Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| saturated | B | C |
Material comparison at 20 °C
Resistance overview
NBR shows good but limited resistance (B) to Sodium Sulfite at saturated 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. 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 Sulfite is commonly encountered in water treatment and chemical storage. NBR (Nitrile butadiene rubber) is an elastomer typically used for seals, O-rings, hoses and flexible connections. The compatibility between these two is therefore an important consideration for engineers and procurement teams selecting containment, transfer, or processing equipment.
Practical recommendation
NBR is suitable for use with Sodium Sulfite 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?
The ratings shown here apply to pure Sodium Sulfite in contact with the base elastomer. In real-world applications, additives, pigments, and fillers in the material can shift resistance in either direction.
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, Polycarbonate B, PVC Flexible A, Polystyrene A, PETG B, PMP A, SAN A
- Fluoropolymers
- PTFE A, PVDF A, FEP A
- Elastomers
- EPDM A, Viton (FPM) A
- Metals
- SS 316 A, SS 304 A, Aluminium 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.