Views: 0 Author: Site Editor Publish Time: 2026-01-08 Origin: Site
Plastics are polymers, and each type has a unique structure. Heat, chemicals, or radiation can break molecular bonds, causing:
Cracking or warping
Loss of clarity (cloudiness or yellowing)
Weakening and reduced lifespan
Leaching of harmful chemicals
Therefore, matching the material to the method is critical.
These are the tough ones, built for repeated high-heat cycles.
Polycarbonate (PC): Clear and impact-resistant. Used in surgical instrument handles, lens housings, and respiratory masks.
Polysulfone (PSU) & Polyethersulfone (PES): The champions of repeated sterilization. Excellent heat and water resistance. Found in hemodialyzers, surgical tool handles.
Medical-Grade Polypropylene (PP): Not all PP qualifies! Specific grades are used for syringes, labware, and sterilizable containers.
Polytetrafluoroethylene (PTFE / Teflon™): Chemically inert and can handle extreme heat. Often used as a coating for catheters and seals.
Polyetheretherketone (PEEK): A high-performance, expensive polymer for implants and specialized surgical instruments.
These are common in single-use or disposable devices.
Polyvinyl Chloride (PVC): Flexible and low-cost. The king of disposables: IV bags, tubing, oxygen masks.
Polyethylene (PE): Used for bottles, packaging, and containers.
Polyurethane (PU): Elastic and biocompatible. Ideal for central venous catheters and wound dressings.
Acrylonitrile Butadiene Styrene (ABS): Good mechanical strength for device housings and connectors.
Process: High-pressure saturated steam (e.g., 121°C/250°F for 20-30 min).
Best For: PC, PSU/PES, PEEK, medical-grade PP.
Avoid: PVC, PU, ABS, PE. They will melt or deform.
Process: Low-temperature gas (37-60°C) that alkylates microbial DNA.
Best For: Almost all plastics, especially heat-sensitive ones (PVC, PU, ABS). It’s the most common method for disposable devices.
Drawback: Long cycle time (due to aeration), toxic gas residuals, environmental concerns.
Process: Exposure to Cobalt-60 gamma rays, which destroy microbial DNA at room temperature.
Best For: PP, PE, PS, PVC. Excellent for high-volume, pre-packaged products.
Watch Out: Can cause yellowing in Polycarbonate (PC) and severe degradation of PTFE.
Process: Similar to gamma but uses accelerated electrons. Faster, with less penetration.
Best For: Thin-walled products like syringes, gloves, and thin packaging made of PE, PP.
Note: Material effects differ from gamma radiation and require separate testing.
Process: Vaporized hydrogen peroxide activated into plasma in a vacuum at low temperatures (<60°C).
Best For: Heat-sensitive, moisture-sensitive精密 devices like endoscopes made of PC, ABS.
Limitation: Cannot penetrate long lumens, cellulose, or liquids.
| Material | Steam (Autoclave) | EtO Gas | Gamma Radiation | H₂O₂ Plasma | Key Use |
|---|---|---|---|---|---|
| Polycarbonate (PC) | ✓ | ✓ | (Yellows) | ✓ | Housings, lenses |
| Polysulfone (PSU) | ✓ | ✓ | Test Required | ✓ | Surgical tools, dialyzers |
| Polypropylene (PP) | (Medical grade ✓) | ✓ | ✓ | Test Required | Syringes, containers |
| PVC | ✗ | ✓ | ✓ | ✗ | Tubing, bags (disposable) |
| Polyurethane (PU) | ✗ | ✓ | May Degrade | Test Required | Catheters, dressings |
| ABS | ✗ | ✓ | ✓ | ✓ | Device housings |
Start with the Material Data Sheet (MDS): Always consult the manufacturer's specifications for sterilization compatibility.
Define the "Sterility" Level: Is it for single-use (factory-sterilized) or reusable (hospital-reprocessed) devices?
Consider the Device Design: Complex shapes with long, narrow channels limit options like plasma or steam penetration.
Validate, Validate, Validate: Regulatory standards (like ISO 11135 for EtO, ISO 11137 for radiation) require rigorous validation to ensure the chosen method is both effective and safe for the material.
There's no universal "best" method. Ethylene Oxide remains the workhorse for complex, disposable devices, while Steam is ideal for robust, reusable tools. Radiation excels for high-volume simples, and Plasma is key for delicate electronics.
Understanding this plastic-process pairing is fundamental to creating medical devices that are safe, effective, and reliable throughout their lifecycle.
