# US 2019/0314534 A1 · Sterilization method and apparatus

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- Number: US 2019/0314534 A1
- Document ID: US20190314534A1
- Status: Published application
- Kind: A1
- Application number: 16/456,979
- Filed: 2019-06-28
- Published: 2019-10-17
- Earliest claimed: 2009-09-30
- Assignees: Tso3 Inc.
- Applicants: Tso3 Inc.
- Inventors: SYLVIE DUFRESNE; CYNTHIA MARTEL; HELENE LEBLOND; NANCY DASSIE; KARINE MARTEL
- Web page: https://patentgrep.com/patent/US20190314534A1

## CPC

- A61L 2/202: Ozone
- A61L 2/20: Gaseous substances, e.g. vapours
- A61L 2/208: Hydrogen peroxide
- B65D 23/001: {Supporting means fixed to the container}
- A61L 2103/15: Laboratory, medical or dentistry appliances, e.g. catheters or sharps
- A61L 2202/122: Chambers for sterilisation
- A61L 2202/13: Biocide decomposition means, e.g. catalysts, sorbents
- A61L 2202/14: Means for controlling sterilisation processes, data processing, presentation and storage means, e.g. sensors, controllers, programs
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES

## Abstract

Disclosed is a method of sterilizing an article by sequentially exposing the article under vacuum first to a gaseous conditioning agent for forming radicals and then to a sterilant. The preferred conditioning agent is hydrogen peroxide and the preferred sterilant is ozone. The chamber is initially evacuated to a first vacuum pressure and then sealed for the remainder of the sterilization process and during all sterilant injection cycles, without removal of any component of the sterilization atmosphere, which means without any measures to reduce the water vapor content. Keeping the chamber sealed and maintaining the conditioning agent and the radicals generated thereby in the chamber for the sterilization with sterilant results in a synergistic increase in the sterilization efficiency and allows for the use of much lower sterilant amounts and sterilization cycle times than would be expected from using the conditioning agent and the sterilant in combination.

## Claims

### Claim 1

A method for sterilizing an article in a sealable sterilization chamber, comprising the steps of
a. placing the article into the sterilization chamber,
b. sealing the sterilization chamber,
c. applying to the sealed sterilization chamber a vacuum of a first pressure,
d. injecting into the sealed sterilization chamber a gaseous conditioning agent other than hydrogen peroxide for forming free radicals, the conditioning agent being selected from the group of acidic water, carbonated water, peracetic acid, acetic acid, alcohol, ethanol or methanol,
e. continuing to maintain the sterilization chamber sealed for a first exposure period,
f. injecting into the sealed sterilization chamber, after the first exposure period, a sterilant gas for creating or regenerating the free radicals in the sealed sterilization chamber,
g. maintaining the sterilization chamber sealed for a second exposure period,
h. evacuating the sterilization chamber at the end of the second exposure period for removing all residual sterilant gas from the sterilization chamber,
i. returning the sterilization chamber to atmospheric pressure, and
j. removing the sterilized article from the sterilization chamber.

### Claim 2 (depends on 1)

The method of claim 1, wherein the sterilant gas is ozone, nitrogen oxide or chlorine dioxide.

### Claim 3 (depends on 1)

The method of claim 1, wherein after step c) removal of any component of the sterilization atmosphere is interrupted until the end of the second exposure period.

### Claim 4 (depends on 1)

The method of claim 1, wherein in step d) said injecting a gaseous conditioning agent comprises injecting repeated pulses of the conditioning agent.

### Claim 5 (depends on 1)

The method of claim 1 where steps c) to h) are repeated at least once.

### Claim 6 (depends on 1)

The method of claim 1, wherein the first pressure is about 1 Torr.

### Claim 7 (depends on 1)

The method of claim 1, wherein the injecting of the gaseous conditioning agent is stopped when a second pressure of 17-54 Torr is reached.

### Claim 8 (depends on 7)

The method of claim 7, wherein the second pressure is about 20 Torr.

### Claim 9

A method for sterilizing an article in a sealable sterilization chamber, comprising the steps of
a. placing the article into the sterilization chamber,
b. sealing the sterilization chamber,
c. applying to the sterilization chamber a vacuum of a first pressure,
d. injecting into the sealed sterilization chamber gaseous hydrogen peroxide as conditioning agent for forming free radicals and until a second pressure is reached,
e. maintaining the sterilization chamber sealed for a first exposure period,
f. injecting into the sealed sterilization chamber, after the first exposure period, nitrogen oxide as sterilant gas for creating or regenerating the free radicals in the sealed sterilization chamber,
g. continuing to maintain the sterilization chamber sealed for a second exposure period,
h. evacuating the sterilization chamber at the end of the second exposure period for removing all residual sterilant gas from the sterilization chamber,
i. returning the sterilization chamber to atmospheric pressure, and
j. removing the sterilized article from the sterilization chamber.

### Claim 10 (depends on 9)

The method of claim 9, wherein step d) includes injecting repeated pulses of hydrogen peroxide solution at a pulse volume of less than 75 μL for evaporating the hydrogen peroxide solution.

### Claim 11 (depends on 10)

The method of claim 10, wherein the pulse volume is less than 35 μL.

### Claim 12 (depends on 11)

The method of claim 11, wherein the pulse volume is about 20 μL.

### Claim 13 (depends on 9)

The method of claim 9, wherein steps c) to h) are repeated at least once.

### Claim 14 (depends on 9)

The method of claim 9, wherein the first pressure is about 1 Torr.

### Claim 15 (depends on 9)

The method of claim 9, wherein the injecting of the gaseous conditioning agent is stopped when a second pressure of 17-54 Torr is reached.

### Claim 16 (depends on 15)

The method of claim 15, wherein the second pressure is about 20 Torr.

### Claim 17 (depends on 9)

The method of claim 9, wherein an amount of nitrogen oxide of 2 mg per liter of sterilization atmosphere is injected in the injecting step f.

### Claim 18 (depends on 9)

The method of claim 9, wherein after step c) removal of any component of the sterilization atmosphere is interrupted until the end of the second exposure period.