Summary
- ECTFE/ETFE is rated better with
- Mineral acids (+95 points); Organic acids (+66 points); Oxidising agents and halogens (+57 points); Amines and nitrogen compounds (+26 points); Salts and salt solutions (+24 points); Alkalis (+24 points); Halogenated hydrocarbons (+20 points)
- Within 10 points of each other
- Alcohols and glycols; Ketones and aldehydes; Esters and ethers; Fuels, mineral oils and aliphatic hydrocarbons; Foods and beverages
Points are the difference in the share of rows rated A or B.
The two materials
Acetal (POM)
Polyoxymethylene (acetal)
Acetal (POM) resists many organic solvents and fuels. Strong acids and oxidising agents degrade it.
Rated rows: 956. A 41 %, B 32 %, C 12 %, D 15 %
ECTFE/ETFE
Ethylene chlorotrifluoroethylene / ethylene tetrafluoroethylene
ECTFE and ETFE are tough fluoropolymers with broad resistance. Hot amines and some chlorinated solvents at elevated temperature are their main limits.
Rated rows: 374. A 94 %, B 6 %, C 0 %, 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 | Acetal (POM): rated A or B | ECTFE/ETFE: rated A or B |
|---|---|---|
| Mineral acids | 5 % (63 rows) | 100 % (37 rows) |
| Organic acids | 34 % (64 rows) | 100 % (33 rows) |
| Alkalis | 76 % (21 rows) | 100 % (14 rows) |
| Salts and salt solutions | 76 % (197 rows) | 100 % (114 rows) |
| Oxidising agents and halogens | 43 % (63 rows) | 100 % (17 rows) |
| Alcohols and glycols | 96 % (57 rows) | 100 % (25 rows) |
| Phenols | 0 % (14 rows) | – |
| Ketones and aldehydes | 91 % (35 rows) | 100 % (14 rows) |
| Esters and ethers | 88 % (68 rows) | 95 % (20 rows) |
| Amines and nitrogen compounds | 74 % (38 rows) | 100 % (9 rows) |
| Aromatic hydrocarbons | 100 % (14 rows) | – |
| Fuels, mineral oils and aliphatic hydrocarbons | 96 % (73 rows) | 100 % (13 rows) |
| Vegetable and animal oils, fats, essential oils | 100 % (45 rows) | – |
| Halogenated hydrocarbons | 80 % (70 rows) | 100 % (16 rows) |
| Foods and beverages | 100 % (46 rows) | 100 % (26 rows) |
Where the ratings differ most
Rows where the two ratings at 20 °C are at least two grades apart: 97 in total, the first 40 shown.
| Chemical | Concentration | Acetal (POM) | ECTFE/ETFE |
|---|---|---|---|
| Acetic Acid | 90 % | D | A |
| Aqua Regia | D | A | |
| Arsenic Acid | D | A | |
| Arsenic Acid | aqueous | D | A |
| Battery Acid | 38 % | D | A |
| Bromine | D | A | |
| Butyric Acid | D | A | |
| Chlorine | 10 % wet | D | A |
| Chlorine Water | D | A | |
| Chloroacetic Acid | D | A | |
| Chromic Acid | 10 % | D | A |
| Chromic Acid | 50 % | D | A |
| Chromic-Sulfuric Acid | concentrated | D | A |
| Cresol | D | A | |
| Fluorine | D | A | |
| Fluorosilicic Acid | 32 % | D | A |
| Formic Acid | 50 % | D | A |
| Formic Acid | 98-100 % | D | A |
| Hydrobromic Acid | 50 % | D | A |
| Hydrochloric Acid | 1-5 % | D | A |
| Hydrochloric Acid | 20 % | D | A |
| Hydrochloric Acid | 35 % | D | A |
| Hydrochloric Acid | concentrated | D | A |
| Hydrochloric Acid Exhaust Gases | any concentration | D | A |
| Hydrofluoric Acid | 4 % | D | A |
| Hydrofluoric Acid | 50 % | D | A |
| Hydrogen Peroxide | 30 % | D | A |
| Hydrogen Peroxide | 90 % | D | A |
| Ferric Chloride (Iron(III) Chloride) | saturated | D | A |
| Nitric Acid | 1-10 % | D | A |
| Nitric Acid | 50 % | D | A |
| Nitric Acid | 66 % | D | A |
| Nitric Acid | 70 % | D | A |
| Oxalic Acid | D | A | |
| Oxalic Acid | aqueous | D | A |
| Ozone | D | A | |
| Ozone-Air Mixture | D | A | |
| Perchloric Acid | 70 % | D | A |
| Phenol | 100 % | D | A |
| Phosphoric Acid | 85 % | 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 Acetal (POM) or ECTFE/ETFE more chemical-resistant?
Of 373 chemicals rated for both materials at 20 °C, Acetal (POM) and ECTFE/ETFE share the same rating in 194 rows (52 %). Acetal (POM) is rated better in 10 rows and ECTFE/ETFE in 169 rows.
How do Acetal (POM) and ECTFE/ETFE compare for chemical resistance?
Based on 373 chemicals tested for both: Acetal (POM) is rated better with –. ECTFE/ETFE is rated better with Mineral acids, Organic acids, Oxidising agents and halogens, Amines and nitrogen compounds. They perform similarly with Alcohols and glycols, Ketones and aldehydes, Esters and ethers, Fuels, mineral oils and aliphatic hydrocarbons.
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.