Germicidal lamp - how to choose a lamp by type, type, power, manufacturer and cost. New germicidal lamps operating in the presence of people

Man is exposed from all sides negative impact environment. Air is also a potential breeding ground for harmful microorganisms. A bactericidal lamp for the home will help you clean and disinfect the indoor air. Previously, such devices were used in highly specialized institutions. At present, the operation of germicidal lamps is feasible at home.

UV germicidal lamp according to the principle of its operation, it resembles fluorescent, but unlike the latter, it creates directional radiation of UV rays in a certain range. A fairly common misconception is that a bactericidal and a quartz lamp are one and the same. In reality, these are two different devices and should not be confused.

Why do you need a home bactericidal irradiator?

• floor type lamps;
• hanging type lamps;
• table lamps.

Floor lamps - type of portable lamps. Such models are best suited for spacious rooms, such as children's playrooms or living rooms. They are of medium size and in the process of work provide complete disinfection of the entire room.

Hanging lamps - variety of stationary lamps. They can be both wall-mounted and ceiling-mounted. The latter are less popular and have a rather limited range. Most commonly used at home wall germicidal lamp. Such demand is due to ease of use. It can be placed in any convenient place, while modern models have a rather attractive design and are able to harmoniously fit into any interior.

Table lamps - type of portable lamps. Thanks to its compact design and optimum power, portable germicidal lamp, similarly to wall models, best suited for home use. Its advantageous advantage is the possibility of local disinfection. The purpose of such lamps is local irradiation and disinfection of surfaces.

Service life of germicidal lamps of any type largely depends on the stability of the power grid. With private fluctuations in the network, it is reduced. It is also affected by the degree of humidity in the room, the number of inclusions, the dust content of the main parts of the device, and so on.

A separate word should be said about the new modified model, which appeared on the domestic market quite recently - lamp with germicidal lamp. It provides for the sequential alternation of the operation of fluorescent and bactericidal lamps. Some models are equipped with an automatic switching mechanism. Such luminaires have a universal compact structure and are intended for placement in any area (wall, closet, etc.)

Quartz lamps: principle of operation, features

Germicidal quartz lamp- a type of disinfectant equipment. Its operating principle is disinfection air environment premises through ultraviolet radiation. But, unlike a conventional germicidal lamp, the lamp shell of which is made of uviol glass, these devices use quartz glass. It transmits the entire spectrum of radiation produced by mercury, including ozone. The latter is quite dangerous in direct contact with living organisms. Therefore, after processing the premises, its mandatory ventilation is required.

However, a special model has been developed for a relatively long time - quartz germicidal lamp for home. On the this moment There are two types of such lamps:

• open (in the process of work, people should not be in the room)
• shielded (the presence of a person is possible only if the lamp is located in an appropriate way, excluding direct radiation on a person).

In addition, quartz lamps are divided into types, depending on the purpose. Some are designed to disinfect the air environment of the room, others - directly for disinfection. The latter are most often used in the presence of children with reduced immunity, the elderly or people suffering from chronic diseases in the house.

Operation of bactericidal and quartz lamps

When deciding to buy a disinfection device for the home, a logical question arises: how to choose germicidal lamp?

First of all, be guided by its purpose. There are lamps for direct air disinfection, and there are models designed for local disinfection of surfaces and various enclosed spaces (inside cabinets, refrigerators, etc.)

Secondly, it is also necessary to decide what requirements the device must meet: prevention and prevention of the development of pathogens or targeted treatment of household inhabitants.

Different types of germicidal lamps have differences in the spectrum of their action.

Working hours bactericidal lamp is determined by the purpose of the room itself and its size, as well as the type of the device itself. These indicators are indicated in the technical documentation and depend on their model.

05/17/2015 - We present to your attention the instructions for labor protection when working with bactericidal lamps. The instruction includes five chapters: 1) general requirements for labor protection; 2) labor protection requirements before starting work; 3) requirements for labor protection when performing work; 4) requirements for labor protection upon completion of work; 5) requirements for labor protection in emergency situations.

Chapter 1. General requirements on labor protection

1 TO independent work using bactericidal lamps (ultraviolet irradiators) are allowed persons who have reached the age of 18, who have the appropriate medical education and training in the specialty, who have theoretical knowledge and professional skills in accordance with the requirements of the current regulatory legal acts, who do not have contraindications to work in this specialty for health reasons who passed in the prescribed manner preliminary (when applying for a job) and periodic (during employment) medical examinations.

2. When working with germicidal lamps, workers must be trained safe methods and methods of performing work, he conducted an introductory briefing on labor protection and briefing on labor protection at the workplace, undergo an internship at the workplace and test knowledge on labor protection.

Repeated briefing on labor protection should be carried out at least once every six months.

When working with electrical medical devices, an employee must have 1 electrical safety group.

3. Medical devices must comply with the requirements of TNLA, documents of manufacturing organizations.

4. All medical electrical appliances must:

have a technical passport;

be equipped with grounding;

be in good condition.

5. Employees are obliged:

comply with the work and rest regime established by the legislation, the internal labor regulations of the organization, labor discipline, comply with the requirements of labor protection, personal hygiene rules;

comply with fire safety requirements, know the procedure in case of fire, be able to use primary fire extinguishing means;

smoke only in designated smoking areas;

know how to provide first aid in case of accidents;

about the malfunction of bactericidal lamps and other comments on working with medical equipment, devices and tools, report to the head of the office or persons involved in the maintenance of the equipment;

comply with the requirements for labor protection, as well as the rules of conduct on the territory of the institution, in production, auxiliary and amenity premises;

maintain order in your workplace;

undergo medical examinations, training (education), retraining, advanced training and testing of knowledge on labor protection issues in accordance with the procedure established by law;

carefully fulfill their official duties;

use germicidal lamps strictly in accordance with the manufacturer's instructions;

correctly apply personal and collective protective equipment in accordance with the conditions and nature of the work performed.

6. When performing work using bactericidal lamps, medical workers may be exposed to the following hazardous and harmful production factors:

increased voltage in the electrical circuit, the closure of which can occur through the human body;

increased levels of ultraviolet radiation;

increased content of nitrogen oxides and ozone in the air of the working area.

7. When carrying out work using bactericidal lamps, it is necessary to control the content of mercury vapor (not more than 0.0003 mg/m) and ozone (not more than 0.03 mg/m) in the air of the working area.

8. When working in offices with bactericidal lamps installed, workers must be provided with access to primary fire extinguishing equipment, first aid kits. The employee must know the list of medicines included in the first aid kit, know its location, be able to use fire extinguishing equipment.

9. When performing work with the use of bactericidal lamps, the employee must work only in special medical clothing, strictly observe the rules of personal hygiene.

10. When working with germicidal lamps, taking into account the hazardous and harmful production factors affecting them, medical personnel must be provided with personal protective equipment (hereinafter referred to as PPE), in accordance with the Model Industry Standards for the free issuance of personal protective equipment, approved by the Decree of the Ministry of Labor and Social Protection dated September 1, 2008, No. 129.

11. It is not allowed to perform work while in a state of alcoholic, narcotic and toxic intoxication, as well as drinking alcoholic beverages, using narcotic, toxic and psychotropic substances in work time and at the place of work.

12. medical worker obliged to perform the work employment contract, assist and cooperate with the employer in ensuring healthy and safe working conditions, immediately notify his immediate supervisor or other official about the malfunction of equipment, tools, devices, protective equipment, about the deterioration of his health.

13. In the event that in the course of work deficiencies in the operation and malfunction of bactericidal lamps are detected, workers must notify the head of the office about this.

14. Workers who do not comply with the requirements of this manual are held accountable under the law.

Chapter 2. Requirements for labor protection before starting work

15. Check the serviceability of personal protective equipment necessary for the performance of work, put on special medical clothing, special footwear and other personal protective equipment.

16. Work with the use of germicidal lamps ( ultraviolet irradiators) should be carried out in rooms where the parameters of the necessary air disinfection are determined (procedural, dressing, sterilization, operating rooms, laboratories).

17. Before starting work using bactericidal lamps, an employee must check the absence of visible damage to bactericidal lamps, their serviceability and completeness.

18. Bactericidal irradiators are low-pressure discharge lamps with installed self-piercing cathodes. It is necessary to carry out their operation in rooms with an air temperature of at least 5 degrees. WITH.

19. When working with bactericidal lamps, the absence or malfunction of their protective ground is not allowed.

20. Perform work in strict sequence according to the instructions for use of bactericidal lamps.

21. Do not plug bactericidal lamps and other equipment into the electrical network with wet hands.

22. In the room where work on ultraviolet irradiation is carried out, a system of supply and exhaust ventilation or window openings must be installed and operated to ensure a single air exchange for at least 12 minutes.

23. Detected violations of labor safety requirements must be eliminated on their own, and if it is impossible to do this, employees are obliged to report them to the head of the office. It is forbidden to fix on your own malfunctions of bactericidal lamps related to their repair and adjustment, repair of devices must be carried out in specialized organizations or specialists of the organization.

Chapter 3. Requirements for labor protection during work

24. Working on ultraviolet emitters is prohibited:

use wires with damaged insulation;

allow unauthorized persons to enter the workplace;

operation of germicidal lamps without an act of commissioning and a hygiene certificate;

operation of dusty lamps and irradiators;

work without overalls and safety devices;

leave the unit turned on unattended, allow unauthorized persons to switch on bactericidal lamps;

when disinfecting air in the presence of personnel, use bactericidal lamps without a protective screen;

install lamps at a height of less than 2 m from the floor level;

turn on mobile germicidal lamps in electrical network without protective earth;

touch bare wires.

25. When working with bactericidal lamps, medical personnel must comply with the methods and techniques of safe work, use devices in accordance with their operating instructions, technical data sheets and other documentation developed by manufacturers.

26. In the absence of sufficient ventilation, continuous operation of the irradiators should be carried out within an interval of 2 hours of continuous operation and with mandatory ventilation of the room.

27. The inclusion of bactericidal lamps should be carried out from the corridor, before entering the room. The switch must be numbered. When supplying power to lamps with open recipients from the electrical network, it is necessary to make from separate switches installed in the corridor near the entrance door to the room, interlocked with a light board at the entrance door: “Do not enter! Ultraviolet disinfection is in progress.

28. It is allowed to work with germicidal lamps in the presence of patients and staff, also in their absence. When working in the presence of people, the irradiators are switched on during breaks between work, while the use of unshielded bactericidal lamps is allowed.

29. Bactericidal lamps of a closed type must be placed on the wall of the room along the main air flows near the heaters at a height of at least 2 m from the floor.

30. When using combined germicidal lamps, the flow from shielded lamps must be directed to the upper zone of the room to prevent direct flow from entering the lower zone.

31. When using mobile irradiators, it is necessary to apply measures to protect against exposure, use protective equipment and post a warning notice about the danger.

32. Disinfection and cleaning of bactericidal lamps must be carried out by trained electrical personnel according to the schedule within the established preventive period.

33. Starters and lamps should be replaced by electrical personnel. Bactericidal lamps that have worked out their standard period and become unusable must be stored in a separate room with their subsequent disposal in specialized organizations.

34. When working with germicidal lamps, it is necessary to control exposure at the workplace. Measurement of bactericidal irradiance must be carried out using metrological measuring instruments certified by specialized organizations. The results of the work of bactericidal lamps should be reflected in the Journal of their registration and control of work.

35. In the event of a malfunction in the operation of bactericidal lamps, a dangerous or emergency situation, stop work, turn off the devices used and inform the head of the office about this.

Chapter 4. Requirements for labor protection after completion of work

36. Upon completion of work with bactericidal lamps, medical personnel should:

disconnect electric lamps through the supply cable from the electrical network;

treat bactericidal lamps with a 30% hydrogen peroxide solution using a detergent;

remove tools, fixtures and materials to their storage places;

tidy up the workplace.

37. Inform the head of the office about the shortcomings identified when working with bactericidal lamps and other factors affecting labor safety.

Chapter 5. Requirements for labor protection in emergency situations

38. An employee with bactericidal lamps must stop work and turn off the power to the devices:

upon detection of a break in power wires, grounding faults and other damage to devices;

when a strong smell of ozone is detected;

in case of damage to the integrity of the lamps and leakage of mercury;

in the event of a short circuit of electrical equipment and its ignition;

in the event of a fire or accident.

39. In the event of a fire in electrical wiring, equipment and similar incidents, turn off the power supply and take measures to extinguish the fire with available fire extinguishing agents using carbon dioxide or powder fire extinguishers.

The use of foam fire extinguishers and water to extinguish live electrical equipment is not allowed.

40. Turn off the supply and exhaust ventilation, immediately report the fire to the head of the office and the fire brigade, indicating the exact place of its occurrence, notify others and, if necessary, remove people from the danger zone.

41. If a strong smell of ozone is detected, it is necessary to immediately disconnect the lamps from the electrical network, remove people from the room, turn on supply and exhaust system ventilation and open window openings in the room until it is completely ventilated. Call a repair service to determine the health of the lamps used and the possibility of their further operation.

42. If a lamp breakage and mercury spreading is detected, it is necessary to collect the fragments in a separate bag and collect the mercury with a rubber bulb in a container with a lid. Rinse the room with a 1% solution of potassium permanganate. Collected mercury and a broken lamp should be handed over to a special technical service of the organization for further disposal.

43. In the event of an accident at work, it is necessary:

quickly take measures to prevent the impact of traumatic factors on the victim, provide the victim with first aid, call an ambulance to the scene of the incident;

report the incident to the head of the office or the responsible (official) person, ensure the safety of the situation before the start of the investigation, if this does not pose a danger to the life and health of people.

General cleaning, even with the use of modern cleaning products, is not able to ensure the perfect sterility of rooms, especially if there is a person with the flu or respiratory diseases in the house. You can destroy airborne microbes with a quartz lamp, an improved Soviet-era invention.

What is a quartz lamp for?

The ultraviolet emitted by the device disinfects the room by killing bacteria. Using a lamp, you can sterilize not only the air in the rooms, but also upholstered furniture with children's toys, which accumulate a lot of germs and infections.

The equipment is recommended for use in inflammatory processes in the throat and oral cavity, from trophic ulcers, bedsores and dermatological diseases. The device is effective for otitis media, colds, joint pain and muscle dysfunction.

Destroying microbes, a quartz lamp stimulates skin regeneration, helps the immune system to cope with an infection that attacks the body. It is used to sterilize manicure accessories, and some housewives process conservation with ultraviolet light.

Types of quartz lamps

The germicidal type lamp is suitable for disinfection of premises, and is more often used in medical institutions. The ultraviolet rays emanating from the device not only kill bacteria, but also saturate the air with ozone, which is poisonous to humans.

Physiotherapy varieties of lower power are intended for home use and local irradiation, for example, the nasal or oral mucosa.

open and closed
Bulbs for lamps open type they are made of quartz glass, they are fixed on special tripods during switching on, they cling to the walls or ceiling, necessarily directing ultraviolet radiation into the room. A popular type is called "crystal", which can be placed on a table or flooring. The "electronics" variety has additional infrared emitters, similar to the usual table lamp, and the "sun" is used for local irradiation.

Closed options are intended for medical and children's health facilities. They are built into the ventilation system, through which disinfected air is supplied to the premises.

Shielded varieties are equipped with reflective panels, thanks to which ultraviolet rays go up and practically do not fall on people in the room.

Special Purpose Options
Quartz devices with low power, emitting a pleasant blue light, are used at home. They irradiate the skin affected by psoriasis or acne, treat sore joints, inflamed mucous membranes of the nose or throat, ear canals with otitis media. They are compact and safe, usually sold with special attachments and goggles.

By type of attachment
Floor and desktop varieties are convenient in everyday life, they can be transferred from one room to another in order to carry out disinfection. Mounted options fixed on the wall under the ceiling, have a limited scope, so they are not in demand.

How to use a quartz lamp correctly

Before disinfection, it is necessary to remove people from the premises; ultraviolet radiation is especially dangerous for children. Close pets in other rooms, remove flower pots. Install a lamp, put on goggles, turn on the device, leave the room by closing the door or closing the curtains separating him from the rest.

Wait from 15 to 30 minutes, turn off the device, trying not to inhale the air saturated with ozone. Open windows wide to ventilate the room. Use the lamp to disinfect another room only after it has completely cooled down.

Do not touch the glass tube. If there is an imprint on it, you need to wipe the surface of the device with a soft cloth moistened with an alcohol solution.

Irradiation can only be carried out after consulting a doctor. Use only devices with low power, designed for quartzing a person, bactericidal lamps cannot be used.

Protect the cornea of ​​the eyes with special goggles, which must be sold with the lamp. Apply suntan oil or cream to the area of ​​skin to be irradiated. Thin layer distribute evenly over the body. Cover the remaining parts with a towel or other cloth so that they are not exposed to ultraviolet rays.

Warm up the lamp for 5 minutes, and only then bring it to the skin. Potted flowers or pets should not be near the patient during irradiation. Keep the device at a distance of 50 cm from the treated area. The first session should last 30 seconds, it is recommended to carry out 1 quartz treatment per day. The duration of the irradiation course is 5 days. The second session should be increased by 30 seconds. The duration of the fifth is about 3 minutes, but not longer.

The patient should feel a pleasant warmth, so if necessary, the lamp can be brought closer or further away. You can not hold the device perpendicular to the irradiated area, it is correct when the rays fall at a small angle.

Exposure of the lamp over the skin may cause burns or pigment spots. The patient who has undergone the procedure is recommended to rest, it is advisable to lie down in bed and cover yourself with a blanket or blanket. You can not go out into the cold or drafts for an hour, so quartzing is best done before bedtime.

Blue lamp and small children

Babies who are under 3 years old can be irradiated for colds and runny nose. It is recommended to carry out procedures when the child is sleeping. Be sure to put a diaper or a small towel over your eyes. It is recommended to constantly touch the skin of a small patient: it should be warm, but not too hot. It's better to undercook than overheat.

The lamp is brought to the heels and back instead of mustard plasters, the maxillary sinuses, forehead and area behind the ear are treated to spread out the nose. It is better to warm up at night so that the child remains warm after the procedure. Woolen socks can be worn on the legs after irradiation to enhance the effect.

Quartz lamp and runny nose

The device cannot be used for sinusitis, but it does an excellent job with the common cold. It is recommended to purchase devices with special tubes for the treatment of the nasal and oral cavities. First you need to rinse the maxillary sinuses with salt water, rinse your throat. Turn on the device for a few minutes, always putting on glasses.

It is better to start with 30 seconds, carry out 1 procedure per day. It takes 4 days for the inflammation to go away. Do not irradiate the nose or throat for longer than 2 minutes, so as not to burn the mucous membranes. It is advisable not to use drops for a cold for several hours.

Quartz Precautions

• The room after quartzing must be ventilated.
• Safety goggles will protect your eyes from burns.
• Do not look at the switched on lamp, touch the heated surfaces during the operation of the device.
• For patients with dry skin prone to cracking and dilated blood vessels, the quartz device is categorically contraindicated.
• The dosage and duration of the course of treatment should be prescribed by a doctor, you should not engage in amateur activities, because you can’t joke with such medical devices.
• It is forbidden to sunbathe quartz lamps open type.

There is a group of patients who are only harmed by ultraviolet radiation. Irradiation is contraindicated for people with body temperature above 38 degrees, renal and cardiovascular insufficiency, tumors, both malignant and benign.

Do not use the lamp for thyroid diseases and active tuberculosis, hypertension, bleeding tendency and ulcers. The category of people who are contraindicated in ultraviolet treatment includes individuals with advanced atherosclerosis of the brain and coronary vessels, blood diseases and acute inflammatory processes.

Patients who experience headache or other ailments during the procedure should stop irradiation and refuse this method.

A quartz lamp can become great helper for people prone to colds, and young mothers who often get sick children. It must be understood that this medical device does not harm only when correct use and following instructions.

The disinfection mode depends on the power of the irradiator, the volume of the room, the criteria for the effectiveness of disinfection, due to the functional purpose of the room, and is determined in accordance with " Guidelines on the use of bactericidal lamps for the disinfection of air and surfaces, approved by the Ministry of Health and Medical Industry of the Russian Federation on February 28, 1995.

Open (unshielded) bactericidal lamps are used only in the absence of people in the breaks between work, at night or at a specially allotted time - for example, 1-2 hours before the start of aseptic work. The minimum exposure time is 15-20 minutes.

Switches for open lamps should be placed in front of the entrance to the room and equipped with a signal inscription "Do not enter, the bactericidal irradiator is on." It is PROHIBITED to keep people in rooms where unshielded lamps are switched on. Entrance to the room is allowed only after the lamp is turned off, and a long stay in the specified room is allowed 15 minutes after the lamp is turned off.

Screened germicidal lamps can work up to 8 hours a day. It is more rational to irradiate 3-4 times a day for 1.5-2 hours with breaks to ventilate the room for 30-60 minutes, since ozone and nitrogen oxides are formed during the operation of the lamp, causing irritation of the mucous membrane of the respiratory tract. AT last years ozone-free germicidal lamps have been created, which is achieved through the use of special quartz glass that does not transmit UV radiation shorter than 200 nm, which causes the formation of ozone.

Irradiation of air with PRK lamps is carried out for 30 minutes several times a day with intervals used to ventilate the room.

It is necessary to take into account the duration of operation of each irradiator in special magazine, fixing the time of turning on and off the lamp. Expired germicidal lamps must not be used. The average service life of a BUV bactericidal lamp is 1500 hours, of PRK lamps - 800 hours.

Strict observance of the mode of use of bactericidal lamps is important, since the boundary between the conditions of the positive bactericidal effect of UV irradiation and the negative one associated with the selection of resistant microflora under weak exposure to UV rays is not clear enough.

UV rays are effective at a distance of no more than 2 meters and at a relative humidity of 40 to 70%, with more high humidity their bactericidal action is reduced. On dark surfaces treated with UV rays, 10–20% more microbes remain than on light surfaces under the same conditions. In the shade, such as under a table top or on the back of an instrument, UV radiation has no effect.

Mistakes with negative epidemiological consequences include:

Failure to comply with prescribed exposure regimes;

Non-compliance of the type (open, closed) and the number of irradiators with the needs of sanitation of the premises;

Not taking into account the "age" of the lamps, as it increases, their bactericidal activity is significantly reduced;

Surface contamination of lamps;

- "exaggerated expectation" of the effectiveness of ultraviolet irradiators, contributing to the neglect of other equally reliable methods of sanitation of premises - ventilation, cleaning, treatment with chemical disinfectants, increasing the efficiency of ventilation.

To assess the bactericidal effectiveness of specific irradiators, a bacteriological examination of air and washings from surfaces before and after irradiation is carried out. Sanitation is considered effective if, after irradiation, the number of microorganisms in 1 m³ of air has decreased by 80% or more.

Questions for self-control

1. The causative agents of what diseases can be spread through the air, by aerogenic means?

2. What phase of microbial aerosol is the most dangerous in epidemiological terms?

3. What can serve as a source of air pollution in pharmacies by microorganisms?

4. The main factors in the transmission of pathogens from a sick person to a healthy person or to a drug.

5. Norms of microbial air pollution in pharmacies.

6. Modern methods air bacterial research.

7. What area of ​​ultraviolet radiation has a bactericidal effect?

8. What is the mechanism of the bactericidal action of ultraviolet rays?

9. In which pharmacy premises should bactericidal irradiators be installed?

11. What germicidal lamps can be turned on in the presence of people?

12. What is average term bactericidal lamp type BUV?

General information on disinfection of premises with ultraviolet irradiation (UV).

The ultraviolet component of sunlight is main reason death of microbes in the outdoor air. Mortality of microorganisms in the open air reaches 90-99%, but depends on the type of microorganism and can vary from a few seconds to a couple of minutes. Spores and some types of environmental bacteria are resistant to sunlight and can tolerate prolonged exposure to light without much harm to their body. The energy of the ultraviolet component of sunlight causes damage to microorganisms at the cellular and genetic levels, the same damage is done to humans, but it is limited to the skin and eyes. artificial sources Ultraviolet Light (hereinafter referred to as UVR) uses much more concentrated levels of radiation than those found in normal sunlight.
The bactericidal effect of ultraviolet rays was discovered about 100 years ago. The first laboratory tests of UVR in the 1920s were so promising that the complete elimination of airborne infections seemed possible in the very near future. UV radiation has been actively used since the 1930s and in 1936 was first used to sterilize the air in a surgical operating room. In 1937, the first use of ultraviolet radiation in ventilation system one of the American schools impressively reduced the incidence of measles and other infections among students. Then it seemed that a wonderful remedy had been found to combat airborne infections. However, further study of UVR and hazardous side effects severely limited its use in the presence of people.
The force of penetration of ultraviolet rays is small and they propagate only in a straight line, i.e. in any working room, a lot of shaded areas are formed that are not subject to bactericidal treatment.

Three methods of applying ultraviolet radiation are known:

1. Direct irradiation - used only when there are no people in the treated room.
2. Indirect irradiation (by reflected beams) - used in the presence of people with restrictions on the time of operation.
3. Closed exposure (in ventilation systems and self-contained recirculation devices) - used in the presence of people with limited operation time.

Direct irradiation of premises is carried out with the help of lamps suspended from a wall or ceiling and directing a direct beam of rays into the interior of the room. It can also be carried out with lamps mounted on special tripods standing on the floor. Direct exposure can be carried out only in the absence of people (during breaks, before starting work) or with the provision of special safety measures.

Indirect irradiation of premises is carried out using lamps suspended at a height of 1.8-2 m from the floor with a reflector facing upwards, so that the direct radiation flux enters the upper zone of the room; the lower area of ​​the room is protected from direct rays by a lamp reflector.
The air passing through the upper zone of the room is actually exposed to direct radiation. In addition, reflected from the ceiling and the top of the walls (for better reflection, the walls should be painted in White color) ultraviolet rays irradiate the lower area of ​​the room in which people can be. However, the effectiveness of air disinfection in the lower zone is practically zero, since the intensity of the reflected radiation is 20-30 times less than the direct one.
Closed irradiation is actively used as an additional stage of bactericidal treatment of indoor air. The air passing through the bactericidal lamps located inside the recirculator body is exposed to direct radiation and enters the room again disinfected.

Technical means that provide UV disinfection of air and surfaces in rooms include:
1. UV sources (germicidal lamps);
2. Bactericidal irradiators;
3. Bactericidal installations, which are a group of irradiators installed indoors.

1. Sources of ultraviolet germicidal radiation.

Discharge lamps are used as sources of UV radiation, in which radiation is generated during an electric discharge, containing in its composition the wavelength range of 205-315 nm (the rest of the radiation spectrum plays a secondary role). These lamps include mercury lamps of low and high pressure and xenon flash lamps.

Low-pressure mercury lamps are structurally and electrically identical to conventional lighting fluorescent lamps, except that their bulb is made of special quartz or uvio glass with high UV transmittance, on the inner surface, which is not coated with a phosphor layer. These lamps are available in a wide power range from 8 to 115 watts. The main advantage of low-pressure mercury lamps is that more than 60% of the radiation falls on the line with a wavelength of 254 nm, which lies in the spectral region of maximum bactericidal action. They have a long service life of 5.000-10.000 h and an instantaneous ability to work after their ignition.
The flask of mercury-quartz high-pressure lamps is also made of quartz glass. The advantage of these lamps is that, despite their small dimensions, they have a large unit power from 100 to 1,000 W, which makes it possible to reduce the number of lamps in a room, but they have a low bactericidal output and a short service life of 500-1,000 hours. In addition, the normal combustion mode occurs 5-10 minutes after their ignition.

A significant disadvantage continuous radiant lamps is the risk of mercury vapor contamination of the environment when the lamp breaks. In case of violation of the integrity of bactericidal lamps and mercury ingress into the room, a thorough demercurization of the contaminated room should be carried out.

In recent years, interest in UV radiation has been due to the emergence of a new generation of short-pulse emitters with much greater biocidal activity. The principle of their operation is based on high-intensity pulsed irradiation of air and surfaces with continuous spectrum UV radiation. Pulsed UV is obtained using xenon lamps, as well as using lasers. There are currently no data on the difference between the biocidal action of pulsed UVR and that of traditional UVR.

The advantage of xenon flash lamps is due to the higher bactericidal activity and shorter exposure time. Another advantage of xenon lamps is that if they are accidentally destroyed, the environment is not polluted by mercury vapor.

The main disadvantages of these lamps, which hinder their widespread use, is the need to use high-voltage, complex and expensive equipment for their operation, as well as a limited emitter resource. (average 1-1.5 years).

Germicidal lamps are divided into ozone and ozone-free.
Ozone lamps in the emission spectrum have a spectral line with a wavelength of 185 nm, which, as a result of interaction with oxygen molecules, forms ozone in the air. High concentrations of ozone can have adverse effects on human health. The use of these lamps requires control of the ozone content in the air and thorough ventilation of the room.

To eliminate the possibility of ozone generation, so-called bactericidal "ozone-free" lamps have been developed. For such lamps, due to the manufacture of the bulb from a special material (coated quartz glass) or its design, the emission of the 185 nm line radiation is excluded.
Germicidal lamps that have burned out their service life or failed should be stored packed in a separate room and require special disposal in accordance with the requirements of the relevant regulatory documents.

2. Bactericidal irradiators.

A bactericidal irradiator is an electrical device that contains: a bactericidal lamp, a reflector and other auxiliary elements, as well as devices for its fastening. Bactericidal irradiators redistribute the radiation flux into the surrounding space in a given direction and are divided into two groups - open and closed .

Open irradiators use direct germicidal flow from lamps and a reflector (or without it), which covers a wide zone of space around them. Mounted on the ceiling or wall. Irradiators installed in doorways, are called barrier (slit) irradiators or ultraviolet curtains, in which the bactericidal flux is distributed in a small solid angle.
A special place is occupied open combined irradiators . In these irradiators, due to the rotary screen, the bactericidal flow from the lamps can be directed to the upper or lower zone of the space. However, the efficiency of such devices is much lower due to the change in wavelength during reflection and some other factors. When using combined irradiators, the bactericidal flow from shielded lamps should be directed to the upper zone of the room in such a way as to exclude direct flow from the lamp or reflector to the lower zone. At the same time, the irradiance from reflected flows from the ceiling and walls on a conditional surface at a height of 1.5 m from the floor should not exceed 0.001 W/m2.

For closed irradiators (recirculators) the bactericidal flow from the lamps is distributed in a limited small enclosed space and has no outlet to the outside, while air disinfection is carried out in the process of pumping it through the ventilation openings of the recirculator. When using supply and exhaust ventilation, bactericidal lamps are placed in the outlet chamber. Speed air flow provided either by natural convection or forced by a fan. Irradiators closed type(recirculators) should be placed indoors on the walls along the main air flows (in particular, near heating appliances) at a height of at least 2 m from the floor.

According to the list of typical rooms divided into categories (GOST), it is recommended to equip rooms of categories I and II with both closed irradiators (or supply and exhaust ventilation), and open or combined ones, when they are turned on in the absence of people.

3. Bactericidal installations.

A bactericidal installation is understood as a group of irradiators installed in a room to provide a given level of reduction in microbial contamination. Disinfection of premises with the help of bactericidal irradiators is accompanied by a rather high energy consumption.

For premises equipped with bactericidal irradiators, a list of requirements has been developed, the fulfillment of which is mandatory in order to exclude the possibility of harmful effects on humans of UV radiation, ozone and mercury vapor:
- From the outside of the room, they are equipped with a light panel above the door with the inscription: "Do not enter. Dangerous. Ultraviolet disinfection in progress";
- The height of the room must be at least 3 m;
- The room must be either equipped with supply and exhaust ventilation, or have conditions for intensive ventilation through window openings, providing a single air exchange for no more than 15 minutes;
- The premises are divided into two types: the first are the premises in which decontamination is carried out in the presence of people, and the second - in the absence, for which the storage of personal protective equipment for personnel from direct UV radiation (glasses, face masks and gloves) is provided;
- The content of ozone in the air environment of a room with bactericidal irradiators should not exceed 0.03 mg/m3, and mercury vapor - 0.0003 mg/m3 (average daily MPC for atmospheric air);
- All premises with bactericidal installations, operating or being introduced again, must have an Act of putting them into operation and a Journal of their registration and control.

The operation of ultraviolet bactericidal installations requires constant monitoring by the bodies of the State Sanitary and Epidemiological Supervision, and personnel who have undergone the necessary instruction should be allowed to operate them.
In laboratory experiments, ultraviolet radiation achieves high rates of lethality of microorganisms when creating ideal conditions. In real applications, equipment efficiency is much lower and depends on many factors, including the following:
- Mains voltage. As the mains voltage increases, the service life of germicidal lamps decreases.
- Lifetime. As the lamps work, the bactericidal flux decreases; in order to compensate for this, it is necessary to increase the initially set irradiation duration by 1.2 times after the expiration of 1/3 of the nominal service life of the lamps and by 1.3 times after 2/3 of the period. A particularly rapid decrease in the bactericidal flux is observed during the first tens of hours of combustion and can reach 10%. After several hundred hours of operation, the parameters of the lamps do not correspond to the design norm (with a shelf life of at least 1,000 hours declared by the manufacturers). Accounting for the operating time of the irradiators and changes in the duration of irradiation should be entered in the Journal of registration and control of the operation of the bactericidal installation.
- Number of on/off lamps.
- Dust on the surface of the reflector and lamp bulb. Settled particles sharply reduce the yield of bactericidal flow. Dusting and lamp replacement should be done monthly.
- Air movement. The cooling effect of the moving air on the surface of the lamp, in turn, cools the plasma inside the lamp, the temperature of which determines the efficiency of the UVR.
- The speed and mixing of air in the room should not prevent microorganisms from receiving a lethal dose of radiation.
- Dust content in the air with particles that protect microorganisms from UV rays (shielding phenomenon).
- relative humidity. An increase in humidity results in a decrease in the rate of degradation under UV exposure. With an increase in relative humidity in the room to 80-90%, the bactericidal effect is reduced by 30-40%.
- Ambient temperature. With a decrease in the ambient temperature, it is difficult to light the lamps. At temperatures below 100C, a significant number of lamps may not light. At temperatures above 300C, overheating of the switching devices and fire of the equipment is possible.
- exposure time. Should be sufficient to irradiate the maximum spectrum of microorganisms.

Operating principle

Ultraviolet rays propagate in a straight line and act mainly on nucleic acids, exerting both lethal and mutagenic effects on microorganisms. Only those rays that are adsorbed by the protoplasm of the microcell have bactericidal properties.
The biophysical effect of UV radiation on the genetic or functional apparatus of bacteria looks like in the following way: UV radiation causes destructive-modifying DNA damage, disrupts cellular respiration and DNA synthesis, which leads to the cessation of reproduction and lysis of microbial cells. In violation of DNA synthesis, the main one is the oxidation of sulfhydryl groups, which causes inactivation of nucleotidase and death of microbial cells in the first or subsequent generations.
The penetration power of ultraviolet rays is low. A thin layer of glass is enough to keep them out. The action of the rays is limited to the surface of the irradiated object and its purity has great importance: UVR is highly active if microorganisms and dust particles are located in one layer, with a multi-layer arrangement, the upper ones protect the underlying ones (shielding phenomenon).

The protective sheath around the bacterial cell prevents the achievement of an antimicrobial effect. In any living cell, there are biochemical mechanisms capable of fully or partially restoring the original structure of a damaged DNA molecule. Due to radiation mutagenesis, surviving microorganisms are able to form new colonies with less susceptibility to radiation.

The probabilistic nature of UVR sterilization has been studied to a sufficient extent, and there are various equations that characterize the process of bacterial death. On average, resistant microorganisms make up about 0.01% of the microbiological population, but some studies suggest that for certain species it can be as high as 10%.

With increasing resistance, the distribution of microorganisms can be represented as follows: viruses and gram-negative bacteria, gram-positive, fungi and protozoa, the causative agent of tuberculosis, spore forms of bacteria and mold fungi. However, there are significant differences within species and even between young and old cultures of the same strain. There are also known data on the manifestation of the mechanisms of protection of microbial cells from the lethal effects of UV radiation, called photoreactivation.

Sterilization effect

The effectiveness of the bactericidal action of UV radiation depends on the wavelength, irradiation intensity, exposure time, species of treated microorganisms, distance from the source, as well as on the state of the indoor air environment: temperature, humidity, dust content, air flow velocity.

Bactericidal systems using continuous radiant lamps have low sterilization efficiency due to the difficulty of selecting the required radiation dose and insufficient power level. The radiation dose is a function of the pulse intensity and exposure time, individual for each type of microorganisms and viruses. It is extremely difficult to combine the parameters of the pulse intensity, exposure time, the state of the air in the room and the wavelength in such a way that it is possible to simultaneously affect the entire spectrum of microorganisms and viruses.

When flash lamps are operated for 15 minutes, the radiation dose at a distance of 1 m from the lamp is 510 mJ / cm2, and the reduction in air contamination in a room of 100 m3 reaches 87-91%. The death of microorganisms on surfaces directly located 2 m from the pulsed UV source after 15 minutes reaches 99.99% at a dose of 50 mJ/cm2. At the same time, on surfaces turned to the source by 45-90 degrees, the death of microbes already varies within 57.6-99.99%.

The effectiveness of UV radiation for disinfection of air and surfaces in each case is calculated separately, taking into account all the parameters that affect the process of irradiation of microorganisms. To inactivate moving microflora in the air (according to research by American scientists), the UVR dose should be 4 times greater than that used to inactivate microflora that is motionless on surfaces. UV radiation is highly active if microorganisms and dust particles are located in one layer, with a multi-layer arrangement, the upper ones protect the underlying ones (shielding phenomenon).

Filtering effect

There is no filtering effect. To implement UV filtration, irradiators are included in ventilation systems with various purification filters.

Ppresence of people

UVI when hit open areas human skin and the retina of the eyes can cause burns of I-II degree, exacerbation of cardiovascular diseases, and in some cases lead to cancer.

open irradiators (UFO, OBNP series) are intended for disinfection of premises only in the absence of people, open combined (series OBN, OBP) only for a short stay of people, and closed(RBB series) - in the presence of people.

Disinfection of surfaces, walls and floors of premises can be carried out using open, combined, portable and mobile irradiators, only in the absence of people.
If a characteristic smell of ozone is detected, immediately remove people from the room and thoroughly ventilate it until the smell of ozone disappears. The frequency of control is at least 1 time in 10 days, according to GOST. SSBT. 12.1.005-88 "General sanitary and hygienic requirements for the air of the working area".