Definition

Mercuric oxide is a form of mercury. It is a type of mercury salt. There are different types of mercury poisonings. This article discusses poisoning from swallowing mercuric oxide.

This article is for information only. DO NOT use it to treat or manage an actual poison exposure. If you or someone you are with has an exposure, call the local emergency number (such as 911), or the local poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States.

Poisonous Ingredient

Mercuric oxide

Where Found

Mercuric oxide may be found in some:

• Button batteries (batteries containing mercury are no longer sold in the United States)
• Disinfectants
• Fungicides

There have been reports of inorganic mercury poisoning from the use of skin-lightening creams.

Note: This list may not be all inclusive.

Symptoms

Symptoms of mercuric oxide poisoning include:

• Abdominal pain (severe)
• Breathing difficulty (severe)
• Bloody diarrhea
• Decreased urine output (may stop completely)
• Drooling
• Metallic taste in the mouth
• Mouth sores (ulcers)
• Throat swelling (swelling may cause throat to close)
• Shock (extremely low blood pressure)
• Vomiting, including blood

Home Care

Seek immediate medical help. DO NOT make a person throw up unless told to do so by Poison Control or a health care professional. If clothing is contaminated with the poison, try to safely remove it while protecting yourself from contact with the poison.

Before Calling Emergency

The following information is helpful for emergency assistance:

• Person's age, weight, and condition (for example, is the person awake or alert?)
• Name of the product (ingredients and strengths, if known)
• Time it was swallowed
• Amount swallowed

However, DO NOT delay calling for help if this information is not immediately available.

Poison Control

Your local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. This national hotline will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

What to Expect at the Emergency Room

The health care provider will measure and monitor vital signs, including temperature, pulse, breathing rate, and blood pressure. Symptoms will be treated as appropriate. The person may receive:

• Airway support, including oxygen, breathing tube through the mouth (intubation), and breathing machine (ventilator)
• Blood and urine tests
• Camera down the throat (endoscopy) to see burns in the food pipe (esophagus) and stomach
• Chest x-ray
• ECG (electrocardiogram, or heart tracing)
• Fluids through a vein (intravenous or IV)
• Medicines to treat symptoms
• Medicines called chelators that remove mercury from the bloodstream and tissues, which may reduce long-term injury

Any person who swallowed a battery will need immediate x-rays to make sure the battery is not stuck in the esophagus. Most swallowed batteries that pass through the esophagus will pass out of the body in the stool without complication. However, batteries stuck in the esophagus can cause a hole in the esophagus very quickly, leading to serious infection and shock, which may be fatal. It is very important to seek immediate medical help after a battery is swallowed.

Outlook (Prognosis)

This substance is very poisonous. How well a person does depends on the amount of poison swallowed, what symptoms occur within the first 10 to 15 minutes after swallowing it, and how quickly treatment was received. The faster a person gets medical help, the better the chance for recovery. Kidney dialysis (filtration) through a machine may be needed if the kidneys do not recover after acute mercury poisoning. Kidney failure and death can occur, even from small doses.

If the poisoning has occurred slowly over time, any brain damage may be permanent.

Mercuric oxide poisoning can lead to multiple organ failure and death.

References

Kao LW, Rusyniak DE. Chronic poisoning: trace metals and others. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 19.

Theobald JL, Mycyk MB. Iron and heavy metals. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 146.