US3852034A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Indicator for effectiveness of ethylene oxide sterilization
Assignee: American Sterilizer Co
•
Filing: 1972-06-21
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Granted: 1974-12-03
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Expires: 1992-06-21
Abstract
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.
Inventors
- 👤 D Gunther
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:27
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/226; Y; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/142222
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
65 words
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.
Claim 2
Dependent Claim
65 words
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.
Claim 3
Dependent Claim
28 words
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.
Claim 4
Dependent Claim
13 words
Chemical indicator as recited in claim 2 wherein the acid salt is hydrochloride.
Claim 5
Dependent Claim
23 words
Chemical indicator as recited in claim 3 wherein the indicating compound is pararosaniline hydrochloride and the color change is from red to blue.
Claim 6
Dependent Claim
25 words
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.
Claim 7
Dependent Claim
14 words
Chemical indicator as recited in claim 5 wherein the carrier means is filter paper.
Claim 8
Independent Claim
65 words
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.
Claim 9
Independent Claim
65 words
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.
References Cited (Backward Citations)
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US3627469A
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US3732147A
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |