Hydrofluoric acid 48%
| Chemical formula | HF |
| Density | ~1.16 g/cm3 (20°C) |
| HS Code | 28111100 |
| Storage | store at +15 to +30 °C |
| SDS | available |
| R phrase | R 26/27/28-35 |
| S phrase | S 7/9-26-28.1-36/37/39-45 |
| Odour | pungent |
| Form | liquid |
| Color | colourless |
| Solubility in water | soluble (20°C) |
| Boiling point | ~ 106 °C |
| Melting point | ~ -35 °C |
| Assay | 48.0 – 52.0 | % | |
| Description | Conforms | ||
| Identification | Conforms | ||
| Solubility | Conforms | ||
| Chloride | ≤ | 0.002 | % |
| Hexafluorosilicate | ≤ | 0.01 | % |
| Sulfate | ≤ | 0.001 | % |
| Sulfite | ≤ | 0.002 | % |
| Heavy metals | ≤ | 0.0005 | % |
| Fe (Iron) | ≤ | 0.001 | % |
| Residue on ignition | ≤ | 0.002 | % |
Hydrofluoric acid 48% is a clear, highly corrosive, and toxic aqueous solution of hydrogen fluoride widely used in chemical and pharmaceutical laboratories, particularly known for its ability to dissolve silica and its role in etching, cleaning, and synthetic processes.
🏭⚗️ Production
Hydrofluoric acid is typically produced industrially by reacting concentrated sulfuric acid with calcium fluoride, which results in the release of hydrogen fluoride gas that is subsequently absorbed in water to form hydrofluoric acid solutions of varying concentrations, including the commonly used forty-eight percent solution for laboratory and industrial purposes.
🔬 Properties
Hydrofluoric acid at forty-eight percent concentration is a colorless, fuming liquid with a sharp, irritating odor. It has a boiling point of approximately one hundred twelve degrees Celsius and is fully miscible with water. Despite being classified as a weak acid in terms of dissociation, it is extremely aggressive chemically and can penetrate human tissue upon contact. It is one of the few acids capable of dissolving oxides and silicates, making it uniquely useful for glass etching and mineral digestion. The forty-eight percent concentration is a standard grade used in many technical and analytical procedures.
🧪 Applications
In laboratory and pharmaceutical environments, hydrofluoric acid is used in trace metal analysis, preparation of silicon-containing samples, and etching of glassware and semiconductor materials. It is also employed in the synthesis of fluorinated organic compounds, in catalysis studies, and in pharmaceutical intermediate preparation. Due to its ability to react with a wide range of materials, it is commonly found in procedures involving surface treatment, oxide removal, and chemical milling.
⚠️ Safety
Hydrofluoric acid is extremely dangerous and poses severe health hazards even at low concentrations. Skin exposure can result in deep tissue damage and systemic fluoride poisoning, while inhalation of vapors can lead to serious respiratory injury. It is toxic, corrosive, and potentially fatal if not handled properly. Calcium gluconate gel must be readily available in case of skin exposure. Full personal protective equipment including acid-resistant gloves, face shield, chemical splash goggles, and fume hood use is mandatory. Hydrofluoric acid must be stored in containers made of compatible materials such as polyethylene or Teflon and kept tightly sealed in well-ventilated, cool areas away from glass and incompatible chemicals.
