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NBR and Hydrocyanic Acid (Hydrogen Cyanide): Chemical Resistance

Nitrile butadiene rubber

Rating

Concentration20 °C50 °CRemark
aqueousC–
technical gradeC–

Material comparison at 20 °C

Hydrocyanic Acid (Hydrogen Cyanide): Material comparison at 20 °CNBR: C (highlighted); Aluminium: A; EPDM: A; FEP: A; Viton (FPM): A; HDPE: A.Aluminium: AEPDM: AFEP: AViton (FPM): AHDPE: ALDPE: APP: APolystyrene: APTFE: APVC Rigid: APVC Flexible: APVDF: ASS 304: ASS 316: ANBR: CNBRNylon (PA): CPolycarbonate: DPMP: DAcetal (POM): DECTFE/ETFE: –PETG: –Polysulfone: –SAN: –Silicone: –
A very good resistanceB good resistanceC limited resistanceD not resistantno data
Each bar is one material. Taller bars indicate better resistance. The highlighted bar is the current material.

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 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.