Summary
- Acetal (POM) is rated better with
- Aromatic hydrocarbons (+100 points); Vegetable and animal oils, fats, essential oils (+96 points); Fuels, mineral oils and aliphatic hydrocarbons (+95 points); Esters and ethers (+63 points); Ketones and aldehydes (+60 points); Halogenated hydrocarbons (+57 points); Alcohols and glycols (+43 points); Amines and nitrogen compounds (+41 points)
- EPDM is rated better with
- Mineral acids (+35 points); Alkalis (+24 points); Salts and salt solutions (+22 points); Oxidising agents and halogens (+22 points); Organic acids (+13 points)
- Within 10 points of each other
- Phenols; 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 %
EPDM
Ethylene propylene diene rubber
EPDM resists water, steam, alkalis, ketones and alcohols. Mineral oils, fuels and aromatic solvents swell it severely.
Rated rows: 976. A 44 %, B 9 %, C 20 %, D 28 %
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 | EPDM: rated A or B |
|---|---|---|
| Mineral acids | 5 % (63 rows) | 40 % (63 rows) |
| Organic acids | 34 % (64 rows) | 47 % (64 rows) |
| Alkalis | 76 % (21 rows) | 100 % (22 rows) |
| Salts and salt solutions | 76 % (197 rows) | 98 % (198 rows) |
| Oxidising agents and halogens | 43 % (63 rows) | 65 % (62 rows) |
| Alcohols and glycols | 96 % (57 rows) | 53 % (58 rows) |
| Phenols | 0 % (14 rows) | 7 % (14 rows) |
| Ketones and aldehydes | 91 % (35 rows) | 31 % (35 rows) |
| Esters and ethers | 88 % (68 rows) | 25 % (72 rows) |
| Amines and nitrogen compounds | 74 % (38 rows) | 33 % (39 rows) |
| Aromatic hydrocarbons | 100 % (14 rows) | 0 % (14 rows) |
| Fuels, mineral oils and aliphatic hydrocarbons | 96 % (73 rows) | 1 % (78 rows) |
| Vegetable and animal oils, fats, essential oils | 100 % (45 rows) | 4 % (48 rows) |
| Halogenated hydrocarbons | 80 % (70 rows) | 23 % (71 rows) |
| Foods and beverages | 100 % (46 rows) | 93 % (46 rows) |
Where the ratings differ most
Rows where the two ratings at 20 °C are at least two grades apart: 347 in total, the first 40 shown.
| Chemical | Concentration | Acetal (POM) | EPDM |
|---|---|---|---|
| 1-Heptanol | A | D | |
| Ammonium Bifluoride | 50 % | D | A |
| Aniline | A | D | |
| Antimony Trichloride | 90 % | D | A |
| Antimony Trichloride | anhydrous | D | A |
| Antimony Trichloride | aqueous | D | A |
| Arsenic Acid | D | A | |
| Arsenic Acid | aqueous | D | A |
| Aviation Fuels (JP) | A | D | |
| Battery Acid | 38 % | D | A |
| Beef Tallow | A | D | |
| Benzene | A | D | |
| Bismuth Chloride | D | A | |
| Bisulfite Liquor | D | A | |
| Bromobenzene | A | D | |
| Bromomethane | technical grade | A | D |
| Calcium Hypochlorite | D | A | |
| Calcium Hypochlorite | aqueous | D | A |
| Chlorobenzene | A | D | |
| Chloroethane (Ethyl Chloride) | A | D | |
| Chloromethane (Methyl Chloride) | technical grade | A | D |
| Chlorotoluene | A | D | |
| Coal Tar Oil | 100 % | A | D |
| Cocoa Butter | A | D | |
| Crude Oil | A | D | |
| Crude Oil | 100 % | A | D |
| Cyclohexane | A | D | |
| Cyclohexanol | technical grade | A | D |
| Cyclohexanone | technical grade | A | D |
| Decahydronaphthalene | A | D | |
| Decane | A | D | |
| Dibromotetrafluoromethane | A | D | |
| Dibutyl Ether | technical grade | A | D |
| Dichlorofluoromethane | 100 % | A | D |
| Diesel Fuel | A | D | |
| Diesel Fuel | 100 % | A | D |
| Diethyl Ether | technical grade | A | D |
| Difluorotetrachloroethane | A | D | |
| Diisobutylene | A | D | |
| Diphenyl Ether | 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 EPDM more chemical-resistant?
Of 954 chemicals rated for both materials at 20 °C, Acetal (POM) and EPDM share the same rating in 321 rows (34 %). Acetal (POM) is rated better in 365 rows and EPDM in 268 rows.
How do Acetal (POM) and EPDM compare for chemical resistance?
Based on 954 chemicals tested for both: Acetal (POM) is rated better with Aromatic hydrocarbons, Vegetable and animal oils, fats, essential oils, Fuels, mineral oils and aliphatic hydrocarbons, Esters and ethers. EPDM is rated better with Mineral acids, Alkalis, Salts and salt solutions, Oxidising agents and halogens. They perform similarly with Phenols, 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.