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EPDM and Stearic Acid: Chemical Resistance

Ethylene propylene diene rubber

Rating

Concentration20 °C50 °CRemark
crystalsC–

Material comparison at 20 °C

Stearic Acid: Material comparison at 20 °CEPDM: C (highlighted); Aluminium: A; ECTFE/ETFE: A; FEP: A; Viton (FPM): A; HDPE: A.Aluminium: AECTFE/ETFE: AFEP: AViton (FPM): AHDPE: ALDPE: ANylon (PA): APolycarbonate: APETG: APMP: AAcetal (POM): APP: APolystyrene: APTFE: APVC Rigid: APVC Flexible: APVDF: ASAN: ASS 304: ASS 316: APolysulfone: BEPDM: CEPDMNBR: CSilicone: –
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

EPDM has limited resistance (C) to Stearic Acid at crystals at 20 °C. This indicates that the chemical has a noticeable effect on the material, which may include visible swelling, softening, or a measurable loss of tensile strength. Use is generally limited to short-term or intermittent contact where full structural integrity is not required. 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

Stearic Acid is commonly encountered in chemical processing and water treatment. EPDM (Ethylene propylene diene 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

EPDM has limited resistance to Stearic Acid 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, Nylon (PA) offer significantly better resistance and are rated A.

Did you know?

The chemical resistance of EPDM depends not only on the chemical concentration but also on exposure time, mechanical stress, and the presence of other chemicals in the mixture.

Materials rated A or B at 20 °C

Based on the row for crystals, 20 °C.

Thermoplastics
HDPE A, PP A, PVC Rigid A, LDPE A, Nylon (PA) A, Acetal (POM) A, Polycarbonate A, PVC Flexible A, Polystyrene A, Polysulfone B, PETG A, PMP A, SAN A
Fluoropolymers
PTFE A, PVDF A, FEP A, ECTFE/ETFE A
Elastomers
Viton (FPM) A
Metals
SS 316 A, SS 304 A, Aluminium A

About EPDM

EPDM resists water, steam, alkalis, ketones and alcohols. Mineral oils, fuels and aromatic solvents swell it severely.

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.