UV-C DISINFECTION

Thanks to its disinfecting properties, UV-C radiation is a real all-rounder. UV-C lamps can be used to disinfect water, air and surfaces. But while the use of such lamps has so far been limited to a few industries, demand has exploded across all sectors worldwide since the outbreak of the COVID-19 pandemic. Learn more about the unique features which have suddenly placed UV-C technology in the global spotlight.

Electromagnetic radiation is characterized by a specific wavelength. Compared to visible light, ultraviolet radiation, UV radiation for short, has a significantly shorter wavelength. Depending on the type of UV radiation, this lies between 10 and 400 nanometres. UV radiation is divided into four ranges according to its wavelength:

• UV-A: UV-A radiation has a wavelength between 315 to 400 nanometres. The light can cause certain substances to fluoresce. Thanks to this, UV-A lamps have a long tradition in the entertainment business, but are also used in forensics – for example in marking banknotes. UV-A lamps can be produced easily and cheaply.
• UV-B: UV-B radiation possesses a wavelength between 280 and 315 nanometres. Lamps that emit light in this range are highly valued by tan lovers in particular. UV-B lamps brown the human skin and are therefore used in tanning studios.
• UV-C: UV-C radiation with a wavelength between 100 and 280 nanometres is classified as UV-C. UV-C radiation has an outstanding property: UV-C radiation is very energy-rich and therefore it is able to kill bacteria and viruses. The strongest effect against pathogens (pathogens) occurs at 265 nanometers. UV-C radiation causes considerable DNA damage to micro-organisms, which ultimately leads to decontaminating the corresponding pathogens. Mercury vapour lamps are currently considered to be the most effective UV-C radiation source.
• EUV: Extreme UV with a wavelength between 10 and 100 nanometres is mainly used in manufacturing – for example in chip production.

UV-C radiation: environmentally friendly and efficient

Compared to other disinfection methods, UV-C radiation has a number of advantages:

• UV-C radiation does not require chemicals and toxic compounds.
• Pathogens are unable to form resistance to UV-C radiation.
• The radiation could render pathogens harmless in a matter of seconds.
• The treatment’s short duration does not change the properties of a product.
• UV-C radiation leaves no residue or discolouration on surfaces.
• Ozone is not produced in the corresponding range above 240 nanometres.

For these reasons, UV-C radiation has been used for decades in some sectors such as medicine or food packaging disinfection (for example yoghurt pots) as a clean disinfectant solution.

Up to recently, the implementation of UV-C lamps were still very limited. In addition to medical applications, UV-C radiation was mainly used in the food industry as well as for cleaning pools, aquariums and wastewater. However, as COVID-19 becomes more widespread, the need for UV-C lamps has boomed. Even in areas where UV-C applications have at best been in a very small niche, there is now an increased demand.

UV-C disinfection devices should not be used directly on the body as they can damage the skin and eyes. For this reason, some safety instructions must be observed during use:

• UV-C lamps should only be directed at the surface to be disinfected. It is essential to avoid radiation to the skin or eyes.
• Users must be protected from exposure to UV-C. The use of UV-C radiaton in enclosed rooms is therefore only recommended when there are no people in the room.
• The UV-C lamp should be switched off immediately after disinfection.

In addition, information on the packaging and in the accompanying instruction book must be followed precisely.