JPH01123694A - Back-contamination preventing device and back-contamination preventing method using said device - Google Patents

Abstract

PURPOSE:To surely sterilize the inside of a water introducing pipe from a germ-free water producing device to an intake port so as to prevent back-contamination by supplying an inorg. halide to the electrolytic chamber of an electrolyzing device while germ-free water is kept stored in the electrolytic chamber and utilizing the hypohalogenite generated by effecting an electrolysis. CONSTITUTION:The supply of the germ-free water is stopped by closing water-stop valves 4, 5 provided on the intake port 6 side of the germ-free water producing device 1 and/or the side opposite thereto after the end of using the germ-free water. The inorg. halide is then supplied from a supplying device 2 into the electrolytic chamber of the electrolyzing device 13 provided between the intake port and the germ-free water producing device while the germ-free water is kept stored in said electrolytic chamber. The storage water contg. the aq. halide soln. is then electrolyzed by energization of the electrolyzing device to form the hypohalogenite. The stored water in the electrolytic chamber is sterilized by this hypohalogenite and the inside of the water conduit pipe 10 is sterilized as well. The hypohalogenite-contg. water is further gradually passed to the intake port by the pressure of the gaseous hydrogen generated from the electrode by the electrolysis to disinfect the intake port and to prevent the back-contamination from the intake port.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention completely prevents microorganisms from entering through the water intake ports of various sterile water production devices used in medical institutions such as hospitals, pharmaceutical manufacturers, food manufacturers, etc. The present invention relates to a back-contamination prevention device and a back-contamination prevention method using the same.

[Conventional technology and its problems]

It is well known that sterile water, which does not contain impurities such as particulates and microorganisms such as bacteria, is essential for medical institutions such as hospitals, medical product manufacturers, and food manufacturers.

In recent years, filtration membranes that can remove microorganisms such as bacteria have been developed.
BACKGROUND ART A sterile water production device that can produce sterile water relatively easily and has high reliability has been put into practical use. However, the inside of the water conduit between the sterile water production device and the water intake can be contaminated by microorganisms such as bacteria floating in the air, and preventing contamination caused by such microorganisms has been an issue for some time.

Conventionally, as a method to prevent contamination by microorganisms in the water pipes leading to the sterile water production equipment and the water intake,
The following four methods have been mainly proposed.

(1) At the same time as the flow of sterile water from the sterile water production equipment stops, the heater installed in the water pipe is energized to heat the water inside the water pipe and release it as steam to the outside, thereby preventing bacteria from entering. By drying the inside of a water pipe, we prevent the growth of bacteria. Furthermore, we turn off the heater after a predetermined time has passed using a timer, and take advantage of the fact that the inside of the water pipe becomes pressure-proof as the temperature inside the pipe falls. A heating sterilization method that uses its own weight and pressure to seal the check valve installed in the container, preventing bacteria from entering.

(2) An elastic pinch valve that is an integrally molded cylindrical silicone rubber tube with slanted elliptical ribs on the inside, and has the function of isolating the rib from the outside by pressing the rib from one or both directions. Elastic pinch valve method using a valve.

(3) Silver vapor deposit filling method, in which the faucet is filled with silver vapor deposit and the sterilizing effect of silver ions is used to prevent bacteria from entering through the faucet.

(4) Disinfection method using disinfectant such as sodium hypochlorite water.

However, with these methods, even if it is possible to prevent microorganisms from entering the sterile water production device from the water conduit, it is difficult to avoid microbial contamination at the tip of the faucet. For this reason,
At least the water that initially flows out of the faucet cannot be completely sterile.

The present inventors previously discovered that the sterile water produced by passing raw water into a sterile water production device, which consists of an inorganic halide supply device, an electrolysis device, and a water stop valve installed at a water intake, can be stopped. After the water valve is closed and water is stored in the electrolytic chamber of the electrolyzer, inorganic halide is supplied from an inorganic halide supply device into the electrolytic chamber and electrolyzed, thereby sterilizing the electrolytic chamber and the water pipe. We developed a new reverse contamination prevention device and proposed it in Japanese Patent Application No. 107340/1983.

This device generates hypohalite through electrolysis, and then allows water containing this hypohalite to flow out of the faucet, making it possible to disinfect everything from water pipes to water intakes. .

As a result of further research, the inventors of the present invention found that by providing a water stop valve on the water intake side of the sterile water production device and/or the opposite side, a similar method can be easily achieved without providing a water stop valve on the water intake. The inventors have found that this effect can be obtained and have arrived at the present invention.

[Means to solve the problem]

That is, the present invention provides a back contamination prevention device for a sterile water production device in which an electrolytic device is provided between a water intake and a sterile water production device, in which a stop is provided on the water intake side of the sterile water production device and/or on the opposite side. After closing the water valve and stopping the supply of sterile water,
This is a reverse contamination prevention device characterized by supplying an inorganic halide into the electrolytic chamber of an electrolytic device while sterile water is stored in the electrolytic chamber, and sterilizing the electrolytic chamber and the water pipe by electrolysis. Furthermore, the second invention provides an electrolytic device between the water intake and the sterile water production device, and closes the water stop valve provided on the water intake side of the sterile water production device and/or the opposite side to produce sterile water. After stopping the supply of sterile water, an inorganic halide is supplied into the electrolytic chamber of the electrolytic device while sterile water is stored in the electrolytic chamber, and the hypohalite generated by electrolysis causes water to flow inside the electrolytic chamber. The inside of the tube is sterilized, and the pressure of the gas generated from the electrodes in the electrolytic chamber is used to sterilize the inside of the tube.
This is a reverse contamination prevention method characterized by flowing hypohalite-containing water toward the water intake and sterilizing the water pipe and water intake up to the water intake.

[Effect]

The back contamination prevention device of the present invention is comprised of a water stop valve provided on the side of the halide supply device, the electrolysis device, and the sterile water production device and/or on the opposite side thereof.

If the interior of the water conduit filled with sterile water remains as it is, there is a possibility of secondary contamination due to microorganisms entering from the water intake. In the reverse contamination prevention device of the present invention, in order to prevent this secondary contamination, after the use of sterile water is finished, the water stop valve provided on the water intake side and/or the opposite side of the sterile water production device is closed to sterilize the water. After the water supply is stopped, hypohalite is generated or injected into the water conduit while sterile water is stored in the electrolysis chamber of the electrolyzer. To generate hypohalite, for example, an inorganic halide is injected from an inorganic halide supply device into the water stored in a water conduit, and then electricity is applied to an electrolyzer to electrolyze the water containing the aqueous halide solution. When stored water is electrolyzed, the halogen ions contained in the stored water become halogen molecules through anodic oxidation, and these halogen molecules further react with hydroxide to produce hypohalite.

When sodium chloride, for example, is used as the inorganic halide, the reaction formula for this series of reactions is as follows.

Na1l + HzO→Na0B + '41 Hzi
10IL ↑CL +2NaOH-NaCJJO+NaC
u+HzO The hypochlorite thus produced is effective against most microorganisms such as viruses, general nonspore-forming bacteria, acid-fast bacteria, bacterial spores, filamentous fungi, algae, and protozoa.
Usually, it has the ability to complete sterilization in a short time at a concentration of about 10 ppm.

This sodium hypochlorite sterilizes the water stored in the electrolysis chamber and at the same time sterilizes the water pipes.

Furthermore, gas such as hydrogen gas is generated from the electrodes due to electrolysis, and the space between the sterile water production device and the electrolytic chamber is filled. This filled gas pressure causes hypohalite-containing water to gradually flow into the water intake, which disinfects the water intake.
The effect of preventing back contamination is enhanced.

Also, only when the water intake is composed of pores with a diameter of 2.5 mm or less, disinfectant-containing water is stored due to the pressure-proofing inside the water pipe. Therefore, not only is there no risk of contamination of the water pipes with microorganisms when the equipment is not in use, such as at night, but the water intake can also prevent secondary contamination of microorganisms due to the action of disinfectant-containing water stored in the water intake. more preferable.

〔Example〕

One embodiment of the present invention will be described based on FIG. 1st
In the figure, (1) is a sterile water production device, (2) is an inorganic halide supply device, (3) is an electrolysis device, (4) is a water stop valve on the opposite side of the water intake, and (5) is on the water intake side. water stop valve, (6
) is the water intake, and (10) is the water pipe. Examples of sterile water production equipment (1) include commonly used distilled water production equipment, pure water production equipment, ultraviolet sterilization equipment, ultrafiltration equipment, reverse osmosis equipment, heat sterilization equipment, etc., but not only these. A module consisting of a polyethylene porous hollow fiber membrane having vertical IM and 0.1 M slit-like ultrafine pores on the surface of the hollow fiber, such as Stellabore (registered trademark, manufactured by Mitsubishi Rayon ■), can be used.

It goes without saying that filtration modules using hollow fiber membranes or flat membranes other than these, such as polyacrylonitrile, polysulfone, polyvinyl alcohol, polymethyl methacrylate, etc., can also be used.

As the sterile water production device W(1), a device using porous hollow fibers is particularly preferable because of its simple structure and low cost.

The water stop valve has the function of shutting off the raw water as well as the function of sealing off the sterile water production device to fill it with gas generated by electrolysis, but its installation location differs depending on the type of sterile water production device. For example, when using a sterile water production device made of a porous hollow fiber module, at least a water stop valve (4) is provided on the opposite side of the water intake. When using other sterile water production equipment, at least the water stop valve on the water intake side (
5). However, if the sterile water production apparatus becomes large-sized, both the water stop valves (4) and (5) may be provided.

FIG. 2 shows a sterile water production device using polyethylene porous hollow fibers, in which (7) is an electrode, (8) is a porous hollow fiber, and (9) is an air vent.

Although the polyethylene porous hollow fiber is subjected to a hydrophilic treatment in advance, the other membranes mentioned above maintain their hydrophilicity even without any particular hydrophilic treatment. These hydrophilic membranes have the property of allowing water to pass through them but not allowing water-insoluble gases to pass therethrough.

- The sterile water produced by the sterile water production device (1) is
), but when the use of sterile water is finished, the water stop valve (4) is closed to stop the supply. At this time, the sterile water production equipment (
The raw water in 1) is filtered through the hollow fiber membrane (8) by the atmospheric pressure of the air entering from the air vent (9), and is gradually dripped from the water intake (6). Along with this, the water level of the raw water in the sterile water production device (1) gradually lowers, but since the hollow fibers (8) do not allow air to pass through, after a certain amount of sterile water has dripped due to the pressure barrier, the electrolytic chamber ( 31) and the water conduit between the sterile water production device (1) and the electrolysis chamber (3).

It is more preferable to place the water intake (6) at a higher position than the electrolytic chamber (31) because this increases the amount of water stored in the electrolytic chamber (31) and the water pipes before and after the electrolytic chamber (31).

An inorganic halide is supplied to the sterile water in the electrolysis chamber (31) from an inorganic halide supply device (2).

As the inorganic halide supply device (2), for example, the third
An inorganic halide aqueous solution supply device having a structure as shown in the figure can be used.

That is, a bellows-type inorganic halide aqueous solution container (22), which is stably installed by a container stabilizing rod (21), is installed in the main body of the device for supplying the inorganic halide aqueous solution, and the inorganic halide aqueous solution supply feed handle ( 23), the feed screw (25) is used to release the presser plate (
26) moves a certain distance. Through this operation, the inorganic halide aqueous solution in the inorganic halide aqueous solution container (22) flows into the opening (3) in the electrolytic chamber (31) shown in FIG.
6) A more constant amount is injected. It also prevents the solution in the electrolytic chamber (31) from flowing back into the inorganic halide aqueous solution container (22) and changing the concentration of the inorganic halide aqueous solution in the inorganic halide aqueous solution container (22). In order to prevent gas from entering, a check valve (2) is installed at the boundary between the electrolytic chamber (31) and the inorganic halide aqueous solution container (22).
4) etc. may be provided.

As the inorganic halide aqueous solution container (22), plastic containers having various shapes other than the bellows shape can be used. For example, a polyethylene bottle that can be compressed can be used; in this case, an air valve should be provided to ensure that the container returns to its original shape after supplying the inorganic halide aqueous solution. is preferred. Alternatively, a method may be adopted in which a fixed amount of the inorganic halide aqueous solution is injected by using a container with a syringe-like mechanism and pushing a piston a fixed length.

The concentration and amount of the inorganic halide aqueous solution to be injected into the electrolytic device (3) are determined in the electrolytic chamber (31) in the electrolytic device (3).
Although it cannot be determined generally, the concentration is usually about 0.1 to about 30% for about 10 to 40 ml of sterile water in the electrolytic chamber and water pipe.
of an inorganic halide aqueous solution of about 0.1 to 5. It is used by injecting Qml.

In the present invention, the inorganic halide aqueous solution that can be used includes NaCl, KCI, LiC#, A N CII
3-, aqueous solutions of inorganic chlorides that generate chloride ions by electrolysis, such as N Ha CIl % Ca C122, aqueous solutions of inorganic iodides, such as Na1K1, and aqueous solutions of inorganic bromides, such as Na B r % K Br, etc. Among these, NaCA is preferably used because of its ease of availability.

Further, the inorganic halide aqueous solution may be injected into the electrolytic chamber from an inorganic halide aqueous solution container using a metering pump.

Moreover, in the present invention, in addition to the method of injecting an inorganic halide aqueous solution into the electrolytic chamber (31) as described above,
For example, it is also possible to adopt a method of supplying a predetermined amount to the electrolytic chamber (31) using an inorganic halide exhibiting sustained release properties such as tablets or capsules formed into pellets. The above-mentioned tablets may be sustained-release tablets coated with hydrogel or the like so that the ingredients gradually dissolve. As the hydrogel, a crosslinked 2-hydroxyethyl methacrylate polymer or copolymer is preferably used.

Alternatively, a system may be used in which sustained-release tablets are set near the electrodes and the tablets are replaced periodically depending on the lifespan of the tablets.

The inorganic halide supplied to the electrolytic chamber (31) is mixed with sterile water in the electrolytic chamber (31), and then electrolyzed by applying electricity to the electrodes.

That is, in FIG. 4, an anode (32) and a cathode (33) are provided at the bottom of the electrolytic chamber (31), and the power source (
DC electricity is applied from 34).

The electrodes used for the anode (32) and cathode (33) are usually platinum electrodes that do not undergo corrosion or other changes even when immersed in water for long periods of time, metals such as copper and nickel, synthetic resins, ceramics, etc. Electrodes that are plated or vapor-deposited with gold or platinum are also used. Further, in order to easily replace these electrodes, the cap (35) provided with the electrodes may be fixed with screws, as shown in FIG. 3.

The power source (34) is usually household AC electricity (100cm
) can be transformed into direct current using a transformer, or batteries such as dry cells can be used. Further, a timer may be installed between the power source (34) and the electrodes to ensure that the power is turned on at a predetermined time.

The voltage and current applied to the anode (32) and the cathode (33) as well as the current application time vary depending on the type, concentration, amount, etc. of the inorganic halide aqueous solution in the electrolytic chamber (31), and therefore cannot be determined in part. I can't, but
For example, if the inorganic halide is NaC-1,
Usually, the effective chlorine concentration in the electrolytic chamber (31) is 0.5 to 5.
00ppm1 In particular, in order to sterilize microorganisms such as mold, it is adjusted to about 10ppm or more. Further, the electrolysis time using the sodium chloride aqueous solution varies depending on the concentration of the sodium chloride aqueous solution, the amount of supply, the amount of current, etc., but is preferably 10 to 120 minutes.

In the apparatus shown in FIG. 2, by injecting an inorganic halide into the electrolyzer (3) and electrolyzing it, hypohalite is produced and gas such as hydrogen is generated from the electrodes.

Then, since the porous hollow fiber (8) does not allow gases that are poorly soluble in water to pass through, the gas that is sparingly soluble in water that is generated is blocked and filled in the direction of the sterile water production device (1). The hypohalite-containing water in the electrolyzer (3) is pushed toward the water intake (6) and gradually flows out. By generating a flow of hypohalite-containing water using such gas pressure, the space between the electrolysis chamber and the water intake can be disinfected.

In addition, the water intake (6) is connected to the faucet nozzle (as shown in Figure 5).
60) with one or more pores (61) with a diameter of 2.5 mm or less, part of the hypohalite-containing water flowing from the electrolyzer to the water intake by gas pressure. is stored in the water intake, thereby completely preventing microbial back contamination from the water intake.

The faucet nozzle (60) is removable from the water conduit (5) using screws, fitting means, etc., and the faucet nozzle can be easily cleaned or replaced.

Moreover, the diameter of the pore (61) is 2.5 mm or less, and one or more pores are provided. If the diameter is larger than 2.5 mm, all of the disinfectant-containing water will flow out from the water intake and will not be stored at all, or only a small amount will be stored, making it impossible to fully achieve the object of the present invention.

Figure 6 shows the porous hollow fiber module (4B) (49
) shows an embodiment of the present invention using a sterile water production device. Tap water from (411) to solenoid valve (41)
0) and supply the porous hollow fiber module (4B).
(49), and sterile water flows out from the water intake (41). Solenoid valve (410”) when finished using sterile water
Close. At this time, the water conduit (43) and the electrolysis chamber (44) are filled with sterile water. Next, the handle (47) is turned to supply inorganic halide-containing water (46) to the electrolysis chamber (44), and then electricity is applied to the electrode (45) to perform electrolysis for a certain period of time. As a result, the hypohalite is dissolved in the water conduit (43) in and around the electrolytic chamber. Inside the electrolysis chamber (44) and the water pipe (43) during and after electrolysis
The water inside flows out little by little from the water intake port (41) due to the pressure of gas generated by electrolysis. The water intake (41) is
It consists of pores with a pore diameter of 2.5 mm or less, and hypohalite-containing water is stored in both the water conduit (43) and the water intake (41), completely preventing secondary contamination by microorganisms.

In addition, (412) is a control unit for automatically performing the above operation, and (50) is a control unit (412).
An electric cord connects the solenoid valve (410) and the control unit (412) to the electrode (45).

The water outlet (54) is a sterile water production device using a reverse osmosis membrane. Since sterile water production equipment using reverse osmosis membranes is susceptible to secondary contamination by microorganisms, a small sterilization filter (52) is installed as shown in Figure 7, but it is not necessary as shown in Figure 8. good. The operation and effect are substantially similar to the device of FIG.

Next, FIG. 1 shows an example in which a reverse osmosis membrane device is used as the sterile water production device (1). In this case, a water stop valve (5) is provided and the water stop valve (5) is closed when the use of the sterile water is finished. At this time, some of the sterile water between the water stop valve (5) and the water intake (6) flows out from the water intake (6), but is generated in the water conduit between the water stop valve (5) and the electrolysis chamber. Because it is pressure-proof, all of it remains inside the electrolytic chamber without leaking out. Therefore, by injecting an inorganic halide from the inorganic halide supply device (2) and performing electrolysis, the same effect as in the case of the hollow fiber module can be produced. Moreover, since it is closed by the water stop valve (5), hypohalite-containing water flows into the water intake (6) due to the generated gas pressure, thereby preventing secondary contamination.

Even in this case, it is best to place the water intake at a higher position than the electrolysis chamber, especially higher than the water stop valve (3).

[Example 1] In the apparatus shown in FIG. 1, Stellapore (Mitsubishi Rayon side type) was used as a sterile water production apparatus.

Then, 0.5 ml of the inoculum solution cultured by the method detailed below was inoculated into 30 ml of sterile water in the pipe, and the number of inoculated bacteria was 10 in the electrolytic chamber using a syringe (for lm It). The cells were inoculated at ~106 cells/ml. Then, 0.5 ml of a 10% aqueous sodium chloride solution was injected into the electrolytic chamber using an inorganic halide supply device, and a direct current of 10 mA was applied to the two electrodes to perform electrolysis for 60 minutes.

After the electrolysis is completed, after draining the sodium hypochlorite-containing water, sterile water is passed through the sterile water production equipment, water is sampled from the faucet, and the test is carried out according to the 10th edition of the Japanese Pharmacopoeia, General Test Method 37. Sterility Test. A sterility test was conducted in accordance with the Act. Judgments were made by incubating at 30°C for 7 days for recent tests and 10 days at 20°C for fungal tests.

The results are shown in Table 2.

The inoculum was prepared using the following method.

(Preparation of inoculated bacteria) Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger were used as inoculated bacteria.Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa were cultured at 35°C for 24 hours and then incubated for 3 consecutive days. Candida albicans was cultured for 48 hours at 25°C and then passaged for 2nd generation every 2 days.
Aspergillus niger was cultured at 25°C for one week.

For Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Cansida albicans, the number of bacteria is 10 after washing with sterile physiological saline in a centrifuge for 3 times at 3000 rpm.
A bacterial solution containing 8 cells/mβ was prepared.

In addition, for Aspergillus niger, 0°05%
A spore suspension was prepared using sterile physiological saline containing polysorbate 80, and the suspension was centrifuged at 3000 rpm.
After washing 3 times for 3 minutes, resuspend using sterile saline and 10 minutes.
A bacterial solution containing 7 bacteria/ml was prepared.

[Margin below]

From the above results, it was found that secondary contamination between the water outlet and the water intake of the sterile water production device is completely prevented by the reverse contamination prevention device of the present invention.

[Example 2] In the apparatus shown in FIG. 7, the solenoid valve (410) was opened, tap water was injected into the sterile water production device to produce sterile water, and the water was sent to an electrolytic chamber with a content fi 30 m 12. Sterile water was stored in the electrolysis chamber.

Next, 1 ml of 10% sodium chloride aqueous solution was injected into the electrolytic chamber, electricity was applied to the two electrodes, and the chlorine concentration in the electrolytic chamber was measured after 60 minutes. The effective chlorine concentration was 194 pp.
It was m. The sodium hypochlorite-containing water in the electrolysis chamber gradually flowed out from the water intake due to the gas pressure generated by electrolysis.

When 120 minutes had passed after the end of electrolysis, the effective chlorine concentration of the water stored in the water intake (41) was measured and found to be 4 ppm.

[Example 3] Hscherichia colt I as a test bacterium
F O3972% 5erratia marces
cens I FO12648 was cultured at 35°C for 24 hours, and 3 bales were carried out for 3 consecutive days. Then, using sterile physiological saline, centrifuge at 3000 rpm mlO for 3 minutes.
After washing twice, a bacterial solution of 108 cells/ml is prepared.

After adjusting the test bacterial solution (10' cells 7ml),
1 m of test bacteria solution to 300 mf of sterile physiological saline! After inoculation, the number of viable bacteria in physiological saline was 10” cells/
ml.

After using sterile water, electrolysis was performed in the same manner as in Example 1 using the same equipment as in Example 1, and the number of viable bacteria in 20 ml of water stored in the water intake (41) was measured immediately after hypoxia. By the way, E, Co11. Both S. and marcescens were O. From these results, it is clear that microbial contamination from the water intake can be completely prevented.

〔Effect of the invention〕

As described above, according to the reverse contamination prevention device of the present invention, the inside of the black water pipe from the sterile water production device to the water intake can be reliably sterilized and reverse contamination can be prevented. It is extremely easy to handle. In particular, since there is no need for a water stop valve between the electrolyzer and the water intake, the cost is low and the automation system can be simplified.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the reverse contamination prevention device of the present invention, Fig. 2 shows an example in which the present invention is applied to a sterile water production device consisting of a porous hollow fiber module, and Fig. 3 shows an inorganic halide supply. 4 is a schematic illustration of the electrolyzer, FIG. 5 is a perspective view of the water intake, and FIG. 6 is an example in which the present invention is applied to a sterile water production device consisting of a porous hollow fiber module. 7 and 8 show an example in which the present invention is applied to a reverse osmosis membrane sterile water production apparatus. (Main symbols in the drawings) 1: Sterile water production device 2; Inorganic halide supply device 3: Electrolyzer 4: Water stop valve 5: Water stop valve 6: Water intake 10; Water pipe patent applicant Tomey Sangyo Co., Ltd. Haka 1 person LL 26 figure b

Claims (4)

[Claims] (1) In a back-contamination prevention device for a sterile water production device that has an electrolyzer installed between the water intake and the sterile water production device, a water stop valve is provided on the water intake side of the sterile water production device and/or on the opposite side. After the sterile water is closed and the supply of sterile water is stopped, an inorganic halide is supplied into the electrolytic chamber of the electrolyzer while the sterile water is stored in the electrolytic chamber, and the inside of the electrolytic chamber and the water pipe are sterilized by electrolysis. A device for preventing back contamination. (2) The reverse contamination prevention device according to claim 1, wherein the water intake port is located at a higher position than the electrolysis chamber. (3) By providing one or more pores with a diameter of 2.5 mm or less in the water intake, hypohalite-containing water flows toward the water intake by the pressure of the gas generated from the electrode in the electrolytic chamber. 2. The reverse contamination prevention device according to claim 1, wherein the hypohalite-containing water is stored in a water intake port. (4) An electrolytic device is installed between the water intake and the sterile water production device, and the water stop valve provided on the water intake side and/or the opposite side of the sterile water production device is closed to stop the supply of sterile water. After
While sterile water is stored in the electrolytic chamber of the electrolytic device, inorganic halides are supplied into the electrolytic chamber, the hypohalite generated by electrolysis sterilizes the electrolytic chamber and the water pipe, and then the electrolytic chamber and water pipes are sterilized. A reverse contamination prevention method characterized by flowing hypohalite-containing water toward the water intake using the pressure of the gas generated from the electrode, and sterilizing the inside of the water pipe leading to the water intake and the water intake.