Vaporization method to enhance sterilant penetration

• US 4,744,951 A
• Filed: 05/10/1985
• Issued: 05/17/1988
• Est. Priority Date: 11/07/1983
• Status: Expired due to Term

• Current Assignee: American Sterilizer Company (Steris Corporation)
• Original Assignee: American Sterilizer Company (Steris Corporation)
• Inventors: Young, Jack H., Makinen, Ralph W., Cummings, Arthur L.
• Primary Examiner(s): Lacey, David L.
• Assistant Examiner(s): WARDEN, JILL ALICE
• Application Number:
  US06/733,014
• Time in Patent Office: 1,103 Days
• Field of Search: 422/27, 422/28, 55/279, 430/973
• US Class Current: 422/28
• CPC Class Codes: A01N 59/00 Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
• CPC Class Codes: A61L 2/20 Gaseous substances, e.g. vapours

Abstract

A process for concentrating hydrogen peroxide from a relatively dilute solution of hydrogen peroxide and water and supplying the concentrated hydrogen peroxide in vapor form to a sterilization chamber. The process includes vaporizing a major portion of the water from the solution and removing the water vapor thereby produced before injecting the concentrated hydrogen peroxide vapor into the sterilizing chamber.

Claims

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.

2. The process of claim 1 wherein:

said vapors introduced into said sterilization chamber are concentrated in hydrogen peroxide in the range of 50 to 80% by weight.

3. A process for sterilizing interior surfaces of articles having narrow or tortuous paths, said articles being so disposed within an evacuated sterilization chamber so that said interior surfaces can be contacted by vapor only after the vapor traverses said tortuous or narrow path, comprising the steps of:

substantially completely vaporizing a hydrogen peroxide liquid solution so as to produce vapors concentrated in hydrogen peroxide to greater than about 40% by weight;

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.