A hydrofluoric acid burn is a

chemical burn A chemical burn occurs when living tissue is exposed to a corrosive substance (such as a strong acid, base or oxidizer) or a cytotoxic agent (such as mustard gas, lewisite or arsine). Chemical burns follow standard burn classification and may ca ...

from

hydrofluoric acid Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly Corrosive substance, corrosive. It is used to make most fluorine-containing compounds; examples include th ...

. Where it contacts the skin it results in significant pain, swelling, redness, and skin breakdown. If the fumes are breathed in swelling of the upper airway and bleeding may occur. Complications can include

electrolyte An electrolyte is a medium containing ions that is electrically conducting through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water. Upon dis ...

, heart, lung, kidney, and neurological problems. Most exposures occur at work. With concentrations less than 7%, onset of symptoms may not occur for hours while with concentrations greater than 15% onset of symptoms is nearly immediate. Diagnosis should include blood tests for calcium, potassium, and magnesium along with an electrocardiogram. Initial treatment of exposure involves removing contaminated clothing and washing with large amounts of water over at least 30 minutes. Other measures include applying

calcium gluconate Calcium gluconate is a mineral supplement and medication. As a medication it is used by injection into a vein to treat low blood calcium, high blood potassium, and magnesium toxicity. Supplementation is generally only required when there is no ...

cream. It is estimated that about a thousand cases occur each year. Most people affected are adult males.

Signs and symptoms

Symptoms of HF exposure include irritation of the eyes, skin, nose, and throat, eye and skin burns, and bone damage. Complications may occur due to

fluoride toxicity Fluoride toxicity is a condition in which there are elevated levels of the fluoride ion in the body. Although fluoride is safe for dental health at low concentrations, sustained consumption of large amounts of soluble fluoride salts is danger ...

. Once absorbed into blood through the skin, it reacts with blood calcium and may cause cardiac arrest. Burns with areas larger than 160 cm² (25 square inches) have the potential to cause serious systemic toxicity from interference with blood and tissue calcium levels. In some cases, exposures can lead to

hypocalcemia Hypocalcemia is a medical condition characterized by low calcium levels in the blood serum. The normal range of blood calcium is typically between 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L) while levels less than 2.1 mmol ...

. Breathing in the HF fumes can result in fevers,

pulmonary edema Pulmonary edema, also known as pulmonary congestion, is excessive edema, liquid accumulation in the parenchyma, tissue and pulmonary alveolus, air spaces (usually alveoli) of the lungs. It leads to impaired gas exchange and may cause hypoxemia an ...

(fluid buildup in the lungs), bleeding, and low blood oxygen.

Cause

Hydrogen fluoride is used in a number of industries including glass etching and electronics manufacturing. It is generated upon combustion of many fluorine-containing compounds such as products containing Viton and

polytetrafluoroethylene Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemour ...

(Teflon) parts.

Hydrofluorocarbon Hydrofluorocarbons (HFCs) are man-made organic compounds that contain fluorine and hydrogen atoms, and are the most common type of organofluorine compounds. Most are gases at room temperature and pressure. They are frequently used in air conditi ...

s in

automatic fire suppression Automatic fire suppression systems control and extinguish fires without human intervention. Examples of automatic systems include fire sprinkler system, gaseous fire suppression, and condensed aerosol fire suppression. When fires are extinguished ...

systems can release hydrogen fluoride at high temperatures, and this has led to deaths from acute

respiratory failure Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise ...

in military personnel when a

rocket-propelled grenade A rocket-propelled grenade (RPG) is a shoulder-fired missile weapon that launches rockets equipped with an explosive warhead. Most RPGs can be carried by an individual soldier, and are frequently used as anti-tank weapons. These warheads are a ...

hit the fire suppression system in their vehicle. Hydrofluoric acid can be released from volcanoes, sea salt aerosol, and from welding or manufacturing processes.

Pathophysiology

In the body, hydrofluoric acid reacts with the ubiquitous biologically important

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s Ca²⁺ and Mg²⁺. Formation of insoluble

calcium fluoride Calcium fluoride is the inorganic compound of the elements calcium and fluorine with the formula CaF2. It is a white insoluble solid. It occurs as the mineral fluorite (also called fluorspar), which is often deeply coloured owing to impurities. ...

is proposed as the cause for both precipitous fall in serum calcium and the severe pain associated with tissue toxicity.Hoffman, Robert S. ''et al.'' (2007) ''Goldfrank's Manual of Toxicologic Emergencies''. New York: McGraw-Hill Professional, p. 1333, .

Diagnosis

Diagnosis should include blood tests for calcium, potassium, and magnesium along with an electrocardiogram (ECG). ECG changes may include QRS widening and a prolonged QT interval.

Treatment

Initial treatment of exposure involves removing contaminated clothing and washing the affected area with large amount of water over at least 30 minutes.

Calcium gluconate Calcium gluconate is a mineral supplement and medication. As a medication it is used by injection into a vein to treat low blood calcium, high blood potassium, and magnesium toxicity. Supplementation is generally only required when there is no ...

cream is then usually applied. If pain continues calcium gluconate can be injected into the affected area or given by injection into a vein or artery. Surgical removal of the affected tissue may be required. The calcium gluconate is a source of Ca²⁺ that sequesters the fluoride ions. Other special rinsing solutions may also be used. An element that has been very useful to avoid the adverse effects of chemical burns and counteract the effect of calcium precipitation is the Hexafluorine solution, which is recommended to implement in laboratory kits, along with first aid items and emergency showers. Inhaled HF may require

oxygen therapy Oxygen therapy, also known as supplemental oxygen, is the use of oxygen as medical treatment. Acute indications for therapy include hypoxemia (low blood oxygen levels), carbon monoxide toxicity and cluster headache. It may also be prophylactica ...

and

tracheal intubation Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic catheter, tube into the vertebrate trachea, trachea (windpipe) to maintain an open airway or to serve as a conduit through which to administer ce ...

. In this situation neutralized calcium gluconate may be used. In absolutely all cases, it should be treated in an advanced medical manner after first aid has been rendered.

References

{{Reflist Burns Wikipedia medicine articles ready to translate Fluorine Toxic effects of substances chiefly nonmedicinal as to source