for recreational boats.

Although copper biocides are less toxic to aquatic life than
tributyltin, copper is not environmentally benign. Copper is a pollutant
of concern in several California surface water bodies with ports and
marinas, including San Francisco Bay. The relationship of marine
antifouling paint copper use and the attainment of beneficial uses in
California surface waters has been investigated in studies of the
Shelter Island Yacht Basin in San Diego. In the process of developing a
TMDL for the Shelter Island Yacht Basin, the San Diego Regional Water
Quality Control Board (San Diego RWQCB) has explored the potential
importance of copper-based antifouling paint as a source of copper in
California surface waters. The San Diego RWQCB estimated that 98% of the
approximately 2,000 pounds of copper released into the Yacht Basin each
year comes from marine antifouling paints on the 2,400 boats berthed in
the marina.[^1]

In response to concerns raised in San Diego, the California Department
of Pesticide Regulation (DPR) and the State Water Resources Control
Board are working together to explore the relationship between marine
antifouling paints and copper levels in surface waters. To facilitate
exploration of this issue, the California Interagency Coordinating
Committee (IACC), an existing working group composed of 28 California
state agencies involved in implementing California\'s Nonpoint Source
Pollution Control Program, has created the Copper Antifouling Paint
Sub-Workgroup of its Marina and Recreational Boating Workgroup.[^2] The
purpose of the subgroup is to assess the degree and geographical
distribution of copper pollution caused by copper antifouling paints in
California's aquatic environments. One of the goals of the committee's
work is to facilitate the evaluation of control measures by DPR and
Regional Water Quality Control Boards.

**U.S. EPA Must Prevent Water Quality Impacts Resulting from Possible
Transition Away from Copper-Based Marine Antifouling Paints**

The TMDLs and the IACC Copper Antifouling Paint Sub-Workgroup activities
may lead to restrictions on use of copper-based marine antifouling
paints, forcing a transition to other methods of controlling fouling on
boat hulls. One of those other options could be zinc pyrithione---if
U.S. EPA approves it for use after June 30, 2005. The limited data in
the preliminary risk assessment and in recent literature[^3] suggest
that such a transition could be problematic for water quality.

We support U.S. EPA's plans to evaluate further the risks of the marine
antifouling paint use in the coming months. This evaluation is critical
to fulfilling our mutual responsibility to protect water quality. To
ensure that this evaluation is of the highest quality, we ask U.S. EPA
to do the following:

(1) Draw from the expertise of the California Copper Antifouling Paint
    Sub-Workgroup in designing the required studies and completing the
    scientific review of the risks of zinc pyrithione marine antifouling
    paint uses.[^4]

(2) In evaluating risks, consider scenarios where zinc
    pyrithione-containing marine antifouling paints have replaced
    copper-based marine antifouling paints.

Should the evaluation not be completed as part of this re-registration
process, we ask that U.S. EPA offer us, the scientific community, and
the interested public the opportunity to participate in the risk
evaluation, including the selection of appropriate measures to prevent
or mitigate risks from use of zinc pyrithione in marine antifouling
paints.

**U.S. EPA Offices Should Coordinate Efforts to Protect Water Quality**

We need U.S. EPA's assistance in carrying out our mutual responsibility
to protect water quality. Properly implemented, U.S. EPA's pesticide
registration process can ensure that Clean Water Act water quality
standards are maintained and that aquatic species, including endangered
and threatened species, are protected. In recent years, we have asked
the Office of Pesticide Programs to better coordinate with the Office of
Water to ensure Clean Water Act compliance. For the zinc pyrithione
re-registration process, we again request that the Office of Pesticide
Programs coordinate with the Office of Water to ensure that registered
uses of zinc pyrithione will not impair the nation's surface waters.

Thank you for this opportunity to offer our input regarding the
Preliminary Risk Assessment for the zinc pyrithione Reregistration
Eligibility Decision.

Sincerely,

/s/

Richard Looker

Copper Water Quality Attainment Strategy Coordinator

c\. Thomas Mumley, Ph.D. Diane Beaulaurier

Chief, Planning and TMDL Division Central Valley Regional Water Board

> Stephen Johnson, Assistant Administrator
>
> Office of Prevention, Pesticides and Toxic Substances (OPPTS)
>
> U.S. EPA Headquarters 7101M
>
> Ariel Rios Building
>
> 1200 Pennsylvania Avenue N.W.
>
> Washington, DC 20460
>
> Jim Jones, Director
>
> Office of Pesticide Programs
>
> U.S. EPA Headquarters 7501C
>
> Ariel Rios Building
>
> 1200 Pennsylvania Avenue N.W.
>
> Washington, DC 20460
>
> Arthur-Jean B. Williams, Branch Chief
>
> Environmental Field Branch
>
> Field and External Affairs Division
>
> U.S. EPA Headquarters 7506C
>
> Ariel Rios Building
>
> 1200 Pennsylvania Avenue N.W.
>
> Washington, DC 20460
>
> Debbie Edwards, Director
>
> Special Review and Reregistration Division
>
> U.S. EPA Headquarters 7508C
>
> Ariel Rios Building
>
> 1200 Pennsylvania Avenue N.W.
>
> Washington, DC 20460

Tina Levine, Acting Director

> Biological and Economic Analysis Division\
> U. S. EPA Headquarters 7503C
>
> Ariel Rios Building
>
> 1200 Pennsylvania Avenue N.W.
>
> Washington, DC 20460
>
> Steven Bradbury, Director
>
> Environmental Fate and Effects Division

## U.S. EPA Headquarters 7507C

> Ariel Rios Building
>
> 1200 Pennsylvania Avenue N.W.
>
> Washington, DC 20460

Claire Gesalman, Acting Branch Chief

Communication Services Branch

# Field and External Affairs Division

U.S. EPA Headquarters 7506C

> Ariel Rios Building
>
> 1200 Pennsylvania Avenue N.W.
>
> Washington, DC 20460
>
> Benjamin H. Grumbles, Acting Assistant Administrator
>
> Office of Water

# U.S. EPA Headquarters 4101M

> Ariel Rios Building
>
> 1200 Pennsylvania Avenue, N.W.
>
> Washington, DC 20460
>
> Geoffrey H Grubbs, Director
>
> Office of Science and Technology
>
> USEPA Headquarters 4301T
>
> Ariel Rios Building
>
> 1200 Pennsylvania Avenue, N. W.
>
> Washington, DC 20460
>
> Diane Regas, Director
>
> Office of Wetlands, Oceans, & Watersheds
>
> U.S. EPA Headquarters 4501T
>
> Ariel Rios Building
>
> 1200 Pennsylvania Avenue, N.W.
>
> Washington, DC 20460
>
> Wayne Nastri, Administrator,
>
> Region IX, U.S. EPA
>
> U.S. EPA Region IX, ORA-1
>
> 75 Hawthorne Street
>
> San Francisco, CA 94105
>
> Kathleen Goforth
>
> U.S. EPA Region IX, WTR-5
>
> 75 Hawthorne Street
>
> San Francisco, CA 94105
>
> Raymond Chavira
>
> U.S. EPA Region IX, CMD-5
>
> 75 Hawthorne Street
>
> San Francisco, CA 94105
>
> Glenda Dugan
>
> U.S. EPA Region IX, CMD-5
>
> 75 Hawthorne Street
>
> San Francisco, CA 94105
>
> Debra Denton
>
> U.S. EPA Region IX
>
> c/o State Water Resources Control Board
>
> 1001 I Street
>
> Sacramento, CA 95814
>
> Kathy Brunetti
>
> Environmental Monitoring Branch
>
> California Department of Pesticide Regulation
>
> P.O. Box 4015
>
> Sacramento, CA 95812-4015
>
> Nan Singhasemanon
>
> Environmental Monitoring Branch
>
> California Department of Pesticide Regulation
>
> P.O. Box 4015
>
> Sacramento, CA 95812-4015
>
> Walt Shannon
>
> Division of Water Quality
>
> State Water Resources Control Board
>
> P.O. Box 100
>
> Sacramento, CA 95812

[^1]: Dobalian, L.; Arias, C.; *Total Maximum Daily Load for Dissolved
    Copper in Shelter Island Yacht Basin*, San Diego Bay, San Diego
    Regional Water Quality Control Board, Public Review Draft Report,
    October 24, 2003.

[^2]: Information on this sub-workgroup is available on the Internet:
    http://www.cdpr.ca.gov/docs/sw/caps.htm

[^3]: Karlsson, J.; Eklund, B.; "New Biocide-Free Anti-Fouling Paints
    are Toxic," *Marine Pollution Bulletin*, V. 49, No. 5-6, 2004, p.
    456-464. We request that U.S. EPA consider this and any other
    relevant articles in scientific journals.

[^4]: Please contact the chairman, Nan Singhasemanon, California
    Department of Pesticide Regulation, (916) 324-4122.