Scope note: this page covers wetted materials of construction — which elastomer, polymer or alloy is suitable to physically contact a given process chemical inside equipment (gaskets, seals, tubing, hosing, valve trim, vessel walls). It does not cover which glove protects your hands (see the chemical-resistant glove selection guide) or which chemicals may be stored near one another (see chemical storage compatibility and segregation rules). Those are related but distinct decisions, made against different reference data.
How to read this chart
Every rating below is a starting point for a specification decision, not a substitute for one. Chemical compatibility is not a fixed property of a material — it depends on the specific chemical grade, its concentration, the temperature of service, contact duration, whether the fluid is static or flowing, and mechanical stress on the part. A material rated “Good” at room temperature with a dilute solution can fail rapidly at higher temperature or higher concentration. Manufacturer compatibility charts are themselves generated under specific test conditions that rarely match your exact process — that is one of the most common reasons two published charts disagree on the same pairing (see “Where sources disagree” below).
Ratings used in the tables:
- Excellent — the material class is broadly used for this chemical category in industrial service; little to no attack expected under normal conditions.
- Good — generally suitable, but performance narrows at elevated temperature, high concentration, or extended exposure; confirm against the specific grade and your service conditions.
- Limited — usable in some formulations or dilute/low-temperature conditions only; treat as “verify before specifying,” not as a default choice.
- Avoid — documented incompatibility (swelling, embrittlement, dissolution, stress cracking, or corrosion) is common enough that this pairing should not be specified without a manufacturer’s written confirmation for your exact chemical and conditions.
Elastomers and polymers: wetted-parts compatibility by chemical category
Covers gasket, seal, O-ring, diaphragm, and tubing/hosing materials. EPDM, silicone (VMQ), FKM (Viton is a Chemours trade name for one family of FKM compounds; other manufacturers sell FKM under other names), and Buna-N/NBR are elastomers classified under the ASTM D1418/D2000 rubber designation system that most manufacturer charts use as their baseline vocabulary. PTFE and PFA are fluoropolymers; polypropylene (PP) is a thermoplastic.
| Chemical category (examples) | EPDM | Silicone | FKM / Viton | Buna-N / NBR | PTFE | PFA | Polypropylene |
|---|---|---|---|---|---|---|---|
| Water, steam, glycols | Excellent | Good | Limited (standard grades degrade in hot water/steam) | Good | Excellent | Excellent | Good |
| Dilute mineral acids (e.g. dilute HCl, H₂SO₄) | Good | Limited | Good | Limited | Excellent | Excellent | Good |
| Concentrated/oxidizing acids (e.g. concentrated HNO₃) | Limited | Avoid | Good | Avoid | Excellent | Excellent | Limited |
| Alkalis / caustic solutions | Excellent | Limited | Limited | Good | Excellent | Excellent | Good |
| Alcohols (methanol, ethanol, isopropanol) | Good | Limited | Good | Good | Excellent | Excellent | Good |
| Ketones (acetone, MEK) | Good | Avoid | Avoid | Avoid | Excellent | Excellent | Limited |
| Aromatic hydrocarbons (toluene, xylene, benzene) | Avoid | Avoid | Good | Limited | Excellent | Excellent | Avoid |
| Aliphatic hydrocarbons, fuels, petroleum oils | Avoid | Limited | Excellent | Good | Excellent | Excellent | Limited |
| Esters, amines | Good | Limited | Avoid | Avoid | Excellent | Excellent | Limited |
| Chlorinated solvents (e.g. dichloromethane, chloroform) | Avoid | Avoid | Limited | Avoid | Excellent | Excellent | Avoid |
| Ozone / UV / outdoor weathering | Excellent | Excellent | Excellent | Avoid | Excellent | Excellent | Good |
PTFE and PFA read as “Excellent” across nearly this entire table because fluoropolymers are chemically inert to almost all industrial process chemicals — the practical limitations on PTFE/PFA are mechanical (cold flow/creep under sustained load, permeability to some gases, limited abrasion resistance) rather than chemical attack. The known exceptions are molten alkali metals and elemental fluorine gas at elevated temperature/pressure, which are outside the scope of most process-chemical service.
Metals and glass: wetted-surface compatibility
| Chemical category (examples) | 304 stainless steel | 316L stainless steel | Borosilicate glass |
|---|---|---|---|
| Water, steam, most food/pharma process fluids | Excellent | Excellent | Excellent |
| Chloride-containing solutions (including seawater, many CIP/sanitizing solutions, brines) | Limited — pitting and crevice corrosion risk rises with chloride concentration and temperature | Good — molybdenum content improves chloride resistance vs. 304, but is not chloride-proof at high concentration/temperature | Excellent (glass does not corrode; risk is thermal/mechanical, not chemical) |
| Dilute organic and mineral acids | Good | Excellent | Excellent |
| Reducing acids (e.g. dilute sulfuric, phosphoric under certain conditions) | Limited | Good — 316/316L is the more common choice for this category | Excellent |
| Hydrofluoric acid, any concentration | Avoid | Avoid | Avoid — HF attacks glass itself; this is the standard exception to glass’s general chemical inertness |
| Hot concentrated caustic (alkali) | Good | Good | Limited — hot concentrated alkali slowly etches glass surfaces |
The practical difference between 304 and 316L: 316(L) adds roughly 2–3% molybdenum, which measurably improves resistance to pitting and crevice corrosion in chloride environments and to reducing acids — which is why 316L is the more common default in pharmaceutical, chemical-process, and marine-adjacent equipment. The “L” designation means low carbon content, which reduces carbide precipitation at weld heat-affected zones (sensitization) and lowers the risk of intergranular corrosion near welds. Neither grade is immune to chloride attack at high enough concentration and temperature; for genuinely aggressive chloride or sour (H₂S-containing) service, consult alloy selection guidance built for that duty — NACE/AMPP MR0175 and ISO 15156 are the standards written specifically for materials in sour oil-and-gas service, and ASTM A240 is the base specification covering stainless steel plate grades including 304 and 316/316L.
Where sources disagree
Published compatibility charts do not always agree with each other, and this page will not paper over that. Three specific, common causes:
- Test concentration and temperature differ between publishers. One manufacturer’s chart may rate a pairing at a dilute, room-temperature test condition; another may test near-saturation at elevated temperature. The same chemical name can land in different rating buckets depending on which condition was tested.
- “FKM” is not one material. FKM compounds vary significantly by fluorine content and cure system, and a compatibility rating for one FKM grade does not automatically transfer to another. Viton is a trade name for one manufacturer’s FKM family, not a synonym for the entire FKM class, though the terms are frequently used interchangeably in the field.
- Static vs. dynamic and short-term vs. continuous exposure are often not distinguished. A seal that survives brief, static contact with a chemical during cleaning may fail under continuous dynamic service with the same chemical.
Where this page’s rating for a pairing could plausibly differ from a specific manufacturer’s own chart for their specific compound, treat the manufacturer’s data for the exact grade you intend to buy as authoritative over this general chart.
Limitations of this chart — read before you specify anything
This table is a general reference for narrowing a materials shortlist, not a specification document. Before finalizing a material choice for wetted equipment:
- Confirm compatibility against the exact chemical concentration, temperature range, and duration of contact your process involves — not the general chemical category.
- Request the manufacturer’s published chemical-resistance data for the specific compound/grade you intend to purchase, not a generic “EPDM” or “316 stainless” chart. Formulation and alloy composition both vary between suppliers.
- Where two chemicals mix in service (cleaning-in-place cycles, multi-component process streams), the mixture’s compatibility can differ from either pure component’s rating.
- Mechanical service conditions — pressure, flexing, vibration, and thermal cycling — can cause a chemically compatible material to fail for non-chemical reasons.
- This page does not address regulatory/food-contact/USP Class VI or similar purity requirements, which are a separate qualification from chemical compatibility.
When the consequence of getting this wrong is a safety incident, a batch loss, or an unplanned shutdown, the cost of a manufacturer confirmation call is trivial by comparison.
Sourcing hierarchy used for this chart
Ratings above were built from, in order of precedence: (1) published chemical-resistance data from elastomer, fluoropolymer, and stainless-steel manufacturers for named material grades; (2) the classification framework in ASTM D2000 for rubber materials and ASTM A240 for stainless steel plate; (3) NACE/AMPP MR0175 and ISO 15156 for chloride/sour-service alloy guidance. Where manufacturer sources disagreed on a specific pairing, this page reports the more conservative (cautious) rating and flags the disagreement above rather than silently picking one source.
Selecting wetted-parts hardware
Once a material family is narrowed, the shop stocks live inventory across the relevant hardware categories:
- Gaskets in EPDM, silicone, PTFE, FKM/Viton and other compounds
- Stainless steel hosing for transfer lines and flexible connections
- Valves across wetted-trim material options
- Fittings and adapters for connecting dissimilar tubing/piping runs
- Compression fittings for tubing connections without welding or solvent bonding
This page intentionally does not recommend specific branded parts or state prices — both change, and inventory turns over. Use the material ratings above to filter the category, then confirm the specific product’s material callout against your process chemical before ordering.
Frequently asked questions
What is the difference between EPDM and Viton (FKM) chemical compatibility?
EPDM performs well with water, steam, ketones, alcohols, and alkalis, but degrades in petroleum oils, fuels, and most hydrocarbons. FKM/Viton is the reverse for the most part — strong with petroleum oils, fuels, and aromatic hydrocarbons, but it fails with ketones, esters, and low-molecular-weight amines. Choosing between them starts with identifying whether your process fluid is closer to a polar/aqueous chemical (favors EPDM) or a hydrocarbon/fuel (favors FKM).
Is PTFE compatible with almost every chemical?
For practical process-chemical purposes, yes — PTFE and PFA are chemically inert to nearly the full range of industrial acids, bases, solvents, and hydrocarbons. The real constraints on using PTFE/PFA are mechanical: cold flow (creep) under sustained clamping load, gas permeability, and lower abrasion resistance than metals, not chemical attack.
What is the difference between 304 and 316L stainless steel for chemical service?
316L adds roughly 2–3% molybdenum compared with 304, which improves resistance to pitting and crevice corrosion in chloride-containing environments and to reducing acids. The “L” means low carbon, which reduces the risk of corrosion at weld heat-affected zones. 316L is the more common default for pharmaceutical and chemical-process wetted equipment; 304 remains adequate for many non-chloride, non-aggressive-acid applications.
Why do different chemical compatibility charts give different answers for the same material and chemical?
Most commonly because they were tested at different concentrations, temperatures, or exposure durations, or because the “same” material name covers a family of compounds (FKM in particular) rather than one fixed formulation. Treat any chart, including this one, as a starting point and confirm against the manufacturer’s data for your specific grade and service conditions.
Is silicone rubber chemically resistant?
Silicone (VMQ) has excellent resistance to ozone, UV, and a very wide service temperature range, and is a common choice for food, pharmaceutical, and general low-hazard fluid service. Its chemical resistance to concentrated acids, hydrocarbons, fuels, and steam is comparatively limited, and it has lower mechanical/abrasion resistance than many other elastomers.
What should I check before relying on any chemical compatibility chart?
Confirm the chemical’s exact concentration and your process temperature against the manufacturer’s own published data for the specific material grade you intend to buy, not a generic material-class chart. Also confirm mechanical service conditions (pressure, flexing, cycling) separately — a chemically compatible material can still fail for mechanical reasons.
