UV-C disinfection

What is UV-C disinfection?

Ever since 1878, the ultraviolet (UV) radiation has been a known and recognised method of disinfection using short-wave ultraviolet rays (UV-C) to destroy or inactivate microorganisms by destroying the nucleic acids and their DNA. At certain wave lengths, UV is mutagenic for bacteria, viruses and other microorganisms. Particularly at the wave lengths of around 260 - 270 nm, the UV breaks the molecular ties in the microorganisms’ DNA.

Ultraviolet waves (UV) are electromagnetic waves with a wave length shorter than that of visible light but longer than that of x-rays. The range of the ultraviolet waves can be subdivided into near UV (380–200 nm wavelength) and far or vacuum UV (200–10 nm). When considering the effect of UV radiation on human health and the environment, the range of UV wavelengths is often subdivided into UVA (380–315 nm), also called long wave or "blacklight"; UVB (315–280 nm), also called medium wave; and UVC (280–10 nm), also called short wave or "germicidal” range.

How does UV-C technology work?

The use of direct radiation is one of the most efficient methods in the process of disinfection. SteriPro disinfection technology uses installed ultraviolet bulbs to produce high-intensity ultraviolet light in the entire disinfection spectre, known as UV-C. When SteriPro is activated, it generates artificial UV-C energy with the wave length of 254 nm, which is ideal for disturbing the microorganisms’ DNA.

The UV-C energy penetrates through the cell walls of bacteria, viruses and bacterial spores. The DNA, RNA and proteins in a microorganism absorb this intensive UV-C energy, which damages their DNA in such a manner that they can no longer reproduce and become harmless. The UV-C technology is efficient against most of bacteria, viruses and spores.

Disinfection of premises with UV-C technology improves the safety of patients. By disintegrating the microorganisms’ DNA, it offers additional protection in high-risk environments or areas of health care that cannot be sufficiently cleaned with manual cleaning procedures. The UV-C technology deactivates bacteria, viruses and fungi spores, rendering them harmless. The technology is primarily used in the areas where there is a risk of microbiological contamination.

Disinfection with UV-C can significantly reduce the contamination of the environment and thus protect the next patient in the isolation room. UV-C disinfection may not be used independently; it is intended as upgrade to chemical disinfection. Clinical studies ave shown a decrease in hospital infections by 34.2% after the integration of UV-C disinfection into the established disinfection process of participating hospitals.**

_{** Nathanael A. Napolitano MPH, Tanmay Mahapatra MBBS, Weiming Tang MD, PhD: The effectiveness of UV-C radiation for facility-wide environmental disinfection to reduce health care eacquired infections; American Journal of Infection Control 43 (2015) 1342-6.}

How efficient is UV-C disinfection?

Its efficiency depends on the time/length of time interval in which the microorganism is exposed to UV-C radiation and the intensity and wave length of direct UV-C radiation.

The efficiency of disinfection also depends on the size and shape of the room and the presence of various objects in it, which can offer “protection” for microorganisms against direct exposure to the harmful UV-C waves.

It is therefore important that microorganisms are exposed to UV radiation, which is ensured by appropriately calculated time and production of extremely strong UV-C radiation.

The increase in UV efficiency and intensity can be achieved with the use of reflection. Compared to other metals, aluminium is the most reflective material and thus recommended for the use in UV disinfection. This was the reason why the SteriPro device was designed using the materials that enable strong reflection and thus increase its efficiency.