Preconditioning for moisture control in ethylene oxide sterilization

The moisture condition of a product must be controlled to obtain sterility and maintain product viability during ethylene oxide sterilization. A sterilization process in which prehumidification of product is used to provide moisture condition control was shown to be effective in 2 years of production sterilization experience. On-stream process analysis with a gas chromatograph showed that addition of steam to the chamber was unnecessary when properly preconditioned medical devices packaged in corrugated paper-board were sterilized. Reproducible gas-chamber moisture control and microbial sterility assurance were obtained.