Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| aqueous | A | – | |
| saturated | B | C |
Material comparison at 20 °C
Resistance overview
The resistance of NBR to Sodium Sulfide is concentration-dependent. Across the 2 tested concentrations (aqueous, saturated), 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. 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
Sodium Sulfide is commonly encountered in metal finishing and chemical processing. NBR (Nitrile butadiene rubber) is an elastomer typically used for seals, O-rings, hoses and flexible connections. Because Sodium Sulfide is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.
Practical recommendation
NBR is suitable for use with Sodium Sulfide 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. Avoid prolonged exposure at elevated temperatures, as the resistance decreases further at 50 °C. For safety-critical or long-life applications, consider HDPE, LDPE, Nylon (PA) instead, which are rated A for this chemical.
Did you know?
Nitrile butadiene 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 saturated, 20 °C.
- Thermoplastics
- HDPE A, PP A, PVC Rigid A, LDPE A, Nylon (PA) A, Acetal (POM) A, PVC Flexible A, Polystyrene A, Polysulfone A, PETG A, PMP A, SAN A
- Fluoropolymers
- PTFE A, FEP A
- Elastomers
- EPDM A, Viton (FPM) A
- Metals
- SS 316 A, SS 304 A
About NBR
Nitrile rubber resists mineral oils and fuels. Ketones, esters, chlorinated solvents, strong oxidisers and ozone attack it.
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.