Summary
- FEP is rated better with
- Aromatic hydrocarbons (+90 points); Halogenated hydrocarbons (+87 points); Vegetable and animal oils, fats, essential oils (+71 points); Fuels, mineral oils and aliphatic hydrocarbons (+70 points); Esters and ethers (+64 points); Ketones and aldehydes (+63 points); Amines and nitrogen compounds (+50 points); Oxidising agents and halogens (+33 points); Mineral acids (+29 points); Organic acids (+15 points)
- Within 10 points of each other
- Alkalis; Salts and salt solutions; Alcohols and glycols; Foods and beverages
Points are the difference in the share of rows rated A or B.
The two materials
PMP
Polymethylpentene (TPX)
Polymethylpentene (TPX) is a transparent polyolefin used for labware. It resists many acids and alkalis, while aromatic and chlorinated solvents and strong oxidisers attack it.
Rated rows: 416. A 55 %, B 6 %, C 7 %, D 32 %
FEP
Fluorinated ethylene propylene
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.
Rated rows: 908. A 99 %, B 0 %, C 1 %, D 0 %
Share of rows rated A or B, by chemical class
How often the two ratings agree
Chemical classes were assigned by this site, not by the source. Mixtures and trade products without a clear class are not counted.
By chemical class
| Chemical class | PMP: rated A or B | FEP: rated A or B |
|---|---|---|
| Mineral acids | 71 % (35 rows) | 100 % (55 rows) |
| Organic acids | 85 % (26 rows) | 100 % (64 rows) |
| Alkalis | 100 % (17 rows) | 100 % (18 rows) |
| Salts and salt solutions | 100 % (67 rows) | 100 % (197 rows) |
| Oxidising agents and halogens | 67 % (30 rows) | 100 % (52 rows) |
| Alcohols and glycols | 96 % (28 rows) | 100 % (57 rows) |
| Phenols | – | 100 % (14 rows) |
| Ketones and aldehydes | 37 % (27 rows) | 100 % (33 rows) |
| Esters and ethers | 36 % (42 rows) | 100 % (69 rows) |
| Amines and nitrogen compounds | 50 % (10 rows) | 100 % (38 rows) |
| Aromatic hydrocarbons | 10 % (10 rows) | 100 % (14 rows) |
| Fuels, mineral oils and aliphatic hydrocarbons | 30 % (37 rows) | 100 % (74 rows) |
| Vegetable and animal oils, fats, essential oils | 29 % (14 rows) | 100 % (47 rows) |
| Halogenated hydrocarbons | 3 % (33 rows) | 90 % (49 rows) |
| Foods and beverages | 100 % (13 rows) | 100 % (46 rows) |
Where the ratings differ most
Rows where the two ratings at 20 °C are at least two grades apart: 149 in total, the first 40 shown.
| Chemical | Concentration | PMP | FEP |
|---|---|---|---|
| 1,2-Dibromoethane | D | A | |
| 1,3-Butadiene | D | A | |
| 1-Pentanethiol | D | A | |
| Acetic Anhydride | technical grade | D | A |
| Acetyl Chloride | 100 % | D | A |
| Allyl Acetate | 100 % | D | A |
| Allyl Chloride | 100 % | D | A |
| Allyl Mustard Oil | D | A | |
| Amyl Chloride | D | A | |
| Amyl Cinnamaldehyde | D | A | |
| Anise Oil | D | A | |
| Benzyl Alcohol | D | A | |
| Benzyl Chloride | 100 % | D | A |
| Bromine | D | A | |
| Bromine Vapors | D | A | |
| Bromobenzene | D | A | |
| Bromochloromethane | 100 % | D | A |
| Bromoform | D | A | |
| Butyraldehyde | D | A | |
| Butyric Acid | D | A | |
| Carbon Disulfide | D | A | |
| Carbon Tetrachloride | D | A | |
| Cedar Oil | D | A | |
| Chlorine | 97 % | D | A |
| Chlorine Gas | D | A | |
| Chlorine Water | D | A | |
| Chlorobenzene | D | A | |
| Chlorobutadiene | D | A | |
| Chloroform | 100 % | D | A |
| Chlorotoluene | D | A | |
| Cinnamaldehyde | D | A | |
| Cinnamon Oil | D | A | |
| Cresol | D | A | |
| Crotonaldehyde | technical grade | D | A |
| Cumene | D | A | |
| Cyclohexane | D | A | |
| Cymene | D | A | |
| Decahydronaphthalene | D | A | |
| Dibutyl Ether | technical grade | D | A |
| Dichloroethylene | technical grade | D | A |
Rating scale
- A very good resistance
- B good resistance
- C limited resistance
- D not resistant
- – no data
- K no general statement possible
A rating marked * is an estimate in the source, not a test result. An estimate is given as one value without a temperature.
More comparisons
Frequently Asked Questions
Is PMP or FEP more chemical-resistant?
Of 400 chemicals rated for both materials at 20 °C, PMP and FEP share the same rating in 224 rows (56 %). PMP is rated better in 0 rows and FEP in 176 rows.
How do PMP and FEP compare for chemical resistance?
Based on 400 chemicals tested for both: PMP is rated better with –. FEP is rated better with Aromatic hydrocarbons, Halogenated hydrocarbons, Vegetable and animal oils, fats, essential oils, Fuels, mineral oils and aliphatic hydrocarbons. They perform similarly with Alkalis, Salts and salt solutions, Alcohols and glycols, Foods and beverages.
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.