RU2566727C1 - Steam-peroxide disinfection method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of disinfecting clothes includes placing clothes on hangers in a closed disinfection chamber with thickness of the layer of one set of clothes on a hanger of not more than 0.2 m and with loading capacity of not more than 35.0 kg/m³; heating a steam-air mixture to 99±1°C for 5 minutes; treating with a steam-peroxide mixture and holding at 99±1°C for 15 minutes, wherein the given temperature in the chamber for the entire duration of holding is provided by further releasing steam into the chamber. The steam-peroxide mixture is obtained by injecting into the disinfection chamber using saturated steam a hydrogen peroxide solution with concentration of 10.0±2.0 wt % at a rate of 1 l/m³ for not more than 5 minutes.

EFFECT: invention enables to simultaneously treat materials with a different composition and articles made from said materials without deterioration of consumer properties and also cuts the duration of disinfection.

1 dwg, 2 tbl, 1 ex

Description

The invention relates to the field of disinfection, and in particular to methods of disinfecting (sterilizing) objects in disinfection chambers, and can be used to carry out anti-epidemic and disinfection measures, when eliminating foci of especially dangerous infections, as well as the consequences of emergencies and terrorist acts using biological pathogenic agents .

Known methods for chamber disinfection of clothing, shoes, bedding, various clothing items, books and documents, which consist in processing objects with a steam-air or steam-formalin mixture [1, 2].

Cotton, linen, woolen, woolen, natural silk and chemical fibers, as well as bedding, books and other items, are exposed to steam-air disinfection. The disinfecting agent is a steam-air mixture (a mixture of air and saturated water vapor) at a temperature of from 70 to 100 ° C. Depending on the resistance of the object to the effects of high temperature and the type of infection pathogen, the exposure is from 10 to 30 minutes when processing from vegetative forms of microorganisms and viruses, 40-45 minutes when processing from spore forms [1, 2].

The steam-formalin method disinfects leather, fur, fur-sheepskin and felt products, leather and rubber shoes, clothes with fur lining, cotton and wool products trimmed with fur, chemical fiber products and other objects that deteriorate when exposed to high temperature during steam-air disinfection . The disinfecting agent is a steam-air mixture with formaldehyde vapor, the amount of which in the chamber depends on the microorganism (vegetative or spore form). Disinfection of objects is carried out at a temperature of 58 ° C, humidity from 80 to 100% and exposure of 45 minutes in the case of processing from vegetative forms of microorganisms and 2 hours 45 minutes from spore forms [1, 2].

There are methods for disinfecting equipment, devices and medical devices, various containers for products [3-6], as well as laboratory rooms and air conditioning systems of the so-called evaporated hydrogen peroxide (VHP) [7, 8]. The authors point to the need to use highly concentrated solutions of hydrogen peroxide (30-90%) and its anhydrous organic or inorganic complexes in order to minimize the moisture content of the peroxide vapor and to avoid the process of moisture condensation at the processing objects. To evaporate hydrogen peroxide (PV), electric heaters are used, porous tubes heated by a stream of hot air, hot metal or ceramic plates, onto which a solution of PV is constantly dosed to maintain a given concentration of its vapor in the air. For delivery of VHP from the evaporation area to the processed objects (cavities), as a rule, hot air flows or a pressure gradient created by various types of fans or by vacuum are used. The duration of disinfection of objects decreases from 3 hours to several seconds with increasing temperature of the mixture of vapors of hydrogen peroxide with air from 22-35 ° C to 70-130 ° C and an increase in its concentration in air from 1.7 g · m ^-3 to 500 g m ^-3 (in terms of the volume of the processed object) [3-8].

However, for the disinfection of large volumes of clothing, such as army uniforms, skin protection equipment and other items of equipment, documents and books that are heterogeneous in composition, hydrogen peroxide vapor has not been previously used. Some sources of information mention that the treatment of hydrogen peroxide with steam obtained from concentrated solutions (30% or more) leads to a change in the color of the surfaces of disinfection objects [8].

The classical methods of chamber disinfection of clothing items are quite reliable, they allow you to process a wide range of items made from materials of various purposes and composition. The consumer properties of the products, subject to the “Disinfection Instructions ...” [2], are practically unchanged, with the exception of products from woolen and silk fabrics, as well as with insulation made from natural wool and batting, which shrink due to the properties of the material itself [9, 10] . The main disadvantage of chamber methods is the large exposure (duration of exposure to the disinfecting agent) during the disinfection of property according to the sporocidal regimen. The duration of the full processing cycle, taking into account auxiliary operations for servicing descamers (preparing the chamber for operation, loading the property, heating the property to a predetermined temperature, unloading the property, for the steam-formalin method - additionally neutralizing formalin or airing the property in the chamber), increases by another 20-60 minutes [ 2].

The purpose of the invention is the creation of an effective sporocidal method of chamber disinfection of clothing items, which allows to reduce the duration of disinfection and at the same time process various materials and products from them without compromising consumer properties.

This goal is achieved in that in order to destroy microorganisms that contaminate clothing, they are exposed to a mixture of vapors of hydrogen peroxide, saturated water vapor and air at high temperature and normal atmospheric pressure.

The invention consists in the processing of objects placed in a confined space and preheated to a temperature of (99 ± 1) ° C, steam-peroxide mixture obtained by spraying saturated water vapor with an aqueous solution of hydrogen peroxide with a concentration of (10 ± 2)% wt. and a flow rate of 1 l · m ^-3 , and exposure to the specified mixture with an exposure of 20 minutes at a temperature of (99 ± 1) ° C.

Industrial applicability of the present invention lies in the fact that existing steam-air-formalin disinfection chambers can be used to disinfect clothing items with a steam peroxide method without changing their design.

The cameras are serviced, prepared for operation and put into operation in accordance with their technical description and operating instructions. Disinfection work is carried out in compliance with the requirements of regulatory documents governing the rules for the treatment of pathogenic microorganisms.

The disinfection chamber is prepared for work and before loading the property, it is preheated with steam to a temperature of 70 ° C. Disinfection objects (individual sets of property or individual items of clothing) are pre-hung on hangers-hangers that are included in the package of the camera.

The summer set of property consists of seasonal underwear, socks, a shirt (light jacket or windbreaker without padding) and trousers, the set weight is (1.9 ± 0.1) kg. The winter set of property consists of seasonal underwear, socks, a shirt or a light jacket and trousers without a lining, upper insulated clothing - a jacket and trousers (semi-overalls) on the lining, the mass of the set is (5.0 ± 0.1) kg. Garments are made of cotton, mixed (cotton with the addition of synthetics) or synthetic fabrics.

Hangers with property are loaded into the heated chamber, evenly distributing them along the entire length of the rod located in the upper part of the chamber. The norm of loading of property is not more than 35.0 kg · m ^-3 , which in terms of sets is not more than 32 summer or not more than 12 winter. When loading winter sets, the following condition must be observed: the distance between the sets should be 0.5-2.0 cm, the thickness of the layer of clothing on one hanger should not exceed 20 cm.

After loading the property, the chamber is closed and heated with steam for 5 minutes until the temperature inside the chamber (99 ± 1) ° С is reached. The temperature is determined by the readings of the built-in thermometer in the chamber. After that, the calculated amount of an aqueous solution of hydrogen peroxide with a concentration of (10.0 ± 2.0)% wt., Which is determined taking into account the flow rate of 1 l · m ^-3 of the chamber volume, is poured into the formalin tank. The solution from the formalin tank is injected into the chamber using saturated aqueous steam for no more than 5 minutes. After that, the clothes are kept at a temperature of (99 ± 1) ° С for 15 minutes, and the set temperature is provided during the entire exposure by periodically additionally letting water vapor into the chamber. At the end of the exposition, the camera is opened, the property is unloaded and used for its intended purpose.

The total duration of the full processing cycle is 35 minutes: loading of property - 5 minutes; temperature rise to (99 ± 1) ° С - 5 minutes; the duration of exposure of the disinfecting agent to the objects is 20 minutes (injection of a solution of hydrogen peroxide for 5 minutes, followed by exposure for 15 minutes); unloading of property - 5 minutes.

The proposed method differs from analogues in that a steam peroxide mixture is used to disinfect clothing items, while a low-concentrated (10%) aqueous solution is used to obtain peroxide vapor, hydrogen peroxide vapor has high humidity, and vaporization of the peroxide and delivery of its vapor to disinfection units is carried out at using saturated water vapor with a temperature of (99 ± 1) ° C at a pressure of 1.5 to 4.0 atm (working steam pressure in the steam boiler of the disinfection chamber). Unlike analogues in the claimed method, the concentration of peroxide in the vapor-peroxide mixture is not constant: it increases during the injection process and reaches a maximum after 5 minutes, then within 15 minutes the concentration of PV in the mixture decreases to almost zero values. This is due to the decomposition of peroxide under the influence of high temperature into safe substances water and oxygen, as well as the dilution with water vapor and entrainment of a small amount of peroxide along with it into the atmosphere through the outlet openings in the disinfection chamber. As a result, by the time the exposure ends, there is no need to neutralize or otherwise remove hydrogen peroxide from the disinfection chamber and from the treated objects.

The present invention implements a fundamentally different method of vaporizing hydrogen peroxide. To do this, use the standard system for supplying formalin to the disinfection chamber — a formalin tank or Benjaminson-Kruchin apparatus (Fig. 1). The tank consists of a housing 1, into which a solution of hydrogen peroxide is poured through a pipe 6 and closed with a stopper 7. Before pouring hydrogen peroxide, the drain valve 5 must be closed. After filling the tank through the pipe 2, water vapor is supplied, which exits through the hole 3, passes through a solution of hydrogen peroxide, heats it, as a result, the peroxide evaporates, the vapor of which, together with water vapor, enter the disinfection chamber through the pipe 4 [1].

It has been experimentally proved that the vapor peroxide method provides complete disinfection of clothing with a bacterial spore contamination density of up to 10 ⁵ CFU · cm ^-2 inclusive, while reducing the exposure time of the disinfecting agent by 2 times compared to the classical steam-air chamber disinfection method, and also allows simultaneous processing of various compositions materials and products from them without deterioration of consumer properties.

Example 1. Disinfection of clothing items by the steam-pericidal method was carried out in the combined disinfection and shower units ДДП-2 on a single-axle car trailer ИАПЗ-738 and ДДА-66 on a car GAZ 66 in accordance with the technical description and operating instructions.

The effectiveness of disinfection was evaluated by the bacteriological method using tissue test objects in accordance with the requirements of Guidelines Ρ 4.2.2643-10 [11], “Temporary guidelines ...” [12] and “Guidelines ...” [13]. Methods and means of disinfecting property items must ensure 100% destruction of microorganisms [11, 12], chamber disinfection methods must ensure that this condition is met with an initial density of contamination of objects from 1 · 10 ⁵ spores · cm ^-2 to 1 · 10 ⁶ spores-cm ^{- 2} [13].

An agar spore culture of Bacillus subtilis (strain 3) with a mature spore content of at least 90% was used as a test microorganism. The density of contamination of test objects ranged from 1 · 10 ⁵ spores · cm ^-2 to 1 · 10 spores · em ^-2 . The results of disinfection of clothing were considered positive if, after analysis of bacteriological samples by sowing in a liquid nutrient medium, no living microorganisms were detected at all test objects.

In the experiments, summer and winter individual sets of property were used, weighing respectively (1.9 ± 0.1) kg and (5.0 ± 0.1) kg. Garments were made from cotton, mixed (cotton with the addition of synthetics) or synthetic fabrics. For each load in the disinfection chamber, 5 contaminated sets of property and “clean” sets were placed in the quantity necessary until the camera was fully loaded. The contamination of sets of property was carried out as follows: from 15 to 20 infected test objects were fixed on each, evenly distributing them inside and out across the width and length of the items of clothing. When loading the camera, the contaminated sets were evenly distributed between the “clean” ones, and then the processing was carried out in accordance with the description of the claimed invention. After disinfection, the property was removed from the chamber, test objects were placed in individual containers with a liquid nutrient medium, the obtained bacteriological samples were processed in accordance with the requirements of Guidelines Ρ 4.2.2643-10 [11].

At the same time, during the experiments, the change in the concentration of hydrogen peroxide in the vapor peroxide mixture was evaluated during the exposure during the disinfection of clothing items. We also evaluated the change in consumer properties of the property (shrinkage, color, humidity) and the skin-resorptive effect of clothing materials after processing.

Shrinkage of garments was determined by comparing their linear characteristics before and after processing. Humidity was calculated as the ratio of the difference in mass of garments after and before processing to their mass before processing (to the mass of dry objects). The color change was determined visually.

The concentration of hydrogen peroxide in the initial solution and in the vapor peroxide mixture was determined by the volume permanganometric method. Samples of the vapor peroxide mixture were taken from the chamber using an M-822 vacuum aspirator.

The use of highly concentrated solutions of hydrogen peroxide (20% and higher) for the disinfection of property by the steam peroxide method led to a change in the color of clothes, therefore, the concentration of PV in the initial solution was reduced to (10.0 ± 2.0) mass%. At this concentration of the initial solution, no color change was observed.

Analysis of samples of the steam peroxide mixture showed that at the declared rate of consumption of a 10% PV solution at the rate of 1 liter per 1 m of the chamber, the amount of PV in the steam peroxide mixture reaches its maximum by the 5th minute, then sharply decreases by the 10th minute. Toward the end of the exposure, the concentration gradually decreases to the minimum values (Table 1), which is explained by the thermal decomposition of hydrogen peroxide into safe substances - water and oxygen, as well as dilution with water vapor and the entrainment of a small amount of peroxide along with it into the atmosphere through the outlet openings in the descamer.

Toxicological studies carried out on rabbits by the application method showed that the property after disinfection with the steam peroxide method does not have a skin-resorptive and irritating effect on the skin of experimental animals, which allows us to indirectly judge the safety of disinfected clothing for humans.

After steam-peroxide disinfection, the humidity of property made from synthetic and mixed fabrics was, on average, 1.59%, for property from cotton fabrics - 2.46%, for outerwear insulated - 4.98%. The data obtained comply with the sanitary and hygienic requirements for clothing and property that is issued to the consumer after disinfection or wet-heat treatment: the residual humidity should not exceed 5% [10].

Processing with the steam peroxide method practically does not change the linear characteristics of the clothes: shrinkage is from 0.03% to 1.12%, which corresponds to 0.4-1.1 cm. At the same time, to change the linear characteristics of clothes by one size, the shrinkage should be the width of the product is not less than 4 cm, the length of the product is not less than 6 cm [9].

The data presented in table 2 indicate that the complete disinfection of property with an initial contamination density of B. subtilis spores (strain 3) from 1.05 · 10 ⁵ to 5.27 · 10 ⁵ CFU · cm ^{-2 is} achieved by the vapor peroxide method during exposure 20 minutes and a clothing loading density of not more than 35.0 kg · m ^-3 (which in terms of individual sets is not more than 12 winter or 32 summer). The classic steam-air chamber disinfection method with the same exposure and loading does not ensure the complete disinfection of clothing property.

It has been experimentally proved that the vapor peroxide method provides complete disinfection of clothing with a bacterial spore contamination density of up to 105 CFU · cm ^-2 inclusive, with a 2-fold reduction in the exposure time of the disinfecting agent compared to the classical steam-air chamber disinfection method. The claimed method allows you to simultaneously process different in composition materials and products from them. The effect of the vapor peroxide mixture does not change the color of products, practically does not cause shrinkage of clothes. The property after disinfection does not require drying, does not have a skin-resorptive and irritating effect and can be immediately used for its intended purpose.

INFORMATION SOURCES

1 Karaseva A.N., Makarov A.G., Mikhelson G.A. et al. Chamber disinfection manual. M .: Medicine, 1972.

2. Instructions for the disinfection and disinsection of clothes, bedding, shoes and other objects in steam-formalin, steam and combined disinfection chambers and the disinfection of these objects in air disinfection chambers: Approved. Chief State Sanitary Doctor of the USSR 08/29/1977. // Handbook of sanitary-epidemiological regime. M .: Grant, 1998.

3. Apparatus for sterilizing an object with hydrogen peroxide, a method of sterilizing an object with steam of hydrogen peroxide (options), a sealed container: Pat.2176521 Ros. Federation: IPC ⁷ A61L 2/14, A61L 2/20 / Jacob Paul Taylor (US), Lin Szu-Ming (US), Chen Xiaolan (CN); Applicant and Patent Holder JONSON AND JOHNSON MEDICAL, INC. (US); declared 10/25/1996; publ. 12/10/2001.

4. A method of obtaining a gaseous sterilizing medium containing hydrogen peroxide: US Pat. 2035919 Ros. Federation: IPC ⁷ A61L 2/20 / Jan Andersson (SE), Lara Martensson (SE), Geran Schmitt (SE), Thomas Burborn (SE); Applicant and patent holder Tetra Laval Holdings & Finance S.A. (CH); declared 11/06/1990; publ. 05/27/1995.

5. A method of sterilizing surfaces and a device for sterilizing containers: US Pat. 2167799 Ros. Federation: IPC ⁷ B65B 55/02, A61L 2/20 / Ulrich Metzger (DE), Christian Schmid (CH); Applicant and patent holder SOSTIETE DE PRODUY NESTLE S.A. (CH); declared 08/09/1996; publ. 05/27/2001.

6. A sterilizer for sterilization with hydrogen peroxide vapor and a sterilization method using it: US Pat. 2404813. Grew. Federation: IPC ⁷ A61L 2/00 / KO June Suek (KR); applicant and patentee HUMAN MEDITECH CO., LTD. (KR); declared 11/26/2005; publ. 12/20/2007.

7. The effectiveness of gaseous hydrogen peroxide against mycobacterium tuberculosis. A. Kanert, P. Seiler, M. Stein and others. Institute of Infectious Biology. Max Planck, Berlin, Germany [Electronic resource] // Center for medical technology: [site], [2008-2012] / URL: http: //medtehmka.conVarticles/01/h2o2/.html (accessed date: 06/06/2012) .

8. Biological disinfection of rooms for animals and heat-sensitive equipment using vaporizing hydrogen peroxide. Jürgen Krause, Gerald McDonnell, Hermann Ridezel. American Association for the Study of Laboratory Animals [Electronic resource] // Center for Medical Technology: [site], [2008-2012] / URL: http: //medtehmka.conVarticles/01/h2o2/.html (accessed: 06.06.2012) .

9. Sakulin B.S., Amirova E.K. Designing men's and women's clothing: a Textbook. - M.: Academy, 1998.

10. Gerasimova V.F. Laundry production technology. M .: Legprombytizdat, 1985.

11. Methods of laboratory research and testing of medical prophylactic disinfectants to assess their effectiveness and safety: Guide .2 4.2.2643-10. - M .: Federal Service for Supervision of Consumer Rights Protection and Human Well-Being, 2010.

12. Temporary guidelines for typical methods of microbiological studies of effectiveness and evaluation of disinfection tools and methods: Approved. Head of TsVMU MO of the USSR 07/11/7972 - L .: Medicine, 1978.

13. Guidelines for monitoring the operation of steam and air sterilizers: Approved. Head of the Main Epidemiological Directorate of the Ministry of Health of the USSR, No. 15/6-5, February 28, 1991. - USSR Ministry of Health, 1982.

Claims (1)

A method of disinfecting clothes from woven and non-woven materials contaminated with spore forms of microorganisms, characterized in that these objects are placed on hangers in a closed disinfection chamber with a layer thickness of one set of clothes on a hanger not more than 0.2 m and with a loading rate of not more than 35.0 kg · m ^-3, steam-heated mixture to a temperature (99 ± 1) ° C for 5 min, then conduct processing paroperekisnoy mixture obtained by injecting into the chamber by means of water vapor from the hydrogen peroxide solution to ntsentratsiey (10,0 ± 2,0)% by weight. and a flow rate of 1 l · m ^-3 for no more than 5 minutes, then they are kept at a temperature of (99 ± 1) ° C for 15 minutes, while the set temperature in the chamber during the entire exposure is ensured by the additional release of water vapor into the chamber .

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