A colorless gas with a pungent odor.
Molecular Formula	HF	Molecular Weight	21
Boiling Point	19°C	Melting Point	-83°C
Vapor Density	0.7	Liquid Density	0.958
Vapor pressure	122 kPa at 22°C
Not flammable

Also refer to 2004 Emergency Response Guidebook (ERG2004) Guide 125.

Health Hazards

Hydrogen fluoride is toxic and irritating by inhalation, ingestion, and skin contact. It can damage any tissue it comes into contact with and exposure can be fatal, especially by inhalation. The burns caused by hydrogen fluoride are unusual and deep and need specialized treatment. Exposure to hydrogen fluoride can lead to the loss of calcium from bones and teeth (hypocalcemia.)

Risk and Safety Phrases.

INDUSTRIAL/COMMERCIAL USES

Hydrogen fluoride has a very wide range of uses. These include the manufacture of chlorofluorocarbons used as aerosol propellants, blowing agents to expand plastic foams, and solvents. It is also used as the fluorine donor in a variety of organic syntheses, including a number of pharmaceuticals, agrochemicals, polymers and elastomers. It is also used in the manufacture of inorganic fluorides including boron trifluoride, sulfur hexafluoride and fluoroborates.

The aluminum smelting industry also uses large quantities of hydrogen fluoride in the preparation of aluminum trifluoride and chrysolite.

It has a second use in weapons of mass destruction in the preparation of uranium hexafluoride gas for enrichment.

COMMENTS

Hydrogen fluoride is used to introduce the fluorine atom into G-type nerve agents including sarin. The reaction conditions for this stage in the synthesis are very demanding on the reaction vessel material. It is because of this that Germany was only able to produce limited quantities of sarin and soman compared to large quantities of Tabun, which replaces the fluorine with a cyanide group. Highly corrosion resistant superalloys, such as Hastelloy C (50-64% nickel, 15-17% molybdenum, 15% chromium, 4-7% iron, 3-4% tungsten) are now used for reaction vessels for such reactions. Plant made from these exotic alloys may be an indicator of chemical weapons manufacture.

Annual worldwide manufacture of hydrogen fluoride is about 900,000 tons for commerce, with about 200,000 tons manufactured on site for immediate use. Production has declined as the demand for chlorofluorocarbons has fallen and some plants have been closed.

Hydrogen fluoride is manufactured on a large scale by the action of sulfuric acid on the mineral fluorspar (fluorite or calcium fluoride). The chemistry of the reaction is not complicated, but the reaction is energetic and the engineering is challenging and high quality reagents are needed. Fluorite is widely distributed and sulfuric acid is also manufactured on a massive scale (US manufacture in 2002 was over 36 million tonnes.)