ON UV-RADIATION DURING DISINFECTION
Biocidal effectiveness of UV-C and UV-V radiation
UV C/UV-V lamps are highly effective and inactivate the bioaerosol to 99.9%.
The viruses cause most infections of the upper respiratory tract (up to 90%), including the currently most dangerous pathogen, the SARS-CoV-2
Scientific studies confirm that 254nm reactive oxidants are formed by the ozone dissociation reaction under the influence of UV-C. Therefore, the simultaneous use of lamps with higher energy intensity of photons in UV-V and UV-C lamps can be used for air purification, thus reducing the decontamination time
The effects of UV-C and UV-V radiation on the infectivity of SARS-CoV corona viruses were investigated at the University of Marburg (link). The test results confirmed that the effect of UV-C/UV-V radiation is significant and fast. After only one minute of exposure, laboratory virus samples showed no reproductive capacity. The volume of SARS-CoV particles in the samples used in this research experiment was significantly higher than statistically found in rooms where virus-infected patients stayed
What is UV radiation?
Ultraviolet light has been known for its bactericidal properties for many years. Recently it has also proven effectiveness in fighting influenza viruses and antibiotic-resistant bacteria.
UV radiation is radiation with a wavelength in the range of 100-400 nm.
Types of UV radiation - which one is effective for disinfection?
UV-A
UV-A
UV-A and UV-B rays are part of sunrays that reach the earth and can be noticed after a long day at the beach
UV-A radiation between 315nm and 400nm damages collagen fibres and increases the risk of cataracts
.
It DOES NOT destroy RNA and DNA.
UV-C
UV-C radiation between 200 and 280nm has a strong bactericidal effect and inactivates bacteria, viruses, mites, fungi and moulds. It can cause skin burns and conjunctivitis. Moreover, it can damage nucleic acids, DNA and RNA and is the most important property that we use against germs.
Used for disinfection.
UV-B
UV-B radiation between 280 and 315nm has a therapeutic significance and is necessary for the proper development of the human body. It is involved in the synthesis of vitamin D. It can also cause of sunburn, erythema, skin allergies and skin cancer, including skin melanoma.
It DOES NOT destroy RNA and DNA.
UV-V
UV-V radiation (vacuum) is generated in the vacuum environment and has a wavelength of 100-200nm and generates ozone. It has the property that these short waves falling directly on the exposed surface cause disinfection process and the ozone generated by these waves destroys pathogens in obscured areas that are not directly exposed to radiation.
Used for disinfection.
How does UV-V / UV-C radiation work?
The killing effect of the UV-C/UV-V radiation occurs as result of the absorption of electromagnetic wave energy by the exposed object. This leads to excitation of atoms and ionization of their molecules. Absorbed energy destroys chemical bonds within DNA and RNA nucleic acids. UV-C / UV-V rays act on both the cell nucleus and the cell wall. Nucleic acids are breaking these bonds into single aminoacids and proteins are irreversibly damaged, thus inactivating viruses, bacteria, fungi and mites.
How can you safely disinfect with UV-C and UV-V light?
- The presence of living beings must be excluded while the UV lamp is in operation.
- It is forbidden to be present during the anti-virus to avoid injuries caused by direct UV rays on the eyes and skin.
- Personnel in the presence of ultraviolet radiation should wear protective clothing and eye protection.
- During use, the surface of the UV lamp should be kept clean (it can be wiped with a gauze soaked in alcohol before switching on).
- The disinfected surface should be exposed directly to ultraviolet light.
- Ventilation is required after disinfection.
- Ultraviolet rays can destroy a wide variety of microorganisms, including bacteria, spores, viruses, fungi, and other microorganisms.
- Water and air can be disinfected with UV radiation.