Sulfur Dioxide (dry) vs Buna-N Compatibility
Verified chemical resistance rating (Acceptable with Operating Controls), thermal boundary limits (Ambient service (72°F / 22°C) preferred; monitor wear in continuous service), and material specification guide for Buna-N exposed to Sulfur Dioxide (dry) in Industrial Process Chemical service.
Sulfur Dioxide (dry) vs Buna-N: B-Good
Exposing Buna-N to Sulfur Dioxide (dry) (Formula: SO2 (Anhydrous Gas), CAS: 7446-09-5) carries an official rating of B-Good (Acceptable with Operating Controls). Maximum recommended thermal operating limit: Ambient service (72°F / 22°C) preferred; monitor wear in continuous service. Best Grade A alternative materials for continuous or high-temperature service: Polypropylene, Viton, PTFE, PVDF.
Technical Specifications and Operating Parameters
| Chemical Medium | Sulfur Dioxide (dry) |
|---|---|
| Chemical Formula | SO2 (Anhydrous Gas) |
| CAS Registry Number | 7446-09-5 |
| Chemical Functional Class | Industrial Process Chemical |
| Wetted Material | Buna-N |
| Official Resistance Rating | B-Good (Grade B) |
| Engineering Service Verdict | Acceptable with Operating Controls |
| Max Temp and Concentration Limit | Ambient service (72°F / 22°C) preferred; monitor wear in continuous service |
| Best Grade A Alternatives | Polypropylene, Viton, PTFE, PVDF |
| Backtest and Audit Verification | Verified against Cole-Parmer, ISM, Graco & CP Lab Safety industrial chemical resistance charts. |
Sulfur Dioxide (dry) Cross-Material Comparison Matrix (9 Materials)
Direct benchmark ratings across all 9 reference industrial materials for Sulfur Dioxide (dry):
| Material Name | Compatibility Rating | Service Verdict | Temperature Limit | Datasheet |
|---|---|---|---|---|
| Buna-N | B-Good | Acceptable with Operating Controls | Ambient service (72°F / 22°C) preferred; monitor wear in continuous service | Report |
| EPDM | B-Good | Acceptable with Operating Controls | Ambient service (72°F / 22°C) preferred; monitor wear in continuous service | Report |
| HDPE | A-Excellent | Safe for Continuous Industrial Service | Ambient to elevated operating temperatures within standard material limits | Report |
| Polypropylene | A1-Excellent | Safe for Continuous Industrial Service | Up to 120°F (49°C) verified; up to material thermal limit in non-pressurized service | Report |
| PTFE | A-Excellent | Safe for Continuous Industrial Service | Ambient to elevated operating temperatures within standard material limits | Report |
| PVC | B-Good | Acceptable with Operating Controls | Ambient service (72°F / 22°C) preferred; monitor wear in continuous service | Report |
| PVDF | A-Excellent | Safe for Continuous Industrial Service | Ambient to elevated operating temperatures within standard material limits | Report |
| Stainless Steel | D-Severe Effect | Incompatible — Immediate Failure Risk | Not recommended at any temperature or concentration | Report |
| Viton | A-Excellent | Safe for Continuous Industrial Service | Ambient to elevated operating temperatures within standard material limits | Report |
Chemical and Material Interaction Analysis
Engineering Compatibility Verdict
Sulfur Dioxide (dry) vs Buna-N: B – Good (Minor Effect / Conditional)
Summary Verdict: Buna-N (Nitrile / NBR Elastomer) is rated B-Good (Acceptable with Operating Controls) when exposed to Sulfur Dioxide (dry) (Formula: SO2 (Anhydrous Gas), CAS: 7446-09-5). Acceptable for low-pressure piping, static seals, and scheduled-maintenance components. Implement periodic visual and dimensional inspection.
Quick Engineering Specifications
| Chemical Media | Sulfur Dioxide (dry) |
|---|---|
| Chemical Formula | SO2 (Anhydrous Gas) |
| CAS Registry Number | 7446-09-5 |
| Chemical Classification | Industrial Process Chemical |
| Wetted Material | Buna-N (Nitrile / NBR Elastomer) (Acrylonitrile-Butadiene Copolymer Elastomer) |
| Official Resistance Rating | B – Good (Minor Effect / Conditional) (Grade B) |
| Recommended Temperature Window | Ambient service (72°F / 22°C) preferred; monitor wear in continuous service (Material limit: -40°F to 250°F (-40°C to 121°C)) |
| Top Grade-A Alternatives | Polypropylene, Viton, PTFE, PVDF |
| Data Verification Status | Verified against Cole-Parmer, ISM, Graco & CP Lab Safety industrial chemical resistance charts. |
Chemical & Material Interaction Analysis
Sulfur Dioxide (dry) is classified as an industrial process chemical (requires verification of concentration and thermal operating envelopes prior to deployment). Used in chemical manufacturing, fluid transfer, and industrial storage systems. When selecting wetted components for Buna-N, engineers must account for both concentration-dependent chemical attack and thermal stress:
- Reaction & Failure Mechanism: Exhibits minor chemical interaction—such as slight discoloration, mild dimensional swell, or slow uniform surface etching—that does not immediately compromise structural integrity.
- Material Profile (Buna-N): Workhorse elastomer for petroleum-based hydraulic oils, motor oils, diesel, gasoline, aliphatic hydrocarbons (hexane, heptane), water, and salt brines. However, poor resistance to ozone/weathering and rapidly destroyed by ketones, esters, chlorinated hydrocarbons, aromatic solvents, and strong oxidizing acids.
- Application Scope: Common wetted components include hydraulic O-rings, fuel transfer hoses, rotary shaft seals, oil gaskets, and general-purpose industrial pump elastomers.
Cross-Material Compatibility Comparison for Sulfur Dioxide (dry)
To help you select the longest-lasting piping, valve lining, or O-ring seal for Sulfur Dioxide (dry), the table below compares Buna-N against 8 other common industrial engineering materials:
| Wetted Material | Compatibility Rating | Service Recommendation | Material Temp Range |
|---|---|---|---|
| Polypropylene (PP Homopolymer & Copolymer) | A1-Excellent | Safe for Continuous Industrial Service | 32°F to 180°F (0°C to 82°C) |
| 316 / 304 Austenitic Stainless Steel | D-Severe Effect | Incompatible — Immediate Failure Risk | -325°F to 800°F (-198°C to 426°C) |
| Viton® (FKM Fluoroelastomer) | A-Excellent | Safe for Continuous Industrial Service | -15°F to 400°F (-26°C to 204°C) |
| PTFE (Teflon® / Polytetrafluoroethylene) | A-Excellent | Safe for Continuous Industrial Service | -328°F to 500°F (-200°C to 260°C) |
| EPDM (Ethylene Propylene Diene Monomer) | B-Good | Acceptable with Operating Controls | -60°F to 300°F (-51°C to 149°C) |
| PVC Type I (Unplasticized Polyvinyl Chloride / uPVC) | B-Good | Acceptable with Operating Controls | 32°F to 140°F (0°C to 60°C) |
| PVDF (Kynar® / Polyvinylidene Fluoride) | A-Excellent | Safe for Continuous Industrial Service | -40°F to 280°F (-40°C to 138°C) |
| Buna-N (Nitrile / NBR Elastomer) (Current Page) | B-Good | Acceptable with Operating Controls | -40°F to 250°F (-40°C to 121°C) |
| HDPE (High-Density Polyethylene) | A-Excellent | Safe for Continuous Industrial Service | -60°F to 140°F (-51°C to 60°C) |
Frequently Asked Questions (FAQ)
Is Buna-N compatible with Sulfur Dioxide (dry)?
Buna-N is rated B-Good (Acceptable with Operating Controls) with Sulfur Dioxide (dry) (Formula: SO2 (Anhydrous Gas), CAS: 7446-09-5). Exhibits minor chemical interaction—such as slight discoloration, mild dimensional swell, or slow uniform surface etching—that does not immediately compromise structural integrity. Acceptable for low-pressure piping, static seals, and scheduled-maintenance components. Implement periodic visual and dimensional inspection.
What is the best alternative material for handling Sulfur Dioxide (dry)?
If Buna-N does not meet your temperature or pressure requirements for Sulfur Dioxide (dry), the highest-rated Grade A alternatives are Polypropylene, Viton, PTFE, PVDF. Always verify O-ring elastomers and metallic fasteners separately before full-scale deployment.
Technical Engineering FAQs: Sulfur Dioxide (dry) vs Buna-N
Click any question below for chemical failure-mode specifics, thermal derating limits, and material selection rules: