Summary
- HDPE is rated better with
- Mineral acids (+74 points); Phenols (+62 points); Organic acids (+61 points); Oxidising agents and halogens (+35 points); Salts and salt solutions (+24 points); Alkalis (+24 points); Amines and nitrogen compounds (+16 points)
- Acetal (POM) is rated better with
- Halogenated hydrocarbons (+70 points); Aromatic hydrocarbons (+67 points); Vegetable and animal oils, fats, essential oils (+29 points); Fuels, mineral oils and aliphatic hydrocarbons (+17 points); Esters and ethers (+15 points)
- Within 10 points of each other
- Alcohols and glycols; Ketones and aldehydes; Foods and beverages
Points are the difference in the share of rows rated A or B.
The two materials
HDPE
High-density polyethylene
High-density polyethylene resists most aqueous acids, alkalis and salt solutions. Strong oxidising acids, chlorinated solvents and aromatic hydrocarbons attack or swell it. Continuous service is usually limited to about 80 °C.
Rated rows: 686. A 82 %, B 3 %, C 9 %, D 6 %
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 | HDPE: rated A or B | Acetal (POM): rated A or B |
|---|---|---|
| Mineral acids | 79 % (56 rows) | 5 % (63 rows) |
| Organic acids | 95 % (58 rows) | 34 % (64 rows) |
| Alkalis | 100 % (22 rows) | 76 % (21 rows) |
| Salts and salt solutions | 100 % (193 rows) | 76 % (197 rows) |
| Oxidising agents and halogens | 78 % (40 rows) | 43 % (63 rows) |
| Alcohols and glycols | 93 % (43 rows) | 96 % (57 rows) |
| Phenols | 62 % (8 rows) | 0 % (14 rows) |
| Ketones and aldehydes | 84 % (19 rows) | 91 % (35 rows) |
| Esters and ethers | 73 % (37 rows) | 88 % (68 rows) |
| Amines and nitrogen compounds | 90 % (21 rows) | 74 % (38 rows) |
| Aromatic hydrocarbons | 33 % (9 rows) | 100 % (14 rows) |
| Fuels, mineral oils and aliphatic hydrocarbons | 79 % (38 rows) | 96 % (73 rows) |
| Vegetable and animal oils, fats, essential oils | 71 % (21 rows) | 100 % (45 rows) |
| Halogenated hydrocarbons | 10 % (31 rows) | 80 % (70 rows) |
| Foods and beverages | 100 % (32 rows) | 100 % (46 rows) |
Where the ratings differ most
Rows where the two ratings at 20 °C are at least two grades apart: 204 in total, the first 40 shown.
| Chemical | Concentration | HDPE | Acetal (POM) |
|---|---|---|---|
| Acetic Acid | 90 % | A | D |
| Aluminum Chloride | solid | A | D |
| Aluminum Chloride | saturated | A | D |
| Ammonium Bifluoride | 50 % | A | D |
| Antimony Trichloride | 90 % | A | D |
| Arsenic Acid | A | D | |
| Arsenic Acid | aqueous | A | D |
| Arsenic Pentoxide | A | D | |
| Battery Acid | 38 % | A | D |
| Benzenesulfonic Acid | saturated | A | D |
| Bismuth Chloride | A | D | |
| Bisulfite Liquor | A | D | |
| Bisulfite Liquor with SO2 | saturated | A | D |
| Butanetriol | 100 % | D | A |
| Butene | technical grade | D | A |
| Calcium Bisulfite | saturated | A | D |
| Calcium Bisulfite | aqueous | A | D |
| Chloric Acid | 10 % | A | D |
| Chloroacetic Acid | A | D | |
| Chloroacetic Acid | 50 % | A | D |
| Chromic Acid | 10 % | A | D |
| Dichloroacetic Acid | 50 % | A | D |
| Dichloroacetic Acid | technical grade | A | D |
| Dichlorodifluoromethane (R-12) | D | A | |
| Dichlorodifluoromethane (R-12) | technical grade | D | A |
| Fluorosilicic Acid | 32 % | A | D |
| Formic Acid | 50 % | A | D |
| Formic Acid | 98-100 % | A | D |
| Hydrobromic Acid | 40 % | A | D |
| Hydrobromic Acid | 50 % | A | D |
| Hydrobromic Acid | dilute | A | D |
| Hydrochloric Acid | 1-5 % | A | D |
| Hydrochloric Acid | 20 % | A | D |
| Hydrochloric Acid | 35 % | A | D |
| Hydrochloric Acid | concentrated | A | D |
| Hydrochloric Acid Exhaust Gases | any concentration | A | D |
| Hydrocyanic Acid (Hydrogen Cyanide) | technical grade | A | D |
| Hydrocyanic Acid (Hydrogen Cyanide) | aqueous | A | D |
| Hydrofluoric Acid | 4 % | A | D |
| Hydrofluoric Acid | 50 % | 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 HDPE or Acetal (POM) more chemical-resistant?
Of 678 chemicals rated for both materials at 20 °C, HDPE and Acetal (POM) share the same rating in 288 rows (42 %). HDPE is rated better in 316 rows and Acetal (POM) in 74 rows.
How do HDPE and Acetal (POM) compare for chemical resistance?
Based on 678 chemicals tested for both: HDPE is rated better with Mineral acids, Phenols, Organic acids, Oxidising agents and halogens. Acetal (POM) is rated better with Halogenated hydrocarbons, Aromatic hydrocarbons, Vegetable and animal oils, fats, essential oils, Fuels, mineral oils and aliphatic hydrocarbons. They perform similarly with Alcohols and glycols, Ketones and aldehydes, 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.