Summary
- Polystyrene is rated better with
- Mineral acids (+46 points); Organic acids (+40 points); Oxidising agents and halogens (+28 points); Salts and salt solutions (+24 points); Alkalis (+24 points); Phenols (+22 points)
- Acetal (POM) is rated better with
- Aromatic hydrocarbons (+100 points); Ketones and aldehydes (+86 points); Esters and ethers (+85 points); Halogenated hydrocarbons (+80 points); Fuels, mineral oils and aliphatic hydrocarbons (+72 points); Vegetable and animal oils, fats, essential oils (+52 points); Alcohols and glycols (+32 points); Foods and beverages (+31 points); Amines and nitrogen compounds (+27 points)
Points are the difference in the share of rows rated A or B.
The two materials
Polystyrene
Polystyrene
Polystyrene is attacked by most organic solvents, including ketones, esters, aromatic and chlorinated hydrocarbons. It is used for dilute aqueous solutions.
Rated rows: 504. A 45 %, B 8 %, C 8 %, D 39 %
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 %
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 | Polystyrene: rated A or B | Acetal (POM): rated A or B |
|---|---|---|
| Mineral acids | 51 % (41 rows) | 5 % (63 rows) |
| Organic acids | 74 % (34 rows) | 34 % (64 rows) |
| Alkalis | 100 % (17 rows) | 76 % (21 rows) |
| Salts and salt solutions | 100 % (88 rows) | 76 % (197 rows) |
| Oxidising agents and halogens | 71 % (34 rows) | 43 % (63 rows) |
| Alcohols and glycols | 64 % (36 rows) | 96 % (57 rows) |
| Phenols | 22 % (9 rows) | 0 % (14 rows) |
| Ketones and aldehydes | 5 % (21 rows) | 91 % (35 rows) |
| Esters and ethers | 3 % (38 rows) | 88 % (68 rows) |
| Amines and nitrogen compounds | 47 % (15 rows) | 74 % (38 rows) |
| Aromatic hydrocarbons | 0 % (13 rows) | 100 % (14 rows) |
| Fuels, mineral oils and aliphatic hydrocarbons | 24 % (38 rows) | 96 % (73 rows) |
| Vegetable and animal oils, fats, essential oils | 48 % (27 rows) | 100 % (45 rows) |
| Halogenated hydrocarbons | 0 % (36 rows) | 80 % (70 rows) |
| Foods and beverages | 69 % (32 rows) | 100 % (46 rows) |
Where the ratings differ most
Rows where the two ratings at 20 °C are at least two grades apart: 222 in total, the first 40 shown.
| Chemical | Concentration | Polystyrene | Acetal (POM) |
|---|---|---|---|
| Acetone | D | A | |
| Amyl Acetate | D | A | |
| Aniline | D | A | |
| Arsenic Acid | A | D | |
| Arsenic Acid | aqueous | A | D |
| Battery Acid | 38 % | A | D |
| Benzaldehyde | D | A | |
| Benzene | D | A | |
| Benzyl Alcohol | D | A | |
| Bitter Almond Oil | D | A | |
| Bromobenzene | D | A | |
| Bromomethane | technical grade | D | A |
| Calcium Hypochlorite | A | D | |
| Caraway | ground | D | A |
| Chlorobenzene | D | A | |
| Chlorodifluoromethane | D | A | |
| Chloroethane (Ethyl Chloride) | D | A | |
| Chlorofluorocarbons (CFCs) | D | A | |
| Chloromethane (Methyl Chloride) | technical grade | D | A |
| Chromic Acid | 10 % | A | D |
| Chromic Acid | 20 % | A | D |
| Cyclohexane | D | A | |
| Cyclohexanone | technical grade | D | A |
| Decahydronaphthalene | D | A | |
| Dibutyl Phthalate (DBP) | D | A | |
| Dichlorodifluoromethane (R-12) | D | A | |
| Dichlorodifluoromethane (R-12) | technical grade | D | A |
| Dichlorofluoromethane | 100 % | D | A |
| Diethyl Ether | technical grade | D | A |
| Diethyl Ketone | D | A | |
| Dimethylformamide (DMF) | D | A | |
| Dioxane | D | A | |
| Diphenyl Ether | D | A | |
| Diphyl | D | A | |
| Ethyl Acetate | 100 % | D | A |
| Ethyl Glycol | 100 % | D | A |
| Ethylbenzene | D | A | |
| Ethylene Dichloride | D | A | |
| Ethylene Oxide | D | A | |
| Formaldehyde Solution | 30 % | 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 Polystyrene or Acetal (POM) more chemical-resistant?
Of 497 chemicals rated for both materials at 20 °C, Polystyrene and Acetal (POM) share the same rating in 162 rows (33 %). Polystyrene is rated better in 133 rows and Acetal (POM) in 202 rows.
How do Polystyrene and Acetal (POM) compare for chemical resistance?
Based on 497 chemicals tested for both: Polystyrene is rated better with Mineral acids, Organic acids, Oxidising agents and halogens, Salts and salt solutions. Acetal (POM) is rated better with Aromatic hydrocarbons, Ketones and aldehydes, Esters and ethers, Halogenated hydrocarbons. They perform similarly with –.
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.