Media screening

Chemical compatibility: pick the O-ring material that survives the media

Name the chemicals, fluids or service media your seal will see, and compare five rubber families side by side: NBR, FKM, EPDM, silicone (VMQ) and FFKM. Add up to six media to check a combined service condition. Grades are family-level screening from our own compatibility dataset, not approval of a compound.

Check a chemical
Media in the dataset
2,000+
Rubber families
18
Grades shown
A · B · C · U · R
Compared at once
6 media × 18 families

Screening first, compound second

Rubber family answers most of the media question. What is left over is the compound: cure system, filler, hardness and the actual service conditions.

Confirm before you commit when the medium is concentrated, hot, under pressure, in continuous contact, or when the seal is safety-relevant. Send the media list and conditions for an engineering review.

Request an engineering review

Compatibility checker

Search a chemical, a fluid, a common name, or a service condition such as steam or hydraulic oil. Add up to six media, then read the matrix: rows are your media, columns are rubber families.

2,000+ media · 18 families · worst case wins

Common
Fuels & oils
Chemicals
Service
Comparing
Add a medium to see grades for NBR, FKM, EPDM, silicone (VMQ) and FFKM. The interactive checker needs JavaScript. Until it loads, use the table of 25 common media further down this page, or send us your media list for a review. Request engineering review

How to read a grade

  • AGoodPositive screening in the source scale; allowable swelling or property change varies. Still confirm the compound.
  • BFairMinor to moderate effect. Often acceptable for static seals; watch temperature and concentration.
  • CLimitedNoticeable swelling, softening or hardening. Short-term or static use only, and only after a review.
  • UAvoidSevere effect expected. Pick another family.
  • RReviewSources or compounds disagree, or the answer depends on the compound. Ask for an engineering review.
  • –No dataNot rated in our dataset. No data is not the same as compatible.

Answer first

Which rubber for which medium?

Short version: NBR for petroleum oils, greases and fuels; FKM for hot oils, fuels and many acids, but not for ketones such as acetone, steam or glycol brake fluid; EPDM for water, steam, glycols, brake fluid and weather; silicone (VMQ) for dry heat, air and cold, but not for fuels and only with care in oils; FFKM where nothing else holds up and the budget allows it. When a medium is concentrated, hot or under pressure, treat the label as a starting point only.

Family level, not compound level

Two NBR compounds can behave differently in the same oil. Family screening narrows the shortlist; the compound decides the service life.

Worst case wins

When you compare several media, we rank families by their lowest grade. A seal sees every medium in the list, not an average.

Flags mean disagreement

A graded cell with a flag means our sources differ in test scope, or results vary between compounds. That sends the choice to a review.

Conditions change the answer

Concentration, temperature, pressure, exposure time and static versus dynamic service can turn a Good into a Limited. Rows keep the condition in the name where the data has it.

No grade is not a pass

If a cell shows no data, the medium was never rated for that family in our dataset. Nothing is inferred from a similar-sounding chemical.

Then buy or ask

Every result ends in a place to act: the family collection, the size finder pre-filled with the family, or a quote request carrying the media list.

Conditions disclaimer. Compatibility depends on the exact medium (concentration, grade, additives), temperature, pressure, exposure time and the compound itself (cure system, filler, hardness). Results here are family-level screening from published compatibility references, not approval of a compound and not a service-life guarantee. Static and dynamic seals also differ. Confirm with the actual medium and conditions, or request an engineering review, before committing a seal to critical service.

Reference table

25 common media against the five families we stock

The same grades the checker produces, generated as static text so it is readable without scripts, in search results and when the page is printed. Blank means not rated in our dataset.

Family-level compatibility screening for 25 common media across NBR, FKM, EPDM, silicone (VMQ) and FFKM.
MediumNBRNitrileFKMFluoroelastomerEPDMEthylene propyleneVMQSiliconeFFKMPerfluoroelastomer
WaterAGoodBFairAGoodAGoodAGood
Drinking waterAGoodAGoodAGoodAGoodAGood
Sea waterAGoodAGoodAGoodAGoodAGood
Steam below 400 °FSteam Below 400°FUAvoidUAvoidAGoodCLimitedAGood
Air below 200 °FAir, Below 200° FBFairAGoodAGoodAGoodAGood
NitrogenAGoodAGoodAGoodAGoodAGood
Carbon dioxideAGoodAGoodAGoodAGoodAGood
Ozone and weatherUAvoidAGoodAGoodAGoodAGood
Hydraulic oil, petroleum baseAGoodAGoodUAvoidBFairAGood
Mineral oilAGoodAGoodCLimitedBFairAGood
Motor oil, SAE 10–50Lubricating Oils, SAE 10, 20, 30, 40, 50AGoodAGoodUAvoidUAvoidAGood
Transmission fluidAGoodAGoodUAvoidUAvoidAGood
Diesel oilAGoodAGoodUAvoidUAvoidAGood
GasolineRReviewAGoodUAvoidUAvoidAGood
KeroseneAGoodAGoodUAvoidUAvoidAGood
Ethylene glycol and coolantAGoodAGoodAGoodAGoodAGood
Brake fluid, glycol typeBrake Fluid DOT 3 (Glycol Type)CLimitedUAvoidAGoodCLimitedAGood
EthanolCLimitedCLimitedAGoodBFairAGood
MethanolUAvoidUAvoidAGoodAGoodAGood
Isopropyl alcoholBFairAGoodAGoodAGoodAGood
AcetoneUAvoidUAvoidRReviewRReviewAGood
Sulfuric acid, diluteSulfuric Acid, 3 Molar to 158°FBFairAGoodAGoodAGoodAGood
Hydrochloric acid, diluteHydrochloric Acid, 3 Molar to 158°FBFairAGoodAGoodUAvoidAGood
Sodium hydroxide, diluteSodium Hydroxide, 3 MolarBFairBFairAGoodAGoodAGood
Sodium hypochloriteBFairAGoodAGoodBFairAGood

A Good · B Fair · C Limited · U Avoid · R review needed · – not rated. A flagged cell means our sources or compounds disagree.

Family-level screening from published compatibility references; not an official validation, not a certification and not approval of a compound.

Questions

Chemical compatibility FAQ

Does a Good (A) grade mean the O-ring will work?
No. A is a screening result for the rubber family: it is a positive classification in the source scale, whose allowable swelling and property-change limits vary. Service life also depends on the compound, the temperature, the pressure, the exposure time and the groove. Use A grades to build a shortlist, then confirm the compound for critical service.
Why does one medium get different grades for different families?
Each family is a different polymer with different resistance. Diesel oil, for example, grades Good for NBR and FKM but Avoid for EPDM and silicone, while steam is the other way round for EPDM. That is why the checker shows a column per family instead of one answer.
What does R (review) mean?
R means we will not turn the evidence into a pass or fail. Either our sources disagree on scope or conditions, or results vary between compounds inside the family. Both cases need a human check of the exact medium and compound.
Can I check several chemicals at once?
Yes, up to six. Component screening is not an experimentally validated mixture result; concentrations, interactions, temperature and exposure require review. A seal in a real system usually sees more than one medium (fuel plus water, oil plus coolant, cleaning agents plus process fluid). The matrix shows every medium, and the worst-case row ranks the families, because a seal has to survive all of them.
Does concentration or temperature change the answer?
Often, yes. Dilute and concentrated grades of the same acid can land in different columns, and hot service is harder on rubber than cold. Where our data has the condition in the row name (for example a 3 molar acid tested to 158 °F), the condition applies. Otherwise treat the grade as room-temperature screening and send the real conditions for a review.
Which family should I start with for water and steam?
EPDM is usually the first choice for water, hot water and steam; NBR and FKM both grade Avoid for steam in our data. For intermittent cold water, NBR is often enough. Check the row for the exact medium, then confirm the compound.

Need a decision on a specific medium? Send it for an engineering review with the concentration, temperature, pressure and exposure time.