Information about UVC DESINFECTION

Light 

The light we perceive is only part of the spectrum. From a scientific point of view, it is an electromagnetic radiation consisting of different wavelength regions. The figure below shows the most well-known areas that make up the spectrum: visible light, infrared and ultraviolet light (UV light). The human eye only sees, as the name suggests, visible light. This part contains all the colours of the rainbow. Infrared light and UV light are not visible to the human eye, but ultraviolet light itself has different regions. UVA light consists of long waves and is known to accelerate the skin aging process. UVB light consists of medium waves and causes sunburn on the skin and gives us a tan in the summer.

UVC light

UVC light is short wavelength radiation between 200 and 280 nanometers. This light is harmful to humans because it destroys skin cells. Fortunately, natural UVC light is completely blocked by our atmosphere. However, UVC light is very suitable for microbiological disinfection and is also a very clean technology.

Disinfection with UVC

UVC light is able to disinfect water, air and surfaces. Micro-organisms are rendered harmless very effectively without the use of chemicals. Odour, colour and taste do not change, as does the water composition itself. It is actually quite simple: micro-organisms are ‘killed off’, even those that are resistant to chlorine, antibiotics or organic biocides.

How does UVC disinfection work?

Micro-organisms such as bacteria and fungi naturally absorb UVC light. However, when UVC light enters the cell of a micro-organism, it breaks the DNA connections in the cell. This molecular change makes the DNA unusable for the essential process of transcription (metabolism) and replication (cell division). As a result, the micro-organism is rendered harmless and dies.

UVC lamps

The most efficient method of producing UVC is with the low pressure mercury vapour discharge lamp, where on average 35% of the energy is converted into UVC. Lamps of good quality are made of a special glass that blocks ozone forming radiation and have minimal doses of mercury. Philips lamps also have a special coating that keeps the intensity of the radiation at a minimum of 80% of the initial intensity until the end of the service life.

The advantages of UVC disinfection

– The UVC technique is over 100 years old and has already proven its effectiveness against water and airborne pathogenic microorganisms such as those causing diseases such as Cholera, Hepatitis, Polio, Typhoid, Giardia, Cryptosporidium and many other bacterial, viral and parasitic diseases. – Microorganisms cannot build up resistance to UVC light. – UVC installations have a low purchase and installation cost and are easy to maintain. – UVC technology is environmentally friendly and leaves no residue. – UVC light is not harmful to the environment. It only affects the DNA of the micro-organism and has no effect on other properties. – UVC radiation works immediately and the room is immediately available again. – UVC disinfection is a physical process. No chemicals are used. Taste, colour and odour of the medium (the carrier, such as liquids or surfaces) remain unaffected. Only light is used. – The effect of UVC disinfection is related to the UV dose (the product of the intensity and the exposure time to the micro-organism). The efficiency can easily be measured once the system has been validated.

The disadvantages of UVC light

– On the skin: Because UVC does not have an infrared component such as sunlight, you do not feel anything about it, but it causes redness and a burning sensation on the skin fairly quickly. If this happens incidentally, it is harmless, but with continued exposure it leads to skin aging. – On the eyes: UVC does not penetrate into the eye, but a few hours after exposure it can cause irritation of the cornea. This gives a painful, burning sensation, also known as “welding eye” or “snow blindness”. Again, although this is occasionally unpleasant, it is also quite harmless, but chronic exposure can cause the lens of the eye to cloud (cataract).