Space decontamination method and space decontamination apparatus

Abstract

In this space decontamination method, a solution containing hydrogen peroxide at a concentration of 1-6 w / v% and acetic acid at a concentration of 1-10 w / v% and not containing peracetic acid is sprayed into a space. This space decontamination apparatus includes a spray unit configured to spray a solution into a space, the solution containing hydrogen peroxide at a concentration of 1-6 w / v% and acetic acid at a concentration of 1-10 w / v% and not containing peracetic acid.

Description

Space decontamination method and space decontamination apparatus Cross-reference to related applications

[0001] This international application claims the priority based on Japanese Patent Application No. 2024-199006 filed with the Japan Patent Office on November 14, 2024, and the priority based on Japanese Patent Application No. 2025-078175 filed with the Japan Patent Office on May 8, 2025, and incorporates by reference the entire contents of Japanese Patent Application No. 2024-199006 and Japanese Patent Application No. 2025-078175 into this international application.

[0002] This disclosure relates to a space decontamination method and a space decontamination apparatus.

[0003] In pharmaceutical manufacturing facilities, biohazard facilities, cell culture processing facilities, etc., there are spaces that need to be decontaminated. To perform decontamination, decontamination agents are used. As the decontamination agent, any one of hydrogen peroxide, peracetic acid, formaldehyde, chlorine dioxide, etc. is used at a high concentration. The decontamination methods are disclosed in Patent Documents 1 to 5.

[0004] Japanese Unexamined Patent Application Publication No. 2023-104821, Japanese Unexamined Patent Application Publication No. 2023-044604, Patent No. 7392235, Japanese Unexamined Patent Application Publication No. 2022-101536, Patent No. 5969404

[0005] A space decontamination method with even higher safety is desired. In one aspect of this disclosure, it is preferable to provide a space decontamination method and a space decontamination apparatus with high safety.

[0006] One aspect of this disclosure is a space decontamination method of spraying a solution containing hydrogen peroxide at a concentration of 1 w / v% or more and 6 w / v% or less and acetic acid at a concentration of 1 w / v% or more and 10 w / v% or less and not containing peracetic acid into a space. The space decontamination method which is one aspect of this disclosure has high safety.

[0007] Another aspect of this disclosure is a space decontamination apparatus provided with a spraying unit configured to spray a solution containing hydrogen peroxide at a concentration of 1 w / v% or more and 6 w / v% or less and acetic acid at a concentration of 1 w / v% or more and 10 w / v% or less and not containing peracetic acid into a space. The space decontamination apparatus which is another aspect of this disclosure has high safety.

[0008] Another aspect of this disclosure is a method for decontaminating a space, which involves vaporizing a solution containing hydrogen peroxide at a concentration of 1 w / v% to 6 w / v% and acetic acid at a concentration of 1 w / v% to 10 w / v% but without peracetic acid, to generate a decontamination gas, and supplying the decontamination gas to a space. This other aspect of the disclosure, the method for decontaminating a space, is highly safe.

[0009] Another aspect of this disclosure is a space decontamination device comprising a vaporization unit configured to vaporize a solution containing hydrogen peroxide at a concentration of 1 w / v% to 6 w / v% and acetic acid at a concentration of 1 w / v% to 10 w / v%, but without peracetic acid, in order to generate a decontamination gas. This space decontamination device, which is another aspect of this disclosure, is highly safe.

[0010] This is a block diagram showing the configuration of the air decontamination device. This is an explanatory diagram showing the safety cabinet and the air decontamination device. This is an explanatory diagram showing the air circulation path in the safety cabinet and the installation location of the BI. This is a graph showing the changes in acetic acid concentration, hydrogen peroxide concentration, peracetic acid concentration, temperature, and humidity in Example 1. This is a graph showing the changes in hydrogen peroxide concentration, temperature, and humidity in Comparative Example 1. This is an explanatory diagram showing the microbiology testing room and the air decontamination device. This is a graph showing the changes in acetic acid concentration, hydrogen peroxide concentration, peracetic acid concentration, temperature, and humidity in Example 2. This is an explanatory diagram showing the clean room and anteroom and the air decontamination device. This is a graph showing the changes in hydrogen peroxide concentration, temperature, and humidity in Comparative Example 2. This is an explanatory diagram showing the configuration of the vaporization unit.

[0011] Exemplary embodiments of the present disclosure will be described with reference to the drawings. <First Embodiment> 1. Space Decontamination Method The space decontamination method of the present disclosure decontaminates a space 105. Space 105 is a space located in, for example, a pharmaceutical manufacturing plant, a biohazard facility, a cell culture processing facility, a food factory, etc. Space 105 is a space inside, for example, a safety cabinet, an isolator, a restricted access barrier system, etc.

[0012] Space 105 is, for example, a clean area or a sterile working area. Clean areas and sterile working areas are found, for example, in pharmaceutical factories. Space 105 includes, for example, walls, floors, ceilings, or equipment that form the boundary between space 105 and other areas.

[0013] Decontamination means reducing the number of microorganisms present in space 105. Decontamination means, for example, reducing the number of microorganisms present in space 105 to a predetermined level. Decontamination means, for example, reducing BI by 6 logs or more. BI stands for Biological Indicator, meaning indicator bacteria.

[0014] In the spatial decontamination method of this disclosure, a solution is sprayed into the space 105. Hereinafter, the sprayed solution will be referred to as the spray solution. The spray solution contains hydrogen peroxide at a concentration of 1 w / v% to 6 w / v% and acetic acid at a concentration of 1 w / v% to 10 w / v%.

[0015] The concentration of hydrogen peroxide in the spray solution is preferably 2 w / v% or higher, more preferably 3 w / v% or higher. The concentration of hydrogen peroxide in the spray solution is preferably 5.5 w / v% or lower, more preferably 5 w / v% or lower, and particularly preferably 4.5 w / v% or lower.

[0016] The concentration of acetic acid in the spray solution is preferably 8 w / v% or less, more preferably 6 w / v% or less, and particularly preferably 4 w / v% or less. The concentration of peracetic acid in the spray solution is 0.1 w / v% or less. The spray solution may, for example, not contain peracetic acid. To spray the spray solution, for example, a spray nozzle, a humidifier, etc., can be used. Examples of humidifiers include ultrasonic humidifiers.

[0017] When performing the spatial decontamination method of this disclosure, the humidity of the space 105 is preferably 60% RH or higher and 85% RH or lower. When the humidity of the space 105 is 60% RH or higher, the effect of decontaminating the space 105 is even higher. When the humidity of the space 105 is 85% RH or lower, condensation and corrosion can be suppressed.

[0018] When performing the spatial decontamination method of this disclosure, 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 based on the measured humidity value.

[0019] When performing the spatial decontamination method of this disclosure, the concentration of acetic acid in space 105 is preferably 5 ppm or more and 100 ppm or less, and more preferably 5 ppm or more and 70 ppm or less. When the concentration of acetic acid in space 105 is 5 ppm or more, the effect of decontaminating space 105 is even higher. When the concentration of acetic acid in space 105 is 100 ppm or less, the gas treatment after decontamination becomes simpler.

[0020] If the concentration of acetic acid in space 105 is 70 ppm or less, the gas treatment after decontamination becomes even simpler. The greater the amount of spray solution applied to space 105, the higher the concentration of acetic acid and humidity in space 105. The higher the concentration of acetic acid in the spray solution, the higher the concentration of acetic acid in space 105. The method for measuring the concentration of acetic acid in space 105 is a measurement method using a detector tube.

[0021] When performing the spatial decontamination method of this disclosure, the concentration of hydrogen peroxide in space 105 is preferably 5 ppm or more and 100 ppm or less, and more preferably 10 ppm or more and 100 ppm or less. When the concentration of hydrogen peroxide in space 105 is 5 ppm or more, the effect of decontaminating space 105 is even higher, and when it is 10 ppm or more, the effect of decontaminating space 105 is particularly high. When the concentration of hydrogen peroxide in space 105 is 100 ppm or less, the safety when performing the spatial decontamination method is even higher.

[0022] The higher the concentration of hydrogen peroxide in the spray solution, the higher the concentration of hydrogen peroxide in space 105. The greater the amount of spray solution applied to space 105, the higher the concentration of hydrogen peroxide and humidity in space 105. The method for measuring the concentration of hydrogen peroxide in space 105 is the constant potential electrolysis method. A constant potential electrolysis type portable gas detector is used to measure the concentration of hydrogen peroxide.

[0023] When performing the spatial decontamination method of this disclosure, the concentration of peracetic acid in space 105 is preferably 0.1 ppm or less, and more preferably 0.05 ppm or less. In this case, the safety of performing the spatial decontamination method is further enhanced. The method for measuring the concentration of peracetic acid in space 105 is airborne concentration analysis by MTS oxidation GC-FID analysis using impinger sampling. The lower the concentration of peracetic acid in the spray solution, the lower the concentration of peracetic acid in space 105.

[0024] 2. Space Decontamination Device 1 The space decontamination device 1 of this disclosure has, for example, the configuration shown in Figure 1. The space decontamination device 1 includes a spray unit 3. The spray unit 3 sprays a spray solution into the space 105. The composition of the spray solution is as described in section 1. Space Decontamination Method. The spray unit 3 includes, for example, a spray nozzle, a humidifier, etc. An example of a humidifier is an ultrasonic humidifier.

[0025] The spatial decontamination device 1 further comprises a control unit 5 configured to control, for example, a spray unit 3. The control unit 5 includes a microcomputer having a CPU 5A and a semiconductor memory such as RAM or ROM (hereinafter referred to as memory 5B).

[0026] Each function of the control unit 5 is realized by the CPU 5A executing a program stored in a non-transitional physical recording medium. In this example, the memory 5B corresponds to the non-transitional physical recording medium that stores the program. Furthermore, when this program is executed, the method corresponding to the program is executed. The control unit 5 may consist of one microcomputer or multiple microcomputers.

[0027] The spatial decontamination device 1 further includes, for example, an information acquisition unit 7. The information acquisition unit 7 is configured to acquire information (hereinafter referred to as spatial information) that represents 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, the concentration of hydrogen peroxide in the space 105, and the concentration of peracetic acid in the space 105. The information acquisition unit 7 includes, for example, a sensor capable of detecting spatial information.

[0028] The control unit 5 controls the spraying unit 3 based on spatial information acquired by the information acquisition unit 7, for example. By controlling the spraying unit 3 based on spatial information acquired by the information acquisition unit 7, the control unit 5 sets the humidity of the space 105 to between 60% RH and 85% RH. When the humidity of the space 105 is 60% RH or higher, the decontamination effect of the space 105 is even higher. When the humidity of the space 105 is 85% RH or lower, condensation and corrosion can be suppressed, and when the humidity of the space 105 is 75% RH or lower, condensation and corrosion can be suppressed even further.

[0029] The control unit 5 controls the spray unit 3 based on spatial information acquired by the information acquisition unit 7, for example, to set the concentration of acetic acid in space 105 to between 5 ppm and 100 ppm. When the concentration of acetic acid in space 105 is 5 ppm or higher, the decontamination effect of space 105 is even higher. When the concentration of acetic acid in space 105 is 100 ppm or lower, the gas treatment after decontamination becomes simpler.

[0030] The control unit 5 controls the spray unit 3 based on spatial information acquired by the information acquisition unit 7, for example, to set the concentration of hydrogen peroxide in space 105 to between 5 ppm and 100 ppm. When the concentration of hydrogen peroxide in space 105 is 5 ppm or higher, the decontamination effect of space 105 is even higher. When the concentration of hydrogen peroxide in space 105 is 10 ppm or higher, the decontamination effect of space 105 is particularly high. When the concentration of hydrogen peroxide in space 105 is 100 ppm or lower, the safety of performing the space decontamination method is even higher. The control unit 5 also controls the concentration of hydrogen peroxide in space 105 to between 5 ppm and 70 ppm. When the concentration of hydrogen peroxide in space 105 is 70 ppm or lower, the safety of performing the space decontamination method is particularly high.

[0031] The spatial decontamination apparatus 1 of this disclosure further comprises, for example, a dehumidification unit. The dehumidification unit is, for example, a dehumidifier. 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 spraying a spray solution with the spray unit 3, it is possible to increase the concentration of hydrogen peroxide and acetic acid in the space 105 while suppressing the humidity in the space 105. For example, the control unit 5 can control the dehumidification unit based on spatial information so that the humidity, hydrogen peroxide concentration, and acetic acid concentration in the space 105 are within a suitable range.

[0032] For example, the space decontamination method can be carried out after dehumidifying the space 105 using a dehumidification unit. Alternatively, the space decontamination method can be carried out while dehumidifying the space 105 using a dehumidification unit. The operation mode of the dehumidification unit may be intermittent or continuous. When the space decontamination method is carried out while dehumidifying the space 105 using a dehumidification unit, a larger amount of vaporized hydrogen peroxide, which has a short lifespan, can be supplied to the space 105.

[0033] 3. Effects of the spatial decontamination method and spatial decontamination apparatus 1 (1A) The spatial decontamination method and spatial decontamination apparatus 1 of this disclosure have a high decontamination effect.

[0034] (1B) The spatial decontamination method and spatial decontamination apparatus 1 of the present disclosure are safer than conventional decontamination methods that use high concentrations of decontamination agents. Furthermore, the spatial decontamination method and spatial decontamination apparatus 1 of the present disclosure are safer because the concentrations of peracetic acid and hydrogen peroxide in the space 105 can be suppressed.

[0035] (1C) Acetic acid and hydrogen peroxide decompose in a short time. Therefore, even if a gas containing acetic acid and hydrogen peroxide (hereinafter referred to as decontamination gas) leaks outside of space 105, it remains highly safe.

[0036] (1D) The decontamination gas has high permeability. Therefore, even if there are areas in the space 105 where air circulation is difficult, those areas can be decontaminated. In addition, the decontamination performance of the decontamination gas does not deteriorate easily even after passing through the HEPA filter.

[0037] (1E) The spray solution used in this disclosure can be prepared by keeping the hydrogen peroxide and acetic acid separate until use, and then mixing them when needed. In this case, the spray solution can be stored for a considerably long period of time. Furthermore, the spray solution can be handled safely and is easy to manage. Management includes, for example, transportation and residual liquid treatment. <Second Embodiment> 1. Differences from the First Embodiment The second embodiment has the same basic configuration as the first embodiment, so the differences will be explained below. Note that the same reference numerals as in the first embodiment indicate the same components, and refer to the preceding description.

[0038] In the first embodiment described above, the spray solution was sprayed into the space 105. In contrast, the second embodiment differs from the first embodiment in that the solution is vaporized to generate a decontamination gas, and the decontamination gas is supplied to the space 105. Hereafter, the solution to be vaporized will be referred to as the decontamination solution.

[0039] 2. Space Decontamination Method The space decontamination method of this embodiment decontaminates the space 105. In the space decontamination method of this embodiment, a decontamination agent solution is vaporized to generate a decontamination agent gas, and the decontamination agent gas is supplied to the space 105. The composition of the decontamination agent solution is, for example, the same as the composition of the spray solution in the first embodiment.

[0040] When performing the space decontamination method of this embodiment, the humidity of the space 105 is preferably 60% RH or higher and 85% RH or lower. When the humidity of the space 105 is 60% RH or higher, the decontamination effect of the space 105 is even higher. When the humidity of the space 105 is 85% RH or lower, condensation and corrosion can be suppressed.

[0041] When performing the spatial decontamination method of this embodiment, 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 based on the measured humidity value.

[0042] When performing the space decontamination method of the present embodiment, the concentration of acetic acid in the space 105 is preferably 5 ppm or more and 100 ppm or less, and more preferably 5 ppm or more and 70 ppm or less. When the concentration of acetic acid in the space 105 is 5 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, the gas treatment after decontamination becomes simpler.

[0043] When the concentration of acetic acid in the space 105 is 70 ppm or less, the gas treatment after decontamination becomes even simpler. The greater the vaporization amount of the decontamination agent solution (that is, the amount of decontamination agent gas supplied to the space 105), the higher the concentration of acetic acid and humidity in the space 105. The higher the concentration of acetic acid in the decontamination agent solution, the higher the concentration of acetic acid in the space 105.

[0044] When performing the space decontamination method of the present embodiment, the concentration of hydrogen peroxide in the space 105 is preferably 5 ppm or more and 100 ppm or less, and more preferably 10 ppm or more and 100 ppm or less. When the concentration of hydrogen peroxide in the space 105 is 5 ppm or more, the effect of decontaminating the space 105 is higher, and when it is 10 ppm or more, the effect of decontaminating the space 105 is particularly high. When the concentration of hydrogen peroxide in the space 105 is 100 ppm or less, the safety when performing the space decontamination method is higher.

[0045] The higher the concentration of hydrogen peroxide in the decontamination agent solution, the higher the concentration of hydrogen peroxide in the space 105. The greater the vaporization amount of the decontamination agent solution (that is, the amount of decontamination agent gas supplied to the space 105), the higher the concentration of hydrogen peroxide and humidity in the space 105.

[0046] When performing the space decontamination method of the present embodiment, the concentration of peracetic acid in the space 105 is preferably 0.1 ppm or less, and more preferably 0.05 ppm or less. In that case, the safety when performing the space decontamination method is higher. The lower the concentration of peracetic acid in the decontamination agent solution, the lower the concentration of peracetic acid in the space 105.

[0047] 3. Configuration of the Space Decontamination Device 1 The space decontamination device 1 of this embodiment basically has the same configuration as the first embodiment. However, the space decontamination device 1 of this embodiment includes a vaporization unit 4 shown in Figure 10 instead of a spray unit 3. The vaporization unit 4 vaporizes the decontamination solution 507 and generates a decontamination gas 525. The decontamination gas 525 is supplied to the space 105. The vaporization unit 4 may be located inside the space 105 or outside the space 105. If the vaporization unit 4 is outside the space 105, the decontamination gas generated by the vaporization unit 4 can be supplied to the space 105 using, for example, piping.

[0048] The vaporization unit 4 comprises a decontamination solution tank 501, a pressurized tank 503, and piping 505. The decontamination solution tank 501 contains a decontamination solution 507. The piping 505 extends from the pressurized tank 503 into the interior of the decontamination solution tank 501. The end 505A of the piping 505 on the side of the decontamination solution tank 501 is located in the interior of the decontamination solution tank 501 above the liquid level of the decontamination solution 507.

[0049] The vaporization unit 4 comprises a liquid mass flow meter 509, a vaporizer 511, and piping 513. The vaporizer 511 comprises a gas-liquid mixing section 515 and a heater section 517. The piping 513 extends from inside the decontamination solution tank 501, through the liquid mass flow meter 509, to the gas-liquid mixing section 515. The end 513A of the piping 513 on the side of the decontamination solution tank 501 is located inside the decontamination solution tank 501 below the liquid level of the decontamination solution 507.

[0050] The vaporization unit 4 includes a mass flow controller 519 and piping 521. The piping 521 extends from a supply source of carrier gas 523 (not shown), through the mass flow controller 519, to the gas-liquid mixing section 515.

[0051] The vaporization unit 4 generates the decontamination gas 525 by operating as follows: The pressurized tank 503 and piping 505 pressurize the inside of the decontamination solution tank 501. At this time, the decontamination solution 507 is sent to the gas-liquid mixing unit 515 through piping 513 and liquid mass flow meter 509.

[0052] Furthermore, the carrier gas 523 is sent to the gas-liquid mixing unit 515 through the piping 521 and the mass flow controller 519. In the gas-liquid mixing unit 515, the decontamination solution 507 and the carrier gas 523 are mixed to form a mixture. The mixture is sent to the heater unit 517 at 120 to 160°C. In the heater unit 517, the decontamination solution 507 contained in the mixture vaporizes, generating decontamination gas 525. The decontamination gas 525 is supplied to the space 105.

[0053] For example, the control unit 5 controls the vaporization unit 4. The control unit 5 controls the vaporization unit 4 based on spatial information acquired by the information acquisition unit 7, for example. By controlling the vaporization unit 4 based on spatial information acquired by the information acquisition unit 7, the control unit 5 sets the humidity of the space 105 to between 60% RH and 85% RH.

[0054] When the humidity of space 105 is 60% RH or higher, the decontamination effect of space 105 is even greater. When the humidity of space 105 is 85% RH or lower, condensation and corrosion can be suppressed, and when the humidity of space 105 is 75% RH or lower, condensation and corrosion can be suppressed even further.

[0055] The control unit 5 controls the vaporization unit 4 based on spatial information acquired by the information acquisition unit 7, for example, to set the concentration of acetic acid in space 105 to between 5 ppm and 100 ppm. When the concentration of acetic acid in space 105 is 5 ppm or higher, the decontamination effect of space 105 is even higher. When the concentration of acetic acid in space 105 is 100 ppm or lower, the gas treatment after decontamination becomes simpler.

[0056] The control unit 5 controls the vaporization unit 4 based on spatial information acquired by the information acquisition unit 7, for example, to set the concentration of hydrogen peroxide in space 105 to between 5 ppm and 100 ppm. When the concentration of hydrogen peroxide in space 105 is 5 ppm or higher, the decontamination effect of space 105 is even higher. When the concentration of hydrogen peroxide in space 105 is 10 ppm or higher, the decontamination effect of space 105 is particularly high. When the concentration of hydrogen peroxide in space 105 is 100 ppm or lower, the safety of performing the space decontamination method is even higher. The control unit 5 also controls the concentration of hydrogen peroxide in space 105 to between 5 ppm and 70 ppm. When the concentration of hydrogen peroxide in space 105 is 70 ppm or lower, the safety of performing the space decontamination method is particularly high.

[0057] The space decontamination device 1 of this embodiment further comprises, for example, a dehumidification unit. The dehumidification unit is, for example, a dehumidifier. 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 vaporizing the decontamination solution with the vaporization unit 4, it is possible to increase the concentration of hydrogen peroxide and acetic acid in the space 105 while suppressing the humidity in the space 105. For example, the control unit 5 can control the dehumidification unit based on spatial information so that the humidity, hydrogen peroxide concentration, and acetic acid concentration in the space 105 are within a suitable range.

[0058] For example, the space decontamination method can be carried out after dehumidifying the space 105 using a dehumidification unit. Alternatively, the space decontamination method can be carried out while dehumidifying the space 105 using a dehumidification unit. The operation mode of the dehumidification unit may be intermittent or continuous. When the space decontamination method is carried out while dehumidifying the space 105 using a dehumidification unit, a larger amount of vaporized hydrogen peroxide, which has a short lifespan, can be supplied to the space 105.

[0059] 4. Effects of the Space Decontamination Method and Space Decontamination Apparatus 1 According to the second embodiment described in detail above, the effects (1A) to (1D) of the first embodiment described above are achieved, and further, the following effect (2A) is achieved.

[0060] (2A) The decontamination solution used in this embodiment can be prepared by keeping the hydrogen peroxide and acetic acid separate until use, and then mixing them when needed. In this case, the decontamination solution can be stored for a considerably long period of time. Furthermore, the decontamination solution can be handled safely and is easy to manage. Management includes, for example, transportation and disposal of residual liquid. <Example 1> A safety cabinet 201 shown in Figures 2 and 3 was prepared. The safety cabinet 201 is used, for example, in biohazard facilities that handle highly infectious microorganisms. The safety cabinet 201 is also used, for example, in cell processing and other fields where sterility is required, such as in the field of regenerative medicine.

[0061] The safety cabinet 201 is a device that requires a high decontamination level, for example, 6 log or higher. The interior of the safety cabinet 201 corresponds to 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.

[0062] The safety cabinet 201 includes a workbench 203. A workspace 205 is located above the workbench 203. The safety cabinet 201 has a front opening 207. The workspace 205 is located behind the front opening 207 when viewed from the front. The safety cabinet 201 includes a filter chamber 208, a fan room 209, and a ceiling exhaust port 211. A HEPA filter 213 is provided in the filter chamber 208.

[0063] As shown in Figures 2 and 3, a circulating fan 215 installed in the workspace 205 was connected to the ceiling exhaust port 211 by a duct 219. The front opening 207, except for the portion through which the duct 219 was routed, was sealed with masking tape and protective sheeting. The ceiling exhaust port 211, except for the portion connected to the duct 219, was also sealed with masking tape and protective sheeting. In addition, other gaps in the safety cabinet 201 were sealed with masking tape.

[0064] When the spatial decontamination method was being implemented, the circulation fan 215 was operated. At this time, air circulation occurred along the path indicated by arrow AF in Figures 2 and 3. The circulating air was discharged from the circulation fan 215 and passed through internal spaces such as the work space 205, the area under the workbench 203, the filter chamber 208, and the fan room 209 before proceeding to the ceiling exhaust port 211. Furthermore, the air passed through the inside of the duct 219 and returned to the circulation fan 215.

[0065] As shown in Figure 2, a spraying unit 3 and an information acquisition unit 7 were installed in the workspace 205. In this embodiment, the spraying unit 3 was an ultrasonic humidifier. In this embodiment, the information acquisition unit 7 was a temperature and humidity sensor. A dehumidifier 220 was installed in the workspace 205.

[0066] During the spatial decontamination method, a spray solution was sprayed into the work space 205 by the spray unit 3. The spray solution contained hydrogen peroxide at a concentration of 3 w / v% and acetic acid at a concentration of 1 w / v%. The concentration of peracetic acid in the spray solution was 0.1 w / v% or less.

[0067] While the spatial decontamination method was being implemented, the information acquisition unit 7 detected the temperature and humidity of the air in the work space 205 and sent the detection results to the control unit 5. Based on the temperature and humidity measurements, the control unit 5 controlled the spray unit 3. The control unit 5 controlled the spray unit 3 so that the humidity inside the safety cabinet 201 remained at 75% RH for 180 minutes after the humidity inside the safety cabinet 201 reached 75% RH. In addition, the dehumidifier 220 operated continuously while the spatial decontamination method was being implemented.

[0068] During the spatial decontamination process, the hydrogen peroxide concentration in workspace 205 was measured and recorded using a portable monitor employing a constant potential electrolysis method. Additionally, the acetic acid concentration in workspace 205 was measured periodically using a detector tube. Furthermore, the peracetic acid concentration in workspace 205 was measured periodically using MTS oxidation GC-FID analysis with impinger sampling.

[0069] Before starting the spatial decontamination method, biobuffers (BIs) were placed at locations P1 to P4 as shown in Figure 3. P1 is the furthest point in the air circulation path from the work space 205 where the spray solution is sprayed. Once the elimination of the BIs placed at P1 to P4 is confirmed, it means that the decontamination of the inside of the safety cabinet 201, including the HEPA filter 213, is complete.

[0070] The primary infection (BI) was Geobacillus stearothermophilus (ATCC#12980). The bacterial count of the BI was 1 × 10⁻⁶. ６ That concludes the report. If the BI test is negative, it means that a high level of decontamination, considered to be sterilization level of 6 logs or higher, has been achieved.

[0071] Figure 4 shows the changes in the concentrations of acetic acid, hydrogen peroxide, and peracetic acid, as well as the temperature and humidity, in the workspace 205 while the spatial decontamination method is being implemented. The horizontal axis of Figure 4 represents the elapsed time from the start of spraying the spray solution.

[0072] When the decontamination time was 180 minutes, two biomarkers (BIs) were extracted from each of P1 to P4. The decontamination time was defined as the time elapsed since the humidity inside the safety cabinet 201 reached 75% RH. Next, the extracted BIs were cultured for 7 days in a dedicated culture medium at an appropriate temperature to determine whether they were negative or positive. The results are shown in Table 1.

[0073]

[0074] As shown in Table 1, both BI tests were negative at all locations P1 to P4. When the spatial decontamination method was being implemented, the average concentration of hydrogen peroxide in workspace 205 was 24.5 ppm. The CT value (ppm·min), which serves as an indicator of exposure to hydrogen peroxide, was 4417 ppm·min. When the spatial decontamination method was being implemented, the concentration of peracetic acid in workspace 205 was below the detection limit. The detection limit for peracetic acid concentration was 0.04 ppm.

[0075] In this example, the concentration of hydrogen peroxide in the spray solution was set to 3 w / v%. The decontamination effect is further enhanced when the hydrogen peroxide concentration is 3 w / v% or higher. However, the lower the hydrogen peroxide concentration, the greater the safety. <Comparative Example 1> The spatial decontamination method was basically carried out in the same manner as in Example 1. However, in Comparative Example 1, the spray solution contained only hydrogen peroxide at a concentration of 3 w / v%. That is, in Comparative Example 1, the spray solution did not contain acetic acid or peracetic acid.

[0076] Figure 5 shows the changes in hydrogen peroxide concentration, temperature, and humidity in the workspace 205 during the implementation of the spatial decontamination method. The horizontal axis of Figure 5 represents the elapsed time from the start of spraying of the spray solution. The average hydrogen peroxide concentration during the 480-minute decontamination period was 15.5 ppm. The CT value (ppm·min), which is an indicator of hydrogen peroxide exposure, was 7456 ppm·min. This CT value was approximately 1.7 times the CT value in Example 1.

[0077] When the decontamination time was 480 minutes, two biomarkers (BIs) were extracted from each of P1 to P4. The decontamination time was defined as the time elapsed since the humidity in the workspace 205 reached 75% RH. Next, the extracted BIs were cultured for 7 days in a dedicated culture medium at an appropriate temperature to confirm whether they were negative or positive. The results are shown in Table 2.

[0078]

[0079] As shown in Table 2, the two BI samples extracted at P1 and the one BI sample extracted at P2 were positive. This result indicates that decontamination is difficult even when a decontamination gas containing only hydrogen peroxide is supplied to the workspace 205. In particular, the fact that the two BI samples extracted at P1 were positive indicates that the decontamination capacity of the decontamination gas containing only hydrogen peroxide has clearly decreased after passing through the HEPA filter 213. <Example 2> The microbiology laboratory 401 shown in Figure 6 was used as the subject of the spatial decontamination method. The volume of the microbiology laboratory 401 is 50 m³ ３The entrances and windows of the microbiology laboratory 401 were all closed. The microbiology laboratory 401 was equipped with workbenches 403 and 405, a sink 407, a safety cabinet 201, and a dehumidifier 220. The safety cabinet 201 was of the same type as the one used in Example 1.

[0080] Two spraying units 3, an information acquisition unit 7, and a circulating fan 225 were installed in the microbiology laboratory 401. In this embodiment, the spraying units 3 were electric sprayers. In this embodiment, the information acquisition unit 7 was a temperature and humidity sensor.

[0081] During the spatial decontamination procedure, a spray solution was sprayed into the microbiology laboratory 401 using the spray unit 3. The spray solution contained hydrogen peroxide at a concentration of 2 w / v% and acetic acid at a concentration of 1 w / v%. The concentration of peracetic acid in the spray solution was 0.1 w / v% or less.

[0082] While the spatial decontamination method was being implemented, the information acquisition unit 7 detected the temperature and humidity of the air in the microbiology testing room 401 and sent the detection results to the control unit 5. Based on the temperature and humidity measurement results, the control unit 5 repeatedly started and stopped the spray unit 3. After the humidity in the microbiology testing room 401 reached 75% RH, the control unit 5 controlled the spray unit 3 so that the humidity in the microbiology testing room 401 was maintained at 75% RH for 300 minutes. In addition, while the spatial decontamination method was being implemented, the dehumidifier 220 operated continuously.

[0083] Furthermore, while the spatial decontamination method was being implemented, the indoor air was stirred using a circulator fan 225 to extend the reach of the decontamination gas. Also, while the spatial decontamination method was being implemented, the safety cabinet 201 was operated. As a result, the decontamination gas passed through the inside of the safety cabinet 201.

[0084] BIs were installed at locations P1 to P5 shown in Figure 6. The BIs were the same as those in Example 1. P1 was located at the outlet of the working space 205 in the safety cabinet 201, downstream of the HEPA filter 213. P2 was located on the exhaust side of the safety cabinet 201. P3 was located on the floor. P4 was located near the ceiling. If the BIs installed at P1 and P2 were negative, it meant that the inside of the safety cabinet 201 and the filter chamber 208 through which the decontamination gas passes were also decontaminated.

[0085] Figure 7 shows the changes in hydrogen peroxide concentration, acetic acid concentration, peracetic acid concentration, temperature, and humidity in microbiology laboratory 401 while the spatial decontamination method is being implemented. The horizontal axis of Figure 7 represents the elapsed time from the start of spraying of the spray solution.

[0086] The average concentration of hydrogen peroxide during the 300-minute decontamination period was 22.1 ppm. The CT value (ppm / min), which serves as an indicator of exposure to hydrogen peroxide, was 6644 ppm / min. The concentration of peracetic acid was 0.042 ppm in only one measurement, and was below the detection limit in all other measurements. The detection limit for peracetic acid was 0.04 ppm.

[0087] When the decontamination time was 300 minutes, three BIs were extracted from each of P1 to P5. Similarly, when the decontamination times were 120 minutes, 210 minutes, and 300 minutes, three BIs were extracted from P5. Next, the extracted BIs were cultured for 7 days in a dedicated culture medium at an appropriate temperature to determine whether they were negative or positive. The results are shown in Table 3.

[0088]

[0089] As shown in Table 3, when the decontamination time was 300 minutes, all BIs were negative in all locations, indicating successful decontamination. In P5, when the decontamination time was 120 minutes, 210 minutes, and 300 minutes, all BIs were negative, indicating successful decontamination. <Comparative Example 2> The spatial decontamination method was basically carried out in the same manner as in Example 2. However, in Comparative Example 2, the spray solution was a solution containing only hydrogen peroxide at a concentration of 2 w / v%. That is, in Comparative Example 2, the spray solution did not contain acetic acid or peracetic acid. In Comparative Example 2, the cleanroom 301 and the anteroom 303 shown in Figure 8 were targeted for the spatial decontamination method. The cleanroom 301 and the anteroom 303 were connected. The total volume of the cleanroom 301 and the anteroom 303 was approximately 34 m³. ３ That was the case.

[0090] Inside the cleanroom 301, a dehumidifier 220 and a safety cabinet 201 were installed. The safety cabinet 201 was of the same type as the one used in Example 1. A spray unit 3 and a circulator fan 225 were installed inside the cleanroom 301.

[0091] BIs were installed at locations P1 to P3 as shown in Figure 8. P1 was located at the outlet of the working space 205 in the safety cabinet 201, downstream of the HEPA filter 213. P2 was located on the exhaust side of the safety cabinet 201. P3 was located between the safety cabinet 201 and the wall behind it. If the BIs installed at P1 and P2 are negative, it means that the inside of the safety cabinet 201 through which the decontamination gas passes, and the filter chamber 208, are also decontaminated.

[0092] Figure 9 shows the changes in hydrogen peroxide concentration, temperature, and humidity in cleanroom 301 while the spatial decontamination method is being implemented. The horizontal axis of Figure 9 represents the elapsed time from the start of spraying the spray solution to the time when the decontamination set humidity of 75% RH was reached.

[0093] The average concentration of hydrogen peroxide during the 480-minute decontamination period was 21.9 ppm. The CT value (ppm·min), which serves as an indicator of hydrogen peroxide exposure, was 10,554 ppm·min. This CT value was approximately 1.6 times that of Example 2.

[0094] When the decontamination time was 480 minutes, one biomarker (BI) was extracted from each of P1 to P3. Next, the extracted BIs were cultured for 7 days in a special culture medium at the appropriate temperature, and their negative or positive results were confirmed. The results are shown in Table 4.

[0095]

[0096] As shown in Table 4, P1 and P2 were positive. This indicates that the decontamination gas containing only hydrogen peroxide has a clearly reduced decontamination capacity after passing through the HEPA filter 213. <Other Embodiments> Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above and can be implemented in various modified forms.

[0097] (1) The space 105 in which decontamination is performed may be something else, for example, the space inside an isolator, an access restriction barrier system, etc.

[0098] (2) In Examples 1 and 2, a vaporization unit 4 may be used instead of the spraying unit 3.

[0099] (3) The vaporization unit 4 may be one which drops the decontamination solution onto a hot plate or the like and vaporizes the decontamination solution.

[0100] (4) When the space decontamination method is being carried out in the first or second embodiment, the space 105 does not need to contain peracetic acid.

[0101] (5) The control unit 5 and its method described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control unit 5 and its method described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control unit 5 and its method described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium. The method for implementing the functions of each part included in the control unit 5 does not necessarily have to include software, and all of its functions may be implemented using one or more hardware components.

[0102] (6) The function of one component in each of the above embodiments may be divided among multiple components, or the function of multiple components may be performed by one component. Also, some of the configurations of each of the above embodiments may be omitted. Also, at least some of the configurations of each of the above embodiments may be added to, replaced with, etc., the configurations of other embodiments.

[0103] (7) In addition to the spatial decontamination device 1 described above, this disclosure can also be realized in various forms, such as a system that uses the spatial decontamination device 1 as a component, a program for making a computer function as a control unit 5, a non-transitional physical recording medium such as a semiconductor memory on which this program is recorded, and a method for manufacturing the spatial decontamination device 1.

[0104] 1...Space decontamination device, 3...Spray unit, 4...Vaporization unit, 5...Control unit, 5A...CPU, 5B...Memory, 7...Information acquisition unit, 105...Space, 201...Safety cabinet, 203...Workbench, 205...Work space, 207...Front opening, 208...Filter chamber, 209...Fan room, 211...Ceiling exhaust port, 213...HEPA filter, 215...Circulation fan, 219...Duct, 220...Dehumidifier, 225...Circulator Tafan, 301...Cleanroom, 303...Anteroom, 401...Microbiology testing room, 403, 405...Laboratory bench, 407...Sink, 501...Decontamination solution tank, 503...Pressurized tank, 505, 513, 521...Piping, 505A, 513A...Ends, 507...Decontamination solution, 509...Liquid mass flow meter, 511...Vaporizer, 515...Gas-liquid mixing unit, 517...Heater unit, 519...Mass flow controller, 523...Carrier gas, 525...Decontamination gas

Claims

1. A method for decontaminating a space by spraying a solution containing hydrogen peroxide at a concentration of 1 w / v% to 6 w / v% and acetic acid at a concentration of 1 w / v% to 10 w / v% but without peracetic acid into the space.

2. A method for decontaminating a space according to claim 1, wherein, when the method for decontaminating a space is being performed, the humidity of the space is 60% RH or more and 85% RH or less.

3. A method for decontaminating a space by spraying a solution containing hydrogen peroxide at a concentration of 1 w / v% to 6 w / v% and acetic acid at a concentration of 1 w / v% to 10 w / v% but without peracetic acid into a space, wherein, when the space decontamination method is performed, the concentration of acetic acid in the space is 5 ppm to 100 ppm, the concentration of hydrogen peroxide in the space is 5 ppm to 100 ppm, and the concentration of peracetic acid in the space is 0.1 ppm or less.

4. A space decontamination device comprising a spray unit configured to spray a solution into the space containing hydrogen peroxide at a concentration of 1 w / v% to 6 w / v% and acetic acid at a concentration of 1 w / v% to 10 w / v%, but without peracetic acid.

5. A method for decontaminating a space, comprising vaporizing a solution containing hydrogen peroxide at a concentration of 1 w / v% to 6 w / v% and acetic acid at a concentration of 1 w / v% to 10 w / v% but without peracetic acid to generate a decontamination gas, and supplying the decontamination gas to a space.

6. A method for decontaminating a space according to claim 5, wherein, when the method for decontaminating a space is being performed, the humidity of the space is 60% RH or more and 85% RH or less.

7. A method for decontaminating a space, comprising vaporizing a solution containing hydrogen peroxide at a concentration of 1 w / v% to 6 w / v% and acetic acid at a concentration of 1 w / v% to 10 w / v% but not containing peracetic acid to generate a decontamination gas, and supplying the decontamination gas to a space, wherein, when the space decontamination method is being performed, the concentration of acetic acid in the space is 5 ppm to 100 ppm, the concentration of hydrogen peroxide in the space is 5 ppm to 100 ppm, and the concentration of peracetic acid in the space is 0.1 ppm or less.

8. A space decontamination device comprising a vaporization unit configured to generate a decontamination gas by vaporizing a solution containing hydrogen peroxide at a concentration of 1 w / v% to 6 w / v% and acetic acid at a concentration of 1 w / v% to 10 w / v%, but without peracetic acid.

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