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NBR and Potassium Sulfide: Chemical Resistance

Nitrile butadiene rubber

Rating

Concentration20 °C50 °CRemark
diluteB–

Material comparison at 20 °C

Potassium Sulfide: Material comparison at 20 °CNBR: B (highlighted); EPDM: A; FEP: A; Viton (FPM): A; HDPE: A; LDPE: A.EPDM: AFEP: AViton (FPM): AHDPE: ALDPE: ANylon (PA): APMP: APP: APolystyrene: APTFE: APVC Rigid: APVC Flexible: APVDF: ASAN: ASS 304: ASS 316: ANBR: BNBRPolycarbonate: BPETG: BAcetal (POM): BAluminium: CECTFE/ETFE: –Polysulfone: –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 shows good but limited resistance (B) to Potassium Sulfide at dilute 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. 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

Potassium Sulfide is commonly encountered in metal finishing and water treatment. NBR (Nitrile butadiene rubber) is an elastomer typically used for seals, O-rings, hoses and flexible connections. Because Potassium 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 Potassium 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. For safety-critical or long-life applications, consider HDPE, LDPE, Nylon (PA) instead, which are rated A for this chemical.

Did you know?

In industrial practice, NBR components exposed to Potassium Sulfide are typically inspected for swelling, discoloration, or loss of mechanical strength as early indicators of chemical attack.

Materials rated A or B at 20 °C

Based on the row for dilute, 20 °C.

Thermoplastics
HDPE A, PP A, PVC Rigid A, LDPE A, Nylon (PA) A, Acetal (POM) B, 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

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.