Picking the wrong plastic for chemical contact fails parts in days, not years. This reference compares the six most-specified engineering plastics — UHMWPE, PTFE, PEEK, Nylon (PA6/PA66), POM (Acetal) and HDPE — against 35 common industrial chemicals. Use it to narrow candidates, then verify with the manufacturer's data sheet and a 30-day immersion test before committing to production volumes.
How to read a chemical resistance chart
Chemical compatibility ratings come in two flavours: immersion (continuous contact) and splash (occasional exposure). A material rated 'B' (acceptable) for splash may be 'C' (not recommended) for immersion. Temperature multiplies aggression: a chemical rated 'A' (excellent) at 20 °C may degrade to 'C' at 60 °C. The table below gives 20 °C immersion ratings; for elevated temperature or splash service, derate one grade.
Master chemical resistance chart (20 °C immersion)
A = Excellent (no attack); B = Good (minor swelling/colour change); C = Limited (acceptable for short exposure); D = Not recommended.
| Chemical | UHMWPE | PTFE | PEEK | Nylon (PA6/66) | POM | HDPE |
|---|---|---|---|---|---|---|
| Sulphuric acid 30% | A | A | A | C | D | A |
| Sulphuric acid 70% | B | A | B | D | D | B |
| Hydrochloric acid 10% | A | A | B | D | D | A |
| Hydrochloric acid 35% | B | A | C | D | D | B |
| Nitric acid 30% | B | A | B | D | D | B |
| Phosphoric acid 50% | A | A | A | B | C | A |
| Acetic acid 10% | A | A | A | B | B | A |
| Citric acid (food) | A | A | A | A | A | A |
| Sodium hydroxide 50% | A | A | A | A | D | A |
| Ammonia 25% | A | A | A | A | B | A |
| Hydrogen peroxide 30% | A | A | A | C | C | A |
| Chlorine bleach 5% | A | A | A | C | C | A |
| Ethanol | A | A | A | A | A | A |
| Methanol | A | A | A | A | A | A |
| Acetone | A | A | A | B | A | A |
| MEK (methyl ethyl ketone) | A | A | A | B | A | A |
| Toluene | B | A | A | A | A | B |
| Xylene | B | A | A | A | A | B |
| Diesel fuel | A | A | A | A | A | A |
| Mineral oil | A | A | A | A | A | A |
| Vegetable oil | A | A | A | A | A | A |
| Sea water | A | A | A | B | A | A |
| Brine 25% NaCl | A | A | A | B | A | A |
| Cleaning detergent (alkaline) | A | A | A | A | B | A |
| Hot water 80 °C | A | A | A | B | A | B |
| Steam (saturated) | C | A | A | C | B | C |
| Hydrogen sulphide | A | A | A | B | C | A |
| Iron ore slurry | A | A | A | C | B | A |
| Cement slurry | A | A | A | B | B | A |
| Coal dust + moisture | A | A | A | B | A | A |
| Beer / wine / juice | A | A | A | A | A | A |
| Milk / dairy | A | A | A | A | A | A |
| Pharma intermediates (broad) | A | A | A | B | B | A |
| UV / outdoor weathering | C | A | A | C | C | C |
| Ozone | A | A | A | C | C | A |
Application examples — picking from the chart
Pickling line splash guard (sulphuric + nitric acid, 50 °C): PTFE first choice, PE-1000 acceptable for splash only. Food line conveyor wear strip: PE-1000 FDA grade beats POM on hot detergent cleaning cycles. Marine bollard facing (sea water, UV): PE-1000 with carbon-black UV stabiliser; PTFE is overkill. Pharma reactor stirrer scraper: PEEK or PTFE; PE-1000 is borderline for sterilisation steam cycles. Mining slurry pump impeller wear ring: PE-1000 or PEEK; PTFE not stiff enough.
When to choose UHMWPE vs PTFE vs PEEK
UHMWPE wins on cost-per-year for abrasion duty in chemicals up to ~70 °C. PTFE wins on absolute chemical inertness (it is the polymer of choice for fuming acids, oxidisers, and any unknown chemical). PEEK wins above 150 °C continuous service and where mechanical strength under load matters more than abrasion. Joining for any of these is mechanical fastening, counter-bored bolting, T-bolt capture, tongue-and-groove or fillet plates.
Temperature limits override chemical compatibility
A material rated 'A' against your chemical at 20 °C can drop to 'C' at 60 °C and 'D' at 90 °C. Always check the data sheet for both maximum continuous service temperature and chemical compatibility at your operating temperature. UHMWPE max continuous: 80–90 °C. PTFE: 250 °C. PEEK: 250–260 °C. Nylon: 100 °C (120 °C heat-stabilised). POM: 90 °C. HDPE: 60 °C.
Frequently Asked Questions
Is UHMWPE food-safe?
Yes — FDA grade PE-1000 complies with FDA 21 CFR 177.1520 and EU 10/2011. Standard PE-1000 may contain trace additives not approved for food contact; always specify 'FDA grade' on your PO.
Why does the chart show PE-1000 weak against UV?
Standard PE-1000 yellows and embrittles in direct sunlight after 12–24 months. Carbon-black UV-stabilised grade extends outdoor life to 5–10 years. Specify '2.5% carbon black' for marine, ground protection and outdoor applications.
Can I use UHMWPE with hot water above 80 °C?
Continuous duty above 80 °C is not recommended — PE-1000 starts creeping under load. Short cycles to 95 °C (e.g. cleaning) are acceptable if the part is unloaded during cleaning.
What about chlorinated solvents like dichloromethane?
PE-1000 swells significantly in chlorinated solvents. PTFE or PEEK preferred. We do not recommend PE-1000 for any chlorinated solvent above splash exposure.
Do you supply PEEK and PTFE in addition to UHMWPE?
Yes. We stock PEEK natural and 30% glass-filled, PTFE virgin and 25% glass-filled, in sheet and rod. CNC machining of PEEK and PTFE in-house. MOQ from 1 piece, quote in 24 hours.