Hydrogen peroxide sterilization method

• US 4,952,370 A
• Filed: 05/06/1988
• Issued: 08/28/1990
• Est. Priority Date: 05/06/1988
• Status: Expired due to Fees

• Current Assignee: American Sterilizer Company (Steris Corporation)
• Original Assignee: American Sterilizer Company (Steris Corporation)
• Inventors: Childers, Robert W., Cummings, Arthur L.
• Primary Examiner(s): Richman, Barry S.
• Assistant Examiner(s): Johnston, Jill
• Application Number:
  US07/191,310
• Time in Patent Office: 844 Days
• Field of Search: 422/28, 422/292, 422/27, 514/840, 424/616
• US Class Current: 422/28
• CPC Class Codes: A61L 2/20 Gaseous substances, e.g. vapours

Abstract

This process sterilizes the surfaces within a chamber wherein a first portion of the surfaces is at a temperature below 10° C. and a second portion of the surfaces is at a temperature greater than 20° C. The process includes the steps of introducing vapor phase hydrogen peroxide to the chamber, contacting the first portion with the vapor to effect condensation thereon, contacting the second portion with the vapor, applying a source of vacuum to the chamber and continuing to introduce vapor phase hydrogen peroxide into the chamber until the surfaces are sterile while preserving the temperature ranges of the first and second portions.

Claims

1. A process for sterilizing surfaces within a chamber, a portion of said surfaces being maintained at a temperature below about 10°

C., comprising the steps of;

introducing vapor phase hydrogen peroxide at a temperature above about 10°

into said chamber;

contacting said portion of said surfaces with said vapor phase hydrogen peroxide to effect condensation of said vapor phase hydrogen peroxide on said portion;

applying a source of vacuum to said chamber; and

continuing to introduce vapor phase hydrogen peroxide into said chamber until said surfaces are sterile while preserving said temperature of said portion of said surfaces below about 10°

C.

2. The process recited in claim 1 further comprising the step of evacuating said chamber prior to the initial introduction of vapor phase hydrogen peroxide into said chamber.

3. The process recited in claim 1 wherein the vacuum is drawn to maintain the absolute vapor pressure of the chamber at a level above the vapor pressure of hydrogen peroxide and below the vapor pressure of water at the temperature of said portion of said surface.

4. The process recited in claim 3 further comprising the step of drawing the vacuum after sterility of said surfaces is achieved to lower the absolute pressure of the chamber to another level below the vapor pressure of hydrogen peroxide at the temperature of said portion of said surfaces.

5. The process recited in claim 1 wherein said continuing introduction of vapor phase hydrogen peroxide into said chamber is through at least two locations to facilitate distribution of said vapor phase hydrogen peroxide within said chamber.

6. A process for sterilizing surfaces within a chamber, a first portion of said surfaces being maintained at a first temperature below about 10°

C. and a second portion of said surfaces being at a second temperature greater than about 20°

C., comprising the steps of;

introducing vapor phase hydrogen peroxide at a temperature above about 10°

C. into said chamber;

contacting said first portion of said surfaces with said vapor phase hydrogen peroxide to effect condensation of said vapor phase hydrogen peroxide on said first portion;

contacting said second portion of said surfaces with vapor phase hydrogen peroxide;

applying a source of vacuum to said chamber; and

continuing to introduce vapor phase hydrogen peroxide into said chamber until said surfaces are sterile while preserving said first temperature of said first portion of said surfaces below about 10°

C. and said second temperature of said second portion of said surfaces greater than about 20°

C.

7. The process recited in claim 6 further comprising the step of evacuating said chamber prior to the initial introduction of vapor phase hydrogen peroxide into said chamber.

8. The process recited in claim 6 wherein the vacuum is drawn to maintain the absolute vapor pressure of the chamber at a level above the vapor pressure of hydrogen peroxide and below the vapor pressure of water at the temperature of said first portion.

9. The process recited in claim 8 further comprising the step of drawing the vacuum after sterility of said surfaces is achieved to lower the absolute vapor pressure of the chamber to another level below the vapor pressure of hydrogen peroxide at the temperature of said first portion.

10. The process recited in claim 6 wherein the application of said source of vacuum to said chamber is continued throughout said process.