Hydrogen Fluoride (HF)
Also called Fluoric acid, Hydrofluoride, Hydrofluoric, Fluorine monohydride.
Hydrogen fluoride is corrosive, pungent odour, toxic and irritating, non-flammable and non-explosive.
| Properties | ||
| Molecular formula Molar mass Appearance Density Melting point Boiling point Solubility in water Acidity Refractive index | HF 20.01 g mol-1 colourless gas 1.15 g/L, gas (25 °C) 0.99 g/mL, liquid (19.5 °C) -83.6 °C, 190 K, -118 °F 19.5 °C, 293 K, 67 °F miscible (pKa) 3.2 (nD) 1.00001 | |
Where it comes from
Hydrogen fluoride comes from the presence of F in raw materials or combustibles. Combustion of fluorinated polymers (Teflon) or textiles, decomposition of CaF2, raw materials (Glass). Also present in waste such as inert material, aluminium cans and synthetic tissues.
Impact on people and the environment
The main impact for human beings is the skin, nose, eyes and throat irritation. It can causelung oedema, heart damage, painful burns.
HF reacts with metals and water or steam, attacks glass and concrete, has an impact on plant growth because it is present in food, water and air.
Emission standards
The directive in most industry sectors is the concentration of HF in flue gas of 1mg/Nm3.