Hydrofluoric acid is a combination of hydrogen fluoride in water; it is used mainly for industrial purposes such as glass etching, metal cleaning and pesticide production. It's also found in house hold uses such as rust removers and heavy duty cleaners and aluminum brighteners.
Hydrofluoric acid is a weak acid that exists predominantly in the undissociated state that enables the acid to penetrate deep in the skin and soft tissue. Liquefactive necrosis of soft tissue and bones is caused when fluoride is liberated from hydrofluoric acid in tissue. Electrolyte disturbance can happen when the free fluoride ion binds to calcium and magnesium ions. Systemic toxicity can result from exposure to HF due to its ability to penetrate tissue, the degree of toxicity depend on the duration of exposure, the concentration of HF, the exposure route and the size of surface area affected. Any co morbidities should be considered with these factors to determine poisoning severity and treatment type to be given.
Clinical features of exposure to HF:
From touching the acid:
This type of exposure is the most common type in which the digits of the fingers are the parts of the body affected. The clinical features depend on the concentration of HF the person is exposed to. If the concentration was more than 50% there will be immediate pain with the skin becoming erythematous (Red) within minutes and blistering and edema (swollen) within hours. In severe burns there will be a central grey area of coagulative necrosis. It may take up to 8 hours for erythema and pain to develop at the site of contact when the concentration is between 20-50%. If the concentration is less than 20% symptoms may take more than 24 hours to appear. Burns from HF may be very painful and out of proportion to the burn appearance.
From swallowing the acid:
- Nausea and vomiting.
- Inability to breathe as a result of swelling of the throat.
- Severe pain in the mouth and throat.
- Severe abdominal pain.
- Rapid decrease in blood pressure.
- Perforation of viscus.
- Inflammation and bleeding of the stomach.
From inhaling the acid:
- Bluish discoloration of the fingernails and lips.
- Tightness of the chest.
- Difficulty in breathing.
- Fluid in the lung (pulmonary edema).
- Acute respiratory distress syndrome.
- Lung hemorrhage.
This information is not intended nor implied to be a substitute for professional medical advice; it should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. Call 911 for all medical emergencies.