Abstract: A detection device for testing gloves or other protective clothing or equipment for breakthrough by a contaminant includes a pad carrying a reagent which is responsive to the contaminant for producing a color change. A barrier layer covers the reverse side of the pad to prevent escape of chemicals therefrom and an adhesive strip is secured to the barrier layer for attachment of the pad either to the skin of the user or to the inside of the glove or other clothing so that the obverse side of the pad is adjacent to the inside of the glove. In one embodiment the pad is impregnated with the reagent which directly reacts with the contaminant to produce a color change. In another embodiment, plural reagents are carried respectively in separate regions of the pad and, after exposure to the contaminant, a carrier solvent is applied to the pad which brings the reagents into intimate contact for cooperation to produce the color change.

Abstract: Provided is a system for indicating exposure to a chemical vapor sterilization process. This system comprises a composition applied to a suitable support, which composition comprises a component which is chromatically transformed by the action of a vapor phase sterilant. In particular, the present invention is applicable to a system for indicating exposure to a hydrogen peroxide vapor sterilization process, with the component which is chemically transformed being so transformed in the presence of vaporous hydrogen peroxide. The composition comprises at least the component which is chemically transformed by the action of the hydrogen peroxide, but may also contain additional ingredients or components. For example, the composition also generally comprises a binder to aid in applying the composition to a suitable support or substrate.

Abstract: A method and apparatus for detecting exposure to an oxidation-type sterilant using a chemical indicator comprising bleachable dye is disclosed. Using the method and apparatus disclosed, a bleachable azo dye is incorporated with an anodized aluminum or chromate conversion coated surface and exposed to an oxidation-type sterilant, such as hydrogen peroxide, and inspected upon completion of the sterilization process for color change. If exposed to sterilant for an appropriate amount of time the bleachable dye changes color thereby indicating adequate sterilization. The surface incorporating bleachable dye may be made to change color after a predetermined number of exposures to a oxidation-type sterilant.

Abstract: A steam sterilization indicator composition comprising a bismuth compound, a sulfur source, and a compound capable of generating alkaline conditions when exposed to steam; wherein when exposed to steam the composition noticeably changes color and when exposed to dry heat either does not change color or changes color to one that is markedly different from the color formed when the same composition is exposed to steam.

Abstract: A test pack for evaluating an ethylene oxide sterilization process, comprising an open ended fiber board tubular member, an end cap enclosing each end of said tubular member, said end caps defining a test chamber within the tubular member, one of said end caps having an opening to permit the egress of ethylene oxide into the test chamber. A fiber ball is inserted into the test chamber at a location remote from the end cap having the opening therein, and a chemical type sterilization indicator is placed within the test chamber.

Abstract: A method and metal test pattern for monitoring metal corrosion susceptibility for integrated circuit wafers. Test patterns having an array of metal circles to simulate contact regions, an array of metal strips to simulate electrode regions, and a blanket metal layer to simulate bulk metal regions are formed. A first number of defects per unit area for the test patterns is measured, using a defect scan system. The test pattern wafers are then subjected to environmental stress conditions for a first time and a second number of defects per unit area for the test patterns is measured, again using a defect scan system. The difference between the second number and the first number is compared with a critical number. If excessive corrosion occurs the process for producing wafers is corrected before continuing to process product wafers.

Abstract: A food contamination detector. The food contamination detector comprises a first bar code symbol coded to identify a food product by a bar code reader, a second bar code symbol coded to identify contaminated food by a bar code reader, and an indicator printed onto a substrate which changes color when food is contaminated and causes the first bar code symbol to be unreadable by a bar code reader and causes the second bar code symbol to become readable by a bar code reader.

Abstract: A sterilization system using a sterilization process monitoring device which is capable of indicating the efficacy of the sterilization process in an enclosed sterilization container while still maintaining the sealed state of the sterilization container. The process monitoring device comprises at least one biological indicator and/or at least one chemical indicator. Upon completion of the sterilization cycle, the process monitoring device can be advantageously removed from the system to determine chemical and/or biological efficacy of the sterilization process. The removal of the biological and/or chemical indicators does not disturb the sterilized state of the articles inside the sterilization container.

Abstract: Structure for evaluating the efficacy of sterilization apparatus using either steam or ethylene oxide as sterilant is disclosed. The structure includes an insert of porous material having a cavity formed therethrough for retaining a biological or chemical indicator. The porous material has homogeneous porosity throughout. The insert of porous material and indicator are enclosed within an outer covering which is relatively impervious to penetration of gases and which provides restricted pathways to air and sterilant. The outer covering is provided with removable portions which are removed when the structure is used to evaluate ethylene oxide sterilization. Removal of the portions enlarges the existing pathways for ingress and egress of gases which may be appropriate in certain efficacy testing.

Abstract: A sheet of chemically sensitive paper (54) that exhibits a measurable change in a physical property, such as color, when exposed to a chemical environment is inserted between two sections (20, 22) such that an area of the paper is exposed to the chemical environment through an opening (46) in the upper section. The lower section is connected to a piston (14) that is located in a chamber (10) such that an area at the top of the chamber is sealed by the piston. The piston responds to changes in pressure by moving within the chamber. As it does so, a ratchet mechanism (30) causes the upper and lower sections to rotate one step relative to each other. With each rotational step, a new area of the chemically sensitive paper is exposed to the chemical environment through the opening in the upper section. In this manner, a record of a series of chemical exposures is obtained.

Abstract: This invention discloses a population of cells which have been preserved in non-frozen hydrated form, and which have been chemically treated in a manner that renders them metabolically inert and free of proteolytic enzyme activity, but without significantly altering the cell surface proteins that are of interest in flow cytometry. The absence of alteration of the surface proteins is indicated by the ability of the surface proteins to bind to monoclonal antibodies that bind to untreated proteins of the same type, with approximately the same affinity as proteins on untreated cells. The preserved cells and their surface antigens are stable for at least a month when stored at 4.degree. C. in buffered saline solution. These cell preparations are useful as quality control (QC) reagents for processes such as calibrating and standardizing flow cytometry equipment, and for use as "unknown" test samples for QC testing programs, or as patient specimens for archival storage and subsequent retrospective analysis.

Abstract: A method of indicating a time or a temperature-time accumulated value as a color change (degree of color development), which comprises providing an oxidation-polymerizable dyestuff and the oxidizing agent in a non-contact state and bringing the oxidation-polymerizable dyestuff and the oxidizing agent into contact with each other to polymerize the oxidation-polymerizable dyestuff with the passage of time, and an indicator material therefor.

Abstract: A method and device for determining the presence and concentration of total microbial contamination or the presence and concentration of a specific microbial species on a surface is described. The method consists of a means of a collection device and fluid for removing the microbes from the surface and suspending them in a fluid phase. An aliquot of the fluid phase is introduced into a disposable test ticket which allows filtration of the sample to remove extraneous substances including somatic cells, and concentration of the microbes. The total concentration of microbes is determined by adding a somatic and bacterial releasing reagent to a disposable test device which comprises a membrane containing the luminescent reagents luciferin and luciferase, and introducing the disposable test device into a luminometer that can read the luminescence from the underside.

Abstract: An apparatus and associated method which detects breaks and irregularities in a sealing arrangement, especially in heat-sealed, sterile packages by providing a standardized verification bar on the package adjacent a color coded sealing area. The verification bar may indicate examples of a proper seal, an underseal, and an overseal, as well as common seal problems such as bubbles, hairline voids and regular coextensive voids. The package which is especially useful as a sterilization pouch can be visually inspected both by the user of the package contents just prior to use and by the vendor of articles in the packages post assembly of the article into the sealed and sterilized package.

Abstract: Provided is a valved extended time-temperature indicator. This indicator comprises a base substrate and two transparent polymeric layers on top of the base substrate in adhesive contact with each other. The indicator further comprises a valve member which is restrictive of the flow of dye therethrough, which valve is interposed between the two polymer layers such that there is no adhesive contact between the two polymer layers in the area of the valve. A deposit of colored dye is either on the lower polymeric layer, in which case the valve may be in physical contact with the dye, or on the base substrate. In either case the dye is visible through the polymeric layers, with the dye being positioned directly below the valve member, however, so that the valve member at least partially obstructs visibility of the dye deposit.

Abstract: An enclosure includes a hollow robe disposed at a first end thereof and extending outwardly there-from. A collapsible bulb is attached to a second end of the enclosure for drawing atmosphere into the enclosure through the hollow robe when the bulb is squeezed and released. The enclosure further includes a viewing aperture. An indicating strip is disposed in the enclosure such that the strip is in environmental communication with the interior of the enclosure and viewable through the viewing aperture from outside of the enclosure. The indicating strip is configured to change in appearance when gases indicating the presence of food contamination are absorbed by the strip.

Abstract: A method for determining the presence and concentration of total microbial contamination or the presence and concentration of a specific microbial species on a surface is described. The method consists of a means of a collection device and fluid for removing the microbes from the surface and suspending them in a fluid phase. An aliquot of the fluid phase is introduced into a disposable test device which allows filtration of the sample to remove extraneous substances including somatic cells, and concentration of the microbes. The total concentration of microbes is determined by adding a bacterial releasing reagent and a luminescent reagent to the disposable test device and introducing the disposable test device into a luminometer that can read the luminescence from the side wall.

Abstract: Devices useful to monitor whether or not an article has been exposed to sterilizing conditions are provided and comprise a package and an indicator associated with the package. The package is sufficiently permeable to admit sterilizing gas or vapor into the package. The indicator associated with the package changes color from a first color (indicating ambient conditions) to a second color (indicating exposure to acidic gas or vapor). Both the first and second colors of the indicator are stable and preferably substantially maintain their colors under ambient conditions. Particularly, preferred embodiments are adapted for use with peracetic acid sterilization processes.

Abstract: A processing chamber for the treatment and decontamination of biological or medical waste includes a rotating waste treatment system carried within an open-top processing chamber, a cap for closing the chamber opening, a gas-pervious liner carried within the chamber for preventing waste from adhering to the underside of the cap as a result of waste-treatment operations, a sealing member disposed at and for sealing the interface of the cap and the processing chamber, and a chemical indicator carried within the interior of the processing chamber for confirming the presence of decontaminant during a waste treatment cycle.

Abstract: A method of detecting the permeability of an article to oxygen is disclosed. A fluorescent redox indicator, preferably riboflavin, is dispersed in a carrier and placed on an impermeable substrate. The article to be measured is placed adjacent to the carrier. Residual oxygen is removed, the redox indicator is photoreduced, the article and carrier are exposed to oxygen, and the indicator is exposed to UV light.

Abstract: There is presented a time-temperature indicator capsule comprising a cyliical tube having a closed end and an open end, a cap for connection to and removal from the open end to close and open the tube, and a solution in the tube which is reactive to accumulated temperature and time exposure. There is presented an indicator capsule wherein the solution comprises bacterial spores; a system including the capsule, a pipetting device, and an agar plate for providing a count of the surviving spores to, in turn, provide an indication of the aggregate thermal effect on the solution. There is still further presented methods for determining when food processed under high temperature conditions attains a selected low level of microbial population, the methods utilizing, respectively, the above systems.

Abstract: A pigment such as crystal violet is impregnated in or otherwise affixed to a translucent plastic or porous member (14, 22). The color change material changes at least one of opacity or color with repeated exposure to a fluid sterilant, such as an oxidant solution. A label (10, 24) is mounted behind the translucent plastic material and carries an indicia (12, 26). With repeated sterilizations of the instrument, the color change material becomes progressively more translucent, allowing the indicia to be read through the translucent plastic material. When the indicia becomes visible, such as after about 7 sterilization cycles in FIG. 3, the user is warned to discontinue use of the instrument, either discarding it or having it rebuilt. Rather than having a written indicia, a color scale (30) can be provided for comparison against the current color of the color change material. When the color changes to the discard color on the color scale, the user is again advised to discontinue use of or rebuild the instrument.

Abstract: Biological indicators are provided for use in validating and routinely monitoring oxidizing gas sterilizations. The biological indicators are based on Bacillus circulans spores that are enclosed in packages with sufficient permeability to admit a sterilizing amount of vapor while being substantially bacteria impermeable.

Abstract: A method is disclosed for disinfecting contact lenses with peroxide whereby the usual peroxide neutralization step is eliminated. This is accomplished by carrying out the disinfecting process at a hydrogen peroxide concentration of about 0.01 to less than 0.5% (w/v). In the preferred embodiment the peroxide is introduced into the system utilizing an effervescent tablet of an alkali metal perborate, percarbonate or persulfate, or urea peroxide.

Abstract: The operation of a steam sterilizer is monitored by a test unit and a controller which together comprise a system which can be operated in two principal method schemes: (1) the testing for completeness of air removal from a sterilizer chamber, and (2) the testing for effective sterilization conditions. These methods each have two principal modes of operation: (a) the performance of a Bowie and Dick type test, as is usually done on a once-a-day basis; and (b) monitoring the sterilizer during load conditions. In a preferred embodiment a test unit including temperature and pressure sensors, a moisture sensor and a heat sink are positioned within the chamber of a steam sterilizer and transmit by radio the conditions therein to an external controller. The test unit can employ a replaceable cartridge to assure effective operation even after a large number of cycles of operation.

Abstract: A device for use in a method of detecting the permeability of an article to oxygen is disclosed. A redox indicator and test object are vacuum sealed between a support and a peelable barrier film.

Abstract: A time-temperature indicator device for recording the duration of time over which a temperature has been established above a predetermined temperature, which device includes a dye-compatible polymer composition having a softening point above the predetermined temperature and a polymer-compatible dye composition in contact with the polymer composition and present in a quantity with respect to the polymer composition sufficient for diffusion through the polymer composition whenever the polymer composition is above the predetermined temperature, which quantity is selected so that the extent of diffusion corresponds to the duration of exposure above the predetermined temperature relative to the total time required for substantially complete diffusion. Articles for which a heat history above a predetermined temperature is to be record, in combination with the disclosed time-temperature indicator devices are also described.

Abstract: An in-situ microbial contaminant detection system provides a chemical reagent within a liquid health care product or in close association with product packaging containing the health care product. The chemical reagent interacts with a variety of microbial contaminants or byproducts, such as enzymes and acids, of the microbial contaminants that are commonly found in health care products (e.g., P. cepacia, S. marcescens, E. cloacae, E. gergoviae, E. aerogenes, K. pneumoniae, and P. aeruginosa) and provides a visible indication of microbial contamination that can readily be discerned by a consumer. A color change is preferred.

Abstract: A gas indicator (11) for a modified atmosphere food package (19) comprises a series of strips (12, 13, 14, 15, 16) which progressively change colour as the proportion of carbon dioxide in the atmosphere progressively changes in magnitude due to absorption of the carbon dioxide by the food product (17) over time. The indicator (11) thus is "tuned" to indicate changing atmospheric conditions inside a see-through envelope (10) and thus the condition of the product (17) can be monitored and the package (19) is tamper evident.

Abstract: A sterilization biological test pack includes a first plurality of apertured planar sheets of substantially porous paper disposed to form a stack. Each of the sheets defines a generally centrally disposed aperture, the apertures operatively defining together a single cavity extending through the stack. Second and third pluralities of unapertured planar sheets of substantially porous paper are disposed on opposed sides of the stack and aligned therewith to close the stack cavity at either end thereof and define a chamber about the cavity configured and dimensioned to receive a biological indicator. The first, second and third pluralities together define a sheet pad. A tray formed of unapertured gas-inhibiting material, has a base coextensive and aligned with the exposed side of the third plurality and four sidewalls transverse to the base together substantially covering the exposed edges of the pad. The tray and the pad together define an assembly.

Abstract: A method and apparatus assures effective operation of sterilizers, especially those of the pre-vacuum type. The apparatus performs two principal methods: (1) testing for completeness of air removal from a sterilizer chamber, including the re-entrainment of air in the load due to air leaks in the chamber, vacuum system and/or steam system, and (2) the testing for effective sterilization conditions. Also, performed are three secondary methods: (i) identifying of causes of sterilizer faults, (ii) providing of preventive maintenance procedures (an Early Warning) (iii) identifying of procedures to correct sterilization faults in progress. These methods are illustrated for the two principal modes of operation: (a) the performance of a Bowie and Dick type test, as is usually done on a once-a-day basis; and (b) monitoring the sterilizer during load conditions.

Abstract: A method for determining the concentration of dissolved oxygen in a water sample comprising the steps:(a) providing a water sample of predetermined volume, the oxygen content of which is to be determined;(b) mixing additives with the water sample to form a mixture, the additives comprising an oxidizable metal salt comprising a transition metal cation selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel and copper, and an anion selected from the group consisting of an inorganic anion and an organic anion which, with the cation, results in a water soluble oxidizable metal salt, at least one water soluble alkali metal compound selected from the group consisting of an alkali metal oxide and an alkali metal hydroxide and at least one oxidation-reduction indicator capable of a color change upon oxidation of the metal salt;(c) preventing any substantial contact of the mixture with atmospheric oxygen; and(d) comparing the color of the mixture to a predetermined

Abstract: For quality control of packaged organic substances, preferably packaged foods and drugs, the materials to be examined are brought into contact with a planar optical sensor element which is applied on the inside of the wrapping and responds to a change in the gas composition in the gas space above the sample by a change in color or fluorescence. The change of one of the optical properties of the sensor element is detected visually or opto-electronically.

Abstract: A locking device in the shape of a unitary body formed from a bio-degradable material which includes an element with at least one free end formed integral with said body. The severable element is designed to engage and secure a container lock mechanism when the container is in a closed position, whereby the free end of the element is capable of being mechanically or adhesively secured to said unitary body to form a seal, with said device being designed to fracture upon opening of the container lock mechanism thereby providing visible evidence of the lock mechanism being opened.

Abstract: A method of detecting the permeability of an article to oxygen is disclosed. A fluorescent redox indicator, preferably riboflavin, is dispersed in a carrier and placed on an impermeable substrate. The article to be measured is placed adjacent to the carrier. Residual oxygen is removed, the redox indicator is photoreduced, the article and carrier are exposed to oxygen, and the indicator is exposed to UV light.

Abstract: A food contamination detector. The detector comprises a tray for holding a food product. A collector is placed in the tray for collecting liquids from the food. A bar code detector is located in the collector.

Abstract: The invention provides a method for indicating the level of oral microbial activity comprising providing a sterile liquid for introduction into the oral cavity for swishing therein, providing a transparent vessel having therein an indicator which undergoes a characteristic color change in the presence of oxygen-consuming microbes and placing the swished liquid together with nutrients to enhance microbial growth in the vessel, whereby the indicator undergoes a color change as a function of time, which color change is an indication of the level of microbial activity in the swished expectorated liquid. The invention also provides a kit for use in carrying out the method comprising a sterile liquid, a transparent vessel for use in receiving the expectorate, and an indicator to be provided in the vessel to produce a visual indication of the level of microbial activity in the expectorated liquid.

Abstract: An ink composition for indicating the progress of sterilization with EO is provided which comprises;(1) at least one disperse dye of the general formulaA--N.dbd.N--Bwherein A is the residue of a heterocyclic compound containing nitrogen atom which is not substituted with alkyl group and selected from the group consisting of the pyridine, quinoline, isoquinoline, triazole, tetrazole, indazole, thiazole, benzothiazole and thiadiazole rings, which residue may optionally have one or more undissociated substituents, and B is a coupling component,(2) at least one binder component selected from the group consisting of polyacrylic acid, polymethacrylic acid and acrylic acid-methacrylic acid copolymers,(3) at least one ultrafine filler selected from the group consisting of ultrafine particles of silica, aluminum oxide and titanium oxide, and(4) at least one polar solvent.

Abstract: A method of assessing the degree of thermal processing of a food by preparing an aqueous medium including at least a portion of the processed food and monitoring the medium for the presence of a thermally produced compound not present in the unprocessed food to indicate the exposure of the food to heat.

Abstract: An indicator composition and process capable of changing color in relationship to its exposure to a temperature above and below a base line temperature and to the time of said exposure, for monitoring the time-temperature history of a substrate, depositable as a layer on said substrate, comprising a dispersion of either a binder comprising a reaction inert, neutral finely divided absorbent, in the presence of a reactant comprising a salt of an acid or an organic compound substituted by at least one moiety which, in ionic form, is an anion or a binder/reactant, comprising at least one solid organic polymer whose constituent units contain, as a covalent substituent, at least one moiety which, in ionic form, is an anion; as indicator, at least one acid sensitive pH dye and as activator, at least one base. This composition and process may be utilized to form a solid state device for monitoring integral values of time and temperature during storage of perishables.

Abstract: A sterilization biological test pack comprises a first plurality of apertured planar sheets of substantially porous paper disposed to form a stack. Each of the sheets defines a generally centrally disposed aperture, the apertures operatively defining together a single cavity extending through the stack. Second and third pluralities of unapertured planar sheets of substantially porous paper are disposed on opposed sides of the stack and aligned therewith to close the stack cavity at either end thereof and define a chamber about the cavity configured and dimensioned to receive a biological indicator. Fourth and fifth pluralities of unapertured planar sheets of paper of intermediate porosity are disposed on exposed sides of the third and fourth pluralities, respectively, and aligned therewith.

Abstract: There is disclosed an automated system for testing the sterility of products intended for human health administration or for human consumption. The system permits a plurality of samples of a product to be concurrently tested and is arranged so that multiple samples of a product to be tested can be mixed and then conveyed to test canisters along with appropriate growth media prior to determining that the product is sterile or is free from microbial contamination.

Abstract: A permanent record test device tests the efficiency of a steam sterilizer apparatus to create a vacuum satisfying the Bowie-Dick test procedure. A sheet of selectively porous material such as one hundred pound blotter paper having a steam sensitive indicator ink printed thereon is laminated between layers of steam and air impermeable polymeric material to substantially occlude the sheet from ambient atmosphere, except for a small metering region. The small metering region may include a hole punched through the laminated sheet. Two parallel and spaced apart strips can be used with a metering hole punched at one end of each of the strips or, alternatively, a metering hole is punched at one end of any one of the strips and the strips can be connected with a fluid passageway at the opposite end of the strips. Strips other then straight strips can be used, e.g., an L-shaped strip can be used with a V-shaped strip.

Abstract: A prevacuum steam sterilization test pack, for testing the efficiency of the vacuum system of a steam sterilizer apparatus to create a vacuum, comprises a bundle of layers and a porous overwrap folded about the bundle to maintain the integrity thereof. The bundle includes a porous test sheet with a steam sensitive indicator ink printed thereon positioned between layers of the bundle to indicate the efficiency of the vacuum system of a sterilizer, a plurality of selectively porous layers within the bundle above and below said test sheet, and at least one pair of non-porous gas-impermeable layers disposed intermediate the test sheet and one of the bundle end surfaces. The pair of non-porous layers is spaced from both the test sheet and the one bundle end surface by at least one of the porous layers, and the non-porous layers are spaced apart by at least one and no more than two of the porous layers.

Abstract: A sterility indicator of the type used in hospitals and laboratories. The device uses a cylindrical ampule holder with an ampule containing nutrient media and spore strip disposed therein. One or more gas pervious, liquid impervious tortuous paths lie between the interior and exterior of the ampule holder. Fracturing of the ampule is by the combination of a rotation and rotation prevention means with respect to the cylindrical axis.

Abstract: The present invention provides a chemical indicator for the detection of hydrogen peroxide. A composition containing an aqueous solution of potassium dichromate is applied to a porous substrate. The reaction between the dichromate and chromate ions present in solution and hydrogen peroxide is accompanied by a dramatic color change which is visible to the naked eye. The initial color of the potassium dichromate solution may be enhanced by adjusting the pH of the solution to be basic. The rate of reaction between the dichromate and chromate ions and the hydrogen peroxide may be increased by the addition of the humectant urea to the potassium dichromate solution.

Abstract: Packages which are subject to tampering while in a store or deterioration over time due to the presence of oxygen may be readily identified by placing therein a multi-component visual indicator system which is sensitive to the presence of oxygen. The system, which may be prepared aerobically and then placed into an anaerobic environment for use, is not effected by the presence of reducing agents found commonly in foods, drugs, and cosmetics.

Abstract: A Bowie and Dick type prevacuum steam sterilization test pack for insertion into a sterilization chamber for indicating the presence of unacceptable levels of uncondensable gas comprises a housing, a heat sink and an indicator. The housing defines a single chamber having a large open end, a relatively small closed end opposite the open end, and a sidewall smoothly tapering from the open end to the closed end. The heat sink is disposed in the chamber and extends substantially from the open end to the closed end to define a path through which the steam travels from the open end toward the closed end, the path being adapted to provide sufficient exposure of the steam to the heat sink so that the steam condenses within the path, releasing any noncondensable gas associated with the steam, forcing the noncondensable gas so released toward and concentrating such noncondensable gas within the closed end.

Abstract: An indicator element which provides a visual indication when subjected to correct steam sterilization conditions in an autoclave, the element comprising a substrate having coated thereon an ink formulation comprising as the primary visual change component: (i) a sulfur-containing compound capable of decomposition to yield a metal sulfide under steam sterilization conditions, or (ii) the precursors of which a sulfur-containing compound which will yield said sulfur-containing compound under aqueous conditions.

Abstract: The disclosed pressurized vessel has a door seal which is pressurized by a steam supply. A diaphragm actuated solenoid valve is connected between the steam supply and the door seal. The diaphragm solenoid valve precludes the door seal from depressurizing unless the pressure within the vessel is within a preselected pressure tolerance. Also, a check valve is provided to preclude the door seal from completely depressurizing if the pressure at the steam supply is interrupted.