HFO
HFO is an abbreviation for:
- Semiconductor plant in Frankfurt (Oder), also HWF, former largest producer of microelectronics in the GDR
- Heavy Fuel Oil, see heavy oil, residual oil from the distillation or cracking plants of Erdölverarbeitungdas
- High Frequency Oscillation, see high-frequency ventilation
- Hypofluorous acid, the only known oxygen acid of fluorine
- Disambiguation
- Abbreviation