Zinc Poisoning: What to Know

Medically Reviewed By William C. Lloyd III, MD, FACS
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Zinc is an important mineral for a number of functions involving energy and metabolism. Like any substance, it can be toxic in excessive amounts. Symptoms of acute zinc poisoning include nausea, vomiting, diarrhea, and abdominal pain. Overall, zinc poisoning is rare.

This article explores zinc poisoning in more detail, including the symptoms it causes and how to treat it.

What is zinc poisoning?

A picture of pills spelling out the zinc element symbol
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Zinc is an essential mineral because the body needs it to make hundreds of enzymes. It is critical in supporting the immune system. It also plays a role in carbohydrate breakdown to supply energy and cell growth, division, and reproduction.

Zinc is also a metal with many common industrial applications, such as welding, soldering, and alloy production. Excessive exposure to zinc in these settings can be hazardous and result in poisoning. “Metal fume fever” and “zinc shakes” are common names for this type of occupational exposure. 

Although rare, it is also possible to consume too much zinc in the diet. 

Zinc poisoning can be a life threatening emergency. Seek immediate medical care (call 911) for serious symptoms, such as vomiting, profuse sweating, or difficulty urinating.

What are the symptoms of zinc poisoning?

Zinc poisoning can be acute or chronic. 

Acute zinc poisoning

Acute zinc poisoning can result from taking large amounts at once. Some common symptoms of acute zinc poisoning include:

Doses of 225 milligrams (mg) or more usually result in vomiting, including vomiting blood. This can occur within 30 minutes of ingestion.

Kidney injury, liver damage, and bleeding or blood clotting problems can also occur.

When the poisoning is due to inhaling zinc fumes, symptoms can include:

These symptoms usually begin within 4–8 hours of inhalation. They can last for up to 24 hours after the exposure to zinc fumes ends.

Chronic zinc poisoning

Chronic zinc poisoning can result from long-term daily intakes of higher-than-normal doses. For a healthy adult age 19 years or older, the tolerable upper limit for daily zinc is 40 mg. A sustained intake above this dose can cause health problems.

Some common effects of chronic zinc poisoning include:

  • changes in urinary function, which may require hospitalization
  • copper deficiency, as zinc toxicity interferes with normal copper absorption
  • iron function problems and anemia due to red blood cells that are smaller than usual
  • low levels of high-density lipoprotein, or “good,” cholesterol
  • reduced immune function due to low levels of white blood cells

Symptoms of acute and chronic zinc poisoning can be very serious, and they warrant immediate medical attention. 

What causes zinc poisoning?

Zinc poisoning happens when zinc reaches toxic levels in the body. Most cases of zinc poisoning are accidental ingestions in children under 5 years of age.

Zinc poisoning is rare in people who eat a regular diet. However, it can occur if you consume contaminated foods or beverages. High zinc supplementation or a daily diet that exceeds the recommended daily zinc requirement can also cause poisoning. 

Denture adhesive creams are other potential sources of zinc. Excessive use of zinc-containing creams could result in zinc toxicity.

You can also get zinc poisoning by inhaling industrial fumes containing zinc. Occupational activities that can lead to exposure include welding, soldering, and alloy production.

How to prevent zinc poisoning

Zinc poisoning is a dangerous and potentially life threatening condition. It is best to avoid zinc toxicity through basic preventive measures.

For example, prevention starts with taking in a normal amount of zinc. The recommended daily allowance (RDA) for zinc is 11 mg for adult males and 8 mg for adult females who are not pregnant or lactating. In pregnancy, the RDA is 11 mg per day. It is higher for lactation, at 12 mg per day.

The tolerable upper limit for adults is 40 mg of zinc per day. To prevent zinc toxicity, do not exceed this amount.

Read and follow all dosing instructions for vitamins and minerals containing zinc. If you use denture adhesives, look for reformulated products that do not contain zinc.

In the workplace, you can reduce your risk of zinc poisoning by following all safety protocols. 

How do doctors treat zinc poisoning?

If you or someone you know has taken too much zinc or had a zinc exposure, call Poison Control (800-222-1222). Do not wait until there are symptoms of poisoning. 

Be ready to inform a healthcare professional about the source of the zinc, whether it was exposure or ingestion. Also, convey the estimated time and level of exposure or ingestion. Poison Control may also need the person’s height and weight. 

If the person is not breathing or conscious, call 911.

There is currently no antidote for zinc poisoning. Instead, the treatment is mainly supportive, including:

  • antinausea medications
  • bronchodilators and supplemental oxygen to help with breathing problems
  • chelation medications to bind zinc
  • copper sulfate (for chronic zinc toxicity)
  • fever reducers
  • fluids, either by mouth or through a vein
  • proton pump inhibitors and H2-blockers to reduce stomach acid and the digestion of zinc

In some cases, doctors may use whole bowel irrigation to decontaminate the digestive system. When someone has ingested a foreign body, surgery may be necessary to remove it. A penny is an example of a zinc-containing foreign body.

What are the potential complications of zinc poisoning?

Zinc poisoning is unlikely to be fatal. However, the outcome can depend on how quickly you seek treatment. With immediate treatment, you are much more likely to make a full recovery.  

Possible complications of zinc poisoning include:

Summary

Zinc poisoning is a rare condition. It usually occurs in young children who accidentally ingest zinc. However, it can also happen with long-term intakes of zinc that exceed the safe upper limit of 40 mg per day. Occupational exposures are also possible.

Digestive symptoms are common with zinc poisoning. Treatment is mainly supportive, focusing on relieving the symptoms.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2022 Mar 30
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