Sterilization methods: a plain-language guide

Steam (autoclave)

Saturated steam under pressure, commonly 121–134 °C. Demanding for plastics because of heat and moisture; many commodity resins soften or hydrolyze. Some resins tolerate only a limited number of cycles (e.g. PP, PC under ~100 cycles), while PPSU and PEEK are reported to withstand over 1,000 cycles.[1]

Ethylene oxide (EtO)

A low-temperature gas process (around 55 °C) suited to heat-sensitive devices; most plastics tolerate it, though gas must be aerated out after processing.[2]

Gamma and e-beam radiation

Used for bulk sterilization of single-use devices; typical doses are 20–40 kGy (2–4 Mrad). Radiation can cause yellowing and, in some polymers, loss of mechanical properties; radiation-stabilized grades reduce this.[1] Standard acetal (POM) and unstabilized PP are known to be sensitive.[2]

Vaporized hydrogen peroxide (VHP)

A low-temperature oxidative process. Few supplier documents state VHP compatibility; for example Zeon lists VHP compatibility for its medical COP grades.[3]

Sources: [1] Solvay Healthcare Sterilization Compatibility Overview; [2] Ready Plastics: Plastics for Medical Sterilization; [3] Zeon medical-grade COP.