The potential effect of ETO gas sterilization on medical devices can be combined with material characteristics analysis. The silica gel catheter test proves that through the normal sterilization process (600mg/L concentration, 55℃ temperature, 60% humidity), the rate of tensile strength reduction can be as low as 0.8%, and elongation at break is reduced by 1.2%, much improved compared to the 5.3% and 7.1% performance reduction due to high-temperature steam sterilization. According to Medtronic data in 2023, after 50 sterilization cycles of a 32-bit microcontroller pacemaker sterilized using eto gas sterilization, the electronic component failure rate was as low as 0.05%, and the electrostatic discharge (ESD) sensitivity increased from HBM 500V to 2000V. However, after 100 sterilization of the polycarbonate respirator, the light transmission decreased by 0.4% (initial value 92.3%), and the atomization rate increased to 3.8%.
Under metallic instrument conditions, ETO sterilization spoiled 316L stainless steel coronary stents by the amount of merely 0.002μm/year (ISO 10993-15 standard value 0.1μm/year), while autoclave led to 12% thickness loss of passivation layers. Fatigue tests conducted by Johnson & Johnson Medical on orthopedic implants of titanium alloy showed that the retention rate of flexural strength was 99.6% (starting value 1200MPa) following 200 ETO sterilization cycles, but the surface adhesion of alumina coating decreased by 7.3% (scanning electron microscopy showed an increase in porosity of coating by 0.08%). Gamma-ray sterilization was also determined to raise the likelihood of CoCR hip joint intergranular corrosion by 3.2 times.
Polymer material risk is a very serious issue. eto gas sterilization elevated the crystallinity level by 0.7% (DSC), while wear rate from 0.12mm³/ million rose to 0.15mm³/ million. Boston Scientific research showed that following 50 sterilization of silicone catheters, the contact Angle of the surface decreased from 110° to 103° and the rate of bacterial adhesion increased by 18%. However, the optimized rapid resolution process (14 hours) can reduce the residual ethylene chlorol level from 18ppm to 0.9ppm, which is safer than the standard 72 hour resolution level of 5.2ppm (ISO 10993-7 limit of 25ppm).
For precision electronics, eto gas sterilization affected FBS with impedance changes of ±0.8Ω (initial value 50Ω), while steam sterilization resulted in solder spot derailing to rise by 1.2%. Abbott’s glucose meter test results showed that the attenuation rate of brightness of the sterilized LCD screen was as low as 0.3% for 100 times, but the sensitivity deviation of the ambient light sensor was ±2.1% (±0.5% without sterilization equipment). By adjusting the sterilization parameters (temperature to 45 ° C, humidity 50%), the Bluetooth module communication error rate is reduced from 0.07% to 0.01%.
The risk of damage to the optical instrument is prominent. Olympus endoscopy tests demonstrated that eto gas sterilization resulted in mirror resin transmittance reduction by 0.08% annually (initial reading 91.4%), while low temperature plasma sterilization increased the coating stripping rate to 0.7%. Carl Zeiss surgical microscopes prism set was sterilized 300 times with optical axis deviation of 0.002° and needs recalibration every 5 years (the first cycle is 8 years). However, following nitrogen assisted analysis technology application, surface density of remnant particles was reduced from 82 /cm² to 14 /cm² (requirements of ISO 15883 standard ≤50 /cm²).
The latest test showed that the rate of attenuation of intelligent medical devices’ lithium battery capacity after eto gas sterilization was 0.3%/ 100 times (1.2% for electron beam sterilization in the control group), and charge and discharge efficiency decreased by 1.7%. FDA 2023 warning case demonstrates that if a type of insulin pump is sterilized beyond the usual (concentration 800mg/L), motor torque decreases by 9%, and hence the rate of dose error goes up to 0.8% (usual requirement ≤0.5%). Current ISO 22441:2024 standard provides for a maximum count of 50 ETO sterilization cycles, and polymer devices beyond this quantity are to be provided for replacement mandatorily.