ChemicalResistance
ChemicalResistance.org

Acetal (POM) and Lactic Acid: Chemical Resistance

Polyoxymethylene (acetal)

Rating

Concentration20 °C50 °CRemark
3 %BD
80 %CD
85 %CD

Material comparison at 20 °C

Lactic Acid: Material comparison at 20 °CAcetal (POM): C (highlighted); Aluminium: A; ECTFE/ETFE: A; FEP: A; Viton (FPM): A; HDPE: A.Aluminium: AECTFE/ETFE: AFEP: AViton (FPM): AHDPE: ALDPE: ANBR: APolycarbonate: APMP: APP: APolysulfone: APTFE: APVDF: ASAN: ASS 304: ASS 316: APolystyrene: BPVC Rigid: BPVC Flexible: BEPDM: CNylon (PA): CAcetal (POM): CPOMPETG: –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

The resistance of Acetal (POM) to Lactic Acid is concentration-dependent. Across the 3 tested concentrations (3 %, 80 %, 85 %), the 20 °C rating ranges from B at lower concentrations to D at higher ones. This means engineers must verify which concentration their process actually involves before relying on a single rating. 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

Lactic Acid is commonly encountered in surface cleaning and laboratory work. Acetal (POM) (Polyoxymethylene (acetal)) is a thermoplastic typically used for tanks, piping, containers and liners. Because Lactic 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) has limited resistance to Lactic 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, Polycarbonate offer significantly better resistance and are rated A.

Did you know?

When choosing between thermoplastics for Lactic Acid service, engineers consider not just the resistance rating but also factors such as permeation rate, creep resistance, and weldability.

Materials rated A or B at 20 °C

Based on the row for 85 %, 20 °C.

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