Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| concentration not stated | C | D |
Material comparison at 20 °C
Resistance overview
LDPE has limited resistance (C) to n-Heptane at 20 °C. This indicates that the chemical has a noticeable effect on the material, which may include visible swelling, softening, or a measurable loss of tensile strength. Use is generally limited to short-term or intermittent contact where full structural integrity is not required. However, at 50 °C the resistance rating drops, indicating that temperature must be factored into the design. For heated applications, additional testing under actual service conditions is strongly recommended.
Application context
n-Heptane is commonly encountered in petrochemical processing and lubrication systems. LDPE (Low-density polyethylene) is a thermoplastic typically used for tanks, piping, containers and liners. Since n-Heptane is flammable, material selection must also consider the risk of static charge buildup and the need for proper grounding in storage and transfer systems.
Practical recommendation
LDPE has limited resistance to n-Heptane 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, Nylon (PA), Polycarbonate, PETG offer significantly better resistance and are rated A.
Did you know?
When choosing between thermoplastics for n-Heptane service, engineers consider not just the resistance rating but also factors such as permeation rate, creep resistance, and weldability.
Materials rated A or B at 20 °C
- Thermoplastics
- HDPE B, PP B, PVC Rigid B, Nylon (PA) A, Acetal (POM) A, Polycarbonate A, Polysulfone A, PETG A, SAN A
- Fluoropolymers
- PTFE A, PVDF A, FEP A, ECTFE/ETFE A
- Elastomers
- Viton (FPM) A, NBR A
- Metals
- SS 316 A, SS 304 A, Aluminium A
About LDPE
Low-density polyethylene has a similar profile to HDPE but is softer and more permeable, so solvents swell it sooner. Continuous service is usually limited to about 60 °C.
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.