Hydrofluoric Acid (solution) — properties & hazards overview
HF content (w/w)
~ 5–70%
pH
< 1 (strong acid)
Glass attack
Yes (SiO₂ etching)
Off-gas
HF fumes; ventilation required
Toxicity
systemic fluoride
Flammability
not flammable
Chronic risk
fluorosis; delayed injury
Environmental
fluoride discharge
| Property | Value / Note |
|---|---|
| Physical state | Clear, fuming liquid with sharp odour. |
| Solubility | Fully miscible with water; dilution is exothermic. |
| Compatibility | Attacks glass/silica & many metals. Use PVDF/PTFE/PP/FRP; 316L only with great care. |
| Mist & demister | Sub-µm to few µm; use HE chevrons, add fiberbed where needed. |
| Uses | Metal pickling, etching, fluorochemicals. |
*Concentration-dependent behaviour. Always follow HF-specific medical/safety protocols.