• hydrogen fluoride
• fluoric acid
• hydrofluoride
• hydrofluoric acid
• fluorine monhydride

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Hydrogen fluoride
Other names
Molecular formula	HF
Molecular Mass	20.01 g/mol
Physical State	Liquid
CAS number	7664-39-3
Density	0.922 kg m-3.
Solubility (water)	100% by weight
Melting point	-84°C (190 K, -118ºF)
Boiling point	19.54°C (293 K, 67.2ºF)
NFPA 704
Chemical infobox

Hydrogen fluoride, molecular formula HF, is a fluoride of hydrogen. It usually appears as a colourless liquid or gas and is a rather weak acid. It is used for fluorinating polymers, creating fluorocarbon products, petroleum refining, glassmaking, aluminium manufacturing, titanium pickling, quartz purification, and metal finishing. It is also used in processes separating uranium isotopes. Hydrogen fluoride can be found in consumer products for removing rust, cleaning brass and glass etching, though use in consumer products is discouraged due to the chemical's acidity and toxicity. Hydrogen fluoride is sold in three common forms: anhydrous HF, aqueous 70% HF, aqueous 49% HF. Honeywell is the largest producer of HF in the United States. The manufacture of HF is accomplished by the reaction of calcium fluoride (fluorspar) and sulphuric acid.

Health Effects

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Hydrogen fluoride is toxic to the human body and can be fatal if even small amounts are ingested or absorbed through the skin. HF burns require immediate and specialized medical treatment. HF acid burns are not similar to burns produced by hydrogen chloride (HCl), or other common acids. Onset time of symptoms of HF burns are proportional to concentration. Above 50% instantaneous effects are apparent. Between 20% and 50% clinical symptons may not appear for one to eight hours. Concentrations below 20% may not result in symptoms for 24 hours.

Entry routes include inhalation, ingestion, skin and eyes. Aside from burns to the eyes, skin, lungs, or digestive tract, the lowering of serum calcium (hypocalcemia) is one of the most serious consequences of HF exposure. As the free fluorine ion penetrates the skin it binds serum calcium forming cellular calcium fluoride (CaF₂). This has effects on nerve conduction and can lead to extreme throbbing pain, metabolic changes, and even death.

References

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External links

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Fluorides | Hydrogen compounds

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