Science Overview

The Evolution of UV-C

UV-C: The origin of germicidal ultraviolet light

Most people are familiar with ultraviolet light as UV-A and UV-B, the wavelengths produced by the sun. What is less well known is UV-C, a shorter wavelength that never reaches the earth’s surface because it is blocked by the ozone layer.

For more than 100 years, scientists have been producing UV-C artificially through specialized lamps and using it to inactivate pathogens in water, in the air, and on surfaces. Because of this germ-killing power, UV-C is often called germicidal UV.

All wavelengths within the UV-C spectrum (200–280 nm) are capable of inactivating pathogens. But at the lower end of the spectrum, below 230 nm, science shows a unique advantage: the light cannot penetrate the outer dead layer of the skin (the stratum corneum) or the tear layer of the eye. This discovery opened the door for safe, continuous use of germicidal UV in occupied spaces, ushering in the era of Far-UVC at 222 nm.

Far-UVC

Safety

The safety of UV light on skin is dependent on the wavelength and light intensity. The more UV light you receive, the greater the risk of skin damage. But this risk is proportional to the wavelength of the UV light as well. The shorter the wavelength, the safer for human skin. This is because shorter wavelengths do not travel through skin as well as long wavelengths.

Far-UVC, a shorter wavelength of ultraviolet, is unable to penetrate the superficial layer of our eyes or the dead skin layer (also called the Stratum Corneum). Far-UVC is scattered or absorbed by these peripheral, shedding layers and shield the living tissue below. Because of this protection, Far-UVC does not pose a risk when applied following manufacturer instructions. This difference allows for greater ability to clean occupied spaces.

Today, most UV cleaning systems are contained in air ducts, within boxes, used only in unoccupied spaces, or are shined at ceilings so that the higher, cheaper to produce wavelengths can be used. Small spaces such as bathrooms and elevators are difficult to clean due to lack of airflow, renewing pathogen sources, and concerning surface contamination. Far-UVC applications are the ideal solution for these difficult, insufficiently ventilated, high traffic spaces.

graphic showing UVC light penetration in eye layers

graphic displaying UVC wavelength by skin layers

Far-UVC Light

Effectiveness

Unlike traditional cleaners which depend on causing oxidative stress or damaging membranes leaving them ineffective against some viruses and spores, UV light targets the DNA or RNA of cells and viruses to provide a cleaning effect. Because of this, UV light is effective against bacteria, viruses, fungi, protists, algae, and spores. With UV light, pathogens can be reduced by 99.9% repeatedly in a time and cost effective manner [2].

Independent Visium testing demonstrate up to 99.9% effectiveness against a broad range of pathogens. See the data here.

Dose (Unit: mJ/cm²) — [1]

Why We Need

Far-UVC Light

Far-UVC light is able to kill bacteria, viruses, molds, and spores in the same fashion as traditional UVGI. Far-UVC and traditional UVC cleans all the air exposed to the light, dramatically increasing the air cleanliness of our shared spaces. The greatest advantage of Far-UVC is the ability to shine its light downwards in occupied rooms safely.

Numerous research studies show Far-UVC is as effective at inactivating infectious contaminants as traditional UVC, without the health risk to skin and eyes. By introducing Visium to any existing mitigation process, indoor air can be cleaned more rapidly and efficiently without risk of harm to occupants as verified by UL 8802 testing.

Citations
1) Far UVC Efficacy Example – Eadie, E., Hiwar, W., Fletcher, L. et al. Far-UVC (222 nm) efficiently inactivates an airborne pathogen in a room-sized chamber. Sci Rep 12, 4373 (2022). https://doi.org/10.1038/s41598-022-08462-
2) Far UVC Efficacy and Safety- Hessling, M., Haag, R., Sieber, N., and Vatter, P. (2021). The impact of far-UVC radiation (200-230 nm) on pathogens, cells, skin, and eyes – a collection and analysis of a hundred years of data. GMS hygiene and infection control, 16, Doc07. https://doi.org/10.3205/dgkh000378

Neutralizing Airborne Risks with the Power of Light.

Clean, quiet, and chemical-free, Visium will continuously and safely eliminate harmful indoor pathogens using the power of Far-UVC light.

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Far-UVC

Academic Research

Date	Title	Author
2023	Air and Surface Treatment Using Germicidal Ultraviolet-C (GUV)	Holger Claus, Ushio America, and Michael Clark, Far UV Technologies
2023	Validated computational modeling to evaluate spatial inactivation of airborne pathogens by Far-UVC irradiation	Peñaloza, C. H., Wood, A., Eadie, E., Noakes, C., King, M. F., & Wood, K.
2023	Ocular and Facial Far-UVC Doses from Ceiling-Mounted 222 nm Far-UVC Fixtures	Duncan, M. A., Welch, D., Shuryak, I., & Brenner, D. J.
2023	No Evidence of Induced Skin Cancer or Other Skin Abnormalities after Long-Term (66 week) Chronic Exposure to 222-nm Far-UVC Radiation	Welch, D., Kleiman, N. J., Arden, P. C., Kuryla, C. L., Buonanno, M., Ponnaiya, B., Wu, X., & Brenner, D. J.
2023	Far-UVC: Technology Update with an Untapped Potential to Mitigate Airborne Infections	Bueno de Mesquita, P. Jacob, Sokas, Rosemary K., Rice, Mary B., Nardell, Edward A.
2023	Far-UVC Light at 222 nm is Showing Significant Potential to Safely and Efficiently Inactivate Airborne Pathogens in Occupied Indoor Locations	Brenner, D. J.
2023	Far UV-C radiation: An emerging tool for pandemic control	Blatchley, E. R., Brenner, D. J., Claus, H., Cowan, T. E., Linden, K. G., Liu, Y., Mao, T., Park, S.-J., Piper, P. J., Simons, R. M., & Sliney, D. H.
2023	Experimental study of the disinfection performance of a 222-nm Far-UVC upper-room system on airborne microorganisms in a full-scale chamber	Wang, M. H., Zhang, H. H., Chan, C. K., Lee, P. K. H., & Lai, A. C. K.
2023	Evaluating the Impact of 222 nm Far-UVC Radiation on the Aesthetic and Mechanical Properties of Materials Used in Public Bus Interiors	Drungilas, D., Kurmis, M., Tadzijevas, A., Lukosius, Z., Martinkenas, A., Didziokas, R., Gruode, J., Sapalas, D., & Jankunas, V.
2023	An excimer lamp to provide far-ultraviolet C irradiation for dining-table disinfection	Lv, M., Huang, J., Chen, H., & Zhang, T. T.
2023	222-nm UVC light as a skin-safe solution to antimicrobial resistance in acute hospital settings with a particular focus on methicillin-resistant Staphylococcus aureus and surgical site infections: a review	Panzures, A.
2022	Wavelength-dependent DNA Photodamage in a 3-D human Skin Model over the Far-UVC and Germicidal UVC Wavelength Ranges from 215 to 255 nm	Welch, D., Aquino de Muro, M., Buonanno, M., & Brenner, D. J.
2022	Safety of 222 nm UVC Irradiation to the Surgical Site in a Rabbit Model	Fukui, T., Niikura, T., Oda, T., Kumabe, Y., Nishiaki, A., Kaigome, R., Ohashi, H., Sasaki, M., Igarashi, T., Oe, K., Hamblin, M. R., & Kuroda, R
2022	Local stress control to suppress dislocation generation for pseudomorphically grown AlGaN UV-C laser diodes	Zhang, Z., Kushimoto, M., Yoshikawa, A., Aoto, K., Sasaoka, C., Showalter, L.J., and Amano, H.
2022	Key temperature-dependent characteristics of AlGaN-based UV-C laser diode and demonstration of room-temperature continuous-wave lasing	Zhang, Z., Kushimoto, M., Yoshikawa, A., Aoto, K., Sasaoka, C., Showalter, L.J., and Amano, H.
2022	Far-UVC (222 nm) efficiently inactivates an airborne pathogen in a room-sized chamber.	Eadie, E., Hiwar, W., Fletcher, L., Tidswell, E., O'Mahoney, P., Buonanno, M., Welch, D., Adamson, C. S., Brenner, D. J., Noakes, C., & Wood, K.
2022	Evaluation of UVC Excimer Lamp (222 nm) Efficacy for Coronavirus Inactivation in an Animal Model	Tucciarone, C. M., Cecchinato, M., Vianello, L., Simi, G., Borsato, E., Silvestrin, L., Giorato, M., Salata, C., Morandin, M., Greggio, E., & Drigo, M.
2022	Wavelength-dependent DNA Photodamage in a 3-D human Skin Model over the Far-UVC and Germicidal UVC Wavelength Ranges from 215 to 255 nm	Welch, D., Aquino de Muro, M., Buonanno, M., & Brenner, D. J.
2022	Continuous-wave lasing of AlGaN-based ultraviolet laser diode at 274.8 nm by current injection	Zhang, Z., Kushimoto, M., Yoshikawa, A., Aoto, K., Schowalter, L.J., Sasaoka, C., and Amano, H.
2022	Key temperature-dependent characteristics of AlGaN-based UV-C laser diode and demonstration of room-temperature continuous-wave lasing	Zhang, Z., Kushimoto, M., Yoshikawa, A., Aoto, K., Sasaoka, C., Showalter, L.J., and Amano, H.
2022	Local stress control to suppress dislocation generation for pseudomorphically grown AlGaN UV-C laser diodes	Zhang, Z., Kushimoto, M., Yoshikawa, A., Aoto, K., Sasaoka, C., Showalter, L.J., and Amano, H.
2023	Model Evaluation of Secondary Chemistry due to Disinfection of Indoor Air with Germicidal Ultraviolet Lamps	Zhe Peng, Shelly L. Miller, and Jose L. Jimenez