Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| concentration not stated | B* | – |
* estimated rating, given in the source without a temperature
Material comparison at 20 °C
Resistance overview
FEP shows good but limited resistance (B) to Aqua Regia at 20 °C. The material can be used in contact with this chemical, but minor effects such as slight swelling or a small reduction in mechanical properties may occur over extended exposure periods. Regular inspection of components in service is advisable. The rating remains stable between 20 °C and 50 °C, which means this material can also handle moderately elevated process temperatures without additional risk.
Application context
Aqua Regia is commonly encountered in metal finishing and surface cleaning. FEP (Fluorinated ethylene propylene) is a fluoropolymer typically used for seals, gaskets, valve seats and lined equipment. Because Aqua Regia is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.
Practical recommendation
FEP is suitable for use with Aqua Regia under normal conditions, but some minor effects on the material are expected over time. Periodic monitoring for swelling, softening, or weight change is recommended, especially for long-service components. For safety-critical or long-life applications, consider ECTFE/ETFE, PTFE instead, which are rated A for this chemical.
Did you know?
The chemical resistance of FEP depends not only on the chemical concentration but also on exposure time, mechanical stress, and the presence of other chemicals in the mixture.
Materials rated A or B at 20 °C
- Fluoropolymers
- PTFE A, ECTFE/ETFE A
About FEP
FEP has nearly the chemical resistance of PTFE and can be melt-processed. Its service temperature, about 200 °C, is lower than that of PTFE.
Rating scale
- A very good resistance
- B good resistance
- C limited resistance
- D not resistant
- – no data
- K no general statement possible
A rating marked * is an estimate in the source, not a test result. An estimate is given as one value without a temperature.
About this data
The ratings come from the chemical resistance list published by Bürkle GmbH, which compiled them from raw-material manufacturers’ data. They describe laboratory tests on the raw material at 20 °C and 50 °C.
A finished part also sees pressure, mechanical stress, welds and mixtures that a laboratory test does not. Treat the rating as a first filter and test under your own conditions before relying on it.