Sterilization with in-line concentrating and injection of hydrogen peroxide

摘要

In a hydrogen peroxide gas plasma sterilizer, the concentration of the hydrogen peroxide sterilant is an important factor in determining sterilization efficacy. The present application describes sterilizers, and sterilization methods, which use a novel injector-concentrator arrangement. This arrangement provides accurate control of concentration of the liquid-phase hydrogen peroxide, prior to vaporization of the liquid sterilant into the sterilization chamber. This increases the reliability and efficacy of the sterilization cycle.

主权项

1. A process for introducing concentrated hydrogen peroxide vapor to interior surfaces of medical instruments with lumens in an evacuated and pre-heated sterilization chamber comprising the steps of:
filling an injector concentrator at a predetermined volume of liquid solution of hydrogen peroxide which has a concentration below 60% wt; heating and lowering the pressure in said injector concentrator to vaporize portion of said liquid solution while intermittently withdrawing a portion of the resulting vapor from said injector concentrator, wherein said withdrawing uses a vacuum pump bypassing said sterilization chamber, wherein said vaporizing of portion of liquid solution produces more water vapor than hydrogen peroxide vapor, and wherein pressure in said sterilization chamber is independent to the pressure in said injector concentrator during vaporization; terminating said withdrawal of vapor from said injector concentrator when remaining concentrated hydrogen peroxide liquid reaches a preset concentration level greater than above 80% wt in said injector concentrator; starting diffusion by intermittently transferring said concentrated hydrogen peroxide liquid in small volumes into a separate pre heated vaporizer connected to said sterilization chamber to produce hydrogen peroxide vapor; and maintaining said hydrogen peroxide vapor in contact with said medical instruments until sterilization is achieved.