After the onset of the COVID-19 pandemic, ultraviolet (UV) light disinfection method has drawn significant attention because of its well-known efficacy against a broad range of microbial and viral agents found in a variety of environments. The short-wavelength part (typically, 200 to 280 nanometers) of the ultraviolet spectrum, termed germicidal UV or UV-C, has been proved to be the most effective at disinfection.

The high energy UV-C radiation is strongly absorbed by the genetic material (DNA or RNA bases) of the microorganisms damaging their molecular structure (via a process called photo-dimerization) and thereby, destroying their ability to replicate and thus infect. A vast body of literature demonstrates the efficacy of UV-C light in causing high level of inactivation (~99.9%) of various corona viruses including two of the near-relatives of SARS-CoV-2, namely, MERSCoV and SARS-CoV-1.

Thus, justifiably, it is widely believed that disinfection using UVC radiation, at an appropriate dose, can play a major role in reducing the transmission of SARS-CoV-2, thereby mitigating the risk of acquiring an infection in contact with the virus

Highlights of NeelBhasmi:

The product designed at RRCAT, Indore is an UVC light based mobile sterilization device, termed "NeelBhasmi" which uses single wavelength (254 nm) UVC radiation generated by low-pressure mercury lamps. The device utilizes commercially available off-the-shelf UVC lamps and electronic control circuits. The device offers multiple degrees of freedom of the UVC light sources and thus provides very efficient utilization of the UVC radiation for sanitization purpose. It has a movable trolley base mounted with 4 wheels. It operates from a 230 V mains supply and consumes a maximum of 300 W of electrical power. The device is intended for inactivate various micro-organisms including corona viruses the air as well as the surfaces of various objects inside a room at rooms, laboratories, hospitals, doctors' offices, or many other places of work. The device has the facility of remote on-off control as well as auto-switch-off in case of unsafe conditions. It uses eight numbers of tubular UV lamps each rated for 13 W UVC radiation at 254 nm. The device is capable of sterilizing surfaces kept within one meter distance from its lamps in about 5 minutes. For sterilizing a typical room with a floor area of 10 m2 it will take about 45 minutes.

1. One qualified mechanical / electrical engineer with knowledge of mechanical fabrication and concepts of basic electrical engineering. Two technical assistants with 2 years of experience in assembling electromechanical instruments preferably opto-mechanical systems with electrical controls.
2. Standard mechanical fabrication workshop with clean working environment and basic measurement instruments.
3. Two rooms covering minimum floor space area of 30 square meter and height of minimum 3.5 meter. One room of at least 10 square meter with standard electrical mains supply of 230 V, 50 Hz.
4. Basic electrical instruments like calibrated multi-meter, tools for standard electrical wiring.

Following the onset of the COVID-19 pandemic, ultraviolet (UV) radiation based disinfection method has drawn significant attention because of its well-known efficacy against a broad range of microbial and viral agents found in a variety of environments. The short-wavelength part (typically, 200 to 280 nanometers) of the ultraviolet spectrum, termed germicidal UV or UV-C, has been found to be the most effective at disinfection.

The high energy UV-C radiation is strongly absorbed by the genetic material (DNA or RNA bases) of the microorganisms damaging their molecular structure (via a process called photo-dimerization) and thereby, destroying their ability to replicate and thus infect. A vast body of literature demonstrates the efficacy of UV-C light in causing high level of inactivation (~99.9%) of various coronaviruses including two of the near-relatives of SARS-CoV-2, namely, MERSCoV and SARS-CoV-1. Thus, justifiably, it is widely believed that disinfection using UV-C radiation, at an appropriate dose, can play a major role in reducing the transmission of SARS-CoV-2, thereby mitigating the risk of acquiring an infection in contact with the virus.

The developed device is intended for decontaminating the air as well as the surfaces of various objects inside a room at research centers, hospitals, offices, or many other places of work. It uses eight numbers of 30 W UV-C lamps. The system is capable of sterilizing surfaces kept within one meter distance from the tower in about 5 minutes. For sterilizing a room with a floor area of 10 square meter it will take about 45 minutes.

Sr. No.	Specification	Value
1	Principle of working	UV-C radiation exposure
2	No. of UV-C lamps	8 (Philips TUV (Xtra) 30 W or equivalent)
3	Electrical power of lamp	30 W (per lamp)
4	UV-C Output	(Watts/Lamp) 13 W typical and 104 W (Total)
5	Wavelength	254 nm
6	Number of arms	4 (with 2 lamps on each of the arms)
7	Arm Length	685 mm
8	Adjustable Height of the lamps	1220 mm at the lowest position to 2440 mm at the highest position
9	Arm rotation	360 degree
10	Illumination angle	30 – 145 degree (adjustable)
11	No of Wheels: 4, Lockable Wheels: 2
12	Weight	~ 40 kg
13	Remote Control	RF remote Connectivity up to 10 m ( typical)
14	Switch	Independent on-off control for lamps on each arm
15	Timer setting	0 – 60 min (adjustable)
16	Safety	Auto switch off based on motion sensing
17	Motion sensor	Passive infrared sensor with a range of up to 10 m and sensing angle of 180 degree
18	Power Supply	230 V AC , 50 Hz
19	Total power consumption	300 W (max)

Typical Exposure time requirements

The following table provides the required time of UV-C exposure for inactivating SARS-CoV-2

Sr. No.	Distance of the surface from the lamp (cm)	Required exposure time
1	30	30 s
2	50	55 s
3	100	4.5 min
4	120	6.5 min
5	150	30 s
6	200	20 min #
# Area effectively covered in horizontal surface by a horizontal lamp will be more than 15 square meter.

The exposure times have been calculated considering one UVC lamp (13 W UVC output) in operation and assuming the required irradiation dose (for inactivating SARS CoV-2) ~1.5 times higher than the mean dose reported* for inactivating various other coronaviruses known as on date.
(*Fluence (UV Dose) Required to Achieve Incremental Log Inactivation of Bacteria, Protozoa, Viruses and Algae Revised, updated and expanded by Adel Haji Malayeri1, Madjid Mohseni, Bill Cairns2 and James R. Bolton)

1. Easy to adjust arms for effective utilization for horizontal, vertical and inclined surfaces.
2. Very effective for typical office and laboratory spaces, where areas to be sanitized are combination of horizontal (table tops, floors) and vertical (filing cabinets, doors) surfaces.
3. Remote on off control for UVC lamps on individual arm.
4. Motion sensor for safe operation.
5. Detail guidelines provided for effective utilization of NeelBhasmi.
6. Based on UV-C at 254 nm and ozone is not generated.

NeelBhasmi can be effectively used for decontamination of rooms/ office spaces to inactivate various micro-organisms including corona viruses and this is achieved by enough exposure of UV-C radiation.

Warning: UV-C radiation is dangerous for human and other mammals. Follow detailed instructions provided in the operating manual.

Special features of NeelBhasmi

1. Easy to adjust arms for effective utilization for horizontal, vertical and inclined surfaces.
2. Very effective for typical office and laboratory spaces, where areas to be sanitized are combination of horizontal (table tops, floors) and vertical (filing cabinets, doors) surfaces.
3. Remote on off control for UVC lamps on individual arm.
4. Motion sensor for safe operation.
5. Detail guidelines provided for effective utilization of NeelBhasmi.
6. Based on UV-C at 254 nm and ozone is not generated.

User guidelines

1. NeelBhasmi should be brought in the room where sterilization is to be done and the position, height and angle of the arms of NeelBhasmi should be adjusted depending on the objects one seeks to decontaminate.
2. All the persons should move out of the room and the room should be closed.
3. NeelBhasmi is to be switched on by remote control.
4. After the set time limit the NeelBhasmi will be switched off automatically and by this time the bacterial and viral load in the area exposed will be reduced substantially.
5. In case of bigger rooms/ large areas the NeelBhasmi is to be operated from multiple locations in the area.
6. UV-C is dangerous to humans and so, it is essential to avoid direct exposure to UV-C, especially bare skin and eyes.

Facility and Manpower Requirement for production of NeelBhasmi

1. One qualified mechanical / electrical engineer with knowledge of mechanical fabrication and concepts of basic electrical engineering. Two technical assistants with 2 years of experience in assembling electromechanical instruments preferably opto-mechanical systems with electrical controls.
2. Standard mechanical fabrication workshop with clean working environment and basic measurement instruments.
3. Two rooms covering minimum floor space area of 30 m2 and height of minimum 3.5 m. One room of at least 10 m2 with standard electrical mains supply of 230 V, 50 Hz.
4. Basic electrical instruments like calibrated multi-meter, tools for standard electrical wiring.

Special Note for technology transferee

The basic product design can be easily adapted for specific application requirements like, NeelBhasmi with one arm can be developed where there is no need of 4 arms or where maximum vertical arm movement is less than 2440 mm or the design concept can be adapted to provide 360 degree UV-C radiation in different physical formats (e.g. chamber) for the stated application, that is inactivation of various micro-organisms including corona viruses. Various such models with minor variations can be easily fabricated by the transferee. However considering reliable and safe operation of the product the transferee should get the model type approved from RRCAT, Indore. As per standard terms and conditions of technology transfer, RRCAT, Indore will provide necessary handholding support at the discretion of competent authority at RRCAT, Indore for a period of one year after technology transfer.