Vaporization method to enhance sterilant penetration

Claim 1

A process for furnishing concentrated hydrogen peroxide vapor to interior surfaces of articles having a tortuous or a narrow path, said articles being so disposed within an evacuated sterilization chamber so that said interior surfaces can be contacted by vapor only after it traverses said tortuous or narrow path, comprising the steps of: heating a liquid solution of relatively dilute hydrogen peroxide and water within an evacuated first chamber to preferentially vaporize said water; withdrawing a portion of said water vapor from said first chamber to concentrate said hydrogen peroxide remaining in said first chamber; terminating said withdrawal of water vapor from said first chamber when said remaining hydrogen peroxide is sufficiently concentrated so as to produce, upon complete vaporization, vapors concentrated in hydrogen peroxide to greater than about 40% by weight; continuing heating said liquid solution to completely vaporize said solution; and introducing into said sterilization chamber said vapors concentrated in hydrogen peroxide and maintaining said hydrogen peroxide vapors in contact with said articles until sterilization is achieved.