Summary
- Acetal (POM) is rated better with
- Ketones and aldehydes (+85 points); Esters and ethers (+73 points); Amines and nitrogen compounds (+50 points); Halogenated hydrocarbons (+47 points); Aromatic hydrocarbons (+36 points); Alcohols and glycols (+27 points); Alkalis (+21 points); Vegetable and animal oils, fats, essential oils (+17 points)
- Viton (FPM) is rated better with
- Mineral acids (+78 points); Oxidising agents and halogens (+34 points); Phenols (+29 points); Organic acids (+28 points); Salts and salt solutions (+12 points)
- Within 10 points of each other
- 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 %
Viton (FPM)
Fluoroelastomer (FKM/FPM)
Fluoroelastomer (Viton, FKM/FPM) resists fuels, oils and many acids. Ketones, esters, amines and hot water or steam attack it.
Rated rows: 965. A 57 %, B 10 %, C 18 %, D 15 %
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 | Viton (FPM): rated A or B |
|---|---|---|
| Mineral acids | 5 % (63 rows) | 83 % (63 rows) |
| Organic acids | 34 % (64 rows) | 62 % (64 rows) |
| Alkalis | 76 % (21 rows) | 55 % (22 rows) |
| Salts and salt solutions | 76 % (197 rows) | 88 % (198 rows) |
| Oxidising agents and halogens | 43 % (63 rows) | 77 % (62 rows) |
| Alcohols and glycols | 96 % (57 rows) | 69 % (58 rows) |
| Phenols | 0 % (14 rows) | 29 % (14 rows) |
| Ketones and aldehydes | 91 % (35 rows) | 6 % (35 rows) |
| Esters and ethers | 88 % (68 rows) | 15 % (71 rows) |
| Amines and nitrogen compounds | 74 % (38 rows) | 24 % (37 rows) |
| Aromatic hydrocarbons | 100 % (14 rows) | 64 % (14 rows) |
| Fuels, mineral oils and aliphatic hydrocarbons | 96 % (73 rows) | 90 % (71 rows) |
| Vegetable and animal oils, fats, essential oils | 100 % (45 rows) | 83 % (48 rows) |
| Halogenated hydrocarbons | 80 % (70 rows) | 33 % (70 rows) |
| Foods and beverages | 100 % (46 rows) | 96 % (46 rows) |
Where the ratings differ most
Rows where the two ratings at 20 °C are at least two grades apart: 309 in total, the first 40 shown.
| Chemical | Concentration | Acetal (POM) | Viton (FPM) |
|---|---|---|---|
| Acetamide | saturated | A | D |
| Acetone | A | D | |
| Acetophenone | A | D | |
| Acetyl Chloride | 100 % | D | A |
| Aluminum Acetate Solution | saturated | A | D |
| Aluminum Chloride | saturated | D | A |
| Amyl Acetate | A | D | |
| Antimony Trichloride | 90 % | D | A |
| Antimony Trichloride | anhydrous | D | A |
| Antimony Trichloride | aqueous | D | A |
| Battery Acid | 38 % | D | A |
| Benzaldehyde | A | D | |
| Benzenesulfonic Acid | saturated | D | A |
| Bismuth Chloride | D | A | |
| Bisulfite Liquor | D | A | |
| Bisulfite Liquor with SO2 | saturated | D | A |
| Bitter Almond Oil | A | D | |
| Butylene Glycol | technical grade | A | D |
| Calcium Acetate | aqueous | A | D |
| Calcium Bisulfite | saturated | D | A |
| Calcium Bisulfite | aqueous | D | A |
| Calcium Hypochlorite | D | A | |
| Calcium Hypochlorite | aqueous | D | A |
| Chlorine | 97 % | D | A |
| Chlorine Gas | D | A | |
| Chlorine Water | D | A | |
| Chlorodifluoromethane | A | D | |
| Chlorofluoromethane | A | D | |
| Chloromethane (Methyl Chloride) | technical grade | A | D |
| Chromic Acid | 10 % | D | A |
| Chromic Acid | 20 % | D | A |
| Chromic Acid | 50 % | D | A |
| Chromic-Sulfuric Acid | concentrated | D | A |
| Cresol | D | A | |
| Cyclohexanol | technical grade | A | D |
| Cyclohexanone | technical grade | A | D |
| Diacetone Alcohol | A | D | |
| Dibenzyl Ether | A | D | |
| Dibutyl Ether | technical grade | A | D |
| Dichlorofluoromethane | 100 % | A | D |
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 Viton (FPM) more chemical-resistant?
Of 945 chemicals rated for both materials at 20 °C, Acetal (POM) and Viton (FPM) share the same rating in 329 rows (35 %). Acetal (POM) is rated better in 277 rows and Viton (FPM) in 339 rows.
How do Acetal (POM) and Viton (FPM) compare for chemical resistance?
Based on 945 chemicals tested for both: Acetal (POM) is rated better with Ketones and aldehydes, Esters and ethers, Amines and nitrogen compounds, Halogenated hydrocarbons. Viton (FPM) is rated better with Mineral acids, Oxidising agents and halogens, Phenols, Organic acids. They perform similarly with Fuels, mineral oils and aliphatic hydrocarbons, 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.