I Want To Use In-Room UV-C… Not So Fast!

Far UV-C lights, particularly krypton-chlorine 222 nm LED devices, are designed for in-room use to help mitigate the spread of pathogens in the air. While UV-C lighting (200-280 nm) is well-known for its germicidal properties, it also poses significant risks to human health, primarily due to its to damage skin and eyes, and exposure is a recognized Class 1 Carcinogen. Initial research into Far UV-C suggested that its shorter wavelength might not penetrate human skin cells, thus posing limited risks beyond ocular exposure. Consequently, OSHA’s arc welding standards were used to computer model safe exposure levels.

At UV-Clear, we approached the Far UV-C spectrum with a blend of optimism and caution, recognizing its potential benefits while remaining vigilant about safety. Early on, we engaged with leading experts in human hazard and radiation exposure, whose insights have been crucial in shaping and informing our development process. Their research revealed a critical finding - there is no safe level of exposure to UV-C lighting for humans, regardless of duration or intensity.

In support, we will examine several high-quality studies on 222 nm exposure and its effects on human biomarkers. For additional research, we encourage readers to search PubMed using terms like "222 nm exposure" or "222 nm harm" to explore further findings.

1. "The safety of 222 nm was also studied. We detected changes to the mechanical properties of the stratum corneum of human skins when the 222 nm accumulative exposure exceeded 50 J/cm²." (https://www.nature.com/articles/s41598-022-09930-2)
2. "We compare the emerging 222-nm far UVC and 277-nm UVC LED disinfection modules with the traditional UVC mercury lamp emitting at 254 nm to understand their effects on human retinal cell line ARPE-19 and HEK-A keratinocytes. Cells illuminated with 222-nm far UVC survived while those treated with 254-nm and 277-nm wavelengths underwent apoptosis via JNK/ATF2 pathway. However, cells exposed to 222-nm far UVC presented the highest degree of DNA damage as evidenced by yH2AX staining. Globally, these cells presented transcriptional changes in cell cycle and senescence pathways." (https://www.biorxiv.org/content/10.1101/2022.02.22.481471v1.full?fbclid=IwAR3dj3Cp9En_8tchvFzoHADR6zT2eVgvQARlmnxALkKulyK68Zh0fhLZ6nM)
3. "However, with respect to the phenotype of 222-UVC-irradiated plants, the leaves curled under 1 kJ m⁻² and were markedly bleached under 10 kJ m⁻²compared with those of plants irradiated with 254-UVC... 222-UVC (1 or 5 kJ m⁻²) severely damaged the guard cells within the epidermis, and YFP signals and chloroplast autofluorescence in guard cells within the epidermis exposed to 222-UVC (1 or 5 kJ m⁻²) were not detected compared with those in cells exposed to 254-UVC radiation... These results suggest that 222-UVC severely damages guard cells and epidermal cells and that such damage might have resulted in growth inhibition." (https://link.springer.com/article/10.1007/s43630-021-00123-w)
4. " In contrast, 222-UVC had a significant effect on the loss of motility of C. elegans. The sensory nervous system, which includes dopamine CEP and PVD neurons on the body surface, was severely damaged by 222-UVC, but not by the same dose of 254-UVC. Interestingly, increasing 254-UVC irradiation by about 10-fold causes similar damage to CEP neurons. These results suggest that 222-UVC is less penetrating, so energy transfer occurs more effectively in tissues near the surface, causing more severe damage than 254-UVC. (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0281162)

With this critical knowledge in hand, UV-Clear set out to achieve what was previously thought impossible - treating the moving air in HVAC supply lines to eliminate any risk of human exposure. Traditional in-room UV-C solutions face significant challenges, including high installation costs, the need for multiple devices to cover each room, increased energy consumption, and higher replacement expenses. Furthermore, these setups heighten the cumulative UV exposure for occupants compounding the harms.

The only truly safe use of UV-C light is to avoid direct exposure to people. UV-C remains the most effective method for combating bacteria, mold, pathogens, and viruses as particle filtration alone cannot capture all contaminants. UV lighting is a necessary and crucial tool in preventing future pandemics.

UV-Clear has developed a breakthrough approach with the most advanced UV-C LED chips, integrated into a scalable and modular system designed to retrofit seamlessly into any forced air HVAC system. This innovative solution offers comprehensive air treatment at a fraction of the cost compared to other indoor air quality (IAQ) interventions. For the price of treating a few rooms, we can treat the entire building.

Contact us today to discover how our cutting-edge technology can meet the specific needs of your building and enhance your IAQ goals.

Contact us at: info@uv-clear.com