Ozone Resistant O-Rings
Compatibility ratings for 7 O-ring materials in Ozone service
Ozone (Gases) compatibility with the seven most common O-ring elastomers, rated on the standard A/B/C/D scale: A = excellent, B = good, C = fair, D = not recommended. This data also appears in our interactive chemical compatibility chart and is available machine-readable at /api/chemicals.json.
| Material | Rating | Guidance |
|---|---|---|
| NBR | D | not recommended — rapid degradation expected |
| FKM | A | excellent — recommended for continuous service |
| EPDM | A | excellent — recommended for continuous service |
| VMQ | A | excellent — recommended for continuous service |
| PTFE | A | excellent — recommended for continuous service |
| FFKM | A | excellent — recommended for continuous service |
| HNBR | A | excellent — recommended for continuous service |
Why These Ratings
- NBR (D) — documented weaknesses include “Ozone.”
- VMQ (A) — documented strengths include “Ozone and weathering.”
- PTFE (A) — documented strengths include “Virtually all chemicals.”
- FFKM (A) — documented strengths include “Virtually all chemicals except molten alkali metals.”
GasesService: Concentration & Temperature Notes
Dry gases are easy on elastomers — our compressed-air rows rate most materials A. The exception pattern is oil mist: lubricated compressed air carries petroleum droplets, which is why EPDM drops from B (dry air) to D (oil mist) in our data. Ozone-rich environments demand ozone-proof materials; NBR rates D there.
Recommended
- FKM O-rings (A)
- EPDM O-rings (A)
- VMQ O-rings (A)
- PTFE O-rings (A)
- FFKM O-rings (A)
- HNBR O-rings (A)
Use With Caution
No conditional materials for this chemical.
Avoid
- NBR (D)
Related Chemicals (Gases)
Frequently Asked Questions
Is Ozone compatible with FKM (Viton) O-rings?
FKM is rated A for Ozone: excellent — recommended for continuous service. Ratings are general guidelines; concentration, temperature and exposure time all affect real-world compatibility, so validate critical applications with ASTM D471 immersion testing.
Is Ozone compatible with NBR (nitrile) O-rings?
NBR is rated D for Ozone: not recommended — rapid degradation expected. NBR is the lowest-cost elastomer, so when it earns an A or B rating it is usually the economical default; when it rates C or D, do not substitute it for a higher-rated material to save cost.
Can I use PTFE O-rings with Ozone?
PTFE is rated A for Ozone: excellent — recommended for continuous service. Remember that PTFE has no elastic memory — in demanding service it needs spring energization or an elastomer core (FEP/PFA encapsulation) to maintain sealing force.
What is the best O-ring material for Ozone?
FKM, EPDM, VMQ, PTFE, FFKM, HNBR are rated A (excellent) for Ozone in our compatibility data and are the recommended starting point for material selection. Final selection should also account for operating temperature, pressure and whether the seal is static or dynamic.
Can I use EPDM O-rings with Ozone?
EPDM is rated A for Ozone: excellent — recommended for continuous service. Always confirm the specific fluid concentration and temperature before specifying EPDM for this service.
Need O-Rings for Ozone Service?
Send us your fluid, concentration and temperature — our engineers will confirm the right compound. MOQ 1 piece.