UV LIGHTING GUIDE Lighting Guide 1 UV LIGHTING GUIDE contents About UV U Lighting 3 Guide Types of U 5 D Application of 7 U D Various Sources of U ED 10 Benefits of 12 U ED T U 14 D D U 16 L 17 in U D 2 UV LIGHTING GUIDE About UV Light ltraviolet ray refers to the far end of the to 400 nm), UVB (280 nm to 315 nm), and UVC (100 electromagnetic spectrum, which is invisible to nm to 280 nm). UV radiation possesses sufficient Uthe naked eye. It has a shorter wavelength (100- energy levels to bring about chemical changes by 400 nm) and higher frequency as compared to the breaking chemical bonds when it comes in contact visible violet light. The term wavelength can be defined with certain elements. UV radiation with wavelength as the distance between two successive crests or below 200 nm can break a molecule of oxygen (O2) troughs of a wave (which may be an electromagnetic into its constituent atoms, which when comes in wave, sound wave, or any other wave). Crest is the contact with another molecule of oxygen (O2) gives highest point of the wave while trough is the lowest. The birth to ozone (O3). Ultraviolet radiation below 300 nm wavelength is measured in units of length. The energy has germicidal properties as it could tamper with the associated with an electromagnetic wave is inversely genetic materials (DNA or RNA) of bacteria and virus, proportional to its wavelength. In other words, shorter thus rendering them ineffective. Although ultraviolet the wavelength, higher the energy. radiation between the wavelength below 315 nm can cause sunburns, it helps in generating vitamin D when UV ray can be categorized into 3 types according to its absorbed by the skin. wavelengths or energy levels, which are - UVA (315 nm 3 UV LIGHTING GUIDE Infrared Visible Light Ultraviolet X-Rays required to consider the various properties of matter that UV ray may interact with if they are to be a part of UVA UV UVC a stable UV radiation system. B The origin of UV radiation could be traced back to plasma sources which includes the sun and plasmas 780 400 315 280 100 in electric (or arc) discharge lamps. The radiation Wavelength (NM) generating from plasma sources isn’t limited to UV Electromagnetic Spectrum rays only. It produces a wide spectrum of wavelength which includes infrared radiation and visible light. The range of wavelengths produced by an arc lamp could The chemical effects caused by UV radiation depends be adjusted according to the requirement by adding upon the wavelength of the radiation and chemical certain impurities. By adding mercury, iron, gallium or composition of the matter it is interacting with. This other metals to the plasma in the arc, it is possible to interaction can vary widely depending upon the various generate different wavelengths of UV rays. properties of matter (transparency, reflectivity, and chemical stability). For example, ordinary glass is In a recent development, it has been found that opaque to UV radiation shorter than 350 nm, whereas semiconductor diodes could be used to generate high purity quartz is opaque to UV radiation shorter than UV radiation. Semiconductor diodes sources of UV 200 nm. Similarly, polished surfaces that are a good radiation are very different from traditional UV arc reflector of visible light may not be a good reflector of lamp sources. The next section will talk about the UV light as well. Systems that produce UV radiation are effectiveness of UV light as a disinfectant. 4 UV LIGHTING GUIDE Types of UV Light & their Disinfection Properties s mentioned in the previous section, UV light ozone layer present in the earth’s atmosphere. has germicidal properties though it would be wrong to state that all kinds of UV rays could Studies have shown that UVC at 254 nm could A incapacitate all food borne pathogens, moulds, and be used effectively as a disinfectant. Only UV light of wavelength between 100-280 nm, also known as UVC yeasts in a matter of minutes. Having said that, it should is used for sterilization purposes owing to its high also be mentioned that the time required for killing energy level. It is known to be an effective agent in different microorganisms depends on their shape and deactivating viruses and bacteria. This spectrum of UV size, which influence their UV absorption rate. ray is present in sunlight as well, but it is filtered by the 5 UV LIGHTING GUIDE DIFFERENT TYPES OF U DII U Longest wavelength (315-400 nm). Can penetrate the middle layer of your skin (the dermis). Causes aging & wrinkling. U U U Short wavelength (280-315 nm). U Reaches the outer layer of your skin (the epidermis). Can cause redness, burning or skin cancer. Can penetrate deeper into the skin and eye. U Shortest wavelength (100-280 nm). Does not reach the earth's surface. Blocked by the ozone layer in the atmosphere. Out of all the three, UVC has the strongest germicidal effect. It destroys the outer protein coating of various disease-causing pathogens. How does UV sterilization make it happen? Before progressing towards the next section, it is imperative to understand the difference between UVGI - acronym for Ultraviolet germicidal irradiation sterilization, disinfection, and decontamination as works by breaking down certain chemical bonds these terms are often used interchangeably and may and altering the structure of DNA, RNA, and proteins lead to confusion regarding the effectiveness of UVGI. of microorganism, thereby making them unable to multiply. By not being able to multiply anymore within As per the Center for Disease Control (CDC), sterilization a host cell, it would no longer be considered infectious. is the process of eliminating all forms of microbial life and is carried out by physical or chemical means. How long does it actually take before a CDC defines disinfection as the process of eliminating microorganism becomes ineffective? or reducing harmful microorganisms from inanimate Since the UV sterilization process makes use of the objects or surfaces. energy of UVC to destroy biomolecules, it depends Decontamination is the process of reducing microbial on the total energy applied, which in turn depends contamination. It renders all materials safe for use. on exposure time and distance of the light source. In other words, decontamination could be achieved To sterilize E. Coli in laboratory condition, if the light through sterilization or disinfection. source is within 1 inch of the sample, it will take 1-2 minutes for complete sterilization. For sterilizing Given the recent popularity of UV disinfection, certain surgical instruments in a UV chamber, a duration of myths have also become a conversation topic one can 5-10 minutes is recommended. no longer ignore. We have tried to explain, with facts, some of those myths here: https://axenic-uv.com/blog- In terms of virus elimination, studies have shown that detail/Five-misconceptions-around-uv-sanitization- Ultraviolet C light has been effective in killing various debunked strains of the coronavirus, including SARS and MERS. At least 15 minutes of exposure to the UV rays have been found to render the SARS virus ineffective. 6 UV LIGHTING GUIDE Application of UV Disinfection ontrary to popular belief, UV technology isn’t observed in the field of UV technology as well. Among a recent innovation; the technology has been other things, the size of a UV light bulb has reduced Caround since a long time. Its application could and its lifespan has increased, which has broadened be traced back to as early as mid-20th century. With the scope of its application in multiple areas. the progress of science, a radical change has been Five Application Categories: 1Air 2 Disinfection Disinfection 3 4E 5 Disinfection Disinfection Disinfection 7 UV LIGHTING GUIDE Air Disinfection involve releasing high power electromagnetic energy through UV light that penetrates and destroys harmful UV light could disinfect air in enclosed spaces as microorganisms, and affects their ability to multiply. well, thereby making it more effective with still or Since it doesn’t involve the use of any chemicals to stagnant air as compared to moving air. To improve clean the water, there’s no risk of negative impact on the effectiveness of UV disinfection, many facilities the environment. choose to install lights near coils and drain pans of cooling systems. Another technology that has caught Surface Disinfection attention in this regard is Upper-room UVC that refers to a system of ultraviolet germicidal irradiation (UVGI) The growing popularity of UV rays has further luminaire fixtures that emit UVC light (100-280 nm) broadened its prospects as surface disinfectant as for disinfection purposes. Such systems are usually well. The cleaning and disinfection become efficient installed in the upper part of a room to destroy floating and effective with UV rays that zap disease-causing particles in the air. pathogens from the immediate surrounding space, leaving behind a clean surface. Equipment Disinfection UV light finds effective use in equipment disinfection. This method is dry and doesn’t leave behind moisture and stains unlike washing and bleaching methods. Several airlines like Boeing have even started testing hand-held UV sanitizers to disinfect sensitive flight equipment, cabins, cockpits, and more. Food & Beverage Disinfection Fresh or raw food material have the highest risk of attracting harmful bacteria and viruses either from Water Disinfection exposure to elements or cross-contamination. UV- based sanitizing methods could be a welcome addition UV light is being used for water disinfection and even in food processing units to reduce cases of disease for wastewater treatment since many years now.