Yinso Explains Factors Affecting EO Sterilization of Medical Device Packaging

Ethylene oxide (EO) is a highly effective chemical sterilant capable of killing all microorganisms, including bacterial spores. It causes minimal damage to items due to its alkylation principle rather than oxidation. EO sterilization allows for the use of various wrapping materials, facilitating storage and transportation, and eliminating the risk of cross-contamination upon unpacking. According to Yinso Medical Packing, most medical devices packaged in blister packaging opt for EO sterilization.

Before discussing factors, let's briefly outline EO sterilization's pros and cons.

Pros: Suitable for heat- and moisture-sensitive items, like APET and PETG used in medical blister packaging. Standard chemical and biological monitoring ensures sterilization quality and detects failed packages. EO's strong penetrability makes it ideal for hard-to-reach areas, like narrow, long catheters better suited for EO or irradiation.

Cons: EO is toxic, suspected carcinogenic, requiring indoor concentrations below national standards. It's flammable and explosive, necessitating safe sterilizers, operations, and storage. The sterilization cycle is long, requiring ventilation to remove EO residues.

Yinso Medical Packing focuses on factors affecting EO sterilization: concentration, temperature, relative humidity, and time.

Concentration is crucial, typically 450-1200mg/L. Higher temperatures enhance EO's effectiveness, usually 35-60°C. Item moisture, microbial dryness, and relative humidity (45%-75%, 105-300min) significantly impact EO's action. Balancing these factors ensures sterilization success.

Despite EO's strong penetrability, different materials' densities affect its penetration. For medical blister packaging, designers should consider assembly functionality, sealing, safety, aesthetics, and EO sterilization channels for effective EO penetration and sterilization.