Hydrofluoric acid 40%
| Chemical formula | HF |
| Density | ~1.13 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 | 38.0 – 40.0 | % | |
| Description | Conforms | ||
| Identification | Conforms | ||
| Solubility | Conforms | ||
| Chloride | ≤ | 0.02 | % |
| Heavy metals | ≤ | 0/05 | % |
| Fe (Iron) | ≤ | 0/2 | % |
| Residue on ignition | ≤ | 0/2 | % |
| Iodine reducing matter | ≤ | 0/005 | % |
Hydrofluoric acid 40% is a colorless, fuming aqueous solution of hydrogen fluoride (HF) that is highly corrosive and toxic. It is used extensively in industrial processes such as metal cleaning, glass etching, and chemical synthesis, particularly where fluoride ion activity is required.
🏭⚗️ Production
Hydrofluoric acid 40% is typically produced by dissolving anhydrous hydrogen fluoride gas in deionized water until the desired concentration is reached. Hydrogen fluoride itself is made industrially by the reaction of calcium fluoride (fluorspar) with sulfuric acid.
🔬 Properties
Hydrofluoric acid 40% has the chemical formula HF (aq) and contains 40% hydrogen fluoride by weight in water. It is a clear, corrosive liquid with a sharp, irritating odor. The solution has a density of approximately 1.13 g/cm³ and remains highly reactive. Unlike other strong acids, HF is weak in terms of dissociation but extremely dangerous due to its deep tissue penetration and high toxicity. It readily reacts with silicates, metals, and oxides, and it emits fumes in moist air.
🧪 Applications
Hydrofluoric acid 40% is widely used in glass etching, metal pickling, and semiconductor manufacturing. It is employed in the production of fluorine-containing compounds, fluoropolymers, and aluminum. In petrochemical industries, it is used as a catalyst in alkylation processes. It is also used for cleaning stainless steel and in certain formulations of rust removers.
⚠️ Safety
Hydrofluoric acid 40% is extremely hazardous and poses both chemical and systemic toxicity. It can cause deep, painful burns and systemic poisoning by penetrating skin and binding calcium and magnesium in the body, potentially leading to cardiac arrest. Exposure to even small amounts requires immediate medical attention. Appropriate safety measures include using face shields, chemical-resistant gloves, HF-rated protective clothing, and working under a fume hood. It must be stored in plastic containers (not glass) and kept away from incompatible materials such as bases, glass, and oxidizers.
