US4826772A
Expired / Lapsed
US
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Ethylene oxide monitoring device
Assignee: Graphic Controls Canada Ltd
•
Filing: 1987-04-01
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Granted: 1989-05-02
•
Expires: 2007-04-01
Abstract
Abstract Monitoring exposure to ethylene oxide using a dosimeter or monitoring device avoids using devices that collect a sample for future testing or devices that must be sent away for lab analysis. The device comprises a reactive coating including a layer of activated alumina particles coated with p-nitrobenzyl pyridine and ammonium chloride, and is adapted to instantly produce a color intensity change directly related to the dosage of the reactive coating to ethylene oxide upon the addition of a developer.
Inventors
- 👤 William G. Meathrel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:46
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/226; Y; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/142222
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
78 words
An ethylene oxide monitoring device comprising a reactive coating sensitive to ethylene oxide on an impermeable substrate, the reactive coating including a layer of activated alumina particles, coated with p-nitrobenzyl pyridine and ammonium chloride, adapted to instantly produce a color intensity change directly related to the exposure of the reactive coating to ethylene oxide upon addition of a developer, the color intensity change indicating an exposure sensitivity less than one ppm for an eight hour time weighted average.
Claim 2
Dependent Claim
78 words
An ethylene oxide monitoring device comprising a reactive coating sensitive to ethylene oxide on an impermeable substrate, the reactive coating including a layer of activated alumina particles, coated with p-nitrobenzyl pyridine and ammonium chloride, adapted to instantly produce a color intensity change directly related to the exposure of the reactive coating to ethylene oxide upon addition of a developer, the color intensity change indicating an exposure sensitivity less than one ppm for an eight hour time weighted average.
Claim 3
Dependent Claim
24 words
The monitoring device according to claim 1 including color comparison means to compare color of developed reactive coating therewith to determine ethylene oxide dosage.
Claim 4
Dependent Claim
18 words
The monitoring device according to claim 1 in the form of a badge for attachment to a person.
Claim 5
Dependent Claim
30 words
The monitoring device according to claim 1 wherein the p-nitrobenzyl pyridine in an acetone solution is added to the coating prior to commencing to measurement weighted average ethylene oxide dosage.
Claim 6
Dependent Claim
45 words
The monitoring device according to claim 4 including a chemical thermal paper strip on the device which changes color when the p-nitrobenzyl pyridine in an acetone solution is added to show that the device has been activated to measure time weighted average ethylene oxide dosage.
Claim 7
Dependent Claim
26 words
The monitoring device according to claim 1 including a squeezable reservoir in the device, the reservoir containing the developer with a channel to the reactive coating.
Claim 8
Dependent Claim
25 words
The monitoring device according to claim 6 wherein the p-nitrobenzyl pyridine solution is contained in a squeezable reservoir with a channel to the reactive coating.
Claim 9
Dependent Claim
27 words
The monitoring device according to claim 1 wherein the reactive coating has a pH in the approximate range of 3 to 6 before application of the developer.
Claim 10
Dependent Claim
34 words
The monitoring device according to claim 8 wherein the reactive coating comprises a layer of activated alumina particles, coated with polyvinyl alcohol, ammonium chloride and water together with p-nitrobenzyl pyridine in a solvent solution.
Claim 11
Dependent Claim
47 words
The monitoring device according to claim 8 wherein the reactive coating comprises a layer of activated alumina particles, coated with polyvinyl alcohol; an acid selected from the group consisting of hydrochloric acid, nitric acid and sulphuric acid; and water together with p-nitrobenzyl pyridine in a solvent solution.
Claim 12
Dependent Claim
55 words
The monitoring device according to claim 8 wherein the reactive coating comprises a layer of activated alumina particles, coated with polyvinyl alcohol; mineral acid; chloride salt and water together with p-nitrobenzyl pyridine in a solvent solution, the reactive coating having a pH in the approximate range of 3.0 to 6.0 before addition of the developer.
Claim 13
Dependent Claim
18 words
The monitoring device according to claim 1 wherein a permeable attenuating barrier is provided over the reactive coating.
Claim 14
Dependent Claim
17 words
The monitoring device according to claim 12 wherein the permeable attenuating barrier is a microporous polypropylene film.
Claim 15
Dependent Claim
44 words
The monitoring device according to claim 12 wherein a foam layer is positioned between the reactive coating on the impermeable substrate and the permeable attenuating barrier, and a cavity is provided in the foam layer between the permeable attenuating barrier and the reactive coating.
Claim 16
Dependent Claim
25 words
The monitoring device according to claim 14 including a removable impermeable cover placed over the permeable attenuating barrier to seal the reactive coating before exposure.
Claim 17
Dependent Claim
53 words
The monitoring device according to claim 14 wherein a first squeezable reservoir containing the p-nitrobenzyl pyridine solution is located in the foam layer, having a first channel to the reactive coating, and a second squeezable reservoir containing the developer is located in the foam layer, having a second channel to the reactive coating.
Claim 18
Dependent Claim
34 words
The monitoring device according to claim 1 wherein the reactive coating comprises a layer of activated alumina particles, coated with polyvinyl alcohol, ammonium chloride and water together with p-nitrobenzyl pyridine in a solvent solution.
Claim 19
Dependent Claim
17 words
The monitoring device according to Cl.iam 17 wherein the p-nitrobenzyl pyridine is in about 1-2% acetone solution.
Claim 20
Dependent Claim
17 words
The monitoring device according to Cl.iam 17 wherein the p-nitrobenzyl pyridine is in about 1-2% acetone solution.
Claim 21
Dependent Claim
17 words
The monitoring device according to claim 17 wherein the activated alumina particles are thin layer chromatography grade.
Claim 22
Dependent Claim
15 words
The monitoring device according to claim 17 wherein the developer is an aqueous alkanolamine solution.
Claim 23
Dependent Claim
20 words
The monitoring device according to claim 17 wherein the impermeable substrate is white, has good rigidity, and is chemically inert.
Claim 24
Dependent Claim
16 words
The monitoring device according to claim 21 wherein the impermeable substrate is a white polypropylene film.
Claim 25
Dependent Claim
18 words
The monitoring device according to claim 17 wherein the developer is an aqueous alkaline solution of sodium hydroxide.
Claim 26
Dependent Claim
23 words
The monitoring device according to claim 23 wherein the sodium hydroxide is about a 3% solution and is thickened with a cellulose-type thickener.
Claim 27
Dependent Claim
13 words
The monitoring device according to claim 24 wherein the thickener is sodium carboxymethylcellulose.
Claim 28
Independent Claim
123 words
A method of determining time weighted average ethylene oxide dosage, comprising the steps of: exposing a reactive coating sensitive to ethylene oxide to the atmosphere, the reactive coating including a layer of activated alumina particles coated with p-nitrobenzyl pryidine and ammonium chloride, adapted to instantly produce a color intensity change directly related to the exposure of the reactive coating to ethylene oxide upon addition of a developer, the color intensity change indicating an exposure sensitivity less than one ppm for an eight hour time weighted average; adding the developer to the reactive coating after exposure; and comparing the color intensity of the reactive coating with a color comparison means to determine if time weighted average ethylene oxide dosage is above a predetermined level.
Claim 29
Independent Claim
123 words
A method of determining time weighted average ethylene oxide dosage, comprising the steps of: exposing a reactive coating sensitive to ethylene oxide to the atmosphere, the reactive coating including a layer of activated alumina particles coated with p-nitrobenzyl pryidine and ammonium chloride, adapted to instantly produce a color intensity change directly related to the exposure of the reactive coating to ethylene oxide upon addition of a developer, the color intensity change indicating an exposure sensitivity less than one ppm for an eight hour time weighted average; adding the developer to the reactive coating after exposure; and comparing the color intensity of the reactive coating with a color comparison means to determine if time weighted average ethylene oxide dosage is above a predetermined level.
Claim 30
Dependent Claim
47 words
The method according to claim 26 wherein the developer is added to a portion of the reactive coating initially and the color intensity compared on the portion of the coating, the remaining portion of the coating being developed at a later time and the color intensity compared.
Claim 31
Dependent Claim
26 words
The method according to claim 26 wherein the reactive coating has a pH in the approximate range of 3 to 6 before application of the developer.
Claim 32
Dependent Claim
56 words
The method according to claim 26 wherein the reactive coating is prepared without the p-nitrobenzyl pyridine in a solvent solution and has a pH in the approximate range of 3 to 6, and the p-nitrobenzyl pyridine in a solvent solution is applied prior to exposing the reactive coating to the atmosphere for determining ethylene oxide dosage.
Claim 33
Dependent Claim
22 words
The method according to claim 26 wherein the reactive coating is covered with a permeable cover prior to exposure to the atmosphere.
Claim 34
Dependent Claim
32 words
The method according to claim 26 wherein the color comparison means is a color comparison chart and different color intensities represent different time weighted average dosage of ethylene oxide in the atmosphere.
Claim 35
Dependent Claim
23 words
The method according to claim 26 wherein the color comparison means is a meter to measure change in color and intensity of color.
Claim 36
Dependent Claim
26 words
The method according to claim 26 wherein the reactive coating is applied to an impermeable substrate which is white, has good rigidty and is chemically inert.
Claim 37
Dependent Claim
15 words
The method according to claim 33 wherein the impermeable substrate is a white polypropylene film.
Claim 38
Dependent Claim
33 words
The method according to claim 26 wherein the reactive coating comprises a layer of activated alumina particles, coated with polyvinyl alcohol, ammonium chloride and water together with p-nitrobenzyl pyridine in a solvent solution.
Claim 39
Dependent Claim
18 words
The method according to claim 35 wherein the p-nitrobenzyl pyridine is in about 1 to 2% acetone solution.
Claim 40
Dependent Claim
15 words
The method according to claim 35 wherein the activated alumina particles are thin-layer chromatography grade.
Claim 41
Dependent Claim
17 words
The method according to claim 26 wherein the developer is an aqueous alkaline solution of sodium hydroxide.
Claim 42
Dependent Claim
23 words
The method according to claim 38 wherein the sodium hydroxide is about a 3% solution and is thickened with a cellulose type thickener.
Claim 43
Dependent Claim
13 words
The method according to claim 38 wherein the thickener is a sodium carboxymethylcellulose.
Claim 44
Dependent Claim
21 words
The method according to claim 26 including covering the reactive coating with a permeable attenuating barrier before exposure to the atmosphere.
Claim 45
Dependent Claim
15 words
The method according to claim 41 wherein the attenuating barrier is a microporous polpropylene film.
Claim 46
Dependent Claim
20 words
The method according to claim 41 wherein the attenuating barrier is spaced from the reactive coating by a foam layer.
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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) | 1992-05-01 | 1992-10-31 | 1993-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-01 | 1996-10-31 | 1997-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-01 | 2000-10-31 | 2001-05-02 | $7700.00 | Window Closed / Lapsed |