What are the differences between silicone and EPDM rubber?

Silicone and EPDM are two of the most widely used rubber materials in industrial manufacturing and engineering applications. Both offer flexibility, durability and environmental resistance, but they are designed for different operating conditions and performance requirements.

Choosing between silicone and EPDM rubber depends on factors such as temperature exposure, weather resistance, chemical compatibility, compliance requirements and long-term durability expectations.

For engineers and buyers, understanding how these materials differ can help prevent premature failure, reduce maintenance issues and improve product performance across a wide range of industrial environments.

What is silicone rubber?

Silicone rubber is a synthetic elastomer known for its excellent temperature resistance, flexibility and environmental durability.

It is widely used in applications involving:

• High temperatures
• Low temperatures
• Food processing
• Medical equipment
• Electrical insulation
• Outdoor sealing systems

One of silicone’s biggest advantages is its ability to remain flexible across a broad operating temperature range while resisting UV exposure and ozone degradation.

Silicone products are commonly manufactured into:

• Tubing
• Gaskets
• Seals
• Extrusions
• O rings
• Protective profiles

What is EPDM rubber?

EPDM stands for ethylene propylene diene monomer, a synthetic rubber designed primarily for weather resistance and water resistance.

EPDM is commonly used in:

• Roofing systems
• Automotive seals
• HVAC systems
• Water handling systems
• Outdoor gaskets
• Construction applications

The material offers excellent resistance to weathering, ozone and moisture, making it highly suitable for external environments.

EPDM is often selected where long-term outdoor durability is important and extreme temperatures are less demanding.

How do temperature ranges compare?

One of the biggest differences between silicone and EPDM is temperature performance.

Silicone temperature range

Silicone can typically operate continuously between approximately:

• -60°C to +200°C

Some specialist grades may tolerate even higher intermittent temperatures.

EPDM temperature range

EPDM generally performs within a lower range, often around:

• -40°C to +120°C

Although EPDM offers good heat resistance for many applications, silicone is usually preferred where continuous high temperatures or extreme thermal cycling are involved.

This makes silicone particularly suitable for:

• Industrial processing systems
• Automotive engine environments
• Electrical insulation
• Heated manufacturing equipment

Businesses requiring thermal-resistant sealing solutions often explore specialist silicone rubber gaskets for demanding industrial environments.

Which material performs better outdoors?

Both materials perform well outdoors, but they offer different advantages.

Silicone outdoor performance

Silicone provides excellent resistance to:

• UV exposure
• Ozone
• Weathering
• Temperature fluctuations

It also maintains flexibility over long periods in exposed environments.

EPDM outdoor performance

EPDM is also highly weather resistant and performs extremely well in:

• Rain exposure
• General outdoor sealing
• Roofing applications
• Water-based environments

In many standard outdoor applications, EPDM can provide excellent durability at a lower material cost than silicone.

The best option depends on whether temperature resistance or general weather resistance is the higher priority.

How do water and chemical resistance differ?

Both materials resist moisture well, but their chemical compatibility differs.

EPDM strengths

EPDM performs particularly well with:

• Water
• Steam
• Some cleaning chemicals
• Brake fluids

However, EPDM is generally not suitable for oils or hydrocarbons.

Silicone strengths

Silicone offers good moisture resistance and stability at varying temperatures, but some oils and solvents may affect performance depending on the compound.

Chemical compatibility should always be evaluated against the specific operating environment.

Which material is better for food-grade applications?

Silicone is more commonly used in food and medical applications because FDA-approved and food-grade silicone compounds are widely available.

Advantages of silicone in hygienic applications include:

• Non-toxic properties
• High temperature resistance
• Sterilisation compatibility
• Flexibility
• Low odour and taste transfer

EPDM can be used in certain water and hygiene-related systems, but silicone is generally preferred where strict food or medical compliance is required.

The UK Food Standards Agency provides guidance on food-safe materials and manufacturing practices:
Food Standards Agency

How do flexibility and compression performance compare?

Both materials offer flexibility, but their behaviour under stress differs slightly.

Silicone

• Maintains flexibility at very low temperatures
• Offers excellent compression recovery
• Suitable for thermal cycling environments

EPDM

• Provides strong elasticity
• Performs well in water sealing systems
• Good for general-purpose outdoor sealing

The operating environment usually determines which material performs better over time.

Is one material more expensive than the other?

In many cases, silicone is more expensive than EPDM due to its broader temperature capability and specialist performance properties.

However, material cost should be balanced against:

• Service life
• Maintenance requirements
• Reliability
• Compliance needs
• Environmental exposure

Using a lower-cost material that fails prematurely can create far higher long-term operational costs.

What factors should engineers consider when choosing?

Material selection should always be based on the actual operating conditions rather than general assumptions.

Important considerations include:

Operating temperature

Will the material face sustained heat or freezing conditions?

Environmental exposure

Will the product be exposed to UV, ozone or moisture?

Chemical compatibility

Will oils, solvents or cleaning agents be present?

Compliance requirements

Are food-grade or medical standards necessary?

Compression and sealing demands

Will the material face repeated compression or pressure changes?

Expected service life

How important is long-term durability?

Where bespoke material selection or custom sealing solutions are required, businesses may benefit from discussing technical requirements directly through the Silco Products contact page.

Frequently Asked Questions

Is silicone better than EPDM for high temperatures?

Yes. Silicone generally performs much better than EPDM in continuous high-temperature environments.

Which material is better for outdoor sealing?

Both materials perform well outdoors, but EPDM is often preferred for general weather resistance while silicone is chosen where temperature extremes are involved.

Can EPDM be used in food applications?

Some EPDM compounds may be suitable for certain applications, but silicone is generally preferred where food-grade compliance is required.

Silicone and EPDM rubber both offer excellent performance in industrial sealing and manufacturing applications, but they are designed for different operating environments. Silicone excels in extreme temperatures, hygienic applications and thermal stability, while EPDM offers strong weather resistance and cost-effective outdoor durability.

Choosing the correct material requires careful assessment of temperature exposure, environmental conditions, compliance requirements and long-term performance expectations.

For more information about silicone rubber products and custom manufacturing solutions, contact Silco Products.

Phone: 01903 732088
Email: sales@silcoproducts.co.uk
Find out more: https://siliconerubberproducts.co.uk/