| ||||||||||||||||||
| Amonium bifluoride | Potassium bifluoride | Sodium bifluoride | |
|---|---|---|---|
CA Index Name |
Ammonium fluoride ((NH4)(HF2)) |
Potassium fluoride (K(HF2)) | Sodium fluoride (Na(HF2)) |
| CAS Registry Number | 1341-49-7 |
7789-29-9 | 1333-83-1 |
RTECS Number |
BQ9200000 |
TS6650000 | |
EINECS number |
215-676-4 |
232-156-2 | 215-608-3 |
UN Number |
1727 |
1811 | 2439 |
ICSC Number |
|||
| CWC Schedule: not listed | |||
| Warning Symbols | |
|---|---|
|
|
| Toxic | Corrosive |
| Synonyms | ||
|---|---|---|
| Ammonium bifluoride | Potassium bifluoride | Sodium bifluoride |
|
|
|
CHEMICAL AND PHYSICAL PROPERTIES
| Structural Formula |  |
 |
 |
| Ammonium bifluoride | Potassium bifluoride | Sodium bifluoride | |
|---|---|---|---|
| Appearance | White crystals or clear fuming liquid. | Fine, white, granular crystals | |
| Molecular Formula |
NH4.FH2 | |
NaHF2 |
| Molecular Weight |
57 | 62 | |
| Melting Point |
126°C | Decomposes at 160°C | |
| Boiling Point |
230°C | ||
| Vapor Density |
1.3 | 2.08 | |
| Liquid Density |
1.2 | ||
| Vapor pressure | 5 kPa at 15°C | ||
| Not flammable | |||
| NFPA Hazard Ratings | ||||
|---|---|---|---|---|
SPECIAL |
||||
| Ammonium bifluoride | 0 | 3 | 2 | * |
| Potassium bifluoride | 0 | 3 | 0 | * |
| Sodium bifluoride | 0 | 3 | 1 | * |
Also refer to 2004 Emergency Response Guidebook (ERG2000) Guide 154.
|
| No specific recommendations for any of these materials. |
Health Hazards
Bifluorides are considered toxic although they are not well characterized. Potassium bifluoride is not listed in the TSCA (Toxic Substances Control Act) inventory on the US. They are all considered irritating to the skin and lungs and toxic by inhalation. Chronic overexposure can lead to fluorosis, in which fluorine replaces other components of bone and teeth. Fluorosis was common in workers involved in G-agent manufacture in Germany in World War II. Even though they are not flammable, they may decompose in fire and under certain conditions to yield hazardous products including hydrogen fluoride.
Risk and Safety Phrases.
| Applicable to ammonium bifluoride and potassium bifluoride |
|---|
|
INDUSTRIAL/COMMERCIAL USES
Ammonium bifluoride is considered a high production volume material with annual manufacture exceeding 1 million pounds (500 tons.) It is used mainly in industrial inorganic chemistry, especially in the processing of alloys and in glass etching. It is also used in oil drilling where it is used to improve yields of crude oil from some types of rock and in some harsh cleaning solutions and as a sterilant for food and dairy equipment. Bifluorides are also used in the manufacture of wood preservatives and in soldering fluxes.
COMMENTS
Bifluorides are used as a source of the fluorine atom in the synthesis of all of the G-type nerve agents except Tabun, in which the fluorine atom is replaced by a cyanide group. All bifluorides are synthesized from ammonium bifluoride. Ammonium bifluoride is in turn made from ammonium fluoride which is made by the reaction of ammonium hydroxide with hydrofluoric acid (HF.) Ammonia is manufactured on an extremely large scale (>10 million tons per annum in the US) using the Haber process, for which Fritz Haber (who played a major role in the German chemical weapons program in World War I) won a Nobel Prize. Worldwide hydrogen fluoride manufacture is approximately 400,000 tons. The quantities needed for manufacture of a stockpile of G agent would be miniscule in comparison.
Ammonium fluoride is converted to the bifluoride by dehydrating an aqueous solution of ammonium fluoride. The other bifluorides are manufactured by essentially the same process, except that the water, and the more volatile ammonia, are driven off in the presence of a sodium or potassium compound.
Copyright© 1999-2004 CBWInfo.com
|