ChemicalResistance
ChemicalResistance.org

FEP and Methyl Ethyl Ketone (MEK): Chemical Resistance

Fluorinated ethylene propylene

Rating

Concentration20 °C50 °CRemark
concentration not statedAA

Material comparison at 20 °C

Methyl Ethyl Ketone (MEK): Material comparison at 20 °CFEP: A (highlighted); Aluminium: A; HDPE: A; Nylon (PA): A; Acetal (POM): A; PP: A.Aluminium: AFEP: AFEPHDPE: ANylon (PA): AAcetal (POM): APP: APTFE: ASS 304: ASS 316: AECTFE/ETFE: BEPDM: CLDPE: CPVDF: CViton (FPM): DNBR: DPolycarbonate: DPETG: DPMP: DPolystyrene: DPolysulfone: DPVC Rigid: DPVC Flexible: DSAN: 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

FEP shows very good resistance (A) to Methyl Ethyl Ketone (MEK) at 20 °C, meaning the material remains essentially unaffected by this chemical under standard laboratory test conditions. 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

Methyl Ethyl Ketone (MEK) is commonly encountered in electronics cleaning and pharmaceutical manufacturing. FEP (Fluorinated ethylene propylene) is a fluoropolymer typically used for seals, gaskets, valve seats and lined equipment. Since Methyl Ethyl Ketone (MEK) is flammable, material selection must also consider the risk of static charge buildup and the need for proper grounding in storage and transfer systems.

Practical recommendation

FEP can be used with confidence for Methyl Ethyl Ketone (MEK) 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?

Fluorinated ethylene propylene is commonly chosen for seals, gaskets, valve seats and lined equipment because of its combination of chemical resistance, mechanical strength, and cost-effectiveness.

Materials rated A or B at 20 °C

Thermoplastics
HDPE A, PP A, Nylon (PA) A, Acetal (POM) A
Fluoropolymers
PTFE A, ECTFE/ETFE B
Metals
SS 316 A, SS 304 A, Aluminium A

About FEP

FEP has nearly the chemical resistance of PTFE and can be melt-processed. Its service temperature, about 200 °C, is lower than that of PTFE.

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.