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Publication #PI-66

Pesticide Toxicity Profile: Copper-based Pesticides1

Frederick M. Fishel2

This document provides a general overview of use patterns and human toxicity, a listing of laboratory animal and wildlife toxicities, and a cross reference of the specific uses and common names of copper-based pesticides registered for use in Florida.

General

Pesticides containing copper have a historical significance in that the fungicidal properties of "Bordeaux mixture," named after the Bordeaux region in France, were accidentally discovered. When Bordeaux mixture, a chemically undefined mixture of copper sulfate and hydrated lime, was applied to grapes to discourage local pilfering, it was observed that downy mildew disappeared from the treated plants. It was from this serendipitous event that commercialization of fungicides originated. Today, Bordeaux mixture is still sold commercially, and there are approximately 15 various active ingredients registered for use in Florida that contain some form of copper, depending on how their composition is defined. Because the inorganic forms of copper are relatively water insoluble, they do not wash easily from foliage, thus providing longer protection against disease than many other compounds. Copper is relatively safe from a handling perspective, but there is some concern regarding its buildup in agricultural soils. In Florida, certain citrus areas have experienced problems of copper toxicity on sites that had been treated with fixed copper for disease control for many years. With their wide range of uses, compounds of copper form one of the most useful groups of pesticides. They are used in home and industrial environments for control of algae in various water bodies including backyard swimming pools; they are applied to boat hulls to resist marine and fresh water organisms; and they are used for control of aquatic weeds, for wood preservative treatments, and for control of many fungal and bacterial diseases in fruits, vegetables, ornamentals, and field crops. Table 1 summarizes the uses of available copper-based pesticides registered in Florida. Because there are numerous trade names of products that contain some form of a copper compound as their active ingredient, the reader is referred to the Florida Department of Agriculture and Consumer Services' (FDACS) Pesticide Information Retrieval System at http://state.ceris.purdue.edu/ [3 April 2014]. FDACS keeps this system up to date; therefore it is an accurate reflection of products registered for use in Florida at any given time. Product formulations of copper-based pesticides include aqueous solutions, wettable powders, dry flowables, dusts, flowables, water-dispersible granules, emulsifiable concentrates, and granules.

Toxicity

The dust and powder formulations of copper compounds are irritating to the skin, respiratory tract, and particularly the eyes. Limited solubility and absorption probably account for the generally low systemic toxicity of most compounds. Irritant effects from occupational exposures to copper-based pesticides have been fairly frequent, including allergic reactions, itching, and eczema. Most of what is known about mammalian toxicity of copper-based pesticides has come from veterinary toxicology. Livestock seem uniquely vulnerable to copper's effects. Deliberate ingestion of copper for suicidal purposes in humans has been reported; accidental ingestion has occurred through food or water that had been contained in copper vessels. Early signs and symptoms of copper poisoning include a metallic taste, nausea, vomiting, and abdominal pain. Chronic effects have been reported with vineyard workers who experienced liver disease after 3 to 15 years of exposure to Bordeaux mixture. The EPA does not require data on the teratogenic, mutagenic, carcinogenic, and reproductive effects on mammals for many of the copper-based pesticides. Mammalian toxicities for the copper-based pesticides are shown in Table 2, if available. Table 3 lists the toxicities to wildlife by the common name of the pesticide.

Additional Information

Tables

Table 1. 

Use patterns of copper-based pesticides registered in Florida.

Copper-based pesticide

Use pattern(s)

Copper (metallic)

Algaecide, antifouling paint

Copper (metallic in the form of chelates of copper citrate and copper gluconate)

Algaecide, bactericide, fungicide

Copper carbonate

Algaecide, herbicide, wood preservative

Copper ethanolamine complex

Algaecide, wood preservative

Copper ethylenediamine complex

Herbicide

Copper hydroxide

Antifouling paint, bactericide, fungicide, plant growth regulator, wood preservative

Copper naphthenate

Wood preservative

Copper oxychloride

Algaecide, bactericide, fungicide

Copper salts of fatty and rosin acids

Bactericide, fungicide

Copper sulfates

Algaecide, bactericide, desiccant,fungicide, herbicide

Copper triethanolamine complex

Algaecide

Copper oxides

Algaecide, antifouling paint, wood preservative

Table 2. 

Copper-based pesticide mammalian toxicities (mg/kg of body weight).

Common name

Rat oral LD50

Rabbit dermal LD50

Copper (metallic)

---

---

Copper (metallic in the form of chelates of copper citrate and copper gluconate)

---

---

Copper carbonate

---

---

Copper ethanolamine complex

0.5 – 2

---

Copper ethylenediamine complex

680

700

Copper hydroxide

1,000 – 2,000

---

Copper naphthenate

>5,000

2,000 – 20,000

Copper oxychloride

1,470

---

Copper salts of fatty and rosin acids

---

---

Copper sulfates

30

---

Copper triethanolamine complex

>1,300

---

Copper oxides

1,500

---

Table 3. 

Copper-based pesticide wildlife toxicity ranges.

Common name

Bird acute oral LD50 (mg/kg)*

Fish (ppm)**

Bee

Copper (metallic)

---

MT

---

Copper (metallic in the form of chelates of copper citrate and copper gluconate)

---

---

---

Copper carbonate

---

MT - VHT

---

Copper ethanolamine complex

---

ST - HT

---

Copper ethylenediamine complex

---

---

---

Copper hydroxide

ST – PNT

---

---

Copper naphthenate

PNT

HT

---

Copper oxychloride

---

---

PNT

Copper salts of fatty and rosin acids

ST – PNT

MT – HT

---

Copper sulfates

MT – PNT

MT – VHT

---

Copper triethanolamine complex

PNT

MT – VHT

---

Copper oxides

PNT

ST

PNT

*Bird LD50: Practically nontoxic (PNT) = >2,000; slightly toxic (ST) = 501 – 2,000; moderately toxic (MT) = 51 – 500; highly toxic (HT) = 10 – 50; very highly toxic (VHT) = <10.

**Fish LC50: PNT = >100; ST = 10 – 100; MT = 1 – 10; HT = 0.1 – 1; VHT = <0.1.

Bee: HT = highly toxic (applied product and residues kill upon contact); MT = moderately toxic (kills if applied over bees); PNT = relatively nontoxic (relatively few precautions necessary).

Footnotes

1.

This document is PI-66, one of a series of the Agronomy Department, UF/IFAS Extension. Original publication date September 2005. Revised March 2014. Reviewed March 2014. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Frederick M. Fishel, professor, Agronomy Department, and director, Pesticide Information Office; UF/IFAS Extension, Gainesville, FL 32611.

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition. Use pesticides safely. Read and follow directions on the manufacturer's label.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.