Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| aqueous | C | – | |
| technical grade | C | – |
Material comparison at 20 °C
Resistance overview
NBR maintains a consistent rating of C across all 2 tested concentrations (aqueous, technical grade) of Hydrocyanic Acid (Hydrogen Cyanide) at 20 °C. The fact that the rating does not change with concentration within the tested range simplifies material selection, though the boundary conditions beyond this range remain untested. 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
Hydrocyanic Acid (Hydrogen Cyanide) is commonly encountered in surface cleaning and chemical processing. NBR (Nitrile butadiene rubber) is an elastomer typically used for seals, O-rings, hoses and flexible connections. Since Hydrocyanic Acid (Hydrogen Cyanide) 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
NBR has limited resistance to Hydrocyanic Acid (Hydrogen Cyanide) 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, PP offer significantly better resistance and are rated A.
Did you know?
Temperature is often the deciding factor when selecting materials for Hydrocyanic Acid (Hydrogen Cyanide): even materials rated A at 20 °C may lose performance at elevated temperatures.
Materials rated A or B at 20 °C
Based on the row for aqueous, 20 °C.
- Thermoplastics
- HDPE A, PP A, PVC Rigid A, LDPE A, PVC Flexible A, Polystyrene 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.