Wednesday, July 22, 2020


"My disease has played a very great role for my whole development… I was of course interested to know what benefit the sun really gave. During my work towards this goal I encountered several effects of light-- I then devised the treatment of small-pox in red light (1893) and further the treatment of lupus (1895)."-  Niels Ryberg Finsen

Written by: Cheri Ambrose  /   Introduction by: Dr. Robert L. Bard

In our current health crisis, prevention terms like DISINFECTING, SANITIZING or ANTI-BACTERIAL treatments are part of our common reality. Until recently, noxious "bio-killing" chemicals in atomized /spray form has been the most widely available choice on the market. With proper repeated use, fogging, spraying or ionizing chemistries in our living space are the popular option in contaminant prevention, but public concerns about the many possible physiological side effects of atomizing toxins into our air supply call for new alternatives.

Per-room disinfecting UV-C "Robot" (Skytron)
A sustainable upgrade in sanitizing was developed through the use of UV-C light. The CDC recognizes this innovation as one of the 'best disinfecting practices'. Ultraviolet germicidal irradiation (or UVGI) is the use of ultraviolet (UV) energy (electromagnetic radiation with a wavelength shorter than that of visible light) to kill or inactivate viral, bacterial, and fungal species. The UV spectrum is commonly divided into UV-A (wavelengths of 400 nm to 315 nm), UV-B (315 nm to 280 nm), and UV-C (280 nm to 200 nm). The entire UV spectrum can kill or inactivate many microorganisms, but UV-C energy provides the most germicidal effect, with 265 nm being the optimum wavelength. [1]

(From an interview with Skytron technology)
The earlier studies on the germicidal efficacy of far UVC light were performed exposing bacteria irradiated on a surface or in suspension. Modern developments have since honed the science of deactivating viruses and their ability to contaminate and transmit diseases with proven success when directly applying 222-254nm of UVC light on airborne viruses and microbes. [4]

On a recent interview, UVC expert Michael Czechowskyj of Skytron, a leading domestic manufacturer of infection prevention technologies presents valuable insight on the effectiveness of light disinfectants and the recent market expansion of UVC devices and installations. He discussed its ease-of-use and integrative friendliness of how a UVC device can take over the age-old spraying solutions.

"Today's UVC lamps are fully automated with complete safety features in place. You literally plug it in, start it up and leave the room to go about your day. Once the machine is done, it's perfectly safe that you can enter immediately. Not all sprayers and foggers can let you do that. And under the wait period, especially with ozone foggers, there's no ongoing chemicals that you're spraying or ongoing chemicals to buy either. Another difference is the coverage; with spray sanitizers, the sprayer can often MISS areas, or not spray enough solution in a specific area that needs it. This manual process of spraying leaves so much room for error and uncertainty. Irradiating a room with a UVC system does it all for you. It calculates the treatment time, intensity and because it's light, it gets into all the nooks and crannies to ensure a complete application."

UV-C devices and lamps uses light wavelengths of around 254 nanometers, which denatures the DNA of the microbe. It creates a Thymine Dimer Pair, which prevents them from replicating. So it essentially does not kill the virus. It prevents it from reproducing, which means it prevents it from being infectious. Within a century of its existence, UV-C technology has maintained a constant design using the 254nm setup with a low pressure mercury amalgam bulb. The latest technology change was the bulb, where we eliminated ozone production. They have a special covering on them, which means that blocks the certain nanometers of light that produces ozone because ozone can be detrimental to humans as well.

Our devices all have a predetermined endpoint- much like filling a bucket of water.  Based on our research and lab studies, our machines identify when to turn itself off once it hits that mark of disinfecting the room. On a safety aspect, its 'dose' or application cycle is contingent upon the exact size of that room. There will be a faint, minor smell (most likely caused by irradiating the many particulates in the air) after the room and we call it "the new smell of clean".

There’s been very few studies done on the SARS COVID-19 virus. Most studies are done on surrogate pathogens. Corona viruses is recognized as a lipid based envelope virus and is fairly easy to kill. As with washing your hands, soap and water alone does a good job of killing this virus. We've also used a lot of similar studies on other types of CoronaViruses like MERS and SARS 14 COVID. Our devices are also calibrated for C-Diff (a spore producing bacteria known to cause a range if disorders from diarrhea to life-threatening inflammation of the colon- a bacteria that is very hard to kill, inactivate or sterilize). It is this lab standard that fosters the health industry's confidence in UVC technology's ability to inactivate the coronavirus.

Our industry undergoes strict efficacy studies with third party labs (to ensure the validity of the data) which is what are our end points were based on. Because of the nature of disinfecting, it's important to gain the confidence of the end user like a hospital- where we try to find more visualization for our clients. Something like a dosimeter color changing device (a device used to measure an absorbed dose of ionizing radiation) lets the director of a medical facility identify the right end point that they're looking for- and to make sure that they know the treatment is working properly.

Facilitating health and safety protocols in this pandemic, UV-C disinfecting has been made available in smaller and larger applications. There's a smaller device that will disinfect masks in about six minutes. We defer to a lot of what the CDC has done with decontaminating N-95's. We know that not all UVC is created the same-- different bulbs, UVC output, wattage etc. And so, you know, we're real careful to make sure that we're keeping the clinicians as safe as possible and giving the people the information. When disinfecting an entire room, we use something called "dose assurance technology". This feature constantly reads the UVC field in real time; it reads the UVC that's being put out by the lamps and the UVC that is being reflected. We calibrated to a predetermined dose, that when they get to that end point, the machines then shut off knowing they've done their job well - within a specified time vs. ray intensity.

For additional information on UV-C technology or SKYTRON, visit or contact Mr. Czechowskyj directly at


Images courtesy of

In 2006, the U.S. Environmental Protection Agency approved a test plan for Biological Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Air Cleaners. (1) The tests were conducted using three organisms, two bacteria (Bacillus atrophaeus and Serratia marcescens) and one bacterial virus (MS2).  These organisms were selected because their sizes, shapes and susceptibility to UV inactivation make them reasonable surrogates for biological warfare agents (BWAs). Generally, vegetative bacteria are readily killed and bacterial spores are more difficult. To model use in a VAC system, RTI used a test duct designed for testing filtration and inactivation efficiencies of aerosol, bioaerosol, and chemical challenges.  The bioaerosol inactivation efficiencies calculated for the three organisms were 9% for B. atrophaeus, 99.96% for S. marcescens and 75% for MS2. The irradiance was measured as 1190 W/cm2 at 161 cm(63 in.) upstream from the lamps with an airflow of 0.93 m3/sec (1970 cfm). The system had four lamps that were burned in for 100 hours prior to measurements.

UV lamps have been used to inactivate airborne microorganisms for many years. Much of the early work was directed at the control of very infectious microorganisms (particularly Mycobacterium tuberculosis, the causative agent of tuberculosis), often in medical facilities. Wavelengths within the short wave, or C band of UV light (UVC), were found to be the most effective germicidal light wavelengths. UVC usually is generated by use of UVC fluorescent lamps. These lamps use electrical discharge through low-pressure mercury vapor enclosed in a glass tube that transmits UVC light (primarily at the mercury wavelength of 253.7 nm). Because this wavelength has been found to be about the optimum for killing microorganisms, UVC from mercury lamps also is referred to as UVG to indicate that it is germicidal. UVG has been shown to inactivate viruses, mycoplasma, bacteria, and fungi when used appropriately.

Due to the recent pandemic, companies developing this technology are (now) on the fast track to advance UVC installations for a wide range of professional and commercial environments.  Specific testing is currently underway as to the efficacy against SARS-CoV-2 (the virus that causes COVID-19) but historically, systems like those developed by Fresh-Aire UV have been tested and proven effective against pathogens that require even greater UVC dosages.  "Every microorganism requires a specific UVC dosage for inactivation including the novel coronavirus. UV disinfection has been employed for decades in water treatment; these microwatt values have been used for reference to gauge UVC efficiency against a large cross-section of microorganisms. UV disinfection systems for room, surface & HVAC are (also) an ideal proactive measure to complement filtration", stated Aaron Engel, VP of Business Development at Fresh-Aire UV. 

Niels Ryberg Finsen (1860-1904) was the first to employ UV rays in treating disease. He was awarded the Nobel Prize for Medicine in 1903 for his invention of the Finsen curative lamp, which was used successfully through the 1950s. [01]  Updates in the technology for commercial use evolved as UV-C germicidal lamps in the 1930's and have been primarily used in healthcare facilities. UVGI is highly recognized for addressing airborne microbial disease prevention (including influenza and tuberculosis). UVC is proven to prevent airborne transmission by deactivating airborne pathogens, but public use has been curtailed due to its potential to cause cancers and cataracts upon direct contact. [02]

The history of UVGI air disinfection has been one of promise, disappointment, and rebirth. Investigations of the bactericidal effect of sunlight in the late 19th century planted the seed of air disinfection by UV radiation. First to nurture this seed was Richard L. Riley and his mentor William F. Wells, who both discovered the spread of airborne infection by droplet nuclei and demonstrated the ability of UVGI to prevent such spread. With the enduring research of Riley and others, and an increase in tuberculosis (TB) during the 1980s, interest in UVGI was revitalized. With modern concerns regarding multi- and extensive drug-resistant TB, bioterrorism, influenza pandemics, and severe acute respiratory syndrome, interest in UVGI continues to grow. Research is ongoing, and there is much evidence on the efficacy of UVGI and the proper way to use it, though the technology has yet to fully mature.  [3]

Epilogue: Straight Answers from the CDC
In our commitment to publish helpful information about innovative solutions, we rely on top health  authorities to provide us with unbiased clarity and technical standards. We inquired about how UV-C Disinfecting technology truly ranked as the future solution to defeating viruses and transmitted diseases. Steve Martin, PhD, an engineer in NIOSH’s Respiratory Health Division provided us with these valuable statements:

Q: Does the CDC see UV-C Disinfecting as the next trend- evolving from chemical spray sanitizing?
A: No.  CDC understands that germicidal UV technologies, including patient room terminal cleaning devices (sometimes called UV robots), can provide enhanced surface disinfection over the use of chemical disinfectants alone. However, UV technologies, as they currently exist, will never replace manual chemical cleaning in healthcare spaces.  While UV can be very efficient at inactivating pathogens on surfaces, UV-C energy cannot substantially penetrate blood and other bodily fluids, or through other simple spills and splashes that occur in the course of patient care, even those that have dried and left residues. Thus, healthcare surfaces need to first be thoroughly cleaned to remove gross contamination before the UV energy can directly impact the surfaces and provide the most disinfection benefit. Then, UV systems that are properly applied can effectively inactivate many of the pathogens that manual cleaning may have left behind.

Q: From an original post on 2016, CDC warned about potential OZONE output from UV.  It has been evident that companies have since been addressing the testing, preventing and validating of ozone output.  Does CDC have enough data on this upgrade?
A: Concerns about UV lamps producing ozone have existed for decades and there have not been any significant “upgrades” since 2016.  There are some UV-C lamps designed specifically to produce ozone.  Ozone-producing lamps generally do not use an internal coating on the glass (or quartz) tube so UV energy at wavelengths below 200 nm (predominantly 185 nm) is emitted from the lamp. These wavelengths are responsible for ozone production.  There is a separate group of UV-C lamps designed specifically not to produce ozone.  This group is the low-pressure mercury vapor lamps used for germicidal ultraviolet (GUV) applications.  GUV lamps have interior coatings to block UV energy at wavelengths below 200 nm from escaping the tube, so ozone is not created. Unfortunately, ozone-producing lamps and GUV lamps of the same type and size can often be powered using the same electrical connectors and electronic drivers (ballasts).  So, it is critical for the end user to choose the proper lamp for their application.  If they choose a typical GUV lamp for a germicidal application, then ozone is not a concern.  If an end user unknowingly chooses an ozone-producing lamp that happens to fit properly into their GUV device, then ozone exposures will happen. CDC always recommends that end users communicate with the UV device manufacturer or a reputable UV system designer when purchasing replacement UV lamps.



Advanced Imaging & Diagnostic Specialist
Dr. Bard received the 2020 nationally acclaimed Ellis Island Award for his lifetime achievement in advanced cancer diagnostic imaging. He co-founded the 9/11 CancerScan program to bring additional diagnostic support to all first responders from Ground Zero. His main practice in midtown, NYC (Bard Diagnostic Imaging- uses the latest in digital imaging technology and has been also used to help guide biopsies and in many cases, even replicate much of the same reports of a clinical invasive biopsy. Imaging solutions such as high-powered sonograms, Power Doppler Histogram, sonofluoroscopy, 3D/4D image reconstruction and the Power Doppler Histogram  are safe, noninvasive, and do not use ionizing radiation. 

Dr. Kory is Board Certified in Internal Medicine, Critical Care, and Pulmonary Medicine. He served as the Medical Director of the Trauma and Life Support Center at the University of Wisconsin where he was an Associate Professor and the Chief of the Critical Care Service. He is considered a pioneer and national/international expert in the field of Critical Care Ultrasound and is the senior editor of the widely read textbook “Point-of-Care Ultrasound” (winner of the President’s Choice Award for Medical Textbooks from the British Medical Association in 2015).  Most recently, Dr. Kory joined the emergency volunteer team during the early COVID-19 pandemic in NYC at Mount Sinai Beth Israel Medical Center. He is also a founding member of the Front Line COVID-19 Critical Working Group ( composed of 5 critical care experts that devised the COVID-19 treatment protocol called MATH+. (

Taking care of patients at the bedside is where Mike Czechowskyj started his nursing career.  After caring for patients in the Progressive Care and Burn ICU, he advanced into different leadership positions at Spectrum Health.  There he helped educate new staff, build new programs and advanced nursing practice.  He then joined the Spectrum Health Innovations team where he worked with local businesses, health systems, and universities to create new medical devices that would help patients and healthcare providers.  This led him to one of their partners, Skytron, where Michael now provides leadership for the Infection Prevention team.

Mr Engel is Vice-President of Business Development for Fresh-Aire UV, a global leader in UV disinfection technologies. Aaron has 20 years experience in the design, manufacturing and marketing of UV disinfection systems for domestic and international applications including those for residential, commercial and healthcare. Aaron has worked on projects with various groups & associations including the definitive study on UV inactivation of airborne bioterrorism agents sponsored by RTI, the United States EPA & US National Homeland Security. Aaron is frequent guest speaker and lecturer and contributes to publications on IAQ technologies and UV disinfection. Aaron is a member on various ASHRAE committees including TC2.9 Ultraviolet Air and Surface Treatment and the Programs Chair for TC2.9.

2) Disinfection and Sterilization Guideline for Disinfection and Sterilization in Healthcare Facilities (2008)
3) US National Library of Medicine National Institutes of Health: The History of Ultraviolet Germicidal Irradiation for Air Disinfection
4) Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases

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