Summary
- Within 10 points of each other
- Mineral acids; Organic acids; Alkalis; Salts and salt solutions; Oxidising agents and halogens; Alcohols and glycols; Phenols; Ketones and aldehydes; Esters and ethers; Amines and nitrogen compounds; Aromatic hydrocarbons; Fuels, mineral oils and aliphatic hydrocarbons; Vegetable and animal oils, fats, essential oils; Halogenated hydrocarbons; Foods and beverages
Points are the difference in the share of rows rated A or B.
The two materials
PTFE
Polytetrafluoroethylene
PTFE is resistant to almost every chemical in this list. The known exceptions are molten alkali metals, elemental fluorine and some fluorinating agents at elevated temperature.
Rated rows: 981. A 98 %, B 2 %, C 0 %, D 0 %
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 | PTFE: rated A or B | FEP: rated A or B |
|---|---|---|
| Mineral acids | 100 % (63 rows) | 100 % (55 rows) |
| Organic acids | 100 % (64 rows) | 100 % (64 rows) |
| Alkalis | 100 % (22 rows) | 100 % (18 rows) |
| Salts and salt solutions | 100 % (198 rows) | 100 % (197 rows) |
| Oxidising agents and halogens | 100 % (63 rows) | 100 % (52 rows) |
| Alcohols and glycols | 100 % (58 rows) | 100 % (57 rows) |
| Phenols | 100 % (14 rows) | 100 % (14 rows) |
| Ketones and aldehydes | 100 % (35 rows) | 100 % (33 rows) |
| Esters and ethers | 100 % (74 rows) | 100 % (69 rows) |
| Amines and nitrogen compounds | 100 % (39 rows) | 100 % (38 rows) |
| Aromatic hydrocarbons | 100 % (14 rows) | 100 % (14 rows) |
| Fuels, mineral oils and aliphatic hydrocarbons | 100 % (78 rows) | 100 % (74 rows) |
| Vegetable and animal oils, fats, essential oils | 100 % (48 rows) | 100 % (47 rows) |
| Halogenated hydrocarbons | 100 % (70 rows) | 90 % (49 rows) |
| Foods and beverages | 100 % (46 rows) | 100 % (46 rows) |
Where the ratings differ most
Rows where the two ratings at 20 °C are at least two grades apart: 5 in total.
| Chemical | Concentration | PTFE | FEP |
|---|---|---|---|
| Chlorodifluoromethane | A | C | |
| Dichlorodifluoromethane (R-12) | A | C | |
| Dichlorodifluoromethane (R-12) | technical grade | A | C |
| Dichlorofluoromethane | 100 % | A | C |
| Trichlorofluoromethane | A | C |
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 PTFE or FEP more chemical-resistant?
Of 906 chemicals rated for both materials at 20 °C, PTFE and FEP share the same rating in 889 rows (98 %). PTFE is rated better in 8 rows and FEP in 9 rows.
How do PTFE and FEP compare for chemical resistance?
Based on 906 chemicals tested for both: PTFE is rated better with –. FEP is rated better with –. They perform similarly with Mineral acids, Organic acids, Alkalis, Salts and salt solutions.
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.