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COPPERS FINAL WORK PLAN

Introduction

This is the Environmental Protection Agency’s (EPA or the Agency) Final Work Plan (FWP)

for the registration review of copper-containing pesticides, which includes four cupric ion case 

designations: copper sulfate (Case 0636), copper group II compounds (0649), copper salts

(4026), and copper oxides (4025). The FWP includes the expected registration review timeline. 

The FWP also addresses public comments received concerning the Preliminary Work Plan

(PWP) in the Summary Document which was posted in the coppers registration review docket 

(EPA-HQ-OPP-2010-0212) and any other comments concerning the initial docket postings. 

The Summary Document provided information on what EPA knows about these pesticides and 

what additional risk analyses and data or information the Agency believes are needed to make a 

registration review decision. 

The Agency is implementing the registration review program and will review each registered 

pesticide every 15 years to determine whether it continues to meet the Federal Insecticide, 

Fungicide, and Rodenticide Act (FIFRA) standard for registration. Changes in science, public 

policy, and pesticide use practices will occur over time. The registration review program is 

intended to make sure that, as the ability to assess risk evolves and as policies and practices 

change, all registered pesticides continue to meet that statutory standard. The public phase of 

registration review begins when the initial docket is opened for each case. Information on this 

program is provided at http://www.epa.gov/oppsrrd1/registration_review/.

The registration review of copper pesticides includes four cupric ion case designations: copper 

sulfate (0636), copper group II compounds (0649), copper salts (4026), and copper oxides

(4025) (for a complete list of copper compounds covered by this registration review see Table 

2). Copper pesticides are registered for use as both conventional pesticides, mainly in 

agricultural settings as fungicides, and direct water applications as aquatic herbicides, 

algaecides, and molluscides, and as antimicrobial pesticides in commercial and residential 

settings mainly as antifoulants, wood preservatives, and material preservatives. Certain copper 

alloys are also registered for use to produce certain antimicrobial products such as doorknobs, 

kickplates, and bedrails. In addition, copper-containing pesticides are also registered for use to 

control leeches, crustaceans, mites and termites, and root growth in sewage and irrigation 

systems. Ecological copper exposure occurs from naturally occurring and anthropogenic 

sources such as mining and copper plumbing, however, this registration review will address 

exposure to copper from pesticidal uses only. Copper is a naturally occurring metal that is 

efficiently regulated in the human system. Currently available toxicity studies and literature do 

not indicate any systemic toxicity associated with copper exposure. As such, no endpoints of 

toxicological concern have been identified and a human health risk assessment will not be 

conducted during registration review. The USEPA Office of Water under the Safe Drinking 

Water Act (SDWA) regulates concentrations of copper in drinking water through a maximum 

contaminant level goal (MCLG). Copper-containing compounds with conventional uses were 

the subject of a July 2006 Coppers Reregistration Eligibility Decision (RED) and a May 2009 

Revised RED. Copper-containing compounds with antimicrobial uses were assessed for 
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potential human health risk exposure as part of the 2006 Coppers RED and 2009 Revised 

Coppers RED and for environmental exposure as part of the August 2010 Revised Addendum 

to the Revised Coppers RED. Documents associated with the reregistration of copper 

compounds can be viewed at www.regulations.gov in docket EPA-HQ-OPP-2005-0558.

The copper Preliminary Work Plan was published September 22, 2010. The 60-day comment 

period ended on November 22, 2010. The Preliminary Work Plan and associated documents

are available on www.regulations.gov, docket number EPA-HQ-OPP-2010-0212.

Comments Received on the Preliminary Work Plan

The Agency received comments during the 60-day public comment period on the Preliminary 

Work Plan, specifically concerning the planned ecological assessment discussed in the 

Preliminary Work Plan. The comments received during the initial public comment period are 

summarized in the “Summary of Comments and Agency Responses” section of this document. 

The complete Agency responses can be found in Response to Public Comments on the Coppers 

(Copper sulfate, copper group II, copper salts, and copper oxides: PC 008001, 008101, 

022702, 022703, 022901, 023104, 023306, 023401, 023501, 023503, 024401, 024403, 024405, 

024407, and 024409) Registration Review Problem Formulation located in the docket. The 

comments did result in changes to the work plan. Changes from the Preliminary Work Plan to 

this Final Work Plan include:

• Clarification that the Agency anticipates requiring down-the-drain data for copper 

products with material preservative and root killer use patterns

• Inclusion of wood leaching special study, “NON-GDLN – Leachability of Wood 

Preservatives in Soil Contact-AWPA E20-06.” This study was inadvertently omitted 

from the PWP, but was listed as anticipated as being needed to be required in the 

September 13, 2010 Registration Review: Preliminary Problem Formulation for 

Ecological Risk, Environmental Fate, and Endangered Species Assessments for 

Coppers.

In the Preliminary Work Plan, EPA also solicited comments on four specific topics: 

environmental justice, water body impairment, trade irritants, and structure activity 

relationships. No comments or information were received during the comment period 

concerning environmental justice, trade irritants, or structure activity relationships. However, 

the Agency did receive comments on listed and potential impaired water bodies in California 

(CA) attributed to coppers. 

The work plan changes are described above. The timeline described in the Preliminary Work 

Plan remain as it was presented initially in the Preliminary Work Plan. Further, this document 

makes final the work plan for the coppers registration review process. 
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Anticipated Risk Assessment and Data Needs

The Agency anticipates the need to require data to conduct a comprehensive ecological risk

assessment, including an endangered species assessment, for all uses of copper. Additional 

ecological fate and effects data are expected to be required, which are listed below. The 

Agency does not expect to require additional data to conduct human exposure risk assessments, 

as new dietary, residential, and occupational risk assessments are not planned for registration 

review, due to a lack of systemic copper toxicity to humans. Below is a summary of the issues 

relevant to the registration review of coppers.

Ecological Risk:

• The most recent ecological risk assessments for coppers were completed in 2005, in 

support of the 2006 Reregistration Eligibility Decision (RED) for conventional uses of 

copper-containing pesticides, and in 2010 an addendum was completed addressing 

antimicrobial uses. 

• The Agency has not conducted a risk assessment that supports a complete endangered 

species determination for the copper compounds included in this registration review. 

The planned ecological assessment will allow the Agency to determine whether use of 

such copper compounds has “no effect” or “may affect” federally listed threatened or 

endangered species (listed species) or their designated critical habitats. When an 

assessment concludes that a pesticide’s use “may affect” a listed species or its 

designated critical habitat, the Agency will consult with the U.S. Fish and Wildlife 

Service and/or National Marine Fisheries Services (the Services), as appropriate.

• The Agency anticipates the need to require the following data to conduct a complete 

ecological risk assessment, including an endangered species assessment, for all 

conventional uses of copper:

• GDLN 850.2100 – Avian Acute Oral Toxicity Test (Passerine)

• GDLN 850.4100 – Terrestrial Plant Seedling Emergence (Tier II)

• The Agency anticipated the need to require the following data to conduct a complete 

ecological risk assessment, including an endangered species assessment, for wood 

preservative and roofing shingle antimicrobial uses:

• NON-GDLN – Aquatic Leaching Study for Wood Preservatives-AWPA 

E11-06 (Special Study)

• NON-GDLN – Leachability of Wood Preservatives in Soil Contact-AWPA 

E20-06 (Special Study)

• NON-GDLN – Leachability of Copper from Roofing Shingles (Special 

Study)
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• Additionally, to conduct a complete ecological risk assessment, the Agency anticipates 

the need to require the following data for copper pesticides with root killer and material 

preservative uses, to conduct a down-the-drain assessment to estimate the 

concentrations delivered to receiving waters following treatment:

• GDLN 835.1110 – Activated Sludge Sorption Isotherm

• GDLN 850.6800 – Modified Activated Sludge Respiration Inhibition

• As a result of public comments received on its planned ecological risk assessment, the 

Agency will revise its risk hypothesis and conceptual model to include ecological 

exposure from non-agricultural runoff (i.e., urban areas), and will consider relevant 

routes of exposure, including applications to impervious surfaces, in the ecological risk 

assessment. 

• In addition, the Office of Pesticide Programs (OPP) intends to coordinate with the 

Office of Water on methods, models, and approaches regarding routes of pesticide 

exposure, effects on aquatic organisms, and regulation of land application of biosolids 

under the Clean Water Act.

• For more information on the comments received and the Agency’s responses, please see 

the “Summary of Public Comments and Agency Responses” section below.

• Please refer to Registration Review: Preliminary Problem Formulation for Ecological 

Risk, Environmental Fate, and Endangered Species Assessments for Coppers, located in 

the docket, for a detailed discussion of these anticipated risk assessment and data needs.

Human Health Risk:

• The most recent risk assessment that evaluated human risk and exposure to coppers was 

a qualitative assessment completed in 2006 to support the 2006 RED, 2009 Revised 

RED for Coppers, and the 2010 Revised Addendum to the Revised Coppers RED.

• The human health exposure database to support the registration review of coppers is 

complete. Previous risk assessments indicate that there are no residential, dietary, 

occupational, or aggregate risks of concern resulting from the use of copper pesticides. 

The Agency anticipates utilizing the conclusions of these assessments for registration 

review. No additional data are needed at this time.

• If toxicological points of departure are established, other new data are received, 

poisoning incident data indicates a problem, or other parameters are modified, the need 

for revised residential, dietary, occupational, and aggregate risk assessments would be 

evaluated at that time. 
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• For more information please refer to Coppers: Human Health Assessment Scoping 

Document in Support of Registration Review, located in the docket.

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic 

and chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of its reregistration decision, EPA reviewed these data and selected 

the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard 

database. However, as required by FFDCA section 408(p), copper is subject to the endocrine 

screening part of the Endocrine Disruptor Screening Program (EDSP). 

Endocrine Disruptor Screening Program

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the 

Administrator may designate.” The EDSP employs a two-tiered approach to making the 

statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to 

identify the potential of a chemical substance to interact with the estrogen, androgen, or thyroid 

(E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening and are found to 

have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of 

the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on 

the available data. Tier 2 testing is designed to identify any adverse endocrine-related effects 

caused by the substance, and establish a dose-response relationship between the dose and the E, 

A, or T effect. 

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between 

October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 

chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. Copper is not 

among the group of 58 pesticide active ingredients on the initial list to be screened under the 

EDSP. Accordingly, as part of registration review, EPA will issue future EDSP orders/data 

call-ins, requiring the submission of EDSP screening assays for copper. For further 

information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, 

future lists, the test guidelines and the Tier 1 screening battery, please visit our website: 

http://www.epa.gov/endo/.
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Timeline:

EPA has created the following estimated timeline for the completion of the coppers registration 

review.

Table 1: Registration Review for Coppers – Projected Registration Review Timeline

Activities Estimated Date

Opening the Docket

Open Docket and Public Comment Period 2010 – September

Close Public Comment 2010 – November

Case Development

Final Work Plan 2011 – March

Issue DCI 2011 – Oct – Dec

Data Submission 2012 – Oct – Dec 

Open Public Comment Period for Draft Risk Assessments 2014 – April – June 

Close Public Comment Period 2014 – July – Sept

Registration Review Decision

Open Public Comment Period for Proposed Registration Review 

Decision

2014 – Oct – Dec

Close Public Comment Period 2015 – Jan – March

Registration Review Decision and Begin Post-Decision Follow-up 2015

Total (years) 5

Summary of Comments and Agency Responses

The copper registration review docket was open for a 60-day comment period beginning on 

September 22, 2010. During the comment period, multiple comments were received. 

Comments that resulted in a change to the work plan are presented below along with EPA’s 

responses. Additional comments were received during the comment period on the species 

included in the endangered species assessment, suggestion for risk mitigation, and the 

availability of monitoring data. EPA’s responses to these comments are included in the 

memorandum, Response to Comments on the Coppers (Copper sulfate, copper group II, copper 

salts, and copper oxides: PC 008001, 008101, 022702, 022703, 022901, 023104, 023306, 

023401, 023501, 023503, 024401, 024403, 024405, 024407, and 024409) Registration Review 

Problem Formulation, which is included in the docket.

While some comments did result in changes to the work plan, they did not affect the timeline 

set out in the Preliminary Work Plan. Changes from the Preliminary Work Plan to this Final

Work Plan include:

• Clarification that the Agency anticipates requiring down-the-drain data for copper 

products with material preservative and root killer use patterns
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• Inclusion of wood leaching special study, “NON-GDLN – Leachability of Wood 

Preservatives in Soil Contact-AWPA E20-06.” This study was inadvertently omitted 

from the PWP, but was listed as required in the September 13, 2010 Registration 

Review: Preliminary Problem Formulation for Ecological Risk, Environmental Fate, 

and Endangered Species Assessments for Coppers.

After consideration of comments received on the initial docket, the Agency will revise the 

Registration Review: Preliminary Problem Formulation for Ecological Risk, Environmental 

Fate, and Endangered Species Assessments (September 13, 2010) and make it available in the 

copper registration review docket (Docket Number: EPA-HQ-OPP-2010-0212) at 

www.regulations.gov. The substantive comments received on the ecological Problem 

Formulation, the Agency’s response, and the revisions to the ecological Problem Formulation 

are described below. The Agency did not receive substantive comments on the Copper Human 

Health Assessment Scoping Document in Support of Registration Review (May 27, 2010). The 

single comment received regarding human health is described below (“Comment on Trace 

Heavy Metal Impurities”) and did not result in any changes to the PWP or the Scoping 

Document.

Comments were submitted by California Stormwater Quality Association (CASQA); 

Department of Water Resources (County of Sacramento, CA); Physicians Committee for 

Responsible Medicine; American Chemistry Council (ACC) Copper Task Force; CA Regional 

Water Quality Control Board; SF Bay Region, CA; Tri-TAC (a technical advisory group for 

Publicly Owned Treatment Works); American Water Works Association (AWWA); and 

California Department of Pesticide Regulation (CalDPR). Due to the large number of similar 

comments submitted, the comments have been combined and summarized, where appropriate. 

Comments on the Scope of the Risk Assessment

Comment [CASQA]: “...EPA’s proposed approach should explicitly account for 

all important urban sources and transport pathways of copper compounds. Urban 

sources and associated water quality impacts are of significant concern to CASQA’s 

member agencies.

On the basis of available scientific information, we request that EPA make specific 

changes to the copper compounds registration review process to better identify and 

mitigate urban water quality impacts. We also request that EPA adopt similar 

changes as part of systematic revisions to EPA’s overall approach to the registration 

review process for all pesticides with urban use patterns.”
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Comment [County of Sacramento, CA]: “The copper compounds registration 

review must cover all common outdoor uses of copper in urban areas, and the 

common pathways by which these sources reach surface waters. Urban uses that are 

expected sources of copper in receiving waters and therefore should be reviewed 

include:

(1) Swimming pools, because when drained, pools are often discharged to urban 

gutters or storm drains

(2) Treated wood

(3) Other outdoor urban uses of copper biocides, such as roofing shingle treatments

Swimming pools are among a list of anti-microbial uses excluded from EPA’s 

proposed Analysis Plan “because they are sporadic.” However, available evidence 

substantiates the importance of swimming pool discharges as sources of copper to 

receiving waters. For example, acute water quality criteria can be exceeded in a 

creek when a pool is drained. In California, because many creeks have very low 

flow much of the year, the possibility of acute water quality impacts resulting from 

sporadic discharges is enhanced.”

Comment [ACC]: “The Task Force requests that EPA clarify the antimicrobial use 

scenarios that it intends to assess in Registration Review. There are contradictory 

statements in EPA’s documentation regarding the uses to be evaluated and assessed. 

The scope of the assessments needs to be clarified at the outset of the Registration 

Review process and before any final decisions can be made on new data needs and 

identification of appropriate models for refined risk assessments.”

Comment [ACC]: “The environmental risk assessment should evaluate all outdoor 

uses of copper in urban areas, and especially:

(1) Swimming pool uses, because pool water is nearly always discharged to either 

gutters/storm drains or to municipal wastewater treatment plants, and

(2) Treated wood and other outdoor urban use of biocides, such as roofing shingle 

treatments.” 

Comment [Tri-TAC]: “We suggest that the uses that particularly need to be 

reviewed are the following: (1) copper-based root control products - these already 

appear in your workplan, (2) copper products that are used in swimming pool 

treatments because pools are often discharged to POTWs. In many municipalities, 

this discharge to POTWs during the cleaning of pools is a requirement. (3) Fabric 

treatments should receive special focus, because POTW discharges occur during 

washing.” 

Agency Response: All registered uses of copper will be considered in the risk assessment during 

registration review, as well as all routes of exposure detailed in the conceptual model described 
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in the problem formulation document. The registered antimicrobial uses for copper are 

grouped into various use categories. A full list of registered antimicrobial uses can be found in 

the Agency’s response, available in the docket.

Comments on the Intersection of FIFRA and the Clean Water Act (CWA)

Comment [CASQA and CalDPR]: “...municipal stormwater agencies in California 

have had to contend with the water quality impacts of registered pesticides in surface 

waters, and the regulatory consequences of those impacts. When urban receiving water 

impacts are discovered, the local stormwater agencies are typically required to conduct 

additional studies and ultimately develop programs to reduce the contribution of urban 

runoff discharges to the in-stream impairments. Because local agencies do not have 

authority to regulate pesticide uses or application patterns, they rely on federal and state 

regulators to control pesticide uses to maintain exposures at levels that prevent surface 

water toxicity.

The Summary Document (EPA–HQ–OPP–2010–0212-0011) notes that there are 

numerous CWA Section 303(d) listings for which the impairment is caused by copper. 

Pursuant to the requirements of the federal Clean Water Act, the Regional Water 

Quality Control Boards in Los Angeles and San Diego have already imposed deadlines 

and copper Total Maximum Daily Load (TMDL) limits on discharges of stormwater to 

California waters. Similar TMDLs are expected to be imposed on other urban 

watersheds across the state in the near future.”

Comment [CASQA and CalDPR]: “The EPA has developed water quality criteria for 

copper to be protective of aquatic life in both freshwater and saltwater surface waters. 

These aquatic life criteria should be used as risk assessment measures of effect. We 

anticipate that one outcome of the OPP/Office of Water Common Effects Assessment 

Methodology Project will be that OPP should employ water quality criteria as measures 

of effect in its risk assessments.” 

Comment [CASQA and CalDPR]: “...USEPA needs to continue its efforts to improve 

integration of surface water quality protection into its pesticide registration and 

regulatory review programs. Coordination between USEPA’s Office of Water and 

Office of Pesticide Programs in reviewing pesticide ingredients is essential to Clean 

Water Act implementation; furthermore it provides an appropriate method of meeting 

FIFRA’s goal of preventing unreasonable adverse impacts from pesticide use.

The risk benefit standards of FIFRA require USEPA to ensure that pesticides are used 

in such a manner that mitigation under the Clean Water Act is minimal or unnecessary. 

Without a complete review of potential pesticide surface water quality impacts—

including impacts from urban uses—USEPA cannot fulfill this obligation. Properly 

implemented, USEPA’s pesticide registration process can help ensure that Clean Water 

Act water quality standards are maintained and aquatic habitats are protected. 
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According to USEPA pronouncements, “When EPA approves a particular pesticide for 

registration, the Agency has assessed the chemical and found that, when used according 

to label directions, it does not pose unreasonable risk to public health and the 

environment.” Full cooperation between the Office of Water and the Office of Pesticide 

Programs will help USEPA meet this goal.” 

Comment [AWWA]: “The proposed re-registration process is the third federal 

regulatory oversight process targeting copper-based aquatic pesticides in the past four 

years. Each of these federal actions also leads to a following round of individual state 

actions.

These overlapping regulatory efforts are at odds with Administrator Jackson’s emphasis 

on breaking down institutional silos within the agency and utilizing available 

environmental statutes in a coordinated fashion. Drinking water systems rely on aquatic 

pesticides, particularly copper-based herbicides to assure safe and aesthetically 

acceptable drinking water. Aquatic plants, particularly algae, can impair compliance 

with drinking water standards for turbidity, affect disinfection byproduct formation, 

introduce toxins, and cause adverse taste and odors. In order to both meet drinking 

water treatment objectives and comply with all applicable federal and state 

requirements, water systems need a stable regulatory framework. In early 2011 EPA 

will finalize a new permit requirement for aquatic pesticide application under the Clean 

Water Act (CWA). This new National Pollutant Discharge Elimination Permit 

(NPDES) requirement is in addition to complying with Federal Insecticide Fungicide 

and Rodenticide Act (FIFRA) label requirements based on the FIFRA Reregistration 

Eligibility Decision (RED) (revised most recently in 2009). The current comment 

period opens yet another round of federal review of the current FIFRA requirements 

(e.g., applicable use rates).

AWWA encourages EPA to coordinate and share data between the NPDES and OPP 

activities in order to:

1. Maximize the value of data collection efforts,

2. Ensure compatible regulatory strategies, and

3. Minimize redundant regulatory activities.” 

Comment (CalDPR): “The current risk-quotient based determination of harm or 

endpoints only serves to address Federal Insecticide, Fungicide, and Rodenticide Act 

(FIFRA) based mandates, which imply that some level of biological impacts is 

acceptable. While this may be scientifically and legally defensible under FIFRA, these 

types of endpoints do not take into consideration the protective mandates that are 

established under the Clean Water Act (CWA). We encourage that protective endpoints 

such as the CTR (California Toxics Rule) and the Biotic Ligand Model (BLM)-based 

fresh water quality criteria for copper somehow be considered by U.S. EPA as part of 

the risk management decision making under Registration Review. It is not clear whether 
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this approach is being considered as part of the Office of Pesticide Programs and Office 

of Water harmonization efforts that the U.S. EPA has been undertaking.” 

Agency Response: While the registration review assessment is being conducted under the 

regulatory authority provided by Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), 

which only considers the pesticidal uses of coppers, OPP has initiated a planning dialogue with 

the Office of Water (OW), with the goal of coordinating regulatory efforts as much as possible

to share and coordinate methods, models, and approaches regarding routes of pesticide 

exposure and effects on aquatic organisms. OPP welcomes further input on how to utilize 

information received from OW in future risk assessments.

The Agency acknowledges the cost of keeping in compliance with the Clean Water Act, and 

will make every effort to ensure that it adequately identifies and mitigates unreasonable adverse 

effects from pesticidal uses of coppers during registration review. It is important to remember, 

however, that the ecological risk assessment for registration review will be nationwide in 

scope. The consideration of generic exposure scenarios for widespread applicability adds to the 

difficulty of estimating the relative contribution of the many sources of copper in individual

watersheds. 

The Agency determined during reregistration that use of copper could result in some risk to 

aquatic organisms in many waterbodies, and acknowledges there are many waterbodies listed 

as impaired because of copper. Many TMDLs for copper and other heavy metals, though, have 

been put in place to deal with inputs from mining operations. A small fraction have been 

caused predominantly from use of copper as a pesticide, as from the use as an antifoulant paint 

in the San Diego TMDL.

Comments on Modeling of Copper in the Environment

Comment [CASQA, CA Regional Water Quality Control Board, SF Bay Region, 

County of Sacramento, CA]: Submitters indicated that the copper risk hypothesis and 

conceptual model do not account for exterior uses of biocides (e.g., roofing shingles and 

treated wood) that are subject to rainfall runoff, where the runoff will traverse across 

either impervious surfaces as a route of exposure or impact of storm drainage systems 

and ultimately receiving waters. Also, the submitters state that the Agency’s modeling 

approach, in particular regarding measures of exposure, is not appropriate for nonagricultural (residential and urban) runoff and suggested a model such as EPA’s 

BASINS be used instead. Submitters stated that the model OPP uses in risk 

assessments, PRZM/EXAMS, produces unrealistic results and that computational 

methods that account for an appropriate washoff fraction from urban impervious 

surfaces would be more appropriate. 

.

Agency Response: It is difficult to translate from the resolution of a nationwide risk assessment 

to assess the relative input of pesticidal use of copper on a local scale. There are models 
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available which can be calibrated to simulate sites and pesticides for which extensive flow and 

pollutant data have been collected in advance. Some commenters have suggested that the 

Agency use the HSPF/NPSM model, which is included in the EPA’s BASINS shell. This has 

been used to calibrate stream flow and copper pesticide use data to simulate loading of these 

pesticides consistent with concentrations measured in surface water monitoring. The Agency 

would not be able to perform such an assessment for all urban watersheds in the nation, and it 

is very unlikely that sufficient monitoring and flow data are available to do so, in any case. 

Development of a screening model which could simulate the fate and transport of pesticides 

applied in an urban setting would require a large body of data which is currently unavailable. 

For instance, an urban landscape cannot be simulated as easily as an agricultural field. The 

PRZM model simulates runoff from an agricultural field using readily available data describing 

surface soil characteristics and laboratory data detailing the persistence and mobility of 

pesticides in these soils. The agricultural field simulated is homogenously planted to a single 

crop, and soil and water are transported from the field to a receiving water body with 

dimensions consistent with USDA farm-pond construction guidelines. 

By contrast, an urban landscape or suburban housing development consists of impervious 

surfaces such as streets and sidewalks, and pervious surfaces such as lawns and parkland. One 

could expect much greater mobility for pesticides applied to impervious surfaces, but 

laboratory soil metabolism studies may not provide an accurate measure of the persistence of 

pesticides on these surfaces. The path runoff water and eroded sediment might take is less 

obvious for an urban setting than an agricultural field. First, an urban landscape cannot be 

considered homogeneous, as the proportion of impervious and pervious surfaces varies for 

different locations. In addition, the flow path of runoff water and sediment is not necessarily a 

direct path over land, but can pass below ground through storm sewer networks, be directed, or 

slowed by pumping stations or temporary holding ponds. 

Currently, the Agency uses PRZM to simulate both pervious and impervious surfaces in an 

attempt to account for these different urban conditions. Because PRZM is an edge-of-field 

model, it does not take path length into account, including potential removal of copper as it 

passes over land or through underground conveyances along with other sediment and organic 

matter. Some commenters indicated that this method is too conservative if it does not account 

for gradual washoff from treated surfaces, while others suggested it was not sufficiently 

conservative if it didn’t reflect scenarios in which copper-laden runoff traveled only over 

impervious surfaces. The Agency will attempt to improve its methods over the next several 

years leading up to the ecological risk assessment for registration review.

The Agency has not previously assessed the potential for environmental exposures from the 

discharge of previously treated swimming pool water. In most cases, pesticides used in pools 

for the purpose of disinfection are dissipated in the process of providing the pesticidal effect 

(e.g., chlorine-based treatments). However, for more persistent chemicals, such as copper 

compounds, the Agency intends to enter into a dialogue with effected stakeholders to determine 

if an assessment would be needed, what that assessment would consist of and what data would 
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be needed to conduct such an assessment from the standpoint of potential exposures or if 

surrogate data can be used. If the Agency determines that such an assessment is needed, it will 

be included in the registration review assessments.

Finally, beyond the constraints of modeling transport in an urban environment, the timing and 

magnitude of urban uses is less well defined for urban uses than agricultural uses. While 

agricultural uses would occur within a predictable window during the growing season, the need 

for urban uses could occur at different times each year, and might occur at different times 

within the same watershed. In addition, since records of how and to what extent copper 

pesticides are applied by homeowners are not well defined, it is harder to estimate the total load 

to model.

Comments on the Biotic Ligand Model

Comment [CA Regional Water Quality Control Board, SF Bay Region, and Tri-TAC]:

Commenters expressed concerns regarding the use of freshwater BLM based measures 

of effect into the exposure modeling, stating that exposure estimates should be 

separated from effects assessments. The above mentioned groups believe the EPA 

water quality objectives based on hardness-based EPA copper water quality criteria, 

such as the California Toxics Rule, should be risk assessment endpoints instead.

Comment [CalDPR]: The submitter supports the use of the BLM for freshwater 

exposure and effects assessments and encourages the EPA to finalize the salt water 

BLM for use as well. 

Comment [ACC]: ACC requested clarification of the derivation of toxicity endpoints 

for marine/estuarine organisms and supports the use of the salt water BLM when it is 

finalized.

Agency Response: The Office of Pesticide Programs intends to use the BLM for its nationwide 

risk assessment for copper pesticides to estimate the fraction of the modeled exposure of total 

copper species that is dissolved copper ion (Cu2+). Research has shown that Cu2+is the form of 

copper that results in the most ecological harm. Because the fraction of the total copper species 

that will be in the Cu2+ form varies with site-specific variations in water quality parameters and 

pesticidal copper discharges are likely to occur over much of the U.S., OPP is using a large 

U.S. Geological Survey (USGS) data set containing measured water quality parameters from 

across the U.S. to determine if the modeled exposure of total copper would result in ecological 

harm if it were discharged at any of the USGS monitored sites. 

OW has used the BLM to derive Aquatic Life Criteria which can account for the speciation and 

toxicity of copper as a function of local water quality conditions (including hardness). The 

Agency understands and accepts that some States have elected to continue using the previous 

hardness-based method to derive their water standards for copper. OW is developing a tool 

which will help States and localities more easily follow the BLM method to develop water 
15

quality criteria, perhaps more States will use this method once OW makes this tool available. 

The Office of Pesticide Programs will work with OW to coordinate regulatory tools and efforts.

The saltwater version of the BLM model is still under development. If the saltwater BLM is not 

completed in time for this assessment, OPP will use the best method available to assess 

saltwater exposures to copper.

Comments on the Down the Drain Assessment 

Comment [ACC]: ACC requested clarification of the down the drain data requirements 

and believes the root killer use is the predominant use that would impact discharges to 

waste water treatment plants (WWTP). ACC further requested the Agency to correct 

the documentation of the use scenarios that drive Guidelines 850.6800 and 835.1110. 

Comment [Tri-TAC]: Tri-TAC stated that publicly owned treatment works (POTW) 

have concerns regarding copper impacting biological treatment processes, biosolids 

management, and incinerator ash management, as copper can and does act as a biocide 

or chemical contaminant. Tri-TAC further indicated that conservative data available 

from OW should be used to reflect actual publicly owned treatment works (POTW) 

copper removal efficiencies. 

Agency Response: The Agency will include the root-killer uses of copper in its assessment of 

potential “down-the-drain” (DTD) exposures. The data requirements for down-the-drain uses 

will apply to these uses as well as to appropriate antimicrobial copper uses. The Agency will 

correct its documentation in the Problem Formulation to reflect this.

The Agency commits to using the best available data in developing input parameters for the 

down-the-drain model. As with the other models described in the Problem Formulation, 

however, the nationwide scale of the risk assessment will preclude consideration of the 

variability at the local level in this case for parameters such as flow regimes and POTW 

removal methods. In addition to questions of scale, the lack of detailed usage data for indoor 

antimicrobial and root killer uses will limit the extent to which down-the-drain exposure 

assessments can be refined. The Agency will characterize the uncertainties in its risk 

assessment which result, as well as the range of potential vulnerabilities which could impact 

copper exposure from these uses.

The Agency appreciates the submission of this conceptual model for exposure pathways of 

biosolid-associated pollutants. Discharge of copper into the environment via effluent will be 

considered to the best degree possible in the assessment. In addition, the Agency is actively 

evaluating the extent to which ecological risk from copper via application of biosolids to land 

should be addressed in its forthcoming ecological risk assessment and, by extension, any 

additional data that may be required. As part of this evaluation, OPP is working closely with 

OW, which has regulates biosolids applied to land under the Clean Water Act, and has 

established ceiling concentration limits of copper in biosolids applied to land.
16

Down-the-drain data requirements are required for all material preservative uses. The Agency 

anticipates requiring down-the-drain data requirements for copper compounds with material 

preservative or root killer use patterns. 

Comments on Marine Antifoulant Model to Predict Environmental Concentrations

(MAMPEC) Model

Comment [ACC]: Another issue that needs to be addressed involves the model that 

will be used to assess antifoulant uses of copper-containing compounds. EPA has stated 

that it will use MAMPEC Version 2 (Marine Antifoulant Model to Predict 

Environmental Concentrations) to evaluate antifoulants and that the “highest available 

leaching rate for Cu will be used for modeling.” First, the Task Force would like to 

point out that MAMPEC Version 3 will be available by the end of this year and believes 

it should be used in EPA’s assessment. MAMPEC 3 will address speciation of cooper 

and also will include a sediment PEC module...EPA intends to use “the highest 

available” rate, so it is of critical importance that the highest available rate is not one 

that so dramatically overestimates leaching as to render EPA risk assessments 

scientifically unsound.”

Comment [CalDPR]: CalDPR indicated that the commercial harbor scenario is not the 

worst case scenario that should be used for MAMPEC modeling of copper oxide 

antifoulant use. Instead, CalDPR believes a poorly-flushed salt water marina scenario 

should be assessed under California environmental and use conditions because they 

have observed that high dissolved copper concentrations tend to occur in large and 

poorly-flushed pleasure-craft marinas along the California Coast. CalDPR indicated 

that it requests this scenario be modeled by all new antifoulant registrants in California 

and that the predicted Estimated Environmental Concentrations (EECs) would exceed 

the acute ambient water quality standards. CalDPR also noted that the current 

conservative scenario OPP uses exceeds the chronic salt water ambient water quality 

standard for copper set under the California Toxics Rule, the highest leach rate OPP 

uses in its modeling is not the highest possible leach rate, and background copper 

concentrations in water bodies should be incorporated in future ecological risk 

assessments. 

Comment [ACC]: ACC indicated that MAMPEC 3 will be available this year and 

should be used in future risk assessments. ACC further noted that the highest available 

leaching rate used in assessments should not grossly overestimate leaching potential and 

thus render risk assessments scientifically unsound. 

Comment [ACC]:: “Future ERAs should also take into account the larger water body’s 

background copper levels and the impacts of underwater hull cleaning on biocide 

leaching from boat hulls. The MAM-PEC model does not factor in these sources in 

generating EECs. This hull maintenance activity is very common in California’s coastal 

marinas. Moreover, certain water bodies in California have relatively high background 
17

copper concentrations that could significantly contribute to a marina’s copper load. 

Brackish water areas, in particular, tend to have high background copper levels.” 

Comment [ACC]:: “In the Registration Review document, “Preliminary Problem 

Formulation for Ecological Risk, Environmental Fate, and Endangered Species 

Assessments for Coppers,” there appears to be an error in the linkage of the antifoulant 

use of copper to the ecosystems at risk (page 25 of 106). U.S. EPA staff may be 

referring to the sites of use for the various antimicrobial uses of copper rather than the 

ecosystems at risk. With antifoulant use of copper, the ecosystems that are most at risk 

are those that are associated with marina areas, as these locations tend to exhibit high 

concentrations of copper as a result of pesticide use.” 

Comment [ACC]: While EPA has not identified leaching data from antifoulant 

application as a data gap, the Task Force believes it is essential that a dialogue be 

opened to determine the appropriate manner by which to assess leach rates from 

antifoulant coatings. Again, laboratory data that EPA has relied upon vastly 

overestimate actual leach rates. The Task Force has requested that EPA adopt an 

approach that is similar to the one that has been developed by Dr. Alistair Finnie, which 

provides specific correction factors for data generated either by the ASTM/ISO rotating

cylinder method and a mass-balance calculation method... There is adequate 

information available to EPA to conduct reliable risk assessments and it is indefensible 

for the Agency to use leach rate data that is widely recognized as overstated and 

unreliable

Agency Response: The Agency agrees that most of the risk for antifoulant use of Cu is 

associated with the marina areas and we have used conservative scenarios to address this issue. 

The commercial harbor scenario used in MAMPEC model has been developed to be a 

reasonable worst case scenario for a risk assessment that must represent a large range of 

conditions nationwide. The Agency will characterize the potential for greater exposure in 

localized scenarios that may have greater vulnerability. Similarly, the Agency will evaluate 

leaching data that are available at the time of the risk assessment to determine which values are 

sufficiently conservative to drive our nationwide-scale risk assessment. The Agency welcomes 

the opportunity to continue working with stakeholders on scenarios and input parameters for 

the MAMPEC model which are pertinent to the United States environmental conditions. 

As with the other models described above, the Agency commits to use the best tool available to 

evaluate copper exposure from its use as an antifoulant. OPP is aware of the availability of the 

beta version 3 for MAMPEC and is in the process of evaluating its utility for our assessments. 

Comment on Copper Alloy Uses

Comment [ACC]: ACC stated that it does not believe copper alloy products should be 

included in the environmental risk assessment and that these are not traditional 
18

antimicrobial uses. ACC believes copper alloys are not relevant to the Registration 

Review Draft Problem Formulation or PWP.

Agency Response: Environmental exposure from the use of registered products such as 

doorknobs, bed rails and kick plates manufactured out of copper alloys is expected to be 

negligible since these items are designed for indoor use and release to the environment is very

unlikely. Therefore, while the assessment to be conducted would cover these uses, no 

quantitative assessment of the uses for the purposes of an ecological risk assessment is 

expected to be needed.

Comments on the Acute Avian Oral Toxicity Requirement

Comment [Physicians Committee for Responsible Medicine]: “The Physicians 

Committee for Responsible Medicine strongly supports the use of the newly revised 

OECD test guideline (TG223) for the acute avian oral toxicity test (passerine and nonpasserine), which has been adopted by the OECD. The new approach could reduce the 

total number of animals by up to approximately 60%.”

Agency Response: The OECD has adopted the TG 223 guideline and has issued a validation 

report. At this time the Agency is actively evaluating the results of the OECD validation report 

to determine if the TG 223 effects endpoints and dose/response information adequately address 

the purposes of the avian acute oral data requirement as described in 40 CFR Part 158 and 40 

CFR Part 161. Until the Agency’s evaluation of that validation report is completed, EPA does 

not expect to be able to routinely classify avian toxicity studies performed using the TG 223 

protocol. The validation report should help inform the interpretation of studies performed 

under the TG 223 guideline, and should clarify what the Agency might find to be generally 

necessary for avian toxicity studies done under TG 223 to be acceptable to meet our data 

requirements.

Validation work conducted on TG 223 test guideline to date has been limited to studies with the 

upland game birds (e.g., northern bobwhite). Because no work has been done to date to 

validate this guideline for passerine species, it is doubtful that the Agency would have 

confidence in studies done under this guideline for fulfilling requirements for passerine acute 

toxicity data unless additional validation work with passerines is done, but the Agency 

recognizes that specific situations might warrant additional examination.

Comment on Trace Heavy Metal Impurities

Comment [ACC]: ACC believes that trace heavy metal impurities in antimicrobial 

copper-containing products are so low as to be insignificant with regard to potential 

toxicity. The commenter supports the Agency statement referencing information 

relating to OSHA indoor air quality standards, OW’s maximum drinking water 

contaminant levels, and average concentrations of trace metals in marine waters.
19

Agency Response: Trace heavy metal impurities in antimicrobial copper-containing products 

are low and their potential toxicity may be low and in most cases insignificant. However, these 

impurities will be assessed on a case by case basis. The Agency is currently reviewing 

available heavy metal data for conventional copper-containing pesticides to determine if further 

evaluation during registration review is warranted.

Availability of Additional Agency Responses to Public Comments:

Comments regarding the ecological fate or effects of coppers have been addressed in the joint 

Antimicrobial Division and Environmental Fate and Effects Division’s document Response to 

Public Comments on the Coppers (Copper sulfate, copper group II, copper salts, and copper 

oxides: PC 008001, 008101, 022702, 022703, 022901, 023104, 023306, 023401, 023501, 

023503, 024401, 024403, 024405, 024407, and 024409) Registration Review Problem 

Formulation, dated March 30, 2011. This document is available in the coppers docket (EPAHQ-OPP-2010-0212).

Next Steps

• Based on comments received during the public comment period, the Agency plans to

update the Registration Review: Preliminary Problem Formulation for Ecological Risk, 

Environmental Fate, and Endangered Species Assessments for Coppers to clarify the 

uses that will be addressed in registration review risk assessments and incorporate an 

impervious runoff scenario. 

• The Agency plans to issue a DCI in late 2011, requiring the copper studies needed to 

complete the ecological risk assessments.

• The Agency will conduct an ecological risk assessment, including an endangered 

species assessment for coppers.
20

 (Case Nos. 0636, 0649, 4025, and 4026)

Table 2: Copper Compounds in This Registration Review

 

Registration 

Review Case

Common name EPA PC 

Code

Formula C.A.S. 

Number 

Molecular 

weight 

(g/mol)

Percent 

Copper

Conventional 

Use

Antimicrobial 

Use

Copper 

Sulfates

0636

Basic copper sulfate 008101 3Cu(OH)2 · CuSO4 1344-73-6 452.29 56.2% X

Copper sulfate pentahydrate 024401 CuSO4 · 5H2O 7758-99-8 249.68 25.45% X X

Group II 

Copper 

Compounds

0649

Basic copper chloride 008001 3 Cu(OH)2 · CuCl2 1332-40-7 427.13 59.5% X

Basic copper carbonate 022901 Cu(OH)2CuCO3 12069-69-1 221.12 57.5 X X

Copper ammonium carbonate 

complex

022703 CuNH3(HCO3)2 33113-08-5 202.61 31.4% X

Copper hydroxide 023401 Cu(OH)2 20427-59-2 97.56 65.1% X X

Copper oxychloride or copper 

chloride hydroxide

023501 Cu2Cl(OH)3 1332-65-6 213.57 59.5% X

Copper oxychloride sulfate 023503 Cu2Cl(OH)3 + 

3Cu(OH)2 · CuSO

8012-69-9

4

665.86 57.3% X

Copper ammonium complex 022702 Cu(NH3)4 16828-95-8 2+ 131.67 48.3% X

Chelates of copper citrate 

Chelates of copper gluconate

024405 (C6H6O7)

-2 · Cu 10402-15-0 +2 253.67 25.1% X X

024405 2(C6H11O7)

-1 · Cu+2 527-09-3 453.838 14.0% X X

Copper and 

Oxides

4025

Cuprous oxide or Copper (I) 

oxide

025601 Cu2O 1317-39-1 143.09 88.8% X X

Cupric oxide or Copper (II) 

oxide

042401 CuO 1317-38-0 79.545 79.9% X

Copper 022501 Cu 7440-50-8 63.546 100% X

Copper Salts

4026

Copper salts of fatty and 

rosin acids

023104 Mixture of 

compounds

9007-39-0 NA 

[depends 

on acid]

% Cu; 

[depends 

on acid]

X

Copper ethylenediamine 

complex

024407 2(C2H8N2) -1 · Cu 13426-91-0 +2 181.74 34.9% X

Copper triethanolamine 

complex or Copper, ((2,2',2''-

nitrilotris(ethanolato))(2-)-

N,O,O',O'')

024403 (C6H13O3N)-2 · 

Cu+2

82027-59-6 210.71 30.2%

X X

Copper 039105 Cu · EDTA 12276-01-6 353.7 18.0% X
21

Registration 

Review Case

Common name EPA PC 

Code

Formula C.A.S. 

Number 

Molecular 

weight 

(g/mol)

Percent 

Copper

Conventional 

Use

Antimicrobial 

Use

ethylenediaminetetraacetate 

(EDTA)

Copper thiocyanate 025602 N≡C–S-1 Cu 1111-67-7 +1 121.63 52.2% X

Other 

Copper 

Compounds

Copper octanoate 023306 2(C8H15O2) -1

 · 

Cu

20543-04-8

+2

349.955 18.2% X

Copper, bis(acetatoO)diamine or Copper 

diammonia diacetate complex 

036011 Cu+2 · 2(NH3) · 

2(CH3CO(O13822-80-5))

215.695 29.5%

X

Copper ethanolamine 

complex; or Copper, bis(2-

aminoethanolato-N,O)

024409 2(C2H6ON)-1 · Cu+2 14215-52-2 183.696 34.6%

X
22

Table 3: Summary of Data Gaps – Coppers

The table below summarizes all anticipated data needs for coppers identified in the Registration Review:

Preliminary Problem Formulation for Ecological Risk, Environmental Fate, and Endangered Species

Assessments for Coppers dated September 13, 2010, and Coppers: Human Health assessment Scoping 

Document in Support of Registration Review dated May 27, 2010.

Use Type Guideline 

Number Anticipated Data Requirement

Test 

Material

Study 

Duration

(Measured in 

months from 

receipt of a 

DCI)

Conventional 850.2100 Avian Acute Oral Toxicity1 TGAI 12

850.4100 Seedling Emergence, Tier II2 TGAI 12

Root Killer and 

Material 

Preservatives 

Uses

835.1110 Activated Sludge Sorption Isotherm3 TGAI 12

850.6800 Modified Activated Sludge Respiration Inhibition TGAI 3 12

Wood 

Preservative 

Antimicrobial 

Use

NON-GDLN Aquatic leaching Study for Wood Preservatives- AWPA 

E11-06 3 TGAI 12

NON-GDLN

NON-GDLN – Leachability of Wood Preservatives in Soil 

Contact-AWPA E20-063 TGAI 12

Roofing 

Shingle 

Antimicrobial 

Use

NON-GDLN Leachability of Copper from Roofing Shingles TGAI 3 12

 1

The anticipated DCI would require a passerine study protocol to be submitted for review and approval by the Agency prior to this study 

being initiated.

2

 A Tier II study is expected to be required. The expected DCI would specify that a Tier I plant study may be conducted in lieu of a Tier II 

study with the understanding that any adverse effects observed by the Tier I study would necessitate conduct and submission of a Tier II 

study as well. The purpose of a Tier II study is to establish both a definitive No Observed Adverse Effect Concentration (NOAEC), or 

alternatively, a concentration at which there is a 5% observed inhibition effect (IC05), to be used in a risk assessment and effects 

determination for endangered or threatened species (listed species), and a definitive IC25 (concentration at which there is a 25% observed 

inhibition effect) for assessing risk to non-listed nontarget plants. If any adverse effects are observed in a Tier I study and neither a definitive 

NOAEC nor a definitive IC05 value is available, then the Agency may have to presume in its effects determination, that copper "may affect" 

and is “likely to adversely affect” listed plant species.

Refer to public draft guideline 850.4225 for guidance on Tier II seedling emergence testing. 

Data are expected to be required for six species of dicots from at least four families, one species of which is soybean (Glycine max). Data 

are expected to be required for four species of monocots from at least two families, one species which is corn (Zea mays). At least one of 

either the monocot or dicot species would need to be a root crop.

3 The anticipated DCI would require a protocol to be submitted for review and approval by the Agency prior to this study being initiated.