Decontamination of surfaces contaminated with prion-infected material with gaseous oxidixing agents

• US 20030086820A1
• Filed: 04/03/2002
• Published: 05/08/2003
• Est. Priority Date: 10/05/2001
• Status: Active Grant

• Current Assignee: American Sterilizer Company (Steris Corporation)
• Original Assignee: Steris Corporation
• Inventors: Kaiser, Herbert J., McDonnell, Gerald E., Antloga, Kathleen M.
• Granted Patent: US 7,803,315 B2
• Time in Patent Office: Days
• US Class Current: 422/28
• CPC Class Codes: A61K 31/327 Peroxy compounds, e.g. hydroperoxides, peroxides, peroxyacids
• CPC Class Codes: A61L 2/0082 using chemical substances
• CPC Class Codes: A61L 2/0088 Liquid substances
• CPC Class Codes: A61L 2/14 Plasma, i.e. ionised gases
• CPC Class Codes: A61L 2/186 Peroxide solutions
• CPC Class Codes: A61L 2/208 Hydrogen peroxide
• CPC Class Codes: A61L 2202/122 Chambers for sterilisation
• CPC Class Codes: A61L 2202/24 Medical instruments, e.g. endoscopes, catheters, sharps
• CPC Class Codes: C11D 2111/14 Hard surfaces
• CPC Class Codes: C11D 3/3947 Liquid compositions

Abstract

A surface which carries a material which is infected with prions is cleaned with an alkaline cleaning solution to remove as much proteinaceous material as possible from the surface. The solution contains an alkaline cleaning agent which attacks prions remaining on the surface and which attacks prions removed from the surface during the cleaning step. After the cleaning step, the surface is exposed to a strong gaseous oxidant, preferably hydrogen peroxide vapor. The hydrogen peroxide or other strong oxidant attacks the prions, particularly the unclumped prion strands, deactivating the prions.

Claims

1. A method of deactivating prions comprising:

pretreating surfaces that carry prion infected material with a cleaner that attacks prions; and

treating the surfaces with an oxidizing agent in gaseous form.

2. The prion deactivation method as set forth in claim 1, wherein the cleaner is an alkaline cleaner.

3. The prion deactivation method as set forth in claim 1, wherein the oxidizing agent includes hydrogen peroxide vapor.

4. The prion deactivation method as set forth in claim 3, wherein the oxidizing agent treating step is carried out at from about 45-60°

C.

5. The prion deactivation method as set forth in claim 2, wherein the alkaline cleaner includes a strong alkali of the group consisting of alkali metal hydroxides, alkali earth metal hydroxides, and combinations thereof.

6. The prion deactivation method as set forth in claim 5, wherein the strong alkali includes one or more of sodium hydroxide and potassium hydroxide.

7. The prion deactivation method as set forth in claim 2, wherein the alkaline cleaner further includes an additive selected from the group consisting of surfactants, cationic polymers, anti-redeposition agents, corrosion inhibitors, buffers, chelating agents, and combinations thereof.

8. The prion deactivation method as set forth in claim 7, wherein the step of treating the surfaces with an oxidizing agent in gaseous form is carried out at 45-60°

C.

9. The prion deactivation method as set forth in claim 2, further including:

rinsing the alkaline cleaner from the surfaces prior to the gaseous oxidizing agent treatment step.

10. The prion deactivation method as set forth in claim 9, further including:

after rinsing the surface, wrapping the surface in a microbe barrier; and

subjecting the wrapped surface to the gaseous oxidizing agent treatment step.

11. The prion deactivation method as set forth in claim 8, wherein the cleaning and gaseous oxidizing agent treatment steps are carried out in a temperature range between 50°

C. and 60°

C.

12. The prion deactivation method as set forth in claim 1, wherein the cleaning and gaseous oxidizing agent treatment steps are carried out in the same vessel.

13. The prion deactivation method as set forth in claim 12, wherein the cleaning and gaseous oxidizing agent treatment steps are carried out without intermediate removal of the surfaces from the vessel.

14. The prion deactivation method as set forth in claim 1, wherein the gaseous oxidizing agent treatment step includes:

a) introducing the surface to be treated to a chamber;

b) reducing the pressure within the chamber to below atmospheric pressure; and

c) introducing hydrogen peroxide vapor to the chamber.

15. The prion deactivation method as set forth in claim 14, wherein the gaseous oxidizing agent treatment step includes repeating steps b) and c) one or more times.

16. The prion deactivation method as set forth in claim 14, wherein step b) includes reducing the pressure within the chamber to about 10 Torr or below.

17. The method as set forth in claim 14, further including:

after step c), reducing the pressure within the chamber to below atmospheric pressure; and

raising the pressure to a higher subatmospheric pressure with filtered air.

18. A method of cleaning and decontaminating a surface which has been contaminated with a biological material which includes prions comprising:

cleaning the surface with an alkaline cleaner which has a pH of at least 10; and

exposing the cleaned surface to a vapor which includes hydrogen peroxide for a sufficient time to destroy viable prions on the surface.

19. A prion deactivation system for removing and deactivating prions on an item comprising:

a chamber for receiving the item;

a well fluidly connected with the chamber for receiving a concentrated alkaline cleaner;

a supply of water fluidly connected with the well for providing water to mix with the concentrated alkaline cleaner and form an alkaline cleaning solution;

a source of hydrogen peroxide vapor fluidly connected with the chamber.

20. The prion deactivation system as set forth in claim 19, further including:

a heater for heating the chamber to a temperature of at least 30°

C.

21. A method of treating a surface which is contaminated with prions and biological material comprising:

cleaning the surface to remove the biological material with a cleaner; and

after the step of cleaning, decontaminating the surface with a gaseous oxidizing agent at a temperature of from 45-60°

C.