Hydrofluoroethers (HFE)
Hydrofluoroethers (HFEs) are partially fluorinated organic compounds that contain ether bonds. Depending on their chemical composition, they are characterized by low electrical conductivity, low surface tension, and good thermal and chemical stability.
Because of these properties, hydrofluoroethers are used as dielectric cooling fluids, heat transfer fluids, and precision cleaning agents in demanding industrial applications.
They do not damage the ozone layer and serve as a more sustainable alternative to chemicals such as CFCs, HCFCs, or perfluorinated hydrocarbons
What are the properties of hydrofluoroethers?
The physical and chemical properties vary depending on the HFE compound. Typical characteristics of suitable technical HFE fluids include:
- Appearance, odor, and toxicity: Colorless, virtually odorless, and practically non-toxic
- Dielectric properties: Suitable for applications requiring electrical insulation.
- Good heat transfer: Used as a cooling and heat transfer medium in industrial processes.
- Low surface tension: Good wetting of complex surfaces and fine structures.
- Low viscosity: Facilitates circulation and penetration into narrow gaps.
- High material compatibility: Compatible with numerous metals, plastics, and electronic components, depending on the product.
- Non-flammable variants: Increase process safety when the appropriate product is selected.
Where are hydrofluoroethers used?
Hydrofluoroethers are used in the following areas, among others:
- Semiconductor manufacturing: Temperature control in equipment for etching, coating, and testing processes. For rinsing, drying, and cooling wafers and components.
- Electronics cooling: Dielectric cooling of sensitive electronic components.
- Industrial heat transfer: Temperature control in technical systems and processes. As a refrigerant and heat transfer fluid—even at very low temperatures (down to approx. –110 °C).
- Precision cleaning: Cleaning of sensitive electronics, printed circuit boards (PCBs), microelectronics, and optical lenses (where water would be too aggressive).
Hydrofluoroethers at Puretecs
Puretecs offers various hydrofluoroethers under the AURON brand for industrial cooling and cleaning applications.
These include, among others, AURON HFE-7000, HFE-7100, HFE-7200, HFE-7300, HFE-7500, and AURON HFE-7500 Pentane.
The products differ in particular with regard to boiling point, temperature range, and application-specific properties.
The selection of the appropriate hydrofluoroether depends on thermal requirements, material compatibility, and the specific process conditions.
Are hydrofluoroethers PFAS?
Yes, chemically speaking, hydrofluoroethers (HFEs) belong to the PFAS (per- and polyfluoroalkyl substances) group.
The official definition by the OECD and European authorities states that any substance containing at least one fully fluorinated methyl (-CF₃) or methylene (-CF₂-) group is classified as a PFAS. Since the vast majority of HFEs exhibit these structural characteristics, they fall under this definition.
The Difference from Traditional PFAS
Although they are legally and structurally classified as PFAS, their environmental behavior differs significantly from that of “forever chemicals” such as PFOA or PFOS:
- Degradability in the atmosphere: HFEs have a built-in weak point (the ether bridge and carbon atoms bonded to hydrogen). As a result, they degrade relatively quickly in the atmosphere (often within weeks or months).
- No bioaccumulation: Based on current scientific knowledge, unlike traditional PFAS, they do not accumulate in the food chain or in organisms.
Related Terms
HFE, hydrofluorether, dielectric fluid, HFE coolant, precision cleaning