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Acetal (POM) and Hydrochloric Acid: Chemical Resistance

Polyoxymethylene (acetal)

Rating

Concentration20 °C50 °CRemark
1-5 %DD
20 %DD
35 %DD
concentratedDD

Material comparison at 20 °C

Hydrochloric Acid: Material comparison at 20 °CAcetal (POM): D (highlighted); ECTFE/ETFE: A; FEP: A; Viton (FPM): A; HDPE: A; LDPE: A.ECTFE/ETFE: AFEP: AViton (FPM): AHDPE: ALDPE: APMP: APP: APolysulfone: APTFE: APVDF: ASAN: APVC Rigid: BEPDM: CPolystyrene: CPVC Flexible: CAluminium: DNBR: DNylon (PA): DPolycarbonate: DPETG: DAcetal (POM): DPOMSS 304: DSS 316: 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 D across all 4 tested concentrations (1-5 %, 20 %, 35 %, concentrated) of Hydrochloric 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. 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

Hydrochloric Acid is commonly encountered in surface cleaning and water treatment. Acetal (POM) (Polyoxymethylene (acetal)) is a thermoplastic typically used for tanks, piping, containers and liners. Because Hydrochloric Acid is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.

Practical recommendation

Acetal (POM) is not recommended for use with Hydrochloric Acid. The D rating indicates that the material will suffer rapid and severe degradation, which may include cracking, dissolution, severe swelling, or complete structural failure. Using this combination risks equipment damage, leaks, and potential safety incidents. Consider using HDPE, LDPE, PMP instead, which are rated A for this chemical and offer reliable long-term performance.

Did you know?

The ratings shown here apply to pure Hydrochloric Acid in contact with the base thermoplastic. In real-world applications, additives, pigments, and fillers in the material can shift resistance in either direction.

Materials rated A or B at 20 °C

Based on the row for 35 %, 20 °C.

Thermoplastics
HDPE A, PP A, PVC Rigid B, LDPE A, Polysulfone A, PMP A, SAN A
Fluoropolymers
PTFE A, PVDF A, FEP A, ECTFE/ETFE A
Elastomers
Viton (FPM) 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.