Choosing the wrong rubber material in chemical applications can lead to leaks, equipment failure, and costly downtime. EPDM rubber is widely used for its excellent chemical resistance, but understanding its limitations is key to maximizing its performance.
EPDM rubber is highly resistant to water-based chemicals, diluted acids, alkalis, and polar solvents. However, it is not suitable for oils, fuels, and many hydrocarbons.
In this guide, I’ll break down the chemicals compatible with EPDM, its strengths and weaknesses, and offer a practical selection guide for industrial buyers.
What Is EPDM Rubber?
EPDM1 (Ethylene Propylene Diene Monomer) is a synthetic rubber that performs well in outdoor and chemical environments.
EPDM offers excellent resistance to weather, ozone, steam, and many polar chemicals. It’s commonly used in seals, gaskets, and hoses in water treatment, HVAC, and chemical industries.
🛠️ Key Properties of EPDM
| Property | Description |
|---|---|
| ✅ Weather/Ozone Resistance | Excellent |
| ✅ Water/Steam Resistance | Excellent |
| ✅ Chemical Resistance | Excellent with polar substances |
| ❌ Oil & Hydrocarbon Resistance | Poor |
| ✅ Temperature Range | -40°C to +150°C |
Chemicals That Are Compatible with EPDM
EPDM rubber works best with polar substances. It resists many water-based chemicals and diluted acids.
EPDM is compatible with water, glycol-based fluids, diluted acids and alkalis, alcohols, ketones, and phosphate ester fluids.
🛠️ Compatibility Table for EPDM
| Chemical Type | Compatibility | Examples |
|---|---|---|
| ✅ Water-based fluids | Excellent | Water, Steam, Coolants |
| ✅ Diluted Acids | Excellent | Acetic Acid, Nitric Acid |
| ✅ Diluted Alkalis | Excellent | Sodium Hydroxide, Ammonia |
| ✅ Alcohols | Good | Methanol, Ethanol |
| ✅ Ketones | Good | Acetone, MEK |
| ✅ Glycol Solutions | Excellent | Ethylene Glycol, Propylene Glycol |
| ✅ Phosphate Esters | Good | Skydrol™, Fire-resistant fluids |
Does Acetone Damage EPDM?
Acetone is a strong solvent and may not always be compatible with rubber materials.
EPDM has moderate resistance to acetone but prolonged exposure can cause swelling and deterioration. Use EPDM with acetone only in controlled, short-term applications.
🛠️ Acetone’s Effect on EPDM
- ✅ Short-term exposure: Minimal damage at room temperature
- ❌ Long-term exposure: Causes swelling and softening
- ✅ Alternatives: For better acetone resistance, use FKM or PTFE
What Breaks Down EPDM Rubber?
Despite its excellent weather and water resistance, EPDM has some chemical vulnerabilities.
EPDM rubber degrades quickly when exposed to petroleum oils, fuels, aromatic hydrocarbons, and strong solvents.
🛠️ Common Causes of EPDM Breakdown
| Cause | Effect on EPDM |
|---|---|
| ❌ Petroleum Oils | Swelling, softening, deterioration |
| ❌ Aromatic Hydrocarbons | Complete breakdown, loss of integrity |
| ❌ Chlorinated Solvents | Cracking, hardening, chemical attack |
| ❌ Prolonged UV Exposure (without stabilizers) | Surface degradation, cracking |
What Should You Not Use on EPDM?
EPDM is not compatible with oils, greases, and hydrocarbon-based lubricants.
Avoid petroleum-based products, mineral oils, and hydrocarbon solvents when using EPDM rubber seals or gaskets.
🛠️ Substances to Avoid
- ❌ Gasoline
- ❌ Diesel Fuel
- ❌ Kerosene
- ❌ Mineral Oil Lubricants
- ❌ Aromatic Solvents (Toluene, Benzene)
Is EPDM Rubber Resistant to Chlorine?
Chlorine resistance depends on concentration and temperature.
EPDM rubber shows good resistance to low-concentration chlorinated water, but prolonged exposure to high levels of chlorine or chlorine gas can degrade EPDM.
🛠️ Chlorine Compatibility
- ✅ Potable Water Treatment: EPDM works well in chlorinated drinking water systems (NSF/WRAS grades).
- ❌ Industrial Chlorine Gas: Degrades EPDM, causing cracking and loss of flexibility.
- ✅ Alternatives: For high chlorine concentrations, use FKM or specialized perfluoroelastomers.
Technical Comparison: EPDM vs. Other Elastomers in Chemical Compatibility
| Material | Water & Steam | Fuel Resistance | Chemical Resistance | Temp Range | Cost |
|---|---|---|---|---|---|
| ✅ EPDM | Excellent | Poor | Excellent (polar) | -40°C to 150°C | Low |
| ✅ FKM (Viton®) | Poor | Excellent | Excellent (broad) | -20°C to 230°C | High |
| ✅ NBR (Nitrile) | Moderate | Good | Moderate | -30°C to 100°C | Medium |
| ✅ PTFE | Excellent | Excellent | Excellent (universal) | -200°C to 260°C | High |
How to Choose EPDM for Chemical Applications?
Choose EPDM if your application involves water-based chemicals, diluted acids, and alkalis at moderate temperatures.
EPDM is an excellent choice for seals and gaskets in water treatment, HVAC, and certain chemical processing systems where polar fluids are used.
🛠️ Buyer Checklist
- ✅ Confirm chemical compatibility2 (polar substances)
- ✅ Verify temperature ranges (-40°C to 150°C)
- ✅ Look for certified grades (NSF, WRAS, FDA)
Conclusion
EPDM offers excellent compatibility with water, diluted acids, alkalis, and glycol-based fluids, but it’s not suitable for oils, fuels, and hydrocarbons. Understanding its limitations ensures reliable and long-lasting seals.
📞 Contact Us for Expert Guidance and Free Samples!
At Julong Rubber, we manufacture custom EPDM seals and gaskets for demanding industrial applications. Get in touch for expert material selection advice and free samples!
✅ ISO 9001 Certified
✅ OEM/ODM Manufacturing
✅ Free Technical Consultation and Samples
📧 Contact Kelly at Julong Rubber
Email: info@rubberandseal.com
Website: www.rubberandseal.com
