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Coronavirus: is the UV sterilizer effective?
Recently, more and more information is appearing about UV sterilizers as effective means to fight the COVID-19 virus. But are they really effective? What should be considered and what equipment to choose to be absolutely sure that we will get sterile and completely safe, pathogen-free tools and masks?
UV sterilizer - what is it?
The UV sterilizer is a device designed to sterilize primarily air and various flat surfaces. It complements the disinfection and sterilization processes of tools in an autoclave, carried out in places such as treatment rooms, operating theatres in hospitals and other healthcare facilities. It occurs mainly in the form of mercury lamps, which job is to sterilize the air. In the era of a pandemic, it is also used in public transport, for example in buses in China, where it is used to minimize the risk of droplet coronavirus infection.
This type of sterilizer uses UV radiation, specifically UV-C. It is short-wave radiation and the wavelength ranges from 210 to 328 nm. It works by creating thymine dimers, changing the structure of nucleic acids, and consequently damaging the microbial DNA. Such lamps, however, do not completely remove all viruses and bacteria - they do not eliminate their spore forms, which can also be a threat. Therefore, this process cannot be called sterilization, but only disinfection. Due to its specificity of operation, the device can only be used as an auxiliary method. It will not replace a professional autoclave, which is the only one that guarantees efficiency and complete elimination of not only live, but also vegetative forms of dangerous microbes.
Risks associated with UV sterilizer
In recent months, we have faced a new, aggressive and very infectious pathogen - coronavirus. It has not only hindered our daily functioning, work and social life. In the near future we will have to learn to live in a new reality. The latest research shows that this virus can survive on various types of surfaces, which means that we can infect it not only during contact with a sick person through a droplet route, e.g. by touching the contaminated surface with your hand, and then your mouth, eyes or nose. Depending on the type of surface, the pathogen can last on them for different lengths of time. According to current knowledge, coronavirus can survive up to 24 hours on paper and cardboard surface, up to 72 hours on stainless steel or plastic, and up to 4 hours on copper surfaces. All this also depends on factors such as air humidity and temperature. That is why it is so important to wash your hands as often as possible, disinfect surfaces, in particular in public places, workplaces, and to sterilize reusable tools and objects using an autoclave, not a UV sterilizer. It is not a device that shows full effectiveness, and using it can be dangerous and cause more harm than good. Why?
1. Does not remove spore forms of bacteria and viruses
UV radiation, which is used in this type of devices, changing the structure of nucleic acids, works mainly on live forms of microorganisms, but does not eliminate their vegetative, spore forms. The use of such devices does not therefore ensure the full effectiveness of the sterilization process. Therefore, there can be no sterilization, which aims to completely remove live and spore forms of pathogens, but only disinfection. This is not class B sterilization, only lower S or N depending on the radiation source used.
2. Inaccurate operation
Due to the performance specifications, germicidal UV lamps are not completely accurate. Ultraviolet rays in both lamps and UV sterilizers propagate linearly and microorganisms can survive in "shaded" areas. The power of such a device also decreases as the distance increases - objects placed further away from the lamp will be less disinfected. Bactericidal UV lamps reduce the risk of droplet infection, but do not penetrate deep into solids and liquids, which means that they only sterilize the air, which can never replace the effective sterilization of reusable items in an autoclave.
3. Harmful to man
UV radiation is extremely harmful to humans. Each time you start such lamps, you should leave the room. UV-C radiation can cause irritation, skin burns, conjunctivitis and even lead to the development of skin cancers. UV light can also damage the retina. Direct-acting lamps are particularly dangerous. Also, exposure to ozone, which is produced during the operation of some such devices, can negatively affect the functioning of the respiratory system.
4. Process length
Depending on the type of UV sterilizer, the length of the process can range from several minutes to several hours. However, it should be remembered that even if we follow the manufacturer's directions and follow all instructions for its use, we are still not 100% sure about the sterile effect. Moreover, if too little radiation power and too short duration of action are selected, there may be intensified mutations in microbial cells, which will have a different effect.
5. Lack of approval of sanitary and epidemiological stations
Such devices are not recommended for sterilization by sanitary and epidemiological stations. Most of the inspections carried out by the employees of such institutions do not consider lamps using UV radiation appropriate for effective sterilization, indicating the need to use professional sterilizers - steam autoclaves. Only these ensure full effectiveness of this process and its safety. It is not without reason that in hospitals and other health facilities the basic mean of combating dangerous microbes is an autoclave, not a UV sterilizer. In United Kingdom places such as beauty salons, tattoo studios and hairdressing salons are not obligated to sterilize or have autoclave, but using sterilization devices is the only option to ensure the safety for all customers. Not only in the fight against coronavirus, but also with other harmful pathogens with which we have contact every day, we cannot resort to half measures - safety and full effectiveness should be a priority. The UV sterilizer can only support the sterilization processes and complement them, but it is certainly not a tool thanks to which you can get rid of the pathogens from the tools.
Steam autoclave - the official tool for fighting coronavirus
The European Union has indicated that, in the era of the coronavirus pandemic, in addition to masks and other personal protective equipment, the autoclave is one of the key devices used to sterilize objects. Only its use in conjunction with existing guidelines will limit the spread of coronavirus and effectively protect people. Steam autoclave sterilization involves the destruction of all forms of harmful microorganisms, including their spores. The object that has undergone the sterilization process is free from over 99% of pathogens. This is an effective method of sterilizing not only reusable objects, but also masks, including disposable masks, prior to their disposal. In the autoclave, you can also sterilize bandages, dressings and even keys and other metal items.
Steam autoclaves manufactured by Enbio are fully effective sterilization devices. They have all the necessary certificates and attestations and have been classified into the highest class B - they have the CE certificate, approving them as medical devices. They meet 100% of Health Department and guarantee full effectiveness and safety of sterilization.
- Dezynfekcja, sterylizacja, antyseptyka, Katedra i Zakład Mikrobiologii, Uniwersytet Medyczny im. Piastów Śląskich we Wrocławiu https://www.lekarski.umed.wroc.pl/sites/default/files/mikrobiologia/files/Dezynfekcja_i_sterylizacja.pdf
- New coronavirus stable for hours on surfaces, NIH, https://www.nih.gov/news-events/news-releases/new-coronavirus-stable-hours-surfaces
- Przestrzeganie higieny chroni przed koronawirusem, https://pacjent.gov.pl/przestrzeganie-higieny-chroni-przed-koronawirusem
- The Benefits and Drawbacks of Disinfecting Surfaces and Killing COVID-19 with UV Lights, You can sanitize things without touching them, but you have to know what you're doing https://www.core77.com/posts/96010/The-Benefits-and-Drawbacks-of-Disinfecting-Surfaces-and-Killing-COVID-19-with-UV-Lights
- Can UV Light Fight the Spread of Influenza? Safe for human exposure, far-UVC light may offer low-cost solution to eradicating airborne viruses in indoor public spaces, Columbia University Irving Medical Center https://www.cuimc.columbia.edu/news/can-uv-light-fight-spread-influenza
- Medyczne lampy bakteriobójcze – zasadniczy element wyposażenia gabinetu lekarza?, MEDNOVA https://mednova.pl/blog/lampy-bakteriobojcze-jakie-wybrac-porownanie
- Opinion on Biological effects of UV-C radiation relevant to health with particular reference to UV-C lamps, European Commission, https://ec.europa.eu/health/sites/health/files/scientific_committees/scheer/docs/scheer_o_002.pdf
- Lampy bakteriobójcze i promieniowanie UV, Mednova https://mednova.pl/blog/lampy-bakteriobojcze-promieniowanie-uv-sterylizacja-jak-wybrac