US Environmental Protection Agency
Office of Pesticide Programs
Copper Facts
June 2008
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United States Prevention, Pesticides EPA 738-F-06-014
Environmental Protection and Toxic Substances June 2008
Agency (7508P)
Coppers Facts
Pesticide Registration
All pesticides sold or distributed in the Unites States must be registered by the
Environmental Protection Agency (EPA or the Agency), based on scientific studies showing that
they can be used without posing unreasonable risks to people or the environment. Because of
advances in scientific knowledge, the law requires that pesticides that were first registered before
November 1, 1984 be reregistered to ensure that they meet today's more stringent standards.
In evaluating pesticides for reregi strati on, EPA obtains and reviews a complete set of
studies from pesticide producers, describing the human health and environmental effects of each
pesticide. To implement provisions of the Food Quality Protection Act (FQPA) of 1996, EPA
considered the special sensitivity of infants and children to pesticides, as well as aggregate
exposure of the public to pesticide residues from all sources, and the cumulative effects of
pesticides and other compounds with common mechanisms of toxicity. The Agency develops
any mitigation measures or regulatory controls needed to effectively reduce each pesticide's
risks. EPA then registers pesticides that meet the safety standard of the FQPA and can be used
without posing unreasonable risks to human health or the environment.
When a pesticide is eligible for reregi strati on, EPA explains the basis for its decision in a
Reregi strati on Eligibility Decision (RED) document. This fact sheet summarizes the information
in the RED document for copper-containing pesticides, hereon referred to as copper, in cases
0636, 0649, 4025, and 4026.
Regulatory History
The first registration for a copper-containing pesticide for agricultural uses was issued in
1956. Currently, 16 copper active ingredients have active food use registrations subject to
tolerance reassessment and reregi strati on review. EPA issued Registration Standards for copper
sulfate in March 1986, Guidance for the Reregistration of Pesticide Products Containing Copper
Sulfate as the Active Ingredient, and for the Group II copper compounds, Guidance for the
Reregistration of Pesticide Products Containing Group II Copper Compounds as the Active
Ingredient in April 1987.
Generic Data Call-In (GDCI) notices were issued in 1987 to the registrants for various
copper compounds to submit data in support of reregi strati on. These comprehensive DCIs
required various ecological fate and effects studies. Additional DCIs were issued in 1993, which
required various product chemistry studies, avian toxicity studies and residue studies. These
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DCIs were issued so that data required by 40 CFR Part 158 would be available to the Agency
before risk assessments for reregi strati on were performed.
Uses
Agricultural Crops
Copper is registered for use on virtually all food/feed crops, including orchard, row, field,
and aquatic crops. Crops include, but are not limited to: root and tubers, leafy vegetables
(including brassica), bulb vegetables, fruiting vegetables, citrus, stone fruit, pome fruit, legumes,
cucurbits, berries, cereals and tree nuts. Copper is also registered for use on various ornamental
crops, such as flowering/non-flowering plants and trees.
Aquatic Applications of Copper Pesticides
Copper is registered for use on numerous aquatic use sites. Below is a description of
algaecide, herbicide, molluscicide, and macro-invertebrate use.
Algaecide Applications. Copper applications for algae control include: aquaculture
facilities, drainage systems (canal, ditch and lateral), ponds (farm, industrial and
recreational), fountains, lakes, reservoirs (crop and non-crop irrigation, potable), sewage
lagoons, stocking (tank, water trough and ponds) and irrigation canals.
Herbicide Applications. Copper applications for aquatic weed control include:
aquaculture facilities, drainage systems (canal, ditch and lateral), ponds (farm, industrial
and recreational), lakes, reservoirs (crop and non-crop irrigation, potable), sewage
lagoons, sewer systems, stocking (tank, water trough and ponds) and irrigation canals.
Molluscicide and Macro-Invertebrate Applications. Copper is registered for use to
control freshwater snails that may be a vector for harmful trematodes. Copper is also
used to control leeches, and tadpole shrimp in rice fields.
Antimicrobial Applications
Copper is registered for use as a wood preservative, mildewcide, water treatment,
bactericide, and as an anti-foulant in many products including paint, glue, building materials and
construction materials.
Non-crop Uses
Copper is registered for use in various residential applications, including home gardens
and lawns. Copper products are also used for in established turf applications to manage moss.
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Health Effects
Dietary Exposure
Copper pesticides are formulated into various forms of copper, i.e., different salts and
complexed forms, which ultimately dissociates into the cupric ion, the active component of
concern. It is one of the micronutrients essential to human health. Copper is ubiquitous in the
environment and naturally occurs in many food sources such as nuts, organ meats and grains.
Copper may also be found in drinking water, commonly due to the use of copper plumbing
fixtures and water pipes. The EPA's Office of Water regulates contaminants in water, with 1.3
parts per million set as the Maximum Contaminant Level Goal for copper.
Current available literature and studies do not indicate any systemic toxicity associated
with dietary exposures to copper. However, some genetic disorders such as Wilson's Disease,
Occipital Horn Syndrome, Tyrolean Infantile Cirrhosis, Indian Childhood Cirrhosis, Idiopathic
Copper Toxicosis, can disrupt the metabolism of copper in the human body. Generally, current
available data and literature studies indicate that there is a greater risk from the deficiency of
copper intake than from excess intake. Given the role copper plays as an essential element to the
human body, its ubiquitous nature in food and drinking water, and the lack of systemic toxicity
resulting from copper, acute and chronic dietary endpoints were not selected. Thus, a
quantitative toxicity assessment was not conducted for dietary, dermal, oral or inhalation
exposures.
Aggregate Risk
Aggregate risk refers to the combined risk from dietary (food and drinking water) and
residential or other non-occupational exposures. Aggregate risk can result from one-time
(acute), short-term or chronic exposures. Because of the lack of systemic toxicity, expected
copper exposures at concentrations from combined pesticide sources do not pose any health risks
of concern.
Occupational and Residential Exposure
Some copper species and formulations containing copper compounds may cause acute
dermal and eye irritation in exposed individuals. Workers can be exposed to copper pesticides
through mixing, loading and/or applying the pesticide (handlers) or re-entering treated sites.
Exposure may also occur to residential handlers from home-use products.
Ecological Risks
Aquatic Organisms
Copper is highly toxic to most aquatic species. The main cause of copper toxicity to fish
and aquatic invertebrates is through rapid binding of copper to the gill membranes, which causes
damage and interferes with osmoregulatory processes. The amount of cupric ion in the
environment, and its toxicity to aquatic animals through gill damage, is dependent on a number
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of water quality parameters including pH, alkalinity, and dissolved organic carbon. To assess
copper exposures to aquatic animals in freshwater bodies, the EPA's Office of Pesticides
Program worked with the Office of Water in utilizing the Biotic-Ligand Model to estimate site-
specific copper levels to which aquatic animals may be exposed. Both acute and chronic risk
quotients (RQs) were exceeded for almost all test species assessed. As expected of copper as an
algaecide, copper is very toxic to algae. In algae, it causes increased permeability of the cell
membrane and leakage of the cell contents. However, the assessment does not indicate a risk of
concern to freshwater vascular plants or estuarine/marine plants.
Terrestrial Organisms
The screening-level ecological risk assessment suggests potential acute and chronic risks
of concern to terrestrial animals exposed to copper resulting from use as an agricultural pesticide.
There is some uncertainty in the finding of risk to birds and mammals because, although copper
is toxic at high concentrations, it is also an important essential trace element for terrestrial
animals. Many terrestrial animals have the ability to cope with some amount of excess copper
exposure by storing it in the liver and bone marrow. As indicated by the laboratory toxicity
studies, exposure to high levels of copper in the diet can overwhelm the ability of birds and
mammals to maintain homeostasis. However, animals which are repeatedly exposed to levels of
copper which do not cause permanent harm may undergo enzymatic adaptation which allows
them to cope with greater levels of exposure. RQs based on limited toxicity data for terrestrial
plants do not exceed the acute level of concern (LOG) from exposure through spray drift.
Available data from a honey bee acute toxicity study indicated that copper is practically nontoxic
to honey bees.
Risk Mitigation
Human Health
There are no human health risks of concern for dietary (food and drinking water)
exposures to the pesticidal uses of copper. However, some of the various copper compounds and
formulations may cause some dermal or eye irritation. To minimize potential irritation effects
from exposures to copper-containing pesticides in residential settings, precautionary language
will be added to labels. Based on acute toxicity studies conducted with each copper compound
and product, the appropriate Personal Protective Equipment (PPE), per the criteria outlined in the
Worker Protection Standard, are required based on the respective copper compound(s) in each
product. Workers that handle copper-containing pesticides within agricultural settings will
minimize exposures by using the appropriate PPE. The Agency is also updating the Restricted
Entry Interval for the respective copper compound, depending on the available acute toxicity
data for that copper specie.
Ecological Risk
To reduce ecological exposures, registrants have agreed to amend their labels, including
the reduction of application rates, defining application intervals, and determining seasonal
maximum application rates. Label language restricting spray applications of copper pesticides
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under certain weather conditions, and advisory language describing steps users can take to
minimize spray drift, will be added to the labels for copper pesticides. In addition, advisory
language will be added to copper pesticide product labels to inform users of surface water quality
conditions which can lead to greater bioavailability and toxicity of copper to non-target aquatic
organisms.
Data Requirements
The generic data base supporting the reregi strati on of coppers has been reviewed and
determined to be substantially complete. However, one data gap, the UV/VIS Absorption study
(Guideline 830.7050), remains. This study will be included in the generic DCI for this RED,
which the Agency intends to issue at a future date. In addition, registrants are required to submit
updated product labels and Confidential Statements of Formula.
Regulatory Conclusion
The Agency has determined that copper-containing products of cases 0636, 0649, 4025,
and 4026, are eligible for reregi strati on provided that the risk mitigation measures are adopted
and labels are amended to reflect these measures.
For More Information
Electronic copies of the Coppers RED and all supporting documents are available in the
public docket EPA-HQ-OPP-2005-0558 located on-line in the Federal docket system at
http://www.regulations.gov.
For more information about EPA's pesticide reregistration program, the Coppers RED, or
reregi strati on of individual products containing copper-containing pesticides, please contact the
Special Review and Reregistration Division (7508P), Office of Pesticide Programs, U.S. EPA,
Washington, D.C. 20460, telephone 703-308-8000.
For information about the health affects of pesticides, of for assistance in recognizing and
managing pesticide poisoning symptoms, please contact the National Pesticide Information
Center. Call toll-free 1-800-858-7378, from 6:30 am to 4:30 pm Pacific Time, or 9:30 am to
7:30 pm Eastern Standard Time, seven days a week. The NPIC internet address is
http^/nnic.orjitedu.
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