ChemicalResistance
ChemicalResistance.org

Acetal (POM) and Mercury(II) Chloride: Chemical Resistance

Polyoxymethylene (acetal)

Rating

Concentration20 °C50 °CRemark
aqueousC–

Material comparison at 20 °C

Mercury(II) Chloride: Material comparison at 20 °CAcetal (POM): C (highlighted); ECTFE/ETFE: A; EPDM: A; FEP: A; Viton (FPM): A; HDPE: A.ECTFE/ETFE: AEPDM: AFEP: AViton (FPM): AHDPE: ALDPE: ANBR: APolycarbonate: APMP: APP: APolystyrene: APolysulfone: APTFE: APVC Rigid: APVC Flexible: APVDF: ASAN: APETG: BAcetal (POM): CPOMAluminium: DNylon (PA): DSS 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) has limited resistance (C) to Mercury(II) Chloride at aqueous 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

Mercury(II) Chloride is commonly encountered in chemical processing and water disinfection. Acetal (POM) (Polyoxymethylene (acetal)) is a thermoplastic typically used for tanks, piping, containers and liners. Because Mercury(II) Chloride is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.

Practical recommendation

Acetal (POM) has limited resistance to Mercury(II) Chloride 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, Polycarbonate offer significantly better resistance and are rated A.

Did you know?

The ratings shown here apply to pure Mercury(II) Chloride 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 aqueous, 20 °C.

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