MXPA00006367A - Method and apparatus for aerating chemically-sterilized articles - Google Patents

Abstract

A method for aerating a chemically-sterilized article, said method comprising exposing said article to at least one co-adsorbate under conditions such that said co-adsorbate remains vaporized, said co-adsorbate having a partial pressure under said conditions sufficient to displace at least a portion of sterilant adsorbed by said article.

Description

METHOD AND APPARATUS FOR AIRING CHEMICALLY STERILIZED ARTICLES FIELD OF THE INVENTION The present invention relates to chemical sterilization. More specifically, this invention relates to a method and system for removing the waste of sterilizing substances, such as ethylene oxide (EO), from chemically sterilized articles. BACKGROUND OF THE INVENTION Many surgical devices and materials must be sterilized before being used for the purpose of protecting the health and safety of patients and hospital staff. Sterilization can be divided into sterilization at high temperatures and sterilization at low temperatures. Generally speaking, sterilization at high temperatures is preferred since it is significantly faster than sterilization at low temperatures. Sterilization at high temperatures includes exposing articles to steam sterilization at high temperatures that range from about 250 to about 270 ° F in an air-tight chamber. The process can be completed in a period usually less than about 2 hours. However, some items, such as plastic items and electrical components, can not withstand such high temperatures and require sterilization at low temperatures. The present invention focuses on sterilization at low temperatures. Typically, sterilization at low temperatures includes the use of chemical sterilizing substances at temperatures of about 100 to about 200 ° F. Typical chemical sterilizing substances include, for example, EO, formaldehyde, hydrogen peroxide, chlorine dioxide, and ozone. In medical applications, ethylene oxide is the most frequently used sterilizing substance. Standards for sterilization with ethylene oxide are established in Good Hospital Practice: Ethylene Oxide Sterility and Sterility Assurance (Good hospital practice: sterilization with ethylene oxide and assurance of sterility) ANSI / AAMI ST41-1992. Sterilization at low temperatures is usually a two-stage process performed in an air-tight chamber. In the first stage (the sterilization stage), the items that have been cleaned and wrapped in gas permeable bags are placed in the chamber. The air is then evacuated from the chamber creating a vacuum and possibly displacing the air with steam. In processes employing ethylene oxide as a sterilizing substance, it is preferable to inject steam into the chamber to achieve a relative humidity which is within a range of preferably from about 30% to about 70%. It is found that these moisture levels optimize the effectiveness of sterilization of the sterilizing substance, ethylene oxide, which is introduced into the chamber after reaching the desired relative humidity level. After a sufficient period for the sterilizing substance to penetrate through the wrap and reach the interstices of the article, the sterilizing substance and the vapor are evacuated from the chamber. In the second step of the process (the aeration step), the articles are aerated to remove the residues of sterilizing substance. The removal of this waste is especially important in the case of toxic sterilizing substances, such as for example ethylene oxide. Typical aeration processes include air washes, continuous aeration, and a combination of the two. An air wash is a batch process and usually involves evacuating the chamber for a relatively short period, for example, 12 minutes and then introducing air at atmospheric pressure or at higher pressure in the chamber. This cycle is repeated several times until the desired removal of the sterilizing substance is obtained. Continuous aeration typically includes introducing air through an inlet on one side of the chamber and then extracting it through an outlet on the other side of the chamber by applying a slight vacuum at the outlet. Frequently, the two approaches are combined. For example, a usual approach includes performing air washes and then an aeration cycle. Sterilization at low temperatures takes a lot of time. Although the sterilization step can be carried out in less than 3 hours, the aeration step typically requires from about 8 to about 10 hours. The time between when an item is sent for sterilization and the time it is returned is known as "" the time of rotation. "There is a need to reduce the time of rotation. Cut costs that are applied to hospitals by governments and insurance companies Since items to be sterilized are not available for use, an inventory of items must be kept available to allow time for rotation. inventories can be costly, they often cost hospitals millions of dollars, therefore a major effort has been made to reduce the time of rotation, particularly the passage of aeration that accounts for most of the rotation time. rotation time, but tend to create other problems that are serious enough to limit their implementation. Prior art effort includes the use of sterilizing substances other than ethylene oxide, such as, for example, hydrogen peroxide in the vapor phase or paracetic acid, and smaller sterilization chambers. Even though these sterilization chambers may cause items to rotate more quickly, their small capacity limits their performance. In addition, the alternative chemical sterilizing substances used in these sterilizers are not as versatile as ethylene oxide. Another prior art effort to reduce aeration time includes the classification of the devices by the ease of aeration. For example, some materials tend to have less tendency to accumulate residues of "sterilizing substances and / or the waste of sterilizing substance can be removed more easily. Other materials can withstand higher temperatures. Each 8 ° F increase in temperature can reduce sterilization and aeration times by 50%. Therefore, by classifying the articles according to their ability to withstand higher temperatures or to retain less waste of sterilizing substance, they can be placed in a "fast track" and avoid their grouping with other articles that require the use of lower temperatures or longer aeration times. Such an approach, however, requires a lot of work and is complicated since different operating conditions must be constantly observed. In addition, the classification approach runs the risk of damaging the articles or of improperly sterilizing them due to grouping errors. Another approach to the problem includes the injection of steam over saturated with the sterilizing substance in accordance with that described in United States Patent No. 4,770,851. The supersaturated vapor condenses in the articles and in its envelope. The condensed value acts as a removal agent for the sterilizing substance by condensation in the interstices of the article and then by evaporation to carry the sterilizing substance. This approach, however, requires costly modifications to existing systems. In addition, vapor condensation on the articles and their wrapping can result in the formation of undesirable "wet packaging". Wet packaging compromises the sterilization process by providing a medium (water) where the bacteria live and migrate. Contact with water can also damage certain items such as electronic components. Thus, this approach reduces the time but can also increase the risk of inadequate sterilization of the articles and can also damage such articles. Accordingly, there is a need for an aeration procedure that requires less time than can be practiced on all items that require sterilization at low temperatures without compromising sterilization or damaging the articles. The present invention meets this need among others. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a graph of the removal rate of ethylene oxide residue from PVC plastic on a semi-logarithmic scale. Figure 2 shows a schematic diagram of an apparatus of the present invention. DESCRIPTION OF THE INVENTION AND PREFERRED MODALITIES The present invention provides a system and method for aerating chemically sterilized articles more efficiently by reducing the absorption by the articles of the sterilizing substance. Adsorption is the ability of a substance ("adsorbent") to retain or otherwise concentrate a gas, liquid or other dissolved substance ("adsorbate") on its surface. By introducing a competing adsorbate into the aeration process, the sterilizing substance adsorbed on the surface of the article is at least partially displaced. The reduction in the amount of sterilizing substance adsorbed significantly improves the aeration efficiency since the adsorbed molecules are especially difficult to remove. The difficulty in the case of the aeration of chemically sterilized articles seems to be related, at least partially, to the adsorption of the sterilizing substance. This relationship is evident in the variable aeration speed of articles sterilized with ethylene oxide. Ethylene oxide is specifically considered here since it is the most common chemical sterilizing substance and its residue tends to be relatively difficult to remove. It should be noted, however, that the underlying principles addressed herein can be applied to other conventional sterilizing substances, and that comments on ethylene oxide should not be considered as limiting the scope of the invention only to sterilization with ethylene oxide. It has been observed that the aeration of an article sterilized with ethylene oxide is a two-phase process. In the first phase, the removal of ethylene oxide is rapid. For example, in the aeration of PVC exposed to 600 mg / 1 of sterilizing substance, ethylene oxide (Oxyfume 2002®, AlliedSignal, Morristown, NJ) for 135 minutes at a temperature of 120 ° F, as shown in Figure 1 , ethylene oxide decreases from 1828 ppm to 125 ppm in about 12 hours. This corresponds to a removal speed of -0.225 ln? EOppm / hr. In the second phase, the removal is considerably slower even on a logarithmic scale. To reduce the concentration of ethylene oxide from 125 ppm to 1 ppm, 57 hours were required, which corresponds to a speed of removal of -0.085 ln? EOppm / hr. This decrease in the rate of removal indicates that the ethylene oxide residue removed in the second aeration phase was maintained more closely than the residue of ethylene oxide removed in the first phase. The number of ethylene oxide molecules on a surface containing adsorbed ethylene oxide is measured by the partial pressure of ethylene oxide (hereinafter "PEO"). As the retention of adsorbed ethylene oxide increases, ethylene oxide molecules on the surface decrease, resulting in a decrease in PEo- PEO is a function of the balance of the amount of EO adsorbed by surface amount (below "qEo") • In current aeration processes , these molecules are removed from the system by blowing air free of ethylene oxide on the surface. The volume of air required to remove the ethylene oxide is inversely proportional to this rate of change of PEo with qEo (? P /? Q). Since the surface attraction for ethylene oxide increases almost exponentially with the removal of successive layers of ethylene oxide molecules,? P /? Q decreases exponentially and the volume of air required to remove ethylene oxide molecules it therefore increases exponentially. The present invention not only identifies a probable cause of the difficulty of removing the waste of sterilizing substance, but also offers an innovative solution focused on the cause. The solution, as mentioned above, includes the introduction of one or more or adsorbates during the aeration process to displace the sterilizing substance. Since a sterilized article has a limited surface area, the sterilized substance and the co-adsorbate will complete the surface area and eventually reach an equilibrium. The equilibrium is represented by the following general equation for adsorption of multiple components: qEo / qnm = kEOf (PEO) / (1 + kEof (PEo) + cf (Pc)) (1) where: qEo is the amount of oxide of ethylene adsorbed in a quantity of the material; qiim is the maximum amount of adsorbates in the amount of material based on the "surface area" of the adsorbent, which, in the context of adsorption, refers to all solid surfaces exposed, typically of dimensions of the order of the miera and Angstrom, which, although not visible to the naked eye, is usually found in the form of pores and cracks in the material; kE0 is an adsorbent constant for ethylene oxide; kc is an adsorbent constant for the co-adsorbate; PEO is the partial pressure of ethylene oxide; Ps is the partial pressure of the co-adsorbate; f (PEO) corresponds to the amount of ethylene oxide in a specific adsorbent surface as a function of the partial pressure of ethylene oxide; and f (Pc) corresponds to the amount of co-adsorbate on a specific absorbent surface as a function of the partial pressure of the co-adsorbate. Looking at equation (1), it can be seen that if there is a co-adsorbate, C, during aeration, then the ethylene oxide residue, qEo, will be lower. For example, when PVC and Teflon were exposed to 4.5 psig of pure ethylene oxide at a temperature of 120 ° F for 135 minutes, the amount of residual ethylene oxide was 3948 and 23 ppm, respectively. However, when the same materials were exposed to a mixture of 4.5 psig of pure ethylene oxide and 12 psig of a mixture of HCFC-124 and HCFC-22 under the same conditions, the residual ethylene oxide reached 1828 and 14 ppm, respectively. Accordingly, it can be seen that even though the partial pressure of ethylene oxide remained the same, the HCFC co-adsorbate reduced the amount of residual ethylene oxide by about half. During the aeration step, as co-adsorbate, enriched air passes into the article, the partial pressure of ethylene oxide decreases while the partial pressure of the co-adsorbate remains the same. This displaces the adsorption equilibrium, in accordance with that expressed in equation (1), in such a way that the adsorption of co-adsorbate is favored. With the passage of time, the ethylene oxide will be substantially displaced by the co-adsorbate. Therefore, instead of merely removing the adsorbed ethylene oxide by decreasing partial suppression, the aeration of the present invention also removes the adsorbed ethylene oxide by its displacement with the co-adsorbate. This provides a faster aeration that can decrease the rotation time and residual ethylene oxide levels. Accordingly, an aspect of the present invention is to provide a method for aerating an article for the purpose of removing waste of sterilizing substance. In a preferred embodiment, said method comprises exposing the article to at least one co-adsorbate under conditions such that said co-adsorbate remains above its dew point. Another aspect of the present invention is the provision of an apparatus for carrying out the above process. In a preferred embodiment, the apparatus comprises (a) a camera; (b) an air supply device for supplying air to said chamber; (c) a co-adsorbate delivery device for delivering a co-adsorbate to said chamber; (d) an evacuation device for evacuating gases from said chamber; (e) a regulation device for regulating the supply and evacuation of air and co-adsorbate in said chamber and outside said chamber; and (f) an instruction device for instructing said regulating device to carry out an aeration process of one or more articles, said aeration process comprising at least the introduction of a co-adsorbate during the aeration of said article. . Another aspect of the present invention is the provision of a method for equipping an existing sterilization apparatus for carrying out the method in accordance with what is described above. In a preferred embodiment, the method comprises re-configuring the apparatus in such a manner that it injects steam not only during the sterilization phase, but also during the aeration phase. Conventional aeration methods and apparatuses can be easily adapted to the method and apparatus of the present invention. In a conventional aeration process, in accordance with that described above, air washes and continuous aeration are employed individually and in combination. The adaptation of these processes in accordance with the present invention simply requires exposure of the co-adsorbate to the article by injection of the co-adsorbate during the step of washing with air or continuous aeration. Suitable co-adsorbates include any non-toxic, vaporized substance having a sufficient partial pressure at the operating temperature of the aeration passage to displace at least a portion of the sterilizing substance adsorbed by said article. Preferably, the co-adsorbate remains above its dew point at degassing temperatures. In a more preferred embodiment, the co-adsorbate has an adsorbed partial pressure not less than about 1/10 of the partial pressure of ethylene oxide in the case of a similar adsorbed concentration at degassing temperatures. Examples of suitable co-adsorbates include, but are not limited to, vapor, C02, hydrofluorocarbons (HFCS), such as pentafluoroethane (HFC-125), 1,1-tetrafluoroethane (HFC-134a), 1,1, 1,3,3-pentafluoropropane (HFC-245fa), and 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea); hydrochlorofluorocarbons (HCFCs), such as chlorodifluoromethane (HCFC-22), and 2-chloro, 1,1,1, tetrafluoroethane (HCFC-124); chlorofluorocarbons (CFCs), such as trichlorofluoromethane (CFC-11) and dichlorodifluoromethane (CFC-12); halocarbons, such as for example brominated and iodinated hydrocarbons; and combinations of two or more of them. The particular selection of one or more co-adsorbates depends on several criteria, for example, the availability and cost of co-adsorbate, the ease of implementing co-adsorbate in existing systems and new systems, the effectiveness of co-adsorbate to displace ethylene oxide, and other co-adsorbate properties such as toxicity, flammability, compatibility with other materials, as well as environmental acceptability. In most situations, the selection of the co-adsorbate usually includes the optimization of these various criteria. For example, even when a material can displace ethylene oxide more easily at a given partial pressure than another material, its cost can be prohibitive. Therefore, a less effective material can be more effective from an economic perspective even when a greater amount of such material is required. From the perspective of ease of implementation, the preferred co-adsorbate is probably steam since most existing sterilization apparatuses employ steam in the sterilization step. Preferably, the co-adsorbate is exposed to the article at its saturation point or near its saturation point, but not beyond that point. A high partial pressure of co-adsorbate is preferred since the degree of adsorption depends on the partial pressure of the co-adsorbate (see equation (1)). The partial pressure, however, should not be so high that the co-adsorbate is condensed at the operating temperature. The condensed co-adsorbate compromises the sterilization process and can damage certain items that are being sterilized, for example, electrical devices. In many cases, the operating conditions of the aeration process are limited by the materials being sterilized. As mentioned above, sterilization with ethylene oxide is generally employed in the case of articles that can not withstand high temperatures. Accordingly, the operating temperature of sterilization with ethylene oxide should not be above about 250 ° F. Preferably, the operating temperature is not greater than about 200 ° F, and preferably even higher, said temperature is not greater than about 140 ° F. In the case of a heated co-adsorbate such as steam, it must be injected into the chamber under conditions in which the temperature inside the chamber does not exceed a predetermined maximum operating temperature. This limitation can be observed in various ways such as, for example, by slow injection of the co-adsorbate heated in the aeration chamber, by its intermittent injection, or by decreasing the temperature. In this last approach, the lowest temperature ) requires a lower partial pressure to avoid condensation. The decrease in partial pressure of co-adsorbate, however, reduces its effectiveness as will be discussed later. The maintenance of a co-adsorbate at the saturation level or below said saturation level for a certain temperature limits the partial pressure of the co-adsorbate. As is known, the increase in the partial pressure of steam brings it closer to its dew point for a given temperature. Therefore, even when high partial pressures result in a higher co-absorption (see formula (1)), this pressure can also result in condensation. Given these limitations, a person with some skill in the art can easily determine the preferred range of partial pressures and temperature of the co-adsorbate employed. This determination is made simply by consulting the phase diagram of the co-adsorbate. For example, a current at a temperature of 200 ° F and 140 ° F has partial saturation pressures of approximately 11.5 psia and 2.9 psia, respectively. Accordingly, in the preferred embodiment, the partial vapor pressure must be maintained at these levels or below these levels when the chamber is maintained at the corresponding temperature.

The apparatus employed to carry out the process of the present invention is easily adaptable from a conventional sterilization apparatus such as those manufactured by Steris Corporation (Mentor, OH), and Getinge Corporation (Rochester, NY), and from apparatus of dedicated aeration such as those employed by medical device factories. With reference to Figure 2, a sterilization apparatus 100 of the present invention is shown. Like any conventional system, the apparatus 100 comprises a containment zone 101 having a door 102 that provides access to a chamber 103 in which the articles to be sterilized are placed. For the sterilization step, ethylene oxide and vapor delivery devices 106, 107, respectively, are provided for supplying ethylene oxide and steam to the chamber 103. Such devices are known in the art and may include fan / pump systems. , heat exchangers, valves, filters, and connection duct. The evacuation devices 108 are used to evacuate the ethylene oxide and vapor from the chamber. Again, such means are known in the art and include, for example, vacuum pumps, valves, filters, and connecting conduit (see also, US Patent 4,770,851 for a description of a suitable sterilizer). The aeration step of the sterilization process is usually carried out by hospitals in the same chamber as the sterilization step, and by manufacturers of medical devices in a different room. However, the basic apparatus for aeration remains the same. Air supply devices 113 supply air to the chamber 103. Such devices may comprise any conventional filtered air assortment system. To maintain the chamber 103 at preferred operating temperatures, the apparatus may include heating devices, such as, for example, internal coils, heating strips, and steam jackets. In Figure 2, the apparatus 100 is illustrated with a steam jacket 110. Since the entire sterilization process may require a long period of time, typically from about 800 to about 900 minutes, and since the chamber must be maintained At specific temperatures and specific pressures during this period, the apparatus is usually automated. The injection of ethylene oxide, vapor and air into the chamber and its subsequent evacuation is controlled by a regulation device typically comprising a central processing unit (CPU) 111. The central processing unit 111 can be a discrete processor, or well a combination of processors configured on a personal computer, controller, work station, large computer or the like, such central processing units are known in the art. The central processing unit 111 receives instructions from the instruction device to control the various devices for carrying out the sterilization process in accordance with what is described above. Typically, the instruction device is loaded into the memory 112 with an instruction program. The memory 112 may be any computer-readable medium, such as RAM, ROM or PROM, which may contain such instructions. The sterilization apparatus described above is basically conventional. The apparatus of the present invention provides the injection of a co-adsorbate during the aeration step. In the preferred embodiment, the co-adsorbate is steam, which is already used in the sterilization step. Accordingly, using steam as the co-adsorbate avoids the need to incorporate another co-adsorbate delivery device 107 into the apparatus. With an automated apparatus, the only change consists in modifying the resident training device in such a way that the central processing unit 111 injects steam not only during the sterilization step, but also during the aeration step. Said modification would be evident to an expert in the field taking this disclosure into account. For example, it may involve loading a new program into the memory 112. The program may be adapted to operate on known and anticipated operating platforms, and may be stored on any computer-readable medium, such as a disk. a tape, CD ROM, RAM or PROM. Alternatively, the modification of the instruction device of the central processing unit may involve the replacement of a ROM or PROM chip with another containing the appropriate set of instructions. In other embodiments of the present invention that involve, for example, either the use of an additional or alternative co-adsorbate, or the use of a dedicated aeration apparatus that does not have steam supply devices, incorporation is required of co-adsorbate delivery means 107. Such delivery means are however known in the art and include, for example, pressurized tanks with regulator valves. EXAMPLES The comparative and illustrative examples presented below show the effectiveness of the aeration techniques provided by the present invention. In these examples, a conventional 30 cubic foot sterilizer was used to sterilize and aerate PVC pipes. It is known that PVC is difficult to aerate and has been frequently used as a material for the manufacture of components in medical devices. After aeration, the ethylene oxide residue was measured. Aeration is considered satisfactory, according to current regulations (recommendation of the FDA 1978), if the ethylene oxide residue is below 25 ppm. Data from the sterilization and aeration steps are shown in Table 1. Table 1 - Summary of examples STEP Example example illustrative comparison STERILIZATION Preheat Time (min) 1.1 1.1 Temperature (° F) 121 121 Pre-vac Time (min) 14.2 15.0 Humidity Time (min.) 39.4 33.3 Relative humidity (%) 45 45 Gas charge Time (min) Conc. (Mg EO / liter) 435 435 Quantity (pound gas / cycle) 8.1 8.1 Sterilization Time (min) 180 180 Temperature (° F) 133 133 Pressure (psig) 21 21 Escape Time (min) 1.5 1.5 AERATION Air wash Time (min) 484 349 Temperature (° F) 132 135 No. of cycles 31 23 Evacuation (min) 12.6 12.8 Pressurization (min) 3.0 2.4 Time per cycle (min) 15.6 15.2 Total washing with air, min 484 349 Steam impulse speed N / A 1/5 (min activated / deactivated) Steam line pressure (psig) N / A 18 Estimated temperature of line N / A 260 of steam (° F) Estimated change in pressure N / A 0.3 of the chamber during injection (psi) Relative humidity per centual esti- N / A 45 mada at the beginning of washing with air Percentage of relative humidity N / A 90. Estimated peak during air wash No. of wash cycles with air 31 without steam Total cycle time 730 590 Residue of average EO 95 12 Comparative Example This example illustrates a known sterilization procedure performed under optimum conditions. The aeration step of this sterilization process was carried out by air washes. The air washes consisted of a series of 15-minute cycles of vacuum application and repressurization with air. The temperature was maintained at a level of approximately 132 ° F. After a total air wash time of 484 minutes, the ethylene oxide residue in the PVC tubes was reduced to 95 ppm. Illustrative example In this example, steam was injected during air washes according to the details presented in tables 1 and 2. The steam was introduced intermittently in such a way that the chamber was not heated to a temperature that could damage the medical devices. During each air wash, a cycle was repeated in which the steam was injected for up to 0.5 minute increasing the chamber pressure by approximately 0.3 psia, and then shutting down for 2.5 minutes. These cycles were performed in 21 of the 23 air washes carried out. No steam was injected during the last two air washes to allow the removal of moisture that remained in materials and hollow spaces in the chamber. The air wash temperature was elevated from 132 ° F to 135 ° F. After a total air wash time of only 349 minutes, the ethylene oxide residue in PVC pipes was reduced to 12 ppm, which is within the guidelines of the FDA of 1978, with a total cycle time less than 10 hours - allowing the realization of two cycles a day in the sterilizer. This cycle of washing with air is not only 2 hours shorter than in the comparative example, but the residue of ethylene oxide is 85% smaller.

Claims (19)

1. CLAIMS A method for aerating a chemically sterilized article to remove a sterilizing substance, said method comprising: exposing said article to at least one co-adsorbate under conditions such that said co-adsorbate remains above its dew point, said co-adsorbate. adsorbate has a partial pressure under these conditions sufficient to displace at least a part of the sterilizing substance adsorbed by said article.
2. The method according to claim 1, wherein said co-adsorbate is selected from the group consisting of vapor, C02, HFCs, HCFCs, CFCs, and halocarbons.
3. The method according to claim 2, wherein said co-adsorbate is vapor.
4. The method according to claim 3, wherein said operating conditions comprise a temperature not greater than about 200 ° F and a partial vapor pressure not greater than about 11.5 psia.
5. The method according to claim 4, wherein said temperature is not greater than about 140 ° F, and said partial vapor pressure is not greater than about 2.9 psia.
6. The method of compliance with claim 5, wherein said vapor partial pressure is approximately at the saturation level.
7. The method according to claim 1, wherein said operating conditions comprise a temperature not greater than about 140 ° F.
8. The method according to claim 7, wherein said co-adsorbate has a partial pressure at about saturation level.
9. The method according to claim 1, wherein the exposure of said article to said co-adsorbate comprises performing one or more air washes until the reduction of sterilizing substance residue to a predetermined level, said air washes comprising: injecting air and said co-adsorbate in a chamber containing said article; and evacuating said air and said co-adsorbate after a predetermined period.
10. The method according to claim 9, wherein several air washes are carried out and at least the last air wash performed does not contain co-adsorbate.
11. The method according to claim 10, wherein said co-adsorbate is vapor.
12. The method according to claim 1, wherein the exposure of said article to said co-adsorbate comprises carrying out a continuous aeration until the reduction of a waste of sterilizing substance to an acceptable level, said continuous aeration comprises: the continuous injection of air to said co-adsorbate in a chamber containing said article; and the continuous evacuation of air and co-adsorbate from said chamber at approximately the same velocity as said air and said co-adsorbate are injected into said chamber. .
13. The method according to claim 12, wherein said co-adsorbate is vapor. .
14. An apparatus for aerating an article, said apparatus comprising: a camera; an air supply device for supplying air to said chamber; a co-adsorbate delivery device for delivering co-adsorbate to said chamber; an evacuation device for evacuating gases from said chamber; a regulating device for regulating the supply and evacuation of air and co-adsorbate in relation to said chamber; and an instruction device for instructing said regulating device to carry out an aeration process of said article, said aeration process comprising at least the introduction of co-adsorbate during the aeration of said article.
15. 15. The apparatus according to claim 16, wherein said instructional means instructs said regulating means to regulate said chamber under conditions such that said co-adsorbate remains vaporized.
16. 16. The apparatus according to claim 16, wherein said co-adsorbate delivery device is a steam delivery device.
17. 17. The apparatus according to claim 15, further comprising: a heating device for heating said chamber to one or several desired temperatures.
18. 18. The apparatus according to claim 17, wherein said conditions comprise a temperature not greater than about 140 ° F and a partial vapor pressure not greater than about 2.9 psia.
19. 19. A method for fitting an existing sterilization apparatus, said method comprising: supplying a conventional sterilization apparatus comprising: a chamber; a means of supplying a sterilizing substance for supplying a sterilizing substance to said chamber; an air supply means for supplying air to said chamber; a steam supply means for supplying steam to said chamber; an evacuation means for evacuating gases from said chamber; a regulating means for regulating the introduction and evacuation of air and co-adsorbate in relation to said chamber; and a means of instructions for instructing said regulating means to carry out a sterilization process of said article that includes a sterilization step and an aeration passage; and reconfiguring said means of instructions such that said aeration process comprises at least the supply of steam to said chamber during said aeration step under conditions such that said vapor remains vaporized. The method according to claim 19, wherein the reconfiguration of said instruction means comprises the installation of a new ROM chip comprising means of instructions for said sterilization apparatus for injecting steam into said chamber during the aeration step.