Chlorine Water Resistant O-Rings

Compatibility ratings for 7 O-ring materials in Chlorine Water service

At a glance:A× 2B× 2C× 1D× 2— 2 of 7 materials recommended for Chlorine Water

Chlorine Water (Oxidizers) 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	B	good — suitable for most applications
EPDM	C	fair — conditional use, verify with testing
VMQ	D	not recommended — rapid degradation expected
PTFE	A	excellent — recommended for continuous service
FFKM	A	excellent — recommended for continuous service
HNBR	B	good — suitable for most applications

Why These Ratings

NBR (D) — documented weaknesses include “Strong acids.”
VMQ (D) — documented weaknesses include “Concentrated acids and alkalis.”
PTFE (A) — documented strengths include “Strong oxidizing acids.”
FFKM (A) — documented strengths include “Concentrated oxidising acids.”

OxidizersService: Concentration & Temperature Notes

Oxidizers attack the polymer backbone itself rather than merely swelling it. Ozone is the classic case — NBR rates D while FKM, EPDM and the fluorocarbons rate A, because NBR's unsaturated backbone is ozone-reactive. Chlorine water and hydrogen peroxide intensify their attack with concentration and temperature; PTFE and FFKM are the safe defaults.

Use With Caution

Avoid

NBR (D)
VMQ (D)

Engineering note: ratings are general guidelines based on typical exposure conditions. Fluid concentration, temperature, pressure and exposure time can shift compatibility by a full grade or more. For critical service, validate the actual compound with ASTM D471 immersion testing before production use. Selecting across multiple chemicals? See the chemical-resistant O-ring selection guide for a material-first comparison.

Related Chemicals (Oxidizers)

Hydrogen Peroxide resistant O-rings

Frequently Asked Questions

Is Chlorine Water compatible with FKM (Viton) O-rings?

FKM is rated B for Chlorine Water: good — suitable for most applications. Ratings are general guidelines; concentration, temperature and exposure time all affect real-world compatibility, so validate critical applications with ASTM D471 immersion testing.

Is Chlorine Water compatible with NBR (nitrile) O-rings?

NBR is rated D for Chlorine Water: 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 Chlorine Water?

PTFE is rated A for Chlorine Water: 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 Chlorine Water?

PTFE, FFKM are rated A (excellent) for Chlorine Water 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 Chlorine Water?

EPDM is rated C for Chlorine Water: fair — conditional use, verify with testing. Always confirm the specific fluid concentration and temperature before specifying EPDM for this service.

Need O-Rings for Chlorine Water Service?

Send us your fluid, concentration and temperature — our engineers will confirm the right compound. MOQ 1 piece.

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