Syringe Plunger O-Ring

🔵 Medical Silicone (VMQ)

Best For: General-purpose medical applications

Advantages:

• Excellent biocompatibility
• Wide temperature range (-60°C to +200°C)
• Good chemical resistance
• Low compression set
• FDA & USP compliant

Applications: Prefilled syringes, insulin delivery, general injections

🟢 Butyl Rubber (IIR)

Best For: Oxygen-sensitive medications

Advantages:

• Excellent gas impermeability
• Superior moisture barrier
• Low extractables
• Good chemical resistance
• Extended shelf life

Applications: Vaccines, biologics, oxygen-sensitive drugs

🟠 EPDM Rubber

Best For: Steam sterilization applications

Advantages:

• Excellent steam resistance
• Good chemical compatibility
• Cost-effective
• Autoclave stable
• Wide temperature range

Applications: Reusable syringes, autoclaved systems

🟣 Fluoroelastomer (FKM)

Best For: Aggressive chemicals

Advantages:

• Exceptional chemical resistance
• High temperature stability
• Low permeability
• Excellent aging properties
• Suitable for harsh environments

Applications: Chemotherapy agents, aggressive formulations

Q: What size O-ring do I need for my syringe?

A: The O-ring size depends on your syringe barrel's inner diameter (ID). Measure the barrel ID and refer to our size chart above. For custom syringes, please send us the barrel specifications or a physical sample, and we will recommend the optimal O-ring dimensions. Free technical consultation is available.

Q: What's the difference between silicone and rubber O-rings?

A: Silicone O-rings offer excellent biocompatibility, a wide temperature range, and are commonly used for general medical applications. Rubber O-rings (such as Butyl or EPDM) provide superior gas barrier properties and are preferred for oxygen-sensitive drugs and vaccines. Material selection depends on your application requirements and drug formulation.

Q: Can you provide biocompatibility certificates?

A: Yes. Our materials comply with applicable biocompatibility requirements. ISO 10993 biocompatibility testing and USP Class VI certification are available upon project request. Testing is conducted by accredited third-party laboratories and supports FDA, EMA, and other regulatory submissions.

Q: What hardness should I choose?

A: Standard recommendation is Shore A 50–60 for most syringe applications. Softer grades (40–50A) are suitable for low-pressure systems and sensitive formulations. Harder grades (60–70A) provide improved sealing under higher pressure or with viscous medications. Very hard compounds (70–80A) are used for demanding or long-life applications. Sample testing is available to determine optimal hardness.

Q: Do you offer sterilized O-rings?

A: Yes. We offer gamma-sterilized (25–50 kGy) and EtO-sterilized O-rings, packaged in cleanroom-compatible pouches for aseptic assembly. Sterilization typically adds 2–3 weeks to standard lead time. Sterilization validation reports and SAL 10⁻⁶ documentation are provided.

Q: How do I test if the O-ring is compatible with my drug formulation?

A: Compatibility testing is recommended by immersing O-rings in the drug formulation at storage temperature for extended periods (typically 3–6 months). Evaluate dimensional changes, hardness variation, extractables, and visual appearance. We can supply samples and technical guidance to support your compatibility testing protocol.