UVGI – Ultraviolet germicidal irradiation is a disinfection method that uses short-wavelength ultraviolet (Ultraviolet C or UV-C) light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions.
Ultraviolet is part of the light spectrum, along with cosmic rays, gamma rays, x-rays, visible light, infrared and radio waves. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation which is reaching from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. These different lamps are used for ultraviolet water purification and air and surface disinfection.
Ultraviolet light is classified into three wavelength ranges:
- UV-C, from 200 nm – 280 nm
- UV-B, from 280 nm – 315 nm
- UV-A, from 315 nm – 400 nm
UV-C refers to ultraviolet light with wavelengths between 200 – 280 nanometers (nm). The UV-C light is germicidal – i.e., it deactivates the DNA of bacteria, virus and other pathogens and thus destroys their ability to multiply and cause disease. UV-C radiation, in the range of 250 nm – 280 nm, renders harmful micro-organisms such as bacteria and viruses ineffective, by causing damage to the nucleic acid of microorganisms by forming covalent bonds between certain adjacent bases in the DNA. The formation of such bonds prevent the DNA from being unzipped for replication, and the organism is unable to reproduce. In fact, when the organism tries to replicate, it dies. The germicidal nature of UV is well suited to treat parasites which are extremely resistant to chemical disinfectants. So the light in the UV-C wavelength can be used for disinfecting water, sterilizing surfaces, destroying harmful micro-organisms in food products and in air.
Is UV-C safe?
We’re exposed to parts of the UV spectrum while outdoors. Generally, excessive UV exposure can produce adverse effects depending on wavelength, type and duration, and UV response differences between individuals.
UV-C – includes the germicidal wavelength of 253.7nm and is used for air and water disinfection. Human overexposure causes temporary skin redness and harsh eye irritation, but no permanent damage, skin cancer, or cataracts.
Dose needed to destroy some of the most common micro-organisms
Kind Dose (mJ / cm 2 )
Bacillus subtilis (spore) 12.0
Clostridium tetani 4.9
Legionella Pneumophilla 2.04
Pseudonomas aeruginosa 5.5
Streptococcus feacalis 4.5
Hepatitis A virus 11.0
Hepatitis Poliovirus 12.0
Saccharomyces cervisiae 6.0
Infectious pancreatic necrosis 60.0
FIG. 4 – E.coli (Waterborne indicator Pathogen) DOSE = 5.4 mJ / cm2
Dose (mJ / cm 2) Reduction of the number of microorganisms
ODEON Securities UV-C devices are made to help you fight against:
Today a lot of viruses (just like SARS-CoV-2) are airborne. That means, that some of the viruses and diseases are carried and transferred through the air between the population through aerosols. An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas. They can be natural or anthropogenic.
Bioaerosols are a subcategory of particles released from terrestrial and marine ecosystems into the atmosphere. They consist of both living and non-living components, such as fungi, pollen, bacteria and viruses. Bioaerosols are typically introduced into the air via wind turbulence over a surface. Once in the atmosphere, they can be transported locally or globally. Common wind patterns/strengths are responsible for local dispersal, while tropical storms and dust plumes can move bioaerosols between continents. They can transmit microbial pathogens, endotoxins, and allergens to which humans are sensitive.
Sick building syndrome (SBS)
Sick building syndrome is a name for a condition that’s thought to be caused by being in a building or other type of enclosed space. It’s attributed to poor indoor air quality. However, the precise cause is unknown. According to World Health Organization (WHO), poor indoor air quality can be found in about 30% of new and remodeled buildings. It is a common worldwide health concern, where people in a building suffer from symptoms of illness or become infected with chronic disease from the building in which they work or reside. The outbreaks may or may not be a direct result of inadequate cleaning or inappropriate cleaning methods. Other causes have been attributed to contaminants produced by outgassing of some types of building materials, volatile organic compounds, mold, improper exhaust ventilation of ozone, light industrial chemicals used within, or lack of adequate fresh-air intake/air filtration.
Sick building syndrome symptoms can affect your skin, respiratory, and neurological systems. Among the possible symptoms are: throat irritation, breathing difficulties, pain in the chest, runny nose, allergy-like symptoms, such as sneezing, burning sensations in the nose, dry, itchy skin rashes, headaches, dizziness, difficulty concentrating, forgetfulness, fatigue, irritability, nausea, body aches, fever, chills. Certain symptoms tend to increase in severity with the time people spend in the building. It is common, that people’s health is often improving over time or even disappearing when they stay away from the building.