UVC surface disinfection uses very short-wave rays from the UV range, specifically UVC rays in the wavelength range of 254 nm (nanometres). This is the primary radiation of UVC low-pressure lamps, which is very close to the absorption maximum of biological cells (260 nm). If microbes are exposed to such radiation, cell division is interrupted and the cells die. UVC radiation is absorbed in the cell nucleus in the DNA and/or RNA, resulting in a photochemical chain, whereby the genetic information for the division process can no longer be duplicated. This is also referred to as inactivation. This purely physically induced mechanism of action depends on the dose, i.e. the radiation power and exposure time. It is irrelevant whether an exposed microorganism is a bacterium, a virus, a yeast or a mould spore. All carriers of genetic material can be inactivated by UVC irradiation. It is simply a question of the UVC dose.

As UVC surface sterilisation involves UV radiation being directed directly onto the surfaces at a short distance, this process technology is particularly efficient. As it is a purely physical process without additives, UV sterilisation leaves no undesirable residues on the surface. It is a particularly fast, energy-saving and efficient method for disinfecting surfaces, which is particularly useful in the food industry.

UVC surface sterilisation offers several advantages in food production: it is extremely effective at inactivating microorganisms such as bacteria, viruses and fungal spores on surfaces by damaging their DNA or RNA. This is done purely physically and without the use of chemicals. No residues of additives remain on the surfaces, which in turn could cause potential contamination. Disinfection takes place extremely quickly and in real time, without additional drying or reaction times, which significantly increases productivity.

The use of UVC radiation also reduces the environmental impact. Not only because no chemical disinfectants are used, but also because this technology is extremely energy-efficient. It also reduces costs as, for example, cleaning cycles for evaporators can be extended, demonstrably increases production hygiene, product safety and shelf life and can also be used 24/7, even during normal working hours. UVC surface disinfection generally helps producers in the food processing industry to comply with high hygiene and safety standards.

Unfortunately, this question cannot be answered with a yes or no and is very complex. This is because there is a great deal of variability in the country-specific regulations and wording, even within the European Union. For example, while the EU only defines in general terms in Annex I, Section II, Chapter V of REGULATION (EC) No 854/2004 that meat must be declared unfit for human consumption if it has been ‘inadmissibly treated with ionising or UV radiation’, the country-specific instructions are in some cases much more specific. In some cases, a distinction is made between carcasses (UV irradiation permitted) and unauthorised meat irradiation. And while fish irradiation is permitted in Scandinavian countries, this does not apply to Germany.

In the relevant German Food Irradiation Ordinance (LMBestrVO), which has been amended several times and in which UV irradiation was placed on the same level as electron, gamma and X-ray radiation in 1958, only the UV irradiation of drinking water, hard cheese, eggs, fruit and vegetable products is explicitly authorised. Here, particular attention must be paid to the wording ‘products’, because while UVC irradiation of an apple - as sensible as it may be - is not permitted, UV treatment of an apple once cut or of apple slices is permitted.

UVC treatment of bread and bakery products has been generally authorised in the EU since 2016, although this is subject to declaration. Whether Directive No. 258/97 has already been implemented nationally must be checked. The aim of this so-called ‘Novel Food Directive’ is to treat yeast-raised baked goods (including biscuits) with ultraviolet rays after baking in order to specifically convert ergosterol into vitamin D2 (ergocalciferol).

Due to the often diffuse legal situation, UVC energy is therefore usually focussed in practice on the safe surface treatment of contact surfaces and packaging materials or on the UVC sterilisation of air and the general production environment. The general aim is therefore to maintain the condition of a flawless product during storage and processing.

UVC surface sterilisation is particularly advantageous in areas where production must meet the highest hygiene standards. UVC technology therefore plays a crucial role in food processing and production. Whether in abattoirs, dairies, bakeries or in convenience food production in general, all these areas are characterised by a particularly high demand for extreme hygiene, because nobody wants to eat spoiled food or be greeted by a carpet of mould when opening a convenience food product such as a packaged ready-made salad. It doesn't matter whether we are talking about fruit, meat, fish or vegetable processing, production in all areas must comply with the highest hygiene standards. On the one hand, to maximise the shelf life of the products and, of course, to avoid the risk of cross-contamination and food infections.

UVC surface disinfection significantly, demonstrably and safely increases product safety and quality throughout the entire supply chain. By using UVC surface disinfection, all conceivable germs such as bacteria and yeasts, but also particularly resistant spore carriers on typical contact surfaces such as conveyor belts, packaging machines, thermoforming and lidding films can be effectively killed without the use of chemicals. In contrast to alcohols and hydrogen peroxide (H₂O₂), treatment with UV radiation is immediately effective, leaves no undesirable residues and does not require any drying time after treatment.

Yes, UVC surface sterilisation can even be integrated into existing production lines quite easily at a later date, especially in the food industry. The technology is not only very flexible, compact, robust and energy-saving, it is even suitable for use in wet areas. Today, high-quality conveyor belt sterilisers are IP69k tested, so cleaning with high-pressure lances during the prescribed cleaning cycles is not a problem.

In principle, UV systems can be used at various points within production lines. It does not matter whether it is a conveyor line in a blast freezer or the racks in a proofer. UV disinfection makes sense everywhere and can also be used effectively in such extreme areas, provided the appropriate expertise is available. Typically, UVC lamps are installed in special devices or in the form of ready-made UVC devices. UV radiation is thus applied specifically to a contaminated surface and the growth of unwanted microorganisms is prevented. Whether on or under conveyor belts, specifically on packaging films and cups, even very thin and heat-sensitive films can be disinfected with UV systems. In addition, it also makes sense to ensure basic air hygiene in a production line by using UV lamps for surface disinfection directly in the area of the evaporator fins of air conditioning and refrigeration systems. In this way, microbiological infestation is suppressed during defrosting cycles and germs cannot be spread through the room air in the first place. The areas of application for UVC surface sterilisation devices are numerous.

Although the integration of UV surface disinfection does not always require customised adaptation to the specific needs and conditions of a production facility, it often does. It is therefore always important to consult specialists and obtain qualified advice! During installation, it must be ensured that UVC radiation is used effectively and safely without interfering with production processes. If this is observed, nothing stands in the way of the effective and very efficient use of UVC sterilisation systems within an existing production line and the quality and safety of products is significantly increased.

This can be answered very briefly and succinctly with NO. For marketing reasons, UVC LEDs are often advertised today with the characteristics of LEDs from the lighting industry, but this is misleading and usually false. The most powerful high-power LEDs today initially generate around 100 mW_uvc @ 350 mA under laboratory conditions and have an energy efficiency of approx. 5 %. In comparison, a conventional UVC low-pressure lamp achieves 18,000 mW_uvc @ 225 mA under the same conditions and has an energy efficiency of 40 %.

The reason for the low yield is the semiconductor material aluminium gallium nitride (AlGaN), which is required for very high frequencies, a typical reverse voltage of ~7 V for LEDs and the high heat development of up to 90° C. The mandatory cooling of such high-power LEDs prevents the formation of high-density LED arrays; homogeneous irradiation of high-intensity surfaces is therefore not possible. In addition, the higher the temperature of an LED, the shorter the expected service life/useful life. Very short-wave LEDs with 260 nm, for example, exhibit a power loss of up to 50 % after just 300 operating hours. In other words: the shorter the wavelength, the worse the energy balance, performance and service life!

Considering the poor recyclability of LEDs, which use materials such as antimony, arsenic, chromium, copper, gallium, gold, indium, iron, lead, nickel, phosphorus, silver and zinc, as well as the environmentally harmful mining of the rare earths required for their manufacture, such as europium (Eu), terbium (Tb) and yttrium (Y), the ecological advantages of LEDs, which are so readily claimed, quickly melt away.

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