JP6649417B2 - Hydrogen peroxide gas decontamination method - Google Patents

Description

  The present invention relates to a hydrogen peroxide gas decontamination method and a hydrogen peroxide gas decontamination apparatus using a hydrogen peroxide gas.

For an isolator used in the pharmaceutical manufacturing field and a safety cabinet used for microbial experiments and handling of viruses, it is important to control suspended particles and control microorganisms, bacteria and viruses. In the field of pharmaceutical manufacturing, it is required to maintain the manufacturing environment aseptically, and its sterility assurance level (SAL) is 10 ⁻⁶ . Further, in the safety cabinet, it is necessary to decontaminate the inside of the device in order to prevent workers from being infected with harmful bacteria and viruses during maintenance of the device.

  Conventionally, as a decontamination method, fumigation using formaldehyde gas has been mainly performed, but formaldehyde is a carcinogenic substance, and its use has been strictly regulated in recent years. On the other hand, as an alternative to formaldehyde decontamination, a decontamination method using an alternative agent such as hydrogen peroxide, peracetic acid, or ozone has been studied. Above all, hydrogen peroxide gas is easier to handle than other alternative drugs, and has been widely used for decontamination of isolators in the field of pharmaceutical production. As an example of a hydrogen peroxide gas decontamination method using hydrogen peroxide and a decontamination apparatus, the one described in Patent Document 1 is known.

JP-A-2006-111992

By the way, the gas concentration of the hydrogen peroxide gas is set relatively high (300 to 1000 ppm) in order to complete the decontamination of a small-volume case such as a safety cabinet or an isolator in a short time. On the other hand, since room decontamination has a large volume, the gas concentration of hydrogen peroxide gas is set relatively low (200 to 400 ppm), and decontamination is performed for a long time.
In these decontaminations, it is necessary to efficiently generate hydrogen peroxide gas because of high concentration or large volume, and in the hydrogen peroxide gas decontamination apparatus described in Patent Document 1, heating was performed at 140 ° C to 170 ° C. A method has been adopted in which a hydrogen peroxide solution is dropped on a plate one by one and evaporated instantaneously to generate a hydrogen peroxide gas.

  Further, in the hydrogen peroxide gas decontamination described in Patent Document 1, it is necessary to maintain the relative humidity during decontamination at about 40 to 60% in addition to the gas concentration. Decontamination often uses a hydrogen peroxide solution with a concentration of about 35%, so there is no need to humidify because water vapor is generated simultaneously with the evaporation of the hydrogen peroxide solution, but on the contrary, the humidity becomes too high and dew condensation occurs. However, there is a possibility that the components may deteriorate. Therefore, an expensive temperature / humidity sensor, a hydrogen peroxide gas concentration sensor, a dehumidifier, and the like are required for controlling humidity and the like.

  As described above, the hydrogen peroxide gas decontamination apparatus described in Patent Document 1 has a problem that the structure of the apparatus itself is complicated, an expensive sensor and the like are required, and the apparatus becomes expensive.

  The present invention has been made in view of the above circumstances, has a simple device configuration, and easily decontaminates a space to be decontaminated in a small-capacity housing such as a safety cabinet or an isolator with hydrogen peroxide gas. It is an object of the present invention to provide a method and apparatus for decontaminating hydrogen peroxide gas.

In order to achieve the above object, the hydrogen peroxide gas decontamination method of the present invention is a hydrogen peroxide gas decontamination method for decontaminating a space to be decontaminated using hydrogen peroxide gas,
In the decontamination target space, the hydrogen peroxide solution is heated to 70 to 90 ° C. to obtain 200 to 400 ppm of hydrogen peroxide gas.

Further, the hydrogen peroxide gas decontamination apparatus of the present invention is a hydrogen peroxide gas decontamination apparatus that decontaminates a space to be decontaminated using hydrogen peroxide gas,
Provided in the decontamination target space, a container in which the hydrogen peroxide solution is placed,
A heater for heating the hydrogen peroxide solution in the container by heating the container,
A temperature controller for controlling the heater to heat and control the hydrogen peroxide solution to 70 to 90 ° C;
In the decontamination target space, the hydrogen peroxide solution is heated to 70 to 90 ° C. by the heater to obtain 200 to 400 ppm of hydrogen peroxide gas.

Here, the reason why the aqueous hydrogen peroxide solution is heated to 70 to 90 ° C. is that it is difficult to efficiently generate hydrogen peroxide gas at a temperature lower than 70 ° C. This is because the temperature approaches ℃, and the evaporation of the hydrogen peroxide solution becomes intense, and the relative humidity increases.
The reason why the concentration of the hydrogen peroxide gas is set to 200 to 400 ppm is that if the concentration is less than 200 ppm, it is difficult to obtain a sufficient decontamination effect, and if the concentration exceeds 400 ppm, the hydrogen peroxide gas condenses without temperature and humidity control. This is because there is a fear.
The space to be decontaminated is preferably a space to be decontaminated in a small-capacity housing such as a safety cabinet or an isolator, and for example, is preferably 2 m ³ or less.

In the present invention, since the hydrogen peroxide solution is heated to 70 to 90 ° C., the hydrogen peroxide solution does not boil, but slowly evaporates to become a hydrogen peroxide gas. When the hydrogen peroxide solution is slowly evaporated, the hydrogen peroxide solution is more easily decomposed than when it is instantaneously evaporated, and the hydrogen peroxide gas generation efficiency is reduced. This is sufficient to obtain a hydrogen peroxide gas having a concentration of 200 to 400 ppm in the space to be decontaminated. Since the decontamination target space is decontaminated with the hydrogen peroxide gas having this concentration, the decontamination target space can be easily decontaminated with the hydrogen peroxide gas.
Further, a container for storing the hydrogen peroxide solution, a heater for heating the hydrogen peroxide solution in the container by heating the container, and a heating control of the hydrogen peroxide solution to 70 to 90 ° C. by controlling the heater. And a simple device configuration including a temperature controller that controls the temperature.

  Further, in the configuration of the present invention, dehumidification may be provided in the space to be decontaminated to prevent dew condensation while maintaining the humidity required for decontamination.

  Here, as the hygroscopic agent, for example, calcium chloride which has low hygroscopicity at low humidity and easily absorbs moisture at high humidity exceeding 60% is preferably used.

  According to such a configuration, when the hydrogen peroxide gas is generated in the space to be decontaminated, the humidity also increases accordingly, but decontamination is performed by removing excess moisture that causes dew condensation using a hygroscopic agent. Since the hydrogen peroxide solution can be prevented from adhering to the wall surface forming the target space, the container containing the hydrogen peroxide solution, the heater, and the temperature controller, such damage can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, while being a simple apparatus structure, the decontamination object space in a small volume housing | casing, such as a safety cabinet and an isolator, can be easily decontaminated with a hydrogen peroxide gas.

It is a figure which shows the hydrogen peroxide gas decontamination apparatus of embodiment of this invention, and shows the schematic structure. 4 is a graph showing a relationship between an elapsed time after starting heating of a hydrogen peroxide solution, a hydrogen peroxide gas concentration, and a relative humidity in the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a hydrogen peroxide gas decontamination apparatus according to the present embodiment.
In FIG. 1, reference numeral 10 denotes a small-capacity housing such as a safety cabinet or an isolator. Inside the small-capacity housing 10, a container 11, a heater 12, a temperature controller 13, a timer 14, a neutralizing device 15, and a hygroscopic agent 16 are provided.
In the present embodiment, the hydrogen peroxide gas decontamination device 1 is constituted by the container 11, the heater 12, the temperature controller 13, the timer 14, and the neutralization device 15. The gas decontamination apparatus 1 may be configured.

The interior of the small-capacity housing 10 is a decontamination target space K, and the decontamination target space K is separated from the outside by a wall constituting the small-capacity housing 10.
As the container 11, for example, a beaker 11 is used, and the upper end thereof is open. A hydrogen peroxide solution having a concentration of 35% is put into the container 11 from this opening.
The heater 12 is a mantle heater 12 having a heating / heating function, and a container 11 is loaded in the mantle heater 12.

A temperature controller 13 is connected to the heater 12, and the temperature controller 13 controls the heater 12 to be turned on and off so that the temperature of the hydrogen peroxide gas contained in the container 11 is reduced to 70 to 90 ° C. Heating is controlled.
Further, a timer 14 is connected to the temperature controller 13, and the timer 14 controls the control time of the temperature controller 13, that is, the heating time of the heater 12, so that the temperature from the hydrogen peroxide solution in the container 11 is controlled. The time for generating (evaporating) the hydrogen oxide gas is controlled. By generating the hydrogen peroxide gas, the space K to be decontaminated starts to be decontaminated, so that the hydrogen peroxide gas generation time is substantially equal to the decontamination time.

Further, a neutralization device 15 is connected to the timer 14. The neutralization device 15 has a function of neutralizing and decomposing the hydrogen peroxide gas in the space K to be decontaminated. For example, the neutralization device 15 decomposes the hydrogen peroxide gas to a concentration of 1 ppm or less with a catalyst such as platinum. It is supposed to.
Further, the neutralization device 15 includes a housing 15a, a catalyst 15b such as platinum provided on an upper portion of the housing 15a, and a fan 15c provided on a lower portion of the housing 15a.
In such a neutralization device 15, the fan 15c is operated by a motor (not shown) to blow the hydrogen peroxide gas in the decontamination target space K to the catalyst 15b, and the hydrogen peroxide neutralized by the catalyst is discharged. By repeatedly sending the gas to the decontamination target space K, the hydrogen peroxide gas is circulated in the decontamination target space K via the neutralization device 15 to decompose the hydrogen peroxide gas to a concentration of 1 ppm or less. It is supposed to.
When the decontamination time is set by the timer 14, when the decontamination time has elapsed, the heating of the hydrogen peroxide solution in the container 11 is stopped, and the neutralizing device 15 is automatically operated, that is, the fan 15c is operated. It has become.

As the hygroscopic agent 16, calcium chloride which has low hygroscopicity at low humidity and easily absorbs moisture at high humidity exceeding 60% is preferably used.
By using such a moisture absorbent 16, it is possible to prevent dew condensation in the space K to be decontaminated while maintaining the humidity required for decontamination without measuring humidity or controlling dehumidification. The moisture absorbent 16 is spread out so as not to overlap using a thin container such as a petri dish, and is installed at a predetermined position in the space K to be decontaminated.

Next, a decontamination method using the hydrogen peroxide gas decontamination apparatus of the present embodiment will be described.
In the present embodiment, the interior of the safety cabinet (BSC) is defined as a decontamination target space K, and the decontamination target space K is decontaminated with hydrogen peroxide gas.

First, measure the temperature and humidity of the room where the safety cabinet is installed, and confirm that the temperature and humidity required for decontamination (under general air conditioning).
Next, with respect to the volume of the safety cabinet, that is, the volume of the space K to be decontaminated, the amounts of the hydrogen peroxide solution and calcium chloride (hygroscopic agent) and the decontamination time (timer setting time) are determined from the parameters shown in Table 1. . The hydrogen peroxide solution and calcium chloride are weighed to the determined amounts, and the timer is adjusted to the determined decontamination time.

Next, as shown in FIG. 1, the hydrogen peroxide gas decontamination apparatus 1 and the hygroscopic agent (calcium chloride) 16 of the present embodiment are installed in the working room of the safety cabinet, that is, in the space K to be decontaminated.
Since the moisture absorption of the hygroscopic agent (calcium chloride) 16 depends on the surface area, it is spread using a thin container such as a petri dish as described above so as not to overlap.

  Next, a hydrogen peroxide solution having a concentration of 35% is placed in a container (beaker) 11 set in a heater (mantle heater) 12. Next, the safety cabinet is sealed using a thick plastic film, duct tape, or the like. In particular, the exhaust port of the safety cabinet is strong because pressure is applied.

  Next, the operation is performed with the fan output of the safety cabinet set to about 60%. Depending on the manufacturer of the safety cabinet, the fan output is controlled by changing the inverter setting frequency, rotation speed, torque, etc. used for fan output control.

Next, when the switch of the hydrogen peroxide gas decontamination apparatus 1 is turned on, the temperature controller 13 automatically controls the heater 12 so that the hydrogen peroxide solution in the container (beaker) 11 becomes about 70 ° C. to 90 ° C. Control and heat the hydrogen peroxide solution.
As shown in FIG. 2, the concentration and humidity of the hydrogen peroxide gas increase due to the evaporation of the hydrogen peroxide solution. The space K to be decontaminated starts to be decontaminated by the evaporation of the hydrogen peroxide gas, but the concentration of the hydrogen peroxide gas reaches 200 to 400 ppm, the concentration is maintained for a predetermined time, and a predetermined time has elapsed therefrom. Thus, the decontamination of the decontamination target space K is completed.
In this embodiment, the concentration of the hydrogen peroxide gas increases from the start of the heating of the hydrogen peroxide solution, and after about 105 minutes from the start of the heating, the concentration of the hydrogen peroxide gas becomes 200 ppm, and the concentration gradually increases from there. It becomes 235 ppm after a lapse of 120 minutes. From there, the concentration of hydrogen peroxide gas gradually decreases, and reaches 200 ppm after 140 minutes, and then the concentration of hydrogen peroxide gas further decreases, and after 180 minutes from the start of decontamination (start of heating of hydrogen peroxide solution). Decontamination ends.
Further, the humidity (relative humidity) gradually increases from the start of decontamination (start of heating of the hydrogen peroxide solution), and becomes 74% after 105 minutes from the start of decontamination. When the humidity (relative humidity) exceeds 60%, moisture is adsorbed to the calcium chloride (hygroscopic agent) 16 and the humidity is maintained at a level that does not cause dew condensation, and the humidity (relative humidity) gradually decreases.

When the decontamination time shown in Table 1 has elapsed and the hydrogen peroxide gas decontamination has been completed, the heater (mantle heater) 12 is automatically stopped by the timer 14 as shown in FIG. Is stopped) and the mode is switched to the neutralization device 15.
In the neutralization device 15, the fan 15c sends air to the catalyst 15b for hydrogen peroxide, and circulates the air in the safety cabinet (the space K to be decontaminated) to decompose the hydrogen peroxide gas. The neutralization of the hydrogen peroxide gas is usually performed until the concentration becomes lower than the allowable concentration (1 ppm). As shown in Table 1, the neutralization time varies depending on the volume in the safety cabinet and the amount of hydrogen peroxide used. When the concentration of the hydrogen peroxide gas becomes equal to or lower than the allowable concentration (1 ppm), the fan 15c stops, and the neutralization of the hydrogen peroxide gas after the decontamination ends.

As described above, according to the present embodiment, since the hydrogen peroxide solution is heated to 70 to 90 ° C., the hydrogen peroxide solution does not boil, but slowly evaporates to become hydrogen peroxide gas. When hydrogen peroxide water is slowly evaporated, hydrogen peroxide is more easily decomposed than when it is instantaneously evaporated, and the hydrogen peroxide gas generation efficiency is reduced. Is sufficient to obtain a hydrogen peroxide gas having a concentration of 200 to 400 ppm in the space to be decontaminated. Then, since the decontamination target space K is decontaminated with the hydrogen peroxide gas having this concentration, the decontamination target space K can be easily decontaminated with the hydrogen peroxide gas.
Further, a container 11 for storing the hydrogen peroxide solution, a heater 12 for heating the hydrogen peroxide solution in the container 11 by heating the container 11, and controlling the heater 12 to reduce the hydrogen peroxide solution to 70 to A simple device configuration including a temperature controller 13 that controls heating to 90 ° C. and a timer 14 can be provided.

  Further, when the hydrogen peroxide gas is generated in the space K to be decontaminated, the humidity also increases with the generation of the hydrogen peroxide gas. Since the hydrogen peroxide solution can be prevented from adhering to the wall surface to be formed, the container 11 in which the hydrogen peroxide solution is put, the heater 12, the temperature controller 13, the neutralization device 15, and the like, these damages can be prevented.

  Further, after decontamination of the space K to be decontaminated with hydrogen peroxide gas, the hydrogen peroxide gas is neutralized and decomposed by the neutralization device 15, so that a safety cabinet, an isolator or the like can be used safely thereafter.

Reference Signs List 1 hydrogen peroxide gas decontamination device 11 container 12 heater 13 temperature controller 14 timer 15 neutralization device 16 hygroscopic agent

Claims (2)

A hydrogen peroxide gas decontamination method for decontaminating a space to be decontaminated using hydrogen peroxide gas,
A container in which the hydrogen peroxide solution is placed,
A heater for heating the hydrogen peroxide solution in the container by heating the container,
A temperature controller for controlling the heater to heat and control the hydrogen peroxide solution to 70 to 90 ° C;
A timer connected to this temperature controller,
Connected to this timer, using a hydrogen peroxide gas decontamination device equipped with a neutralization device having a function of neutralizing and decomposing the hydrogen peroxide gas in the decontamination target space ,
Heating the pre-Symbol aqueous hydrogen peroxide 70 to 90 ° C. by the heater, the concentration of hydrogen peroxide gas in the decontamination target space and 200～400Ppm,
When the decontamination time by the hydrogen peroxide gas set by the timer elapses, the heating of the hydrogen peroxide gas by the heater is stopped, the neutralization device is automatically activated, and the A method for decontaminating hydrogen peroxide gas, comprising decomposing hydrogen gas to a concentration of 1 ppm or less. The absorption humectant provided on the decontamination object space,
The method for decontaminating hydrogen peroxide gas according to claim 1, wherein the moisture absorbent prevents dew condensation while maintaining the humidity required for decontamination .

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