Summary
- SAN is rated better with
- Mineral acids (+56 points); Organic acids (+45 points); Oxidising agents and halogens (+30 points); Phenols (+25 points); Salts and salt solutions (+24 points); Alkalis (+24 points)
- Acetal (POM) is rated better with
- Esters and ethers (+88 points); Halogenated hydrocarbons (+75 points); Ketones and aldehydes (+70 points); Vegetable and animal oils, fats, essential oils (+32 points); Alcohols and glycols (+26 points); Foods and beverages (+18 points); Amines and nitrogen compounds (+18 points); Fuels, mineral oils and aliphatic hydrocarbons (+17 points)
Points are the difference in the share of rows rated A or B.
The two materials
SAN
Styrene-acrylonitrile
Styrene-acrylonitrile resists oils and dilute acids better than polystyrene, but ketones, esters and aromatic and chlorinated solvents still attack it.
Rated rows: 364. A 67 %, B 0 %, C 9 %, D 24 %
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 | SAN: rated A or B | Acetal (POM): rated A or B |
|---|---|---|
| Mineral acids | 61 % (18 rows) | 5 % (63 rows) |
| Organic acids | 79 % (24 rows) | 34 % (64 rows) |
| Alkalis | 100 % (8 rows) | 76 % (21 rows) |
| Salts and salt solutions | 100 % (80 rows) | 76 % (197 rows) |
| Oxidising agents and halogens | 73 % (26 rows) | 43 % (63 rows) |
| Alcohols and glycols | 70 % (33 rows) | 96 % (57 rows) |
| Phenols | 25 % (8 rows) | 0 % (14 rows) |
| Ketones and aldehydes | 21 % (19 rows) | 91 % (35 rows) |
| Esters and ethers | 0 % (19 rows) | 88 % (68 rows) |
| Amines and nitrogen compounds | 56 % (9 rows) | 74 % (38 rows) |
| Aromatic hydrocarbons | – | 100 % (14 rows) |
| Fuels, mineral oils and aliphatic hydrocarbons | 79 % (24 rows) | 96 % (73 rows) |
| Vegetable and animal oils, fats, essential oils | 68 % (22 rows) | 100 % (45 rows) |
| Halogenated hydrocarbons | 5 % (20 rows) | 80 % (70 rows) |
| Foods and beverages | 82 % (22 rows) | 100 % (46 rows) |
Where the ratings differ most
Rows where the two ratings at 20 °C are at least two grades apart: 126 in total, the first 40 shown.
| Chemical | Concentration | SAN | Acetal (POM) |
|---|---|---|---|
| Acetone | D | A | |
| Aluminum Chloride | saturated | A | D |
| Amyl Acetate | D | A | |
| Benzyl Alcohol | D | A | |
| Bismuth Chloride | A | D | |
| Calcium Hypochlorite | A | D | |
| Carbazole | D | A | |
| Chlorobenzene | D | A | |
| Chloroethane (Ethyl Chloride) | D | A | |
| Chloromethane (Methyl Chloride) | technical grade | D | A |
| Cyclohexanone | technical grade | D | A |
| Diacetone Alcohol | D | A | |
| Diethyl Ether | technical grade | D | A |
| Diethyl Ketone | D | A | |
| Dimethylformamide (DMF) | D | A | |
| Dioxane | D | A | |
| Diphenyl Ether | D | A | |
| Ethyl Acetate | 100 % | D | A |
| Ethyl Glycol | 100 % | D | A |
| Ethylbenzene | D | A | |
| Ethylene Dichloride | D | A | |
| Formic Acid | 50 % | A | D |
| Hydrochloric Acid | 1-5 % | A | D |
| Hydrochloric Acid | 35 % | A | D |
| Hydrochloric Acid | concentrated | A | D |
| Hydrogen Peroxide | 30 % | A | D |
| Ferric Chloride (Iron(III) Chloride) | saturated | A | D |
| Methyl Ethyl Ketone (MEK) | D | A | |
| Nitric Acid | 1-10 % | A | D |
| Oxalic Acid | A | D | |
| Ozone | A | D | |
| Phosphoric Acid | 30 % | A | D |
| Phosphoric Acid | 85 % | A | D |
| Pyridine | D | A | |
| Salicylic Acid | saturated | A | D |
| Sodium Hypochlorite (Bleach) | 12,5 % Cl | A | D |
| Sodium Hypochlorite (Bleach) | 15 % | A | D |
| Sodium Hypochlorite (Bleach) | saturated | A | D |
| Sodium Hypochlorite (Bleach) | dilute | A | D |
| Sulfuric Acid | 1-6 % | 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 SAN or Acetal (POM) more chemical-resistant?
Of 359 chemicals rated for both materials at 20 °C, SAN and Acetal (POM) share the same rating in 144 rows (40 %). SAN is rated better in 118 rows and Acetal (POM) in 97 rows.
How do SAN and Acetal (POM) compare for chemical resistance?
Based on 359 chemicals tested for both: SAN is rated better with Mineral acids, Organic acids, Oxidising agents and halogens, Phenols. Acetal (POM) is rated better with Esters and ethers, Halogenated hydrocarbons, Ketones and aldehydes, Vegetable and animal oils, fats, essential oils. 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.