Copper is widely used in its elemental metallic form, in metal alloys, and in the form of copper salts. Each of the copper forms has different physical properties, resulting in different toxicities. Elemental metallic copper is used in electrical wiring and plumbing materials and was formerly the main constituent of pennies (now mostly zinc). Copper salts such as copper sulfate, copper oxide, copper chloride, copper nitrate, copper cyanide, and copper acetate are used as pesticides and algaecides and in a variety of industrial processes. Because of its toxicity, copper sulfate is no longer used as an emetic. Copper levels may be elevated in persons who drink from copper containers or use copper plumbing. The increased acidity of beverages stored in copper alloy (eg, brass or bronze) containers enhances leaching of copper into the liquid.

1. Elemental metallic copper is poorly absorbed orally and is essentially nontoxic. However, inhalation of copper dust or metallic fumes created when copper alloys are welded or brazed may cause chemical pneumonitis or a syndrome similar to metal fume fever. Metallic copper dust in the eye (chalcosis) may lead to corneal opacification, uveitis, ocular necrosis, and blindness unless the dust is removed quickly.
2. Copper sulfate salt is highly irritating, depending on the concentration, and may produce mucous membrane irritation and severe gastroenteritis.
3. Systemic absorption can produce hepatic and renal tubular injury. Hemolysis has been associated with copper exposure from hemodialysis equipment or absorption through burned skin.

Copper is an essential trace metal. The daily adult requirement of 2 mg is supplied in a normal diet.

1. Inhalation. The recommended workplace limit (ACGIH TLV-TWA) for copper fumes is 0.2 mg/m³; for dusts and mists, it is 1 mg/m³. The air level considered immediately dangerous to life or health (IDLH) for dusts or fumes is 100 mg/m³.
2. Ingestion of more than 250 mg of copper sulfate can produce vomiting, and larger ingestions potentially can cause hepatic and renal injury.
3. Water. The US Environmental Protection Agency (EPA) has established a safe limit of 1.3 mg/L in drinking water under the Lead and Copper Rule. According to the EPA, this has led to the reduction in risk of copper exposure that can cause stomach and intestinal distress, liver or kidney damage, and complications of Wilson disease in genetically predisposed people. The WHO (World Health Organization, 2004) guideline value for drinking water is 2 mg/L.

1. Inhalation of copper fumes or dusts initially produces a metallic taste and upper respiratory irritation (dry cough, sore throat, and eye irritation). Large exposures may cause severe cough, dyspnea, fever, leukocytosis, and pulmonary infiltrates (see also “Metal Fume Fever,”).
2. Ingestion of copper sulfate or other salts causes the rapid onset of nausea and vomiting with characteristic blue-green vomit. Gastrointestinal bleeding may occur. Fluid and blood loss from gastroenteritis may lead to hypotension and oliguria. Intravascular hemolysis can result in acute tubular necrosis. Hepatitis has been reported, caused by centrilobular necrosis. Multisystem failure, shock, and death may occur. Chronic interstitial nephritis has been reported after parenteral copper sulfate poisoning. Methemoglobinemia is uncommon. Reduced serum cortisol level with adrenal insufficiency has been reported, but its relation to copper toxicity is uncertain.
3. Chronic exposure to Bordeaux mixture (copper sulfate with hydrated lime) may occur in vineyard workers. Pulmonary fibrosis, lung cancer, cirrhosis, angiosarcoma, and portal hypertension have been associated with this occupational exposure.
4. Ingestion of organocopper compounds is rare. Suicidal ingestion of an organocopper fungicide containing primarily copper-8-hydroxyquinolate caused lethargy, dyspnea, and cyanosis, with 34% methemoglobinemia.
5. Swimming in water contaminated with copper-based algaecides can cause green discoloration of the hair.

Is based on a history of acute ingestion or occupational exposure. Occupations at risk include those associated with handling algaecides, herbicides, wood preservatives, pyrotechnics, ceramic glazes, and electrical wiring, as well as welding or brazing copper alloys.

1. Specific levels. If copper salt ingestion is suspected, a serum copper level should be obtained. Normal serum copper concentrations average 1 mg/L, and this doubles during pregnancy. Serum copper levels above 5 mg/L are considered very toxic. Whole-blood copper levels may correlate better with acute intoxication because acute excess copper is carried in the red blood cells; however, whole-blood copper levels are not as widely available. Normal serum copper levels have been reported even in the face of severe acute toxicity.
2. Other useful laboratory studies include CBC, electrolytes, BUN, creatinine, hepatic aminotransferases (ALT and AST), arterial blood gases or oximetry, and chest radiograph. If hemolysis is suspected, send blood for type and crossmatch, plasma-free hemoglobin, and serum haptoglobin and check urinalysis for occult blood (hemoglobinuria).

1. Emergency and supportive measures
   1. Inhalation of copper fumes or dusts. Give supplemental oxygen if indicated by arterial blood gases or oximetry and treat bronchospasm and chemical pneumonitis if they occur. Symptoms are usually short lived and resolve without specific treatment.
   2. Ingestion of copper salts
      1. Treat shock caused by gastroenteritis with aggressive IV fluid replacement and, if necessary, pressor drugs.
      2. Consider endoscopy to rule out corrosive esophageal or stomach injury, depending on the concentration of the solution and the patient's symptoms.
      3. Blood transfusion may be needed if significant hemolysis or GI bleeding occurs.
2. Specific drugs and antidotes
   1. BAL (dimercaprol) and penicillamine are effective chelating agents and should be used in seriously ill patients with large ingestions.
   2. Trientine hydrochloride is a specific copper chelator approved for use in Wilson disease; although it is better tolerated than penicillamine, its role in acute ingestion or chronic environmental exposure has not been established.
   3. Unithiol (DMPS) has been used, but its efficacy is unclear. Because DMPS and its heavy metal complexes are excreted predominantly by the kidney, caution should be exercised in patients with renal failure.
3. Decontamination
   1. Inhalation. Remove the victim from exposure and give supplemental oxygen if available.
   2. Eyes. Irrigate copiously and attempt to remove all copper from the surface; perform a careful slit-lamp examination and refer the case to an ophthalmologist urgently if any residual material remains.
   3. Ingestion. Perform gastric lavage if there has been a recent ingestion of a large quantity of copper salts. There is no proven benefit for activated charcoal, and its use may obscure the view if endoscopy is performed.
4. Enhanced elimination. There is no role for hemodialysis, hemoperfusion, repeat-dose charcoal, or hemodiafiltration. Hemodialysis may be required for supportive care of patients with acute renal failure, and it can marginally increase the elimination of the copper-chelator complex.