WHAT ARE GERMICIDAL UV-C ULTRAVIOLET RAYS?
Ultraviolet rays are electromagnetic waves which form part of light. Electromagnetic waves are divided into three main wavelength bands, expressed in nanometres (nm)
UV-A (315-400 nm) with tanning properties;
UV-B (280-315 nm) with therapeutic and vitamin “D”
UV-C (100-280 nm) with germicidal properties.
HOW DO GERMICIDAL UV-C RAYS WORK?
UV-C rays (100-280 nm) have a strong germicidal effect and reach their maximum efficacy at the 265 nm wavelength. The germicidal effect of UV-C radiation covers bacteria, viruses, spores, fungi, molds and mites; this is mainly due to the destructive effect of the UV-C rays on their DNA, which damage their reproductive system and prevent them from replicating.
DO UV-C RAYS WORK ON COVID-19?
The emergency of COVID 19 has highlighted the need for an innovative approach to disinfection needs. UV rays have offered positive results in the fight against SARS and MERS, two viruses very similar to the current COV2 Coronavirus. The use of UV-C radiation is a safe, efficient and cost-effective solution, avoiding the use of hazardous chemicals.
ARE UV-C RAYS VISIBLE?
These lamps have an emission of around 90% over the 253.7 nm wavelength. This frequency is invisible to the human eye and has a strong germicidal power. The remaining 10% of the lamp’s emission is visible (typically appearing as a blueish light).
ARE UV-C RAYS FOUND IN NATURE?
Yes, UV-C rays are found in nature as they are generated by the sun, but the ozone layer in the atmosphere acts as a shield which stops them from reaching the earth’s surface.
WHAT ARE THE MAIN ADVANTAGES OF USING GERMICIDAL UV-C LAMPS?
Bacteria, viruses, spores, fungi, molds and mites are all sensitive to UV-C rays and can be eliminated by them - including Microbes cannot acquire resistance to UV-C rays, which only occurs using chemical disinfectants and antibiotics. UV rays are eco-friendly. When using normal disinfectants, environmental pollution is inevitable. They also carry severe risks from the direct inhalation of vapours or the ingestion of foods contaminated after coming into direct contact with chemical disinfectants. Where the use of chemical disinfectants is unavoidable (food/pharmaceutical/healthcare industries, etc.), using ultraviolet rays in the disinfection process can reduce the amount needed, which allows for significant cost savings and is better for the environment, while maintaining - and, most of the time, improving - disinfection quality.
WHO RECOMMENDS USING UV-C RAYS?
Multiple organisations and boards with a global reach, such as FDA, WHO, EPA, CDC, ASHRAE and many others, recommend using UV-C rays to disinfect water, environments and air-conditioning systems.
WHO USES UV-C RAYS?
Food and pharmaceutical industries - for disinfecting air and surfaces in production spaces, disinfecting product containers (packaging), isolating “protected” areas for product manufacturing and packaging (such as clean rooms), and areas at risk of contamination. These procedures significantly increase the safety and conservation of the products we purchase and provide multiple health benefits since they leave no residue and help reduce or even eliminate the need for chemical disinfectants, which can leave harmful residues on products.
Hospitals - for preventing the transmission, and therefore contagion, of dangerous bacteria or viruses that may be found in the air or carried following contact with infected persons or visitors, such as TBC and Legionella.
Air conditioning systems - for preventing the problematic and harmful build-up of mould and bacteria in air treatment systems or ducts, which can cause Building Related Illnesses (BRI), extrinsic allergic alveolitis, viral, fungal and Rickettsial infections, bronchial asthma, humidifier fever, Pontiac fever and Legionnaire's disease, asthma and Sick Building Syndrome. Many armies use UV-C systems to prevent biological attacks such as the dispersal of anthrax in pipelines.
Systems for treating water intended for human and animal consumption and for sanitary use, to eliminate any microorganisms that may be found in water deriving from wells, cisterns and aqueducts. The system must be installed after an active carbon filter, such as in water distributors, which are becoming increasingly common in cities. There are no limits to the possible applications of UV-C rays. Even in domestic environments, they are used to prevent build-up of mold on walls, eliminate mites from bedrooms, keep room air healthy and treat water. UV-C rays are even able to eliminate odors and fatty deposits in industrial kitchens and in the restaurant industry in general, in conjunction with the emission of ozone.
WHICH MICROORGANISMS ARE ELIMINATED BY UV-C RAYS?
Bacteria, viruses, spores, fungi, molds and mites are all sensitive to and eliminated by UV-C radiation.
HOW DO UV-C RAYS DISINFECT THE AIR?
Viruses, bacteria and mold, animal waste, mites and pollens are among the main causes of dangerous infections and allergies. Each of these contaminants is dispersed in a different way: mites, spores, bacteria and mold, for example, are continuously transported by air, while other bacteria and viruses are “grouped” into solid particles, such as spores or drops of moisture, and then inhaled by humans. In air conditioning systems, when contaminants get inside the air treatment unit (ATU) and air distribution ducts, the system, which is dark and moist, becomes a breeding ground for them to grow and multiply, making the air we breathe unsafe. The air also contains concentrations of chemical pollutants which are dangerous if inhaled in large quantities or on a continuous basis. Irradiating air using a UV-C device or installing an air purifier complete with UV-C lamps greatly reduces the likelihood that these pollutants (whether microbiological or physicochemical) will result in health problems that often can only be diagnosed after many years.
HOW DO UV-C RAYS DISINFECT SURFACES?
When a UV-C light is turned on, the number of microbes in the air and on all surfaces reached by the UV rays is reduced significantly. For example, in just a few minutes the bacteria Bacillus, Coli, Clostridium, Legionella, Vibrio, Salmonella, Listeria, Pseudomonas, Staphylococcus, Streptococcus, etc. can be reduced by 99% at a distance of 3 m from the device. This enables the system to reach areas that would otherwise be unreachable with solid objects such as cleaning products and disinfectants, like hidden areas in flooring and furniture. Where chemical disinfectants must be used, irradiating the surfaces prevents black-out areas, does not generate resistant species and can be used both day and night (without human presence), avoiding rapid re-contamination of surfaces and keeping them constantly in optimal microbiological conditions.
CAN UV-C RAYS PENETRATE SOLID BODIES (IONISATION)?
UV-C rays cannot penetrate solid bodies. To eliminate microorganisms using UV-C rays, they must be present on the surface of an object or transported by the air.
ARE THERE ANY MATERIALS THAT CAN BE PENETRATED BY UV-C RAYS?
There are very few materials that will not block the passage of the germicidal wavelength (253.7 nm, invisible). Regular window glass, polycarbonate and other transparent materials through which it is possible to see the bluish light of UV-C light completely nullify their germicidal effect, acting as a screen.
WHAT EFFECT DO UV-C RAYS HAVE ON THE HUMAN BODY?
Continuous irradiation of the eyes and skin could cause erythema and conjunctivitis, which normally clear up in a few hours. In any case, it is sensible to avoid direct, close-up exposure to sources of UV-C rays even for short periods of time. To avoid direct exposure simply cover the area to be protected using any material that is not transparent to visible light (cotton or woollen clothing or overalls) or using glass or transparent plastics (masks, helmets, glasses, etc.).
WHAT EFFECT TO UV-C RAYS HAVE ON PLASTIC SURFACES?
UV-C rays are similar to solar rays, but do not transmit heat. However, like solar rays, they tend have a yellowing effect on plastics that are exposed for long periods of time (especially white plastics).