Medical Device O-Ring Materials & Specifications
USP Class VI, FDA 21 CFR 177.2600, and ISO 10993 biocompatible sealing solutions for life-science equipment.
Medical device seals must satisfy strict biocompatibility, extractables, and sterilization requirements. From autoclave-compatible silicone to drug-contact EPDM, material selection is dictated by regulatory compliance and the sterilization method. This guide explains how to choose O-ring materials for surgical instruments, drug delivery systems, dialysis equipment, and bioreactors. We cover USP Class VI testing, platinum-cured versus peroxide-cured silicone, compatibility with gamma and steam sterilization, and when to specify an extractables profile.
Application Requirements
Recommended Materials
Platinum-Cured VMQ
Surgical instruments, respiratory devices, bioreactors
Temp: -60°C to +230°C
Lowest extractables. Preferred for drug-contact and implantable-device assembly.
Peroxide-Cured EPDM
Dialysis equipment, steam-sterilized valves
Temp: -50°C to +150°C
Excellent steam and hot-water resistance. Passes USP Class VI when formulated correctly.
FFKM
High-temp sterilization, aggressive cleaning agents
Temp: -15°C to +260°C
Used for CIP/SIP processes with aggressive acids and caustics.
Design Tips
- 1.Specify platinum-cured silicone for any seal that contacts bodily fluids or drug products to minimize extractables.
- 2.Ensure the compound has been tested to the full USP Class VI protocol (intracutaneous, systemic, implantation) not just one test.
- 3.Account for compression set after repeated steam sterilization cycles. Platinum-cured VMQ generally outperforms peroxide-cured grades in autoclave cycling.
- 4.Keep O-ring grooves free of dead volumes where fluid can stagnate and harbor bacterial growth.
Common Sizes
| Size | Typical Use |
|---|---|
| AS568-001 to -010 | Small-diameter precision medical fittings |
| ISO 3601 1.80×1.80 to 10.00×1.80 | Metric medical devices and European OEM equipment |
| Custom micro sizes | Miniature drug-delivery pumps and catheters |
Frequently Asked Questions
What is the difference between platinum-cured and peroxide-cured silicone?
Platinum curing produces lower extractables and better clarity, making it preferred for medical and pharmaceutical applications. Peroxide curing is more economical but can leave residue.
Can EPDM be used in medical devices?
Yes, peroxide-cured EPDM that passes USP Class VI and FDA 21 CFR 177.2600 is commonly used in dialysis and steam-sterilized equipment.
How many autoclave cycles can a silicone O-ring survive?
High-quality platinum-cured VMQ can withstand 500+ steam autoclave cycles at 134°C with minimal compression set.
Medical seal inquiry
We supply USP Class VI platinum-cured silicone and FDA EPDM O-rings with lot traceability and certificates.