Integrated chemical indicator device

• US 8,858,887 B2
• Filed: 07/19/2007
• Issued: 10/14/2014
• Est. Priority Date: 07/19/2007
• Status: Active Grant

• Current Assignee: Steris Inc (Steris Corporation)
• Original Assignee: Steris Inc (Steris Corporation)
• Inventors: Lacy, Stephen Michael, Tyers, Neil David
• Primary Examiner(s): Jarrett, Lore
• Application Number:
  US11/879,987
• Publication Number:
  US 20090023217A1
• Time in Patent Office: 2,644 Days
• Field of Search: 422/85, 436/38
• US Class Current: 422/85
• CPC Class Codes: A61L 2/28 Devices for testing the effectiveness or completeness of sterilisation, e.g. indicators which change colour apparatus involving enzymes or microorganisms C12M1/34; methods involving enzymes or microorganisms C12Q1/00
• CPC Class Codes: G01N 31/005 investigating the presence of an element by oxidation G01N31/12 takes precedence
• CPC Class Codes: G01N 31/226 for investigating the degree of sterilisation
• CPC Class Codes: G01N 31/228 for peroxides

Abstract

A chemical indicator device for use in detecting exposure to an oxidizing agent, such as hydrogen peroxide, comprising a substrate or support upon which is disposed a chemical indicator composition (ink) for detecting an oxidizing agent, such as hydrogen peroxide. The chemical indicator composition further comprises an indicator dye that achieves a distinct range of different color changes with clear transitions between colors, upon exposure to different doses of the oxidizing agent, thus allowing for both a qualitative and semi-quantitative assessment of exposure to the agent.

Claims

1. A chemical indicator device for monitoring the effectiveness of a sterilization process that uses an oxidizing agent as a sterilant and for semi-quantitatively assessing exposure to the oxidizing agent, consisting of:

a. a substrate; and

b. a chemical indicator composition uniformly disposed upon the substrate, consisting of a single dye, pararosaniline base, which when reacted directly with the oxidizing agent sterilant, achieves a range of different, distinct color changes over time in response to direct exposure to different doses of the oxidizing agent sterilant during a single sterilization cycle,

wherein the colors achieved by the pararosaniline base are compared to a pre-calibrated, visual color chart so that a semi-quantitative assessment of the dose of the oxidizing agent sterilant to which the device was exposed during the sterilization cycle can he made.

2. The device according to claim 1, wherein the substrate consists of one or more polymeric materials, paper, woven fibers, non-woven fibers, or a combination of two or more thereof.

3. The device according to claim 2, wherein the polymeric material is selected from the group consisting of polyesters, polystyrenes, polyolefins, polyamides, polymethacrylates, polyvinyl chlorides and mixtures thereof.

4. The device according to claim 3, wherein the polymeric material is spun bonded polyolefin.

5. The device according to claim 1, wherein the oxidizing agent sterilant being assessed by the device is hydrogen peroxide.

6. The device according to claim 1, wherein the dose of the oxidizing agent to which the pararosaniline base is exposed at any given point in time in a single sterilization cycle is determined by multiplying a known concentration of the oxidizing agent by the time of exposure of the pararosaniline base to the oxidizing agent.

7. The chemical indicator device according to claim 1, further consisting of the pre-calibrated, visual color chart for use in making a semi-quantitative assessment of the dose of the oxidizing agent sterilant to which the device was exposed.

8. A method of monitoring the effectiveness of a sterilization process that utilizes an oxidizing agent as a sterilant and of determining, semi-quantitatively, exposure to the oxidizing agent, comprising the steps of:

a. providing a chemical indicator device comprising a chemical indicator composition uniformly disposed on a support, wherein the composition consists of a single dye, pararosaniline base, which itself achieves different, distinct color changes over time in response to exposure to different doses of the oxidizing agent sterilant;

b. placing the device into a sterilizing environment wherein the dye will be directly exposed to the oxidizing agent sterilant; and

c. comparing the color change achieved by the dye at any point in time during a sterilization cycle to a pre-calibrated, visual color chart to assess the dose of oxidizing agent sterilant to which the chemical indicator composition was exposed.