INDICATOR FOR EFFECTIVENESS OF ETHYLENE OXIDE STERILIZATION

• US 3,852,034 A
• Filed: 06/21/1972
• Issued: 12/03/1974
• Est. Priority Date: 06/21/1972
• Status: Expired due to Term

• Current Assignee: Donald A. Gunther
• Original Assignee: Donald A. Gunther
• Inventors: Gunther, Donald A.
• Primary Examiner(s): Serwin, R. E.
• Application Number:
  US05/264,746
• Time in Patent Office: 895 Days
• Field of Search: 23/253TP,232R 195/103.5 252/408
• US Class Current: 436/1
• CPC Class Codes: G01N 31/226 for investigating the degree of sterilisation
• CPC Class Codes: Y10T 436/142222 Hetero-O [e.g., ascorbic acid, etc.]

Abstract

An indicator for placement in an ethylene oxide sterilizer changes color if the sterilization has been effective. The indicator includes an amino substituted indicating compound which undergoes color change based on replacement of labile hydrogen in amino groups with hydroxyethyl, and a buffering agent selected to provide an ionic dissociation equilibrium such that color change occurs only when sterilization has been effective.

Claims

1. CHEMICAL INDICATOR FOR USE IN AN ETHYLENE OXIDE STERILIZER TO SIGNAL WHETHER OR NOT STERILIZING HAS BEEN EFFECTIVE COMPRISING CARRIER MEANS;

AMINO SUBSTITUTED INDICATING COMPOUND WHICH CONTAINS HYDROGEN ATTACHED TO AMINO NITROGEN AND WHICH UNDERGOES COLOR CHANGE WHEN HYDROGEN ATTACHED TO AMINO NITROGEN IS REPLACED BY HYDROXYETHYL, BUFFERING AGENT SELECTED TO PROVIDE AMINO GROUP DISSOCIATION EQUILIBRIUM SUCH THAT READILY VISIBLE COLOR CHANGE INDICATES STERILIZING EFFECTIVENESS.

2. Chemical indicator as recited in claim 1 wherein the indicating compound is selected from the group consisting of acid salts of amino substituted triphenylmethanes, diphenylmethanes, azines and xanthenes.

3. Chemical indicator as recited in claim 2 wherein the acid salt is hydrochloride.

4. Chemical indicator as recited in claim 3 wherein the indicating compound is pararosaniline hydrochloride and the color change is from red to blue.

5. Chemical indicator as recited in claim 4 wherein the buffering agent comprises sodium borate and boric acid in proportions to provide a pH of 8.5.

6. Chemical indicator as recited in claim 5 wherein the carrier means is filter paper.

7. A method of monitoring ethylene oxide sterilization in a chamber by placing in said chamber an indicator which contains an amino-substituted indicating compound which contains hydrogen attached to amino nitrogen and which undergoes color change when hydrogen attached to amino nitrogen is replaced with hydroxyethyl and a buffering agent selected to provide amino group dissociation equilibrium such that readily visible color change indicates sterilizing effectiveness.