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Sodium hydroxide poisoning

Sodium hydroxide is a very strong chemical. It is also known as lye and caustic soda. This article discusses poisoning from touching, breathing in (inhaling), or swallowing sodium hydroxide.

This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or the 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.

Poisonous Ingredient

Sodium hydroxide

Where Found

Sodium hydroxide is found in many industrial solvents and cleaners, including products to strip floors, brick cleaners, cements, and many others.

It may also be found in certain household products, including:

  • Aquarium products
  • Clinitest tablets
  • Drain cleaners
  • Hair straighteners
  • Metal polishes
  • Oven cleaners

Other products also contain sodium hydroxide.


Below are symptoms of sodium hydroxide poisoning or exposure in different parts of the body.


  • Breathing difficulty (from inhaling sodium hydroxide)
  • Lung inflammation
  • Sneezing
  • Throat swelling (which may also cause breathing difficulty)


  • Blood in the stool
  • Burns of the esophagus (food pipe) and stomach
  • Diarrhea
  • Severe abdominal pain
  • Vomiting, possibly bloody


  • Drooling
  • Severe pain in the throat
  • Severe pain or burning in the nose, eyes, ears, lips, or tongue
  • Vision loss


  • Collapse
  • Low blood pressure (develops rapidly)
  • Severe change in blood pH (too much or too little acid in the blood)
  • Shock


  • Burns
  • Hives
  • Irritation
  • Holes in the skin or tissue under the skin

Home Care

Seek medical help right away. DO NOT make a person throw up unless the poison control or a health care provider tells you to.

If the chemical is on the skin or in the eyes, flush with lots of water for at least 15 minutes.

If the chemical was swallowed, give the person water or milk right away, unless a provider tells you something different. Also, DO NOT give water or milk if the person is having symptoms that make it hard to swallow (such as vomiting, convulsions, or decreased alertness).

If the person breathed in the poison, move them to fresh air right away.

Before Calling Emergency

Have this information ready:

  • The person's age, weight, and condition
  • The name of the product (ingredients and strength if known)
  • The time it was swallowed
  • The amount swallowed

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 hotline number will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. 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

Take the container that contains the sodium hydroxide with you to the hospital, if possible.

The provider will measure and monitor the person's vital signs, including temperature, pulse, breathing rate, and blood pressure. Symptoms will be treated.

Treatment depends on how the poisoning occurred. Pain medicine will be given. Other treatments may also be given.

For swallowed poison, the person may receive:

  • Blood tests.
  • Chest x-ray.
  • ECG (electrocardiogram or heart tracing).
  • Endoscopy. The placement of a camera down the throat to see the extent of damage to the esophagus and the stomach.
  • Intravenous fluids (IV, fluids given through a vein).
  • Medicines to treat symptoms.

For inhaled poison, the person may receive:

  • Blood tests.
  • Breathing support, including oxygen and a tube through the mouth or nose into the lungs.
  • Bronchoscopy. Camera is placed down the throat to see damage to the airways and lungs.
  • Chest x-ray.
  • Intravenous fluids (IV, fluids given through a vein).
  • Medicines to treat symptoms.

For skin exposure, the person may receive:

  • Irrigation (washing of the skin). Perhaps every few hours for several days.
  • Skin debridement (surgical removal of burned skin).
  • Ointments applied to the skin.

For eye exposure, the person may receive:

  • Extensive irrigation to flush out the eye
  • Medicines

Outlook (Prognosis)

How well a person does depends on how fast the poison is diluted and neutralized. Extensive damage to the mouth, throat, eyes, lungs, esophagus, nose, and stomach are possible.

The long-term outcome depends on the extent of this damage. Damage to the esophagus and stomach continues to occur for several weeks after the poison was swallowed. Death may occur as long as a month later.

Keep all poisons in their original or childproof container, with labels visible, and out of the reach of children.

Alternative Names

Lye poisoning; Caustic soda poisoning


Agency for Toxic Substances and Disease Registry (ATSDR) website. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. Medical Management Guidelines for Sodium Hydroxide (NaOH). Updated October 21, 2014. Accessed April 10, 2023.

Hoyte C. Caustics. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 143.

Thomas SHL. Poisoning. In: Penman ID, Ralston SH, Strachan MWJ, Hobson RP, eds. Davidson's Principles and Practice of Medicine. 24th ed. Philadelphia, PA: Elsevier; 2023:chap 10.

Review Date 4/1/2023

Updated by: Jesse Borke, MD, CPE, FAAEM, FACEP, Attending Physician at Kaiser Permanente, Orange County, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.