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Acetal (POM) and Benzoic Acid: Chemical Resistance

Polyoxymethylene (acetal)

Rating

Concentration20 °C50 °CRemark
aqueousBD
saturatedBD

Material comparison at 20 °C

Benzoic Acid: Material comparison at 20 °CAcetal (POM): B (highlighted); Aluminium: A; ECTFE/ETFE: A; FEP: A; Viton (FPM): A; HDPE: A.Aluminium: AECTFE/ETFE: AFEP: AViton (FPM): AHDPE: ALDPE: APETG: APMP: APP: APTFE: APVC Rigid: APVC Flexible: APVDF: ASAN: ASS 304: ASS 316: AAcetal (POM): BPOMPolystyrene: BEPDM: CNBR: CNylon (PA): CPolysulfone: CPolycarbonate: DSilicone: –
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

Acetal (POM) maintains a consistent rating of B across all 2 tested concentrations (aqueous, saturated) of Benzoic Acid 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. 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

Benzoic Acid is commonly encountered in water treatment and laboratory work. Acetal (POM) (Polyoxymethylene (acetal)) is a thermoplastic typically used for tanks, piping, containers and liners. The compatibility between these two is therefore an important consideration for engineers and procurement teams selecting containment, transfer, or processing equipment.

Practical recommendation

Acetal (POM) is suitable for use with Benzoic Acid 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, PETG instead, which are rated A for this chemical.

Did you know?

Chemical resistance testing according to DIN and ISO standards typically evaluates weight change, dimensional change, and retention of tensile strength after immersion.

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, PVC Flexible A, Polystyrene 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 Acetal (POM)

Acetal (POM) resists many organic solvents and fuels. Strong acids and oxidising agents degrade 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.