Space decontamination method and space decontamination device

Abstract

To provide a space decontamination method and a space decontamination device with high decontamination effectiveness.SOLUTION: In a spatial decontamination method, a mixed gas containing air and acetic acid is supplied to a space, and the space is humidified using an aqueous solution containing hydrogen peroxide. A space decontamination apparatus includes a mixed gas supply unit and a humidification unit. The gas mixing unit supplies air and a gas mixture containing acetic acid to the space. The humidification unit humidifies the space using an aqueous solution containing hydrogen peroxide. The mixed gas supply unit generates the mixed gas by, for example, blowing air into the acetic acid solution and bubbling.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a spatial decontamination method and apparatus. [Background technology]

[0002] There are spaces that need to be decontaminated in pharmaceutical manufacturing plants, biohazard facilities, cell culture processing facilities, etc. A decontamination method is disclosed in Patent Document 1. One decontamination method is to spray a solution containing peracetic acid into the space using a spray device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2005-526557 Summary of the Invention [Problem to be solved by the invention]

[0004] A spatial decontamination method that provides a higher decontamination effect is desired. In one aspect of the present disclosure, it is preferable to provide a spatial decontamination method and a spatial decontamination device that provide a higher decontamination effect. [Means for solving the problem]

[0005] One aspect of the present disclosure is a space decontamination method, which comprises supplying a mixed gas containing air and acetic acid to a space and humidifying the space with an aqueous solution containing hydrogen peroxide. The space decontamination method according to one aspect of the present disclosure has a high decontamination effect.

[0006] Another aspect of the present disclosure is a space decontamination apparatus including a mixed gas supply unit configured to supply a mixed gas containing air and acetic acid to a space, and a humidification unit configured to humidify the space using an aqueous solution containing hydrogen peroxide. The space decontamination apparatus according to another aspect of the present disclosure has a high decontamination effect. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is an explanatory diagram illustrating a configuration of a mixed gas supply unit. [Diagram 2] FIG. 2 is a block diagram showing the configuration of a spatial decontamination apparatus. [Diagram 3] FIG. 2 is an explanatory diagram showing a small booth and a spatial decontamination device. [Figure 4] 1 is a graph showing the transitions of the concentration of acetic acid, the concentration of hydrogen peroxide, the temperature, and the humidity in Example 1. [Diagram 5] 1 is a graph showing the changes in acetic acid concentration, temperature, and humidity in Comparative Example 1. [Figure 6] FIG. 2 is an explanatory diagram showing a safety cabinet and a spatial decontamination device. [Figure 7] This is an explanatory diagram showing the air circulation path and the installation location of BIs in a safety cabinet. [Figure 8] 11 is a graph showing the transitions of the concentration of acetic acid, the concentration of hydrogen peroxide, the temperature, and the humidity in Example 2. [Figure 9] 1 is a graph showing the changes in hydrogen peroxide concentration, temperature, and humidity in Comparative Example 2. [Figure 10] FIG. 2 is an explanatory diagram showing a clean room and a space decontamination apparatus. [Figure 11] 11 is a graph showing the transitions of the concentration of acetic acid, the concentration of hydrogen peroxide, the temperature, and the humidity in Example 3. [Figure 12] 11 is a graph showing the changes in hydrogen peroxide concentration, temperature, and humidity in Comparative Example 3. [Figure 13] FIG. 2 is an explanatory diagram showing a microbiology testing room and a space decontamination device. [Figure 14] 11 is a graph showing the transitions of the concentration of acetic acid, the concentration of hydrogen peroxide, the temperature, and the humidity in Example 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Exemplary embodiments of the present disclosure will now be described with reference to the drawings. 1. Space decontamination methods The spatial decontamination method of the present disclosure decontaminates a space. The space is, for example, a space in a pharmaceutical manufacturing plant, a biohazard facility, a cell culture processing facility, etc. The space is, for example, a space inside a safety cabinet, an isolator, a restricted access barrier system, etc. The space is, for example, a space in a clean area, a space in a sterile operation area. The space in a clean area and the space in a sterile operation area are, for example, found in a food factory, etc. The space includes, for example, a wall, a floor, a ceiling, or equipment at the boundary between the space and other areas.

[0009] Decontamination means reducing the number of microorganisms present in a space. Decontamination means, for example, reducing the number of microorganisms present in a space to a pre-specified level of bacteria. Decontamination means, for example, reducing the BI by 6 logs or more. BI stands for biological indicator, and refers to indicator bacteria.

[0010] In the spatial decontamination method of the present disclosure, a mixed gas containing air and acetic acid is supplied to a space. In the spatial decontamination method of the present disclosure, for example, a mixed gas is generated by supplying air into a solution containing acetic acid (hereinafter referred to as a first solution) and bubbling the air. The first solution is, for example, an aqueous solution of acetic acid. The concentration of acetic acid in the first solution is preferably 5 w / v% or more and 50 w / v% or less. When the concentration of acetic acid in the first solution is 5 w / v% or more, the effect of decontaminating the space is higher. When the concentration of acetic acid in the first solution is 50 w / v% or less, the safety of performing the spatial decontamination method is higher.

[0011] The mixed gas may further contain water vapor in addition to air and acetic acid. As a method for generating the mixed gas and supplying it to a space, there is a method using a mixed gas supply unit 1 shown in FIG. The mixed gas supply unit 1 includes a flowmeter 11, a container 13, a trap 15, and pipes 17, 19, and 21. The pipe 17 sends air 18 supplied from an air supply source (not shown) through the flowmeter 11 to the inside of the container 13. The flowmeter 11 measures and displays the flow rate of the air 18 sent to the inside of the container 13. The flow rate of the air 18 is, for example, 1 L / min or more and 5 L / min or less.

[0012] A first solution 23 is contained inside the container 13. A tip 17A of the pipe 17 is located in the first solution 23. Therefore, bubbling occurs due to air 18 coming out from the tip 17A. A mixed gas 25 is generated in a portion of the container 13 above the liquid surface of the first solution 23. The mixed gas 25 is made up of air bubbles that have passed through the first solution 23. The mixed gas 25 contains air and acetic acid. The mixed gas 25 also contains a small amount of water vapor.

[0013] The mixed gas 25 flows from the container 13 through the piping 19 to the trap 15. The trap 15 is an empty container. In the trap 15, any water droplets that may have suddenly appeared are removed from the mixed gas 25. The mixed gas 25 flows from the trap 15 through the piping 21 to the space 105 that is the target of the space decontamination method.

[0014] In the spatial decontamination method of the present disclosure, the space 105 is humidified using an aqueous solution containing hydrogen peroxide (hereinafter referred to as the second solution). The concentration of hydrogen peroxide in the second solution is preferably 2 w / v% or more and 6 w / v% or less. When the concentration of hydrogen peroxide is 2 w / v% or more, the effect of decontaminating the space 105 is higher. When the concentration of hydrogen peroxide is 6 w / v% or less, the safety of performing the spatial decontamination method is higher.

[0015] For example, the second solution can be vaporized using a humidifier to humidify the space 105. As the humidifier, a commercially available product can be used. The type of humidifier includes an ultrasonic type, a steam type, an evaporation type, a hybrid type, and the like.

[0016] For example, the second solution can be sprayed using a sprayer, a spray nozzle, or a humidifier to humidify the space 105. Examples of the sprayer include an electric sprayer used to spray a disinfectant. Examples of the humidifier include an ultrasonic humidifier.

[0017] When performing the space decontamination method of the present disclosure, the humidity of the space 105 is preferably 60% RH or more and 80% RH or less. When the humidity of the space 105 is 60% RH or more, the effect of decontaminating the space 105 is higher. When the humidity of the space 105 is 80% RH or less, condensation can be further suppressed.

[0018] When the space decontamination method of the present disclosure is performed, for example, the humidity of the space 105 can be measured using a humidity sensor. For example, the humidity of the space 105 can be adjusted based on the measured humidity value. For example, the humidity of the space 105 can be adjusted by controlling a humidifier or a nozzle based on the measured humidity value.

[0019] When the space decontamination method of the present disclosure is performed, the concentration of acetic acid in the space 105 is preferably 10 ppm or more and 100 ppm or less, and more preferably 10 ppm or more and 70 ppm or less. When the concentration of acetic acid in the space 105 is 10 ppm or more, the effect of decontaminating the space 105 is higher. When the concentration of acetic acid in the space 105 is 100 ppm or less, gas processing after decontamination is simplified. When the concentration of acetic acid in the space 105 is 70 ppm or less, gas processing after decontamination is further simplified. The greater the amount of mixed gas 25 supplied to the space 105, the higher the concentration of acetic acid in the space 105. The higher the concentration of acetic acid in the first solution 23, the higher the concentration of acetic acid in the space 105. The method for measuring the concentration of acetic acid in the space 105 is a measurement method using a detector tube.

[0020] When performing the spatial decontamination method of the present disclosure, the concentration of hydrogen peroxide in the space 105 is preferably 10 ppm or more and 60 ppm or less. When the concentration of hydrogen peroxide in the space 105 is 10 ppm or more, the effect of decontaminating the space 105 is higher. When the concentration of hydrogen peroxide in the space 105 is 60 ppm or less, the safety of performing the spatial decontamination method is higher. The higher the concentration of hydrogen peroxide in the second solution, the higher the concentration of hydrogen peroxide in the space 105. The more the humidification using the second solution is promoted, the higher the concentration of hydrogen peroxide and humidity in the space 105 will be.

[0021] The method for measuring the concentration of hydrogen peroxide in the space 105 is the constant potential electrolysis method. A constant potential electrolysis portable gas detector is used to measure the concentration of hydrogen peroxide. In the space decontamination method of the present disclosure, for example, the mixed gas 25 is supplied to the space 105 and the space 105 is humidified using the second solution at the same time. In this case, the effect of decontaminating the space 105 is further enhanced. When the spatial decontamination method of the present disclosure is performed, the concentration of peracetic acid in the space 105 is preferably 1 ppm or less. In that case, the safety of performing the spatial decontamination method is further increased.

[0022] 2. Space Decontamination Equipment 101 The spatial decontamination apparatus 101 of the present disclosure has, for example, the configuration shown in Fig. 2. The spatial decontamination apparatus 101 has a mixed gas supply unit 1. The mixed gas supply unit 1 generates a mixed gas 25 containing air and acetic acid, and supplies the mixed gas 25 to a space 105.

[0023] An example of the mixed gas supply unit 1 is shown in Fig. 1. The configuration of the mixed gas supply unit 1 shown in Fig. 1 is the same as that described in the above section "1. Space decontamination method." The spatial decontamination apparatus 101 of the present disclosure is used, for example, to perform the spatial decontamination method of the present disclosure. The first solution 23 and the mixed gas 25 are, for example, those described in the above section "1. Spatial decontamination method."

[0024] The space decontamination apparatus 101 includes a humidification unit 103. The humidification unit 103 humidifies the space 105 using the second solution. The humidification unit 103 humidifies the space 105 by vaporizing the second solution using, for example, a humidifier. A commercially available product can be used as the humidifier. Examples of the type of humidifier include ultrasonic, steam, vaporization, and hybrid types. The second solution is, for example, the one described in the above section "1. Space decontamination method."

[0025] The humidification unit 103 humidifies the space 105 by spraying the second solution using, for example, a sprayer, a spray nozzle, or a humidifier. Examples of the sprayer include an electric sprayer used to spray a disinfectant. Examples of the humidifier include an ultrasonic humidifier.

[0026] The spatial decontamination apparatus 101 further includes a control unit 107 configured to control, for example, at least one of the mixed gas supply unit 1 and the humidification unit 103. The control unit 107 includes a microcomputer having a CPU 107A and, for example, a semiconductor memory such as a RAM or a ROM (hereinafter, referred to as memory 107B).

[0027] Each function of the control unit 107 is realized by the CPU 107A executing a program stored in a non-transient real recording medium. In this example, the memory 107B corresponds to the non-transient real recording medium storing the program. Furthermore, the program is executed to execute a method corresponding to the program. The control unit 107 may include one microcomputer or multiple microcomputers.

[0028] The spatial decontamination apparatus 101 further includes, for example, an information acquisition unit 109. The information acquisition unit 109 is configured to acquire information (hereinafter referred to as spatial information) representing one or more selected from the group consisting of the humidity of the space 105, the temperature of the space 105, the concentration of acetic acid in the space 105, and the concentration of hydrogen peroxide in the space 105. The information acquisition unit 109 includes, for example, a sensor capable of detecting the spatial information.

[0029] The control unit 107 controls at least one of the mixed gas supply unit 1 and the humidification unit 103 based on the spatial information acquired by the information acquisition unit 109, for example. The control unit 107 controls the humidification unit 103 based on the space information acquired by the information acquisition unit 109, for example, to set the humidity in the space 105 to 60% RH or more and 80% RH or less. When the humidity in the space 105 is 60% RH or more, the effect of decontaminating the space 105 is higher. When the humidity in the space 105 is 80% RH or less, condensation can be further suppressed, and when the humidity in the space 105 is 75% RH or less, condensation can be particularly suppressed.

[0030] The control unit 107 controls the mixed gas supply unit 1 based on the spatial information acquired by the information acquisition unit 109, for example, to set the concentration of acetic acid in the space 105 to 10 ppm or more and 100 ppm or less. When the concentration of acetic acid in the space 105 is 10 ppm or more, the effect of decontaminating the space 105 is higher. When the concentration of acetic acid in the space 105 is 100 ppm or less, gas processing after decontamination is simplified. The control unit 107 sets the concentration of acetic acid in the space 105 to 10 ppm or more and 70 ppm or less, for example. When the concentration of acetic acid in the space 105 is 70 ppm or less, gas processing after decontamination is further simplified.

[0031] The control unit 107 controls the humidification unit 103 based on the space information acquired by the information acquisition unit 109, for example, to set the concentration of hydrogen peroxide in the space 105 to 10 ppm or more and 100 ppm or less. When the concentration of hydrogen peroxide in the space 105 is 10 ppm or more, the effect of decontaminating the space 105 is higher. When the concentration of hydrogen peroxide in the space 105 is 100 ppm or less, the safety of performing the space decontamination method is higher. The control unit 107 sets the concentration of hydrogen peroxide in the space 105 to 10 ppm or more and 70 ppm or less, for example. When the concentration of hydrogen peroxide in the space 105 is 70 ppm or less, the safety of performing the space decontamination method is particularly high.

[0032] The spatial decontamination apparatus 101 of the present disclosure, for example, supplies the mixed gas to the space 105 and simultaneously humidifies the space 105 using the second solution. In this case, the effect of decontaminating the space 105 is further enhanced. The spatial decontamination apparatus 101 of the present disclosure further includes, for example, a dehumidification unit. The dehumidification unit reduces the humidity of the space 105. For example, by reducing the humidity of the space 105 with the dehumidification unit while humidifying with the humidification unit 103, it is possible to increase the concentration of hydrogen peroxide in the space 105 while suppressing the humidity in the space 105. For example, the control unit 107 can control the dehumidification unit based on the space information so that the humidity and the concentration of hydrogen peroxide in the space 105 are in a suitable range.

[0033] For example, the space decontamination method can be performed after the space 105 is dehumidified using a dehumidification unit. Also, for example, the space decontamination method can be performed while the space 105 is dehumidified using a dehumidification unit. The operation mode of the dehumidification unit may be intermittent or continuous. 3. Effects of the spatial decontamination method and the spatial decontamination device 101 (1A) The spatial decontamination method and spatial decontamination apparatus 101 disclosed herein have a high decontamination effect.

[0034] (1B) By using the spatial decontamination method and spatial decontamination apparatus 101 of the present disclosure, the space 105 can be effectively decontaminated while suppressing the humidity of the space 105. The reason is as follows. The mixed gas 25 contains a large amount of acetic acid, but the content of water vapor is small. Therefore, by supplying the mixed gas 25 to the space 105, the concentration of acetic acid in the space 105 can be increased while suppressing the humidity of the space 105. In addition, by humidifying the space 105 using the second solution, the humidity of the space 105 can be appropriately increased and the concentration of hydrogen peroxide in the space 105 can be increased. By suppressing humidification using the second solution, the humidity of the space 105 can be suppressed without decreasing the concentration of acetic acid in the space 105. As a result, the space 105 can be effectively decontaminated by the synergistic effect of acetic acid and hydrogen peroxide while suppressing the humidity of the space 105.

[0035] (1C) The spatial decontamination method of the present disclosure is safer than decontamination methods that use peracetic acid or formaldehyde. In addition, the spatial decontamination method of the present disclosure can suppress the concentration of hydrogen peroxide in the space 105 while maintaining the decontamination effect. Therefore, gas processing after decontamination is easy.

[0036] (1D) Acetic acid and hydrogen peroxide decompose in a short time. Therefore, even if the gas containing acetic acid and hydrogen peroxide leaks out of the space 105, the safety is high. (1E) A gas containing acetic acid and hydrogen peroxide has high permeability. Therefore, even if there is a part in the space 105 where air circulation is difficult, the part can be decontaminated.

[0037] 4. Working Example (4-1) Example 1 A small booth 111 shown in Figure 3 was prepared. The capacity of the small booth 111 is 1 m 3 The inside of the small booth 111 corresponds to the space 105. Inside the small booth 111, a mixed gas supply unit 1, a circulator fan 225, a humidification unit 103, an information acquisition unit 109, and a dehumidifier 307 were installed.

[0038] The mixed gas supply unit 1 was equipped with an air pump 223. The air pump 223 takes in air 18 from inside the small booth 111 and supplies the taken in air 18 to the flow meter 11. The flow rate of the air 18 was 5 L / min. The first solution 23 was an aqueous solution of acetic acid with a concentration of 6 w / v %. The amount of the first solution 23 was 40 ml.

[0039] The position from which mixed gas supply unit 1 supplies mixed gas 25 is in front of circulator fan 225. Mixed gas 25 supplied by mixed gas supply unit 1 is diffused by the wind generated by circulator fan 225.

[0040] The humidification unit 103 was a humidifier. The humidification unit 103 humidified the inside of the small booth 111. The second solution was an aqueous solution of hydrogen peroxide with a concentration of 2 w / v %. In this embodiment, the information acquisition unit 109 was a temperature and humidity sensor. The information acquisition unit 109 detected the temperature and humidity of the air inside the small booth 111, and sent the detection results to the control unit 107. The control unit 107 controlled the humidification unit 103 based on the measurement results of the temperature and humidity. The control unit 107 controlled the humidity inside the small booth 111 to about 75% RH.

[0041] The BI was placed at the location P1 shown in Figure 3. P1 was a location near the center of the small booth 111. The BI was an indicator bacterium (Geobacillus stearothermophilus (ATCC#12980)) manufactured by Mesa Labs, part number HMV-091. The number of bacteria in the BI was 1 x 10 6 That was it. The BI was for hydrogen peroxide.

[0042] The spatial decontamination method was carried out by supplying mixed gas 25 from mixed gas supply unit 1 and humidifying it with humidification unit 103. Figure 4 shows the transitions of the hydrogen peroxide concentration, acetic acid concentration, temperature, and humidity inside small booth 111 while the spatial decontamination method was being carried out. The horizontal axis of Figure 4 represents the elapsed time from the time when humidification and supply of mixed gas 25 were started. When the spatial decontamination method was carried out, the dehumidifier 307 was operated continuously. When the humidity was controlled to about 75% RH while the dehumidifier 307 was operating continuously, the amount of spray from the humidifier unit 103 increased compared to when the dehumidifier 307 was not operating. Although the airborne life of hydrogen peroxide is short, the concentration of hydrogen peroxide in the small booth 111 can be increased by increasing the amount of spray from the humidifier unit 103.

[0043] The BIs were removed from position P1 when the decontamination time was 70 minutes, 80 minutes, and 90 minutes, respectively. The decontamination time is the time elapsed from the time when the humidity inside the small booth 111 reached 75% RH. Next, the removed BIs were cultured in a dedicated culture medium at an appropriate temperature for 7 days, and it was confirmed whether they were negative or positive. A negative result means that the BI was dead. A positive result means that the BI was not dead. The confirmation results are shown in Table 1.

[0044] [Table 1]

[0045] The BI taken out at 90 minutes of decontamination time was negative. This result confirmed that a decontamination level of 6 logs or more could be achieved by 90 minutes of decontamination. During the period from 50 to 90 minutes of decontamination time, the average concentration of acetic acid inside small booth 111 was 17 ppm, and the average concentration of hydrogen peroxide was 31 ppm.

[0046] In addition, when the spatial decontamination method was carried out, the concentration of peracetic acid inside the small booth 111 was measured. The method for measuring the concentration of peracetic acid was to collect a sample with an impinger and measure the concentration of peracetic acid in the collected sample by MTS oxidation GC-FID analysis. The concentration of peracetic acid was below the detection limit of 0.04 ppm. Therefore, it was confirmed that peracetic acid did not contribute to decontamination. In the examples described later, the concentration of peracetic acid was also below the detection limit.

[0047] (4-2) Comparative Example 1 Decontamination was basically performed in the same manner as in Example 1. However, in Comparative Example 1, the second solution was pure water, not an aqueous solution of hydrogen peroxide. Therefore, in Comparative Example 1, hydrogen peroxide was not supplied to the inside of small booth 111. Also, in Comparative Example 1, the first solution 23 was an aqueous solution of acetic acid with a concentration of 12 w / v %.

[0048] FIG. 5 shows the transition of the acetic acid concentration, temperature, and humidity inside the small booth 111 when the spatial decontamination method was being carried out. The horizontal axis of FIG. 5 is the elapsed time from the time when humidification and the supply of the mixed gas 25 were started. The BI was removed from the position P1 when the decontamination time was 90 minutes and 180 minutes, respectively. The decontamination time is the elapsed time from the time when the humidity inside the small booth 111 reached 75% RH. Next, the removed BI was cultured in a dedicated culture medium at an appropriate temperature for 7 days, and it was confirmed whether it was negative or positive. The confirmation results are shown in Table 2.

[0049] [Table 2]

[0050] As shown in Table 2, all BIs were positive, and the BIs were not killed. During the decontamination time period of 60 to 180 minutes, the average concentration of acetic acid inside the small booth 111 was 64 ppm, which was significantly higher than the average concentration in Example 1, but the decontamination effect was low. This result indicates that decontamination is difficult even if only acetic acid is supplied to the space 105.

[0051] (4-3) Example 2 A safety cabinet 201 shown in Figures 6 and 7 was prepared. The safety cabinet 201 is used, for example, in a biohazard facility that handles highly infectious microorganisms. The safety cabinet 201 is also used, for example, in cell processing that requires sterility in technical fields such as regenerative medicine.

[0052] The safety cabinet 201 is an apparatus that requires a high decontamination level of, for example, 6 logs or more. The inside of the safety cabinet 201 corresponds to the space 105. The opening width of the safety cabinet 201 was 1.3 m. The safety cabinet 201 was a class II cabinet for biohazard countermeasures.

[0053] The safety cabinet 201 includes a work table 203. A work space 205 exists above the work table 203. The safety cabinet 201 includes a front opening 207. The work space 205 is located at the back side of the front opening 207 when viewed from the front side. The safety cabinet 201 includes a fan room 209, a ceiling exhaust port 211, and a HEPA 213.

[0054] As shown in Figures 6 and 7, a circulation fan 215 installed outside the safety cabinet 201 was connected to the front opening 207 by a duct 217. In addition, the ceiling exhaust port 211 and the circulation fan 215 were connected by a duct 219. The front opening 207 was sealed with masking tape and a PVC panel except for the part where the duct 217 was connected. In addition, the ceiling exhaust port 211 was sealed with masking tape and a PVC panel except for the part where the duct 219 was connected. In addition, other gaps in the safety cabinet 201 were also sealed with masking tape.

[0055] When the circulation fan 215 is operated, air circulates along the path indicated by the arrows in Fig. 7. Air in the work space 205 passes from the front opening 207 through the duct 217, the circulation fan 215, the duct 219, and the ceiling exhaust port 211 in this order, and enters the fan room 209. Part of the air in the fan room 209 passes through the HEPA 213 and enters the work space 205. Part of the air in the fan room 209 passes through the rear passage 221 and enters the work space 205 from the rear side of the workbench 203.

[0056] As shown in Fig. 6, the mixed gas 25 generated in the mixed gas supply unit 1 was supplied to the working space 205. The mixed gas supply unit 1 was equipped with an air pump 223. The air pump 223 takes in air 18 from the working space 205 and supplies the taken-in air 18 to the flow meter 11. The flow rate of the air 18 was 5 L / min. The first solution 23 was an aqueous solution of acetic acid with a concentration of 40 w / v %. The amount of the first solution 23 was 40 ml.

[0057] 6, a circulator fan 225 was installed on the workbench 203. The position from which the mixed gas 25 was supplied was in front of the circulator fan 225. The mixed gas 25 supplied by the mixed gas supply unit 1 was diffused by the wind generated by the circulator fan 225 and sent to the duct 217.

[0058] As shown in FIG. 6, the humidification unit 103 was placed on the workbench 203, and the work space 205 was humidified by the humidification unit 103. The second solution was an aqueous solution of hydrogen peroxide with a concentration of 3 w / v %. In this embodiment, the information acquisition unit 109 was a temperature and humidity sensor. The information acquisition unit 109 detected the temperature and humidity of the air at the ceiling exhaust port 211, and sent the detection results to the control unit 107. The control unit 107 controlled the humidification unit 103 based on the measurement results of the temperature and humidity. The control unit 107 controlled the humidity inside the safety cabinet 201 to about 75% RH.

[0059] BIs were installed at locations P1 to P4 shown in Fig. 7. P1 was located on the HEPA 213 side of the work space 205. P2 was located at the lower side inside the back passage 221. P3 was located at the punching metal provided at the ceiling exhaust port 211. P4 was located below the workbench 203.

[0060] The BI was Geobacillus stearothermophilus (ATCC#12980). The bacterial count of the BI was 1×10 6 That was all. Decontamination was started in the safety cabinet 201 with the air circulating as shown in Fig. 7. Decontamination means supplying mixed gas 25 by mixed gas supply unit 1 and humidifying the gas by humidification unit 103. Fig. 8 shows the transitions of the acetic acid concentration, hydrogen peroxide concentration, temperature, and humidity in the safety cabinet 201 during decontamination. The horizontal axis of Fig. 8 represents the elapsed time from the time when humidification and supply of mixed gas 25 started.

[0061] When the decontamination time was 120 minutes, BIs were taken out from P1, P2, and P3, respectively. The decontamination time is the time elapsed from the time when the humidity inside the safety cabinet 201 reached 75% RH. In addition, when the decontamination time was 60 minutes, 75 minutes, 90 minutes, 105 minutes, and 120 minutes, BIs were taken out from P4, respectively. Next, the taken out BIs were cultured in a dedicated medium at an appropriate temperature for 7 days, and it was confirmed whether they were negative or positive. The confirmation results are shown in Table 3. The number of BIs taken out under one condition was three. A condition is a combination of the location of the BI and the decontamination time when the BI was taken out. If two or more of the three BIs were negative, it was determined that the decontamination under that condition was successful.

[0062] [Table 3]

[0063] As shown in Table 3, decontamination was successful at all locations, P1 to P4, and at all decontamination times. (4-4) Comparative Example 2 Decontamination was basically performed in the same manner as in Example 2. However, in Comparative Example 2, mixed gas 25 was not supplied to the working space 205. That is, in Comparative Example 2, acetic acid was not supplied to the working space 205. A BI was installed at the location of P4.

[0064] The transition of the hydrogen peroxide concentration, temperature, and humidity in the safety cabinet 201 during decontamination is shown in Fig. 9. The horizontal axis of Fig. 9 represents the elapsed time from the time when humidification started.

[0065] When the decontamination time was 150 minutes, BIs were taken out from P1, P2, and P3. The decontamination time is the time elapsed from the time when the humidity inside the safety cabinet 201 reached 75% RH. In addition, when the decontamination time was 80 minutes, 90 minutes, 100 minutes, 110 minutes, 120 minutes, 130 minutes, 140 minutes, and 150 minutes, BIs were taken out from P4. Next, the taken out BIs were cultured in a dedicated culture medium at an appropriate temperature for 7 days, and it was confirmed whether they were negative or positive. The confirmation results are shown in Table 4. The number of BIs taken out under each condition was one.

[0066] [Table 4]

[0067] As shown in Table 4, the BI was positive at all locations P1 to P4 and at all decontamination times. This result indicates that decontamination is difficult when only hydrogen peroxide is supplied to the working space 205.

[0068] (4-5) Example 3 The clean room 301 and the front room 303 shown in Fig. 10 were the targets of the spatial decontamination method. There was a door 305 between the clean room 301 and the front room 303. The door 305 was always kept open. The total volume of the clean room 301 and the front room 303 was about 34 m 3Inside the clean room 301, a dehumidifier 307, a safety cabinet 201, and a dehumidifier terminal box 309 were installed. The safety cabinet 201 was an indoor circulation type class II cabinet for biohazard countermeasures.

[0069] In the clean room 301, the mixed gas supply unit 1, the humidification unit 103, the information acquisition unit 109, and the circulator fan 225 were installed. The mixed gas supply unit 1 was located in the center of the clean room 301.

[0070] The first solution 23 was an aqueous solution of acetic acid with a concentration of 40 w / v%. The amount of the first solution 23 was 150 ml. The flow rate of the air 18 was 10 L / min. The second solution was an aqueous solution of hydrogen peroxide with a concentration of 2 w / v%.

[0071] BIs were installed at locations P1 to P7 shown in FIG. 10. P1 was the position of the blowing part of the work space 205 of the safety cabinet 201, and was a position downstream of the HEPA 213. P2 was a position on the exhaust side of the safety cabinet 201. P3 was a position between the safety cabinet 201 and its rear wall. P4 was inside the dehumidifier terminal box 309. It is noted that air does not easily circulate between the inside and outside of the dehumidifier terminal box 309. P5 was a position on the surface of the wall of the clean room 301. P6 was a position on the surface of the wall of the antechamber 303. P7 was a position inside the clean room 301.

[0072] First, the humidity in the clean room 301 and the anteroom 303 was lowered to 50-60% RH using the dehumidifier 307. Next, the mixed gas 25 was supplied by the mixed gas supply unit 1 and humidified by the humidification unit 103, thereby carrying out the spatial decontamination method. While carrying out the spatial decontamination method, the safety cabinet 201 was operated. By operating the safety cabinet 201, the decontamination gas was circulated inside the safety cabinet 201. The decontamination gas is a gas containing acetic acid and hydrogen peroxide.

[0073] When the spatial decontamination method was performed, the humidity inside the clean room 301 and the anteroom 303 was controlled to about 75% RH by controlling the humidification unit 103. When the spatial decontamination method was performed, the dehumidifier 307 operated intermittently. The dehumidifier 307 may also operate continuously. When attempting to control the humidity to about 75% RH while the dehumidifier 307 is operating intermittently or continuously, the amount of spray from the humidification unit 103 increases compared to when the dehumidifier 307 is not operating. Although the airborne life of hydrogen peroxide is short, the concentration of hydrogen peroxide in the clean room 301 and the anteroom 303 can be increased by increasing the amount of spray from the humidification unit 103.

[0074] When the spatial decontamination method was being carried out, the air inside the clean room 301 was agitated by the circulator fan 225. The humidifier unit 103 and the mixed gas supply unit 1 were present in the path of the air blown out by the circulator fan 225.

[0075] Fig. 11 shows the changes in hydrogen peroxide concentration, acetic acid concentration, temperature, and humidity inside the clean room 301 when the spatial decontamination method was being carried out. The horizontal axis in Fig. 11 is the decontamination time. The decontamination time is the elapsed time from the time when the humidity inside the clean room 301 reached 75% RH. In the decontamination time section from 30 to 90 minutes, the average hydrogen peroxide concentration inside the clean room 301 was 42 ppm, and the average acetic acid concentration was 67 ppm.

[0076] When the decontamination time was 180 minutes, BIs were extracted from P1, P2, P3, and P4. When the decontamination time was 60 minutes, 90 minutes, 120 minutes, 150 minutes, and 180 minutes, BIs were extracted from P7. Next, the extracted BIs were cultured in a dedicated medium at an appropriate temperature for 7 days, and it was confirmed whether they were negative or positive. The results of the confirmation are shown in Table 5. The number of BIs extracted under one condition was three.

[0077] [Table 5]

[0078] As shown in Table 5, all the locations P1 to P4 were negative. Also, at P7, it was negative when the decontamination time was 90 to 180 minutes. The decontamination gas in the clean room 301 flows in from the lower part of the work surface at the front of the safety cabinet 20, and is separated into the exhaust port and the HEPA blowing part of the work surface before reaching the clean room. The fact that the BIs at P1 and P2 were negative means that the inside of the safety cabinet 201 and the filter part through which the decontamination gas passes have also been successfully decontaminated. From this, it was confirmed that the decontamination gas has high permeability and can penetrate into the filter part.

[0079] The BI in P4, an area with poor air circulation, also tested negative, indicating that the decontamination gas has high permeability. (4-6) Comparative Example 3 Basically, the spatial decontamination method was carried out in the same manner as in Example 3. However, in Comparative Example 3, mixed gas 25 was not supplied to the inside of clean room 301. That is, in Comparative Example 3, acetic acid was not supplied to the inside of clean room 301.

[0080] Fig. 12 shows the changes in hydrogen peroxide concentration, acetic acid concentration, temperature, and humidity inside the clean room 301 when the spatial decontamination method was being carried out. The horizontal axis in Fig. 12 is the decontamination time. The decontamination time is the elapsed time from the time when the humidity inside the clean room 301 reached 75% RH. In the decontamination time range of 0 to 480 minutes, the average hydrogen peroxide concentration inside the clean room 301 was 22 ppm.

[0081] When the decontamination time was 480 minutes, BIs were taken out from P1, P2, P3, P4, P5, and P6. Next, the taken out BIs were cultured in a special medium at an appropriate temperature for 7 days, and it was confirmed whether they were negative or positive. The confirmation results are shown in Table 6. Note that the number of BIs taken out under each condition was one.

[0082] [Table 6]

[0083] As shown in Table 6, BI was positive in P1, P2, and P4. (4-7) Example 4 The microbiology testing room 401 shown in Fig. 13 was the subject of the spatial decontamination method. All entrances and windows of the microbiology testing room 401 were closed. In the microbiology testing room 401, laboratory tables 403 and 405, a sink 407, a safety cabinet 201, and a dehumidifier 307 were installed.

[0084] A mixed gas supply unit 1, two humidification units 103, an information acquisition unit 109, and a circulator fan 225 were installed in a microbiology testing room 401. The humidification unit 103 was a sprayer. The first solution 23 was an aqueous solution of acetic acid with a concentration of 40 w / v%. The amount of the first solution 23 was 150 ml. The flow rate of the air 18 was 15 L / min. The second solution was an aqueous solution of hydrogen peroxide with a concentration of 2 w / v%.

[0085] BIs were installed at locations P1 to P5 shown in Fig. 13. BIs were installed similarly to those in Example 1. P1 was the position of the blowing part of the working space 205 of the safety cabinet 201, and was located downstream of the HEPA 213. P2 was located on the exhaust side of the safety cabinet 201.

[0086] P3 and P5 were on the floor. P4 was at the back of the thermostatic chamber (not shown). The thermostatic chamber was placed on the experimental bench 405. The door of the thermostatic chamber was left open about 2 cm. Air circulation between the inside and outside of the thermostatic chamber was difficult.

[0087] The spatial decontamination method was carried out by supplying the mixed gas 25 by the mixed gas supply unit 1 and humidifying the mixed gas by the humidification unit 103. When the spatial decontamination method was carried out, the safety cabinet 201 was operated. By operating the safety cabinet 201, the decontamination gas was circulated inside the safety cabinet 201.

[0088] When the spatial decontamination method was being performed, the humidity inside the microbiology testing room 401 was controlled to about 75% RH by controlling the humidification unit 103. When the spatial decontamination method was being performed, the air inside the microbiology testing room 401 was agitated by the circulator fan 225. The mixed gas supply unit 1 was present in the path of the wind blown out by the circulator fan 225.

[0089] FIG. 14 shows the transitions of the hydrogen peroxide concentration, acetic acid concentration, temperature, and humidity inside the microbiology testing room 401 when the spatial decontamination method is being carried out. The horizontal axis of FIG. 14 represents the elapsed time from the time when humidification and the supply of the mixed gas 25 were started. In the section where the decontamination time was 30 to 210 minutes, the average hydrogen peroxide concentration inside the microbiology testing room 401 was 30 ppm, and the average acetic acid concentration was 35 ppm. The decontamination time is the elapsed time from the time when the humidity inside the microbiology testing room 401 reached 75% RH.

[0090] When the decontamination time was 210 minutes, BIs were extracted from P1, P2, P3, and P4, respectively. When the decontamination time was 90 minutes, 120 minutes, 150 minutes, 180 minutes, and 210 minutes, BIs were extracted from P5, respectively. Next, the extracted BIs were cultured in a dedicated medium at an appropriate temperature for 7 days, and it was confirmed whether they were negative or positive. The results of the confirmation are shown in Table 7. The number of BIs extracted under one condition was three.

[0091] [Table 7]

[0092] As shown in Table 5, when the decontamination time was 120 minutes or more, the majority of BIs were negative at all locations, and the decontamination was successful. The decontamination gas in the clean room 301 flows in from the lower part of the work surface at the front of the safety cabinet 20, and is divided into the exhaust port and the HEPA outlet part of the work surface before reaching the clean room. The fact that the BIs of P1 and P2 are negative means that the inside of the safety cabinet 201 and the filter part through which the decontamination gas passes are also successfully decontaminated. This confirmed that the decontamination gas has high permeability and can penetrate into the filter part.

[0093] The BI in P4, an area with poor air circulation, also tested negative, indicating that the decontamination gas has high permeability. 5. Other embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0094] (1) In the above-mentioned Example 2, the space inside a safety cabinet is decontaminated, but the present invention is not limited to this. For example, the space inside an isolator, an access restriction barrier system, etc. may be decontaminated. (2) The control unit 107 and the method described in the present disclosure may be realized by a dedicated computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit 107 and the method described in the present disclosure may be realized by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit 107 and the method described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. Also, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer. The method for realizing the functions of each part included in the control unit 107 does not necessarily need to include software, and all of the functions may be realized using one or more hardware.

[0095] (3) The function of one component in each of the above embodiments may be shared by multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Also, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0096] (4) In addition to the spatial decontamination apparatus 101 described above, the present disclosure can also be realized in various forms, such as a system including the spatial decontamination apparatus 101 as a component, a program for causing a computer to function as the control unit 107, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and a method for manufacturing a spatial decontamination apparatus. [Technical idea disclosed in this specification] [Item 1] Supplying a mixed gas containing air and acetic acid to the space; humidifying the space with an aqueous solution containing hydrogen peroxide; Space decontamination methods. [Item 2] The spatial decontamination method according to item 1, The mixed gas is generated by supplying air into a solution containing acetic acid and bubbling the air. Space decontamination methods. [Item 3] The spatial decontamination method according to item 1 or 2, When performing the space decontamination method, the humidity of the space is 60% RH or more and 80% RH or less; Space decontamination methods. [Item 4] A spatial decontamination method according to any one of items 1 to 3, When performing the space decontamination method, the concentration of acetic acid in the space is 10 ppm or more and 100 ppm or less, and the concentration of hydrogen peroxide in the space is 10 ppm or more and 100 ppm or less, Space decontamination methods. [Item 5] a mixed gas supply unit configured to supply a mixed gas comprising air and acetic acid to the space; a humidification unit configured to humidify the space using an aqueous solution comprising hydrogen peroxide; A space decontamination device equipped with the following. [Item 6] Item 6. The space decontamination apparatus according to item 5, The mixed gas supply unit is configured to generate the mixed gas by supplying air into an acetic acid solution and bubbling it. Space decontamination equipment. [Explanation of symbols]

[0097] 1...mixed gas supply unit, 13...container, 15...trap, 17, 19, 21...piping, 17A...tip, 18...air, 20...safety cabinet, 23...first solution, 25...mixed gas, 101...space decontamination device, 103...humidification unit, 105...space, 107...control unit, 107A...CPU, 107B...memory, 109...information acquisition unit, 111...small booth, 201...safety cabinet, 203... Work bench, 205...work space, 207...front opening, 209...fan room, 211...ceiling exhaust port, 215...circulation fan, 217, 219...duct, 221...rear passage, 223...air pump, 225...circulator fan, 301...clean room, 303...anteroom, 305...door, 307...dehumidifier, 309...dehumidifier terminal box, 401...microbiology testing room, 403, 405...laboratory bench, 407...sink

Claims

1. Supplying a mixed gas containing air and acetic acid to the space; humidifying the space with an aqueous solution containing hydrogen peroxide; Space decontamination methods.

2. The spatial decontamination method according to claim 1, The mixed gas is generated by supplying air into a solution containing acetic acid and bubbling the air. Space decontamination methods.

3. The spatial decontamination method according to claim 1 or 2, When performing the space decontamination method, the humidity of the space is 60% RH or more and 80% RH or less. Space decontamination methods.

4. The spatial decontamination method according to claim 1 or 2, When performing the space decontamination method, the concentration of acetic acid in the space is 10 ppm or more and 100 ppm or less, and the concentration of hydrogen peroxide in the space is 10 ppm or more and 100 ppm or less. Space decontamination methods.

5. a mixed gas supply unit configured to supply a mixed gas comprising air and acetic acid to the space; a humidification unit configured to humidify the space using an aqueous solution comprising hydrogen peroxide; A space decontamination device equipped with the following.

6. The spatial decontamination apparatus according to claim 5, The mixed gas supply unit is configured to generate the mixed gas by supplying air into an acetic acid solution and bubbling it. Space decontamination equipment.

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