Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| 1-5 % | A | – | |
| 20 % | A | – | |
| 30 % | A | – | |
| 85 % | C | – |
Material comparison at 20 °C
Resistance overview
The resistance of EPDM to Phosphoric Acid is concentration-dependent. Across the 4 tested concentrations (1-5 %, 20 %, 30 %, 85 %), the 20 °C rating ranges from A at lower concentrations to C at higher ones. This means engineers must verify which concentration their process actually involves before relying on a single rating. 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
Phosphoric Acid is commonly encountered in chemical processing and surface cleaning. EPDM (Ethylene propylene diene rubber) is an elastomer typically used for seals, O-rings, hoses and flexible connections. Because Phosphoric Acid is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.
Practical recommendation
EPDM has limited resistance to Phosphoric Acid and should only be used for short-term or intermittent contact at ambient temperature. The C rating means the material undergoes noticeable changes — swelling, loss of strength, or surface degradation — that make it unsuitable for permanent installations. For prolonged or continuous exposure, HDPE, LDPE, Polycarbonate offer significantly better resistance and are rated A.
Did you know?
Ethylene propylene diene rubber is commonly chosen for seals, O-rings, hoses and flexible connections because of its combination of chemical resistance, mechanical strength, and cost-effectiveness.
Materials rated A or B at 20 °C
Based on the row for 85 %, 20 °C.
- Thermoplastics
- HDPE A, PP A, PVC Rigid A, LDPE A, Polycarbonate A, PVC Flexible A, Polystyrene A, Polysulfone A, PMP A, SAN A
- Fluoropolymers
- PTFE A, PVDF A, FEP A, ECTFE/ETFE A
- Elastomers
- Viton (FPM) A
- Metals
- SS 316 A, SS 304 B
About EPDM
EPDM resists water, steam, alkalis, ketones and alcohols. Mineral oils, fuels and aromatic solvents swell it severely.
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.