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PP and Potassium Hydroxide: Chemical Resistance

Polypropylene

Rating

Concentration20 °C50 °CRemark
1 %AA
10 %AA
30 %AA
50 %AA
concentratedAA

Material comparison at 20 °C

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

PP shows excellent resistance to Potassium Hydroxide across all 5 tested concentrations (1 %, 10 %, 30 %, 50 %, concentrated) at 20 °C, making it a reliable choice for storage, transfer, and handling applications involving this chemical at any of the tested strengths. 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 cleaning and sanitation and chemical processing. PP (Polypropylene) is a thermoplastic typically used for tanks, piping, containers and liners. 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

PP can be used with confidence for Potassium Hydroxide containment and handling. The A rating indicates that the material shows no significant change in weight, dimensions, or mechanical properties after prolonged contact under test conditions. This holds true at both 20 °C and 50 °C, giving a good safety margin for typical process environments.

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, 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 PP

Polypropylene resists most acids, alkalis and salt solutions. Concentrated oxidising acids, chlorinated solvents and aromatic hydrocarbons attack it, and it turns brittle below about 0 °C.

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.