Oxalic acid is a poisonous, colorless substance. It is chemical known as a caustic. If it contacts tissues, it can cause severe damage, such as burning or ulcers, on contact.
This article discusses poisoning from swallowing oxalic acid.
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.
Oxalic acid
Oxalic acid may be found in some:
Note: This list may not be all inclusive.
Symptoms of oxalic acid poisoning include:
Symptoms from getting oxalic acid on the skin or in the eyes include:
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 the chemical was swallowed, immediately give the person water or milk, unless instructed otherwise by a health care provider. DO NOT give water or milk if the person is having symptoms (such as vomiting, convulsions, or a decreased level of alertness) that make it hard to swallow.
If the chemical is on the skin or in the eyes, flush with lots of water (at least 2 quarts or 1.9 liters) for at least 15 minutes.
The following information is helpful for emergency assistance:
However, DO NOT delay calling for help if this information is not immediately available.
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.
The health care provider will measure and monitor vital signs, including temperature, pulse, breathing rate, and blood pressure. The person may receive:
Note: Activated charcoal does not effectively treat poisoning by acids.
For skin exposure, treatment may include:
Hospital admission may be needed. Surgery may be required if the esophagus, stomach, or intestines have developed holes (perforations) from exposure to the acid.
How well a person does depends on the amount of poison swallowed, how concentrated the poison is, and how quickly treatment was received. The faster a person gets medical help, the better the chance for recovery.
Severe damage to the mouth, gastrointestinal tract, or airway may occur and quickly cause death if not treated. Holes (perforations) in the esophagus and stomach may cause serious infections in both the chest and abdominal cavities, which may result in death. Surgery may be needed to repair the perforations.
Hoyte C. Caustics. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 143.