Chemical resistance of twelve engineering plastics against eight chemical families, rated from A (no effect) to D (not recommended), with the failure mechanisms that produce each rating.
Data verified 2026-09-29 · based on ISO 175:2010
| Material[1] | Dilute acids[1] | Concentrated acids[1] | Bases (alkalis)[1] | Ketones[1] | Aromatic hydrocarbons[1] | Chlorinated solvents[1] | Oils & fuels[1] | Hot water > 60 °C[1] |
|---|---|---|---|---|---|---|---|---|
| PTFE # | A | A | A | A | A | A | A | A |
| PEEK # | B | C | A | A | A | B | A | A |
| PPS # | A | B | A | A | B | B | A | A |
| UHMW-PE # | A | B | A | B | C | C | A | A |
| Rigid PVC # | A | B | A | D | C | D | A | A |
| POM-C (Acetal copolymer) # | C | D | B | A | A | A | A | C |
| POM-H (Delrin) # | C | D | C | B | B | B | A | D |
| PET-P (Ertalyte) # | B | C | C | B | B | C | A | C |
| Nylon 6/6 # | D | D | B | A | B | B | A | C |
| Polycarbonate # | C | D | C | D | D | D | B | C |
| PEI (Ultem) # | C | D | C | D | C | D | B | C |
| Acrylic (PMMA) # | B | C | C | D | D | D | B | B |
A = no significant effect at ambient temperature · B = minor effect, suitable for most service · C = limited use, swelling, softening or property loss expected · D = not recommended, rapid attack or dissolution. Ratings assume ambient temperature unless the column says otherwise, and assume no mechanical stress. Stress and temperature both accelerate chemical attack: a material rated C unstressed can crack in days when stressed, and a rating that holds at 20 °C may not hold at 60 °C.
Dilute acids attack nylons and acetals by hydrolysing the polymer chain — nylon is dissolved outright by formic acid and degraded by mineral acids. Polyolefins, PVC, PTFE and PPS are essentially unaffected.
Concentrated acids are a much smaller set of survivors: PTFE, and to a lesser degree PPS and UHMW-PE. PEEK resists most acids but is dissolved by concentrated sulphuric acid. Everything else in the table is degraded.
Bases are the mirror image. Most plastics tolerate alkalis well, but polyester-based materials hydrolyse, and acetal homopolymer is attacked by strong bases and hot water.
Ketones (acetone, MEK) and chlorinated solvents (dichloromethane, chloroform) are the two families that destroy amorphous plastics. Polycarbonate, PEI and acrylic dissolve or stress-crack in ketones and chlorinated solvents; PVC is attacked by both. Semi-crystalline plastics — PEEK, PPS, acetal, nylon, PTFE, polyolefins — are generally resistant to both, which is one of the practical advantages of a crystalline structure.
Aromatic hydrocarbons (benzene, toluene, xylene) swell polycarbonate, acrylic and PEI badly, and affect polyolefins moderately. PEEK, PPS, acetal and PTFE are resistant.
Hot water is the most underrated item in the table. Hydrolysis is temperature-driven, so water that is harmless at 20 °C can destroy a part at 80 °C. Acetal homopolymer is the classic example: fine in cold water, fails in hot. Use copolymer if hot water is unavoidable, and PPS, PSU or PEEK if it is continuous.
The letter in this table describes an unstressed specimen in the chemical at ambient temperature. Real parts are stressed, and that changes the answer.
Environmental stress cracking is the failure mode to design against. A chemical that merely swells an unstressed part can crack a stressed one in hours — the chemical lowers the energy needed for a crack to grow, and the stress provides the driving force. Polycarbonate, acrylic and PEI are the most susceptible of the materials here; the classic case is a polycarbonate part assembled with a press fit and then cleaned with an alcohol or ketone, which cracks at the press fit days later.
Temperature accelerates everything. Reaction rates roughly double for every 10 °C, so a rating that holds at 20 °C may fail at 50 °C. Whenever a part sees both a chemical and an elevated temperature, treat the table rating as one grade worse.
Mixtures are not averages. A blend of two chemicals can attack a plastic that neither attacks alone. This is common with cleaning solutions, where surfactants and solvents act together.
For any part in continuous contact with a chemical — a pump housing, a tank liner, a seal — the compatibility table is a shortlisting tool, not a qualification. Immersion-test the actual material in the actual medium at the actual temperature, under the actual stress, before committing to production.
Each data column on this page is tied to the source it came from. The numbers in square brackets correspond to the table headers above.
| # | Source | Type | Revision / method |
|---|---|---|---|
| [1] | Published polymer chemical-compatibility tables (supplier and resin-producer compilations) | standard | compilations as published 2024–2026 |
| Standard | Revision | What it covers on this page |
|---|---|---|
| ISO 175 — Plastics — Determination of the effects of immersion in liquid chemicals | ISO 175:2010 | the immersion-test basis behind the ratings |
| ASTM D543 — Resistance of Plastics to Chemical Reagents | ASTM D543-21 | the standard practice for the resistance ratings |
| Supplier chemical-compatibility tables (resin producers and stock-shape distributors) | compilations as published 2024–2026 | the individual rating letters |
Cross-checked against:
Ratings describe unstressed specimens at ambient temperature in the pure chemical. Stress, elevated temperature, chemical mixtures and long exposure all make attack more likely, so treat the rating as an optimistic bound rather than a guarantee. For continuous contact with a chemical, immersion-test the actual material in the actual medium at the actual temperature under the actual stress before production. Ratings for filled and modified grades can differ from the base polymer.
Every value on this page is traceable to the sources listed above. If you use the data in a document, paper or report, cite it as:
Each row in the tables above also has a permanent link — hover a row and use the # link to cite a single value rather than the whole page.
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