Ultraviolet rays are electromagnetic waves which are part of light. Electromagnetic waves are divided into three main wavelength bands, expressed in nanometers, nm: Ultraviolet rays (UV) 100-400 nm Visible rays (light) 400-700 nm Infrared rays (IR) 700-800,000 nm UV rays are in turn identified in three bands:

  • UV-A (315-400 nm) with tanning properties;
  • UV-B (280-315 nm) con proprietà terapeutiche e di sintesi della vitamina "D";
  • UV-C (100-280 nm) with germicidal properties.

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, moulds 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.

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).

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.

Bacteria, viruses, spores, fungi, moulds and mites are all sensitive to UV-C rays and can be eliminated by them.
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.
UV-C ray devices can be installed in most environments and machinery and can be programmed to maintain the same level of disinfection day and night, ensuring ideal conditions of hygiene without any fluctuation in quality. In contrast, chemical disinfectants are most effective at the time of use.
LIGHT PROGRESS UV-C-equipped devices offer low running costs and are maintenance-free, besides normal bulb replacement. These powerful and highly durable systems provide exceptional value for money. For this reason, eliminating germs using UV-C as opposed to (or together with) other systems offers excellent results at a low cost.

UV-C light genuinely works if properly applied and with the necessary precautions. The difference between a quality project, and an application that fails to bring the desired results, lies in the degree of knowledge about the subject, and level of experience acquired over time. Light Progress has been developing successful projects worldwide since 1987, and has built a client portfolio consisting of important companies in all fields requiring certified hygienic conditions to produce quality products and services.

Several world-class bodies and organisations, such as WHO, EPA, CDC, ASHRAE, and many others all recommend the use of UV-C light for the disinfection of water, venues, and air conditioning systems; LIGHT PROGRESS is a member of IUVA (International UltraViolet Association), a world organisation that collects and publishes the available information for users, organising several international meetings each year; IUVA, in collecting all the available information, has also published a document providing the basis for the design of various UVGI (UltraViolet Germicidal Irradiation) systems and applications.

UV-C rays are used every day, primarily in:

Food and pharmaceutical industries to disinfect the air and surfaces of production environments, to disinfect product containers (packaging), to isolate “protected” areas for the production and packaging of products, such as clean rooms, from areas at risk of contamination. These actions significantly increase the safety and shelf life of the products we buy, with numerous benefits to our health given that they do not leave any residue and allow the elimination or reduction of chemical disinfectants, which to the contrary, may leave hazardous residue on the products.

Hospitals, to avoid the transmission, and therefore contagion of dangerous bacteria or viruses that may be found in their air, or transmitted by contact between the sick, but also among visitors.

Sistemi di condizionamento dell’aria, per evitare il fastidioso e pericoloso formarsi di muffe e batteri all’interno delle centrali di trattamento aria o nelle canalizzazioni, responsabili delle Building Related Illness (BRl) o "Malattia correlata all'edificio" alveoliti allergiche estrinseche, infezioni da virus e funghi e da rickettsie, asma bronchiale, febbre da umidificatori, febbre di Pontiac e legionellosi, asma e Sick Building Syndrome. Molti eserciti prevedono sistemi UV-C per prevenire attacchi biologici come la dispersione di Antrace nelle condotte.

Water treatment systems to provide drinking water for humans and animals, and for healthcare use, to eliminate all microorganisms that might be found in water coming from wells, tanks, and aqueducts. This system is mandatory downstream of a carbon activated filter, for example in water dispensers, which are becoming increasingly popular in cities.

There are no limits to the possible applications of UV-C light; even in domestic environments, it is used to prevent the formation of mould on walls, to eliminate mites from the bedroom, to keep the indoor air healthy, to treat water.
UV-C light can also eliminate odours and grease deposits in industrial kitchens and restaurants in general, assisted by the emission of Ozone. LIGHT PROGRESS has developed a specific system also for this type of application.

Bacteria, viruses, spores, fungi, moulds and mites are all sensitive to and eliminated by UV-C radiation.

Each bacterium, virus, yeast, mould or mite requires a different UV-C dose to be deactivated or eliminated.
There are widely recognised documents which report these levels. Light Progress has one of these documents and uses it regularly in designing and implementing its systems. To give an approximate idea regarding the application times of UV-C rays, these can range from fractions of a second to several seconds.

Viruses, bacteria and mould, 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 mould, 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 in a central system or installing an air purifier complete with UV-C lamps and a TiOx titanium dioxide filter 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.

The legal microbiological limits for drinking water contained in Legislative Decree 31/2011 are very strict.
Methods for eliminating microorganisms from water may be chemical (chlorination) or physical (UV-C rays, heat).
In the first case, ingested water may contain harmful, chlorine-derived waste substances such as chloramines, which alter the smell and taste of the water, or other undesired by-products that are harmful to human health and to the environment such as volatile organic substances, including trihalomethanes, which are highly carcinogenic.
Heating (boiling water before use) could be helpful in preventing the above problems, but it is certainly not practical, besides creating handling problems, requiring long-term cooling.
A UV-C ray system installed close to the point of use a on water line safely removes all microorganisms, irradiating them at a dose far higher than the minimum safe dose – making it very effective – without leaving a residue. The purchase and maintenance costs of the system and its replacement parts (bulbs) are extremely low. UV-C rays also reduce the amount of chlorine and any derivatives (aqueduct) into minuscule particles that are harmless to health.

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.

The efficacy of disinfection systems can easily be ascertained through microbiological analyses, or simple swab tests used to identify the presence of microorganisms on the tested surfaces. Regardless, in order to precisely verify the exact microbial load present on surfaces, in the air and in water, before and after the treatment, it is necessary to carry out lab tests such as those for HACCP.
For chemical disinfectants, producers need to provide tests declaring their disinfectant capacity; Light Progress has similarly carried out important tests in university labs and at private accredited bodies. Of course for both chemical disinfectants and UVGI technology, in order to obtain the same laboratory results it is important that the products be used in compliance with the instructions for use.


UV-C rays cannot penetrate solid bodies, unlike ionising radiation such as x-rays and gamma rays, both of which are highly dangerous to humans, even at low doses. To eliminate microorganisms using UV-C rays, they must be present on the surface of an object or transported by the air.


There are very few materials that will not block the passage of the germicidal wavelength (253.7 nm, invisible), including quartz and certain plastics such as PE or tetrafluoro-derivatives, but only if these are just a few microbes thick.
Regular window glass, polycarbonate and other transparent materials through which it is possible to see the bluish light of UV-C lights completely nullify their germicidal effect, acting as a screen.


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.).


Yes. Light Progress offers two solutions in a special plastic material called Uvlon Frame and Uvlon Pipe. Uvlon Frame is made from a film which is attached to the device and collects any fragments deriving from breakage. Uvlon Pipe is a casing that is thermally applied to the UV-C tube in the factory which increases its mechanical strength (car windscreen effect) and collects and retains any broken fragments inside.


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).