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Aluminium and Potassium Hydroxide: Chemical Resistance

Aluminium

Rating

Concentration20 °C50 °CRemark
1 %DD
10 %DD
30 %DD
50 %DD
concentratedDD

Material comparison at 20 °C

Potassium Hydroxide: Material comparison at 20 °CAluminium: D (highlighted); ECTFE/ETFE: A; EPDM: A; FEP: A; HDPE: A; LDPE: A.ECTFE/ETFE: AEPDM: AFEP: AHDPE: ALDPE: ANylon (PA): APMP: APP: APolysulfone: APTFE: APVC Rigid: APVC Flexible: ASAN: ASS 304: ASS 316: APolystyrene: BNBR: CAcetal (POM): CPVDF: CAluminium: DAlViton (FPM): DPolycarbonate: DPETG: 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

Aluminium maintains a consistent rating of D across all 5 tested concentrations (1 %, 10 %, 30 %, 50 %, concentrated) of Potassium Hydroxide 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

Potassium Hydroxide is commonly encountered in water treatment and cleaning and sanitation. Aluminium (Aluminium) is a metal typically used for vessels, heat exchangers, fittings and structural components. Because Potassium Hydroxide is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.

Practical recommendation

Aluminium is not recommended for use with Potassium Hydroxide. 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, Nylon (PA) instead, which are rated A for this chemical and offer reliable long-term performance.

Did you know?

Temperature is often the deciding factor when selecting materials for Potassium Hydroxide: even materials rated A at 20 °C may lose performance at elevated temperatures.

Materials rated A or B at 20 °C

Based on the row for 50 %, 20 °C.

Thermoplastics
HDPE A, PP A, PVC Rigid A, LDPE A, Nylon (PA) A, PVC Flexible A, Polystyrene B, Polysulfone A, PMP A, SAN A
Fluoropolymers
PTFE A, FEP A, ECTFE/ETFE A
Elastomers
EPDM A
Metals
SS 316 A, SS 304 A

About Aluminium

Aluminium relies on a thin oxide layer. Strong acids, strong alkalis and mercury compounds destroy that layer.

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.