Are UVC Lights Effective For Sterilization? Here’s What You Need to Know!
The global pandemic has most of us living under the constant worry of getting sick or getting one of our loved ones sick. While researchers across the globe are in a relentless pursuit of finding a way to control the spread of Covid-19, the search term “sterilization” and words like it have seen exponential growth on Google, for good reason. Yes! Sterilization is one of the most effective ways of preventing the spread of infection.
How does sterilization work?
In medicine, sterilization essentially means removing any sort of “living organisms” from instruments, devices, materials and surfaces that may come in contact with humans or animals and has the potential to spread disease or infection. These “lives” can be bacteria, virus, fungi or other germs. Killing these germs can be done in 3 ways, which are:
- Heat sterilization
- Chemical sterilization
- Radiation sterilization
“Sterilization is the key to prevention”
Ultra Violet (UV) light is one of the sterilization methods that uses radiation. UV light refers to the region of electromagnetic spectrum between the visible light and x-rays.
Sterilization with radiation is one of the most convenient ways of sterilizing certain areas and surfaces that are not suitable for other methods. For example, you cannot sterilize your room with heat. You could sterilize a room with chemicals, but this method is not very convenient or desirable due to many factors such as the ease of dispersing the chemical, its safety for humans, residual smell, and damage caused to different types of material in the room, etc…
Therefore, UVC irradiation has quickly become to preferred method for sterilizing rooms because it can sterilize entire rooms without the negative side effects of chemical sterilization.
Sterilization with UV- C lights, How are they different from UV lights.
UV lights are invisible to human eyes. They are of three types, UV-A, UV- B and UV-C all of them works at different energy ranges. Of all the types of UV lights, UV-C has the shortest wavelength within a range of 100-280 nm (nanometers) and is found to be relatively safer compared to other UV lights for use in human environment.
How and how efficiently does UV-C lights kill viruses? 1
A virus structurally consist of a genetic material in the centre (RNA or DNA) which is protected by a protein or lipid coating. When UV light falls on germs (Bacteria, viruses or fungi), it breaks down the genetic material of the germ i.e DNA or RNA which is essential for it’s survival and reproduction. This immediately kills the germs and can even kill dangerous germs and their spores that can’t be killed by antibiotics or chemicals.
“Does it really die?”
Coronavirus is a type of RNA virus with a lipid coating around it. UV-C lights have proved to be effective in killing the novel coronavirus by causing damage to it’s RNA. Studies have shown that UV-C lights can kill up to 99 % of the viruses present on the surface when exposed for 6 seconds.
Read what the Harvard School of Public Health has got to say about how UV can help disarm the virus (Source: Harvard School of Public Health) https://www.hsph.harvard.edu/news/hsph-in-the-news/could-ultraviolet-light-help-disarm-the-coronavirus/
Researchers believe that, UV-C lights can prevent the spread of COVID 19.2 Watch the CNBC episode on “How UVC lights can prevent the spread of COVID” here (Source: CNBC) https://www.youtube.com/watch?v=OJ08BuyejuE
UV- C light delivery with devices
If you are a medical practitioner or you work with materials used on human skin or are in frequent contact throughout the day with surfaces that become hot spots for germs and bacteria, you could use a handheld UV sterilizer wand to sterilize instruments, equipment, and surfaces.
Handheld UV Sterilizer wands are also ideal for elementary schools and daycares to sterilize toys and items frequently touched by children throughout the day.
How safe are UV lights?
The same characteristics that make UVC lights so effective at killing viruses also give them the potential to be harmful to your skin and lungs if not used properly. The optimal germicidal wavelength is 254.3 nm. At this wavelength, UV light can penetrate skin and exposure should be avoided. A UV disinfection lamp “tuned” to 185 nm can create ozone from oxygen (O2) in the air by disrupting the O2 molecule and splitting it into two oxygen atoms. These two oxygen atoms attempt to attach to other oxygen molecule (O2). It is the attachment of this third oxygen atom that creates ozone (O3). In humans, ozone can cause irritation to the nose, stomach and sometimes cause inflammation of lungs. Due to this reason, ozone-free UV lights have been introduced.
UV-C lights operate at a wavelength greater than 200 nm and those that function below 200 nm are the ones that are responsible for producing ozone.
“Not all UV lights are harmful”
FAR UVC lights are lights tuned to 222 nm. The theory is that 222 nm wavelength is effective at killing viruses like Covid-19 while being safe for humans. If this theory proves to be true, than FAR UVC lights have the potential to truly revolutionize commercial & residential lighting.
However, for now, FAR UVC lights are not commercially available while testing on the safety of these UVC lights continues.
While using UV light sanitizers, make sure that;
- You don’t look directly into the light, which can cause retinal damage
- You don’t use it on substances or chemicals that may be sensitive to UV lights.
- You don’t have a skin exposure if you are photosensitive (a condition where skin reacts to sunlight)
- You don’t use it on your own body.
UV light sterilizer can be used on just about any inanimate object or surface in homes, commercial centers, offices, hotels, bathrooms, and just about any other place you can think of, so long as they are not used while humans, animals, or plants are nearby while the lights are on.
“Use it anywhere you feel it’s necessary”
UV disinfection lamps are regularly used in Hospital settings such as the Out Patient Department (OPD), Operation Theatres (OT), Reception or receiving areas, hospital corridors, donning/doffing rooms and dental clinics to prevent the risk of any infections that a person can catch from the hospital or the clinic. 3, 4 It is often a routine procedure to disinfect the hospital insides with UV disinfection lamps that are permanently fixed on the sealing.
Today, UV disinfection lamps are used even at office spaces and houses as a precautionary measure against infectious diseases such as COVID 19. 5
Learn about how the US employed UV light sterilization in trains here (Source: good morning America) https://www.youtube.com/watch?v=ncoJe45ORAA
You can use them to disinfect your Kitchen, Bathroom, wardrobe, living room, class room, dining room and even the orange juice you drink. 6
Furthermore, most of the product packaging areas use UV light sterilizers to disinfect the product and the packing. Want to sterilize your orange juice? UV light sanitizers have been used in food industries too, ensuring the food quality by eliminating the germs. The food products are allowed to pass through a UV chamber for 6- 10 seconds that efficiently kills the germs. 7
How to effectively use UVC lights at home, school, office, church, or on the go?
UV lights in the news
“Could this decades old science make an impact?”
The answer is yes! Evidence from our research showed surprising results on the effectiveness of UV light sterilizers and sanitizers in preventing the spread of the disease. Although this technology is not new, it has been catapulted to the limelight due to the recent pandemic.
David Brenner, Professor of radiation biophysics and director of Columbia University’s Center for Radiological Research says that “UV light is like hitting the virus with a hammer”.
Experts across the world agree on this fact. Read the latest news here (Source: The Boston Globe) https://www.bostonglobe.com/2020/07/26/metro/could-century-old-technology-zap-coronavirus-schools-offices/
With all of us gradually slipping into the normalcy of life during the age of Covid-19, UV- C light sterilization is becoming a staple in many homes and businesses around the world. Instead of only being used in hospitals, the new-normal, t hey have become a feature many people look for when booking hotels or Airbnb's.
Recently, MIT has developed a robot that navigates around spaces to blast the virus with UV light. The team has even tested the system at a Boston-area food bank with encouraging results. This can be used for even larger areas. Check out the news here. https://www.extremetech.com/extreme/312198-mit-designs-robot-that-eliminates-coronavirus-with-uv-light
Read the article on Indoor air sterilization with UVC light here (Source: National Public Radio) https://www.npr.org/sections/health-shots/2020/07/13/890387205/coronavirus-sparks-new-interest-in-using-ultraviolet-light-to-disinfect-indoor-a
- Welch D, Buonanno M, Grilj V, Shuryak I, Crickmore C, Bigelow AW, Randers-Pehrson G, Johnson GW, Brenner DJ. Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases. Scientific Reports. 2018 Feb 9;8(1):1-7.
- Hamzavi IH, Lyons AB, Kohli I, Narla S, Parks-Miller A, Gelfand JM, Lim HW, Ozog D. Ultraviolet germicidal irradiation: possible method for respirator disinfection to facilitate reuse during COVID-19 pandemic. Journal of the American Academy of Dermatology. 2020 Apr 1.
- Mackenzie D. Ultraviolet Light Fights New Virus. Engineering (Beijing, China). 2020 Jun 27.
- Botta SB, de Sá Teixeira F, Hanashiro FS, de Araújo WW, Cassoni A, da Silveira Salvadori MC. Ultraviolet-C decontamination of a dental clinic setting: required amount of UV light. Brazilian Dental Science. 2020 Jun 12;23(2):10.
- Lindblad M, Tano E, Lindahl C, Huss F. Ultraviolet-C decontamination of a hospital room: Amount of UV light needed. Burns. 2020 Jun 1;46(4):842-9.
- Tran MT, Farid M. Ultraviolet treatment of orange juice. Innovative Food Science & Emerging Technologies. 2004 Dec 1;5(4):495-502.
- Bintsis T, Litopoulou‐Tzanetaki E, Robinson RK. Existing and potential applications of ultraviolet light in the food industry–a critical review. Journal of the Science of Food and Agriculture. 2000 May 1;80(6):637-45.