Since the outbreak of the coronavirus pandemic, hand sanitizers have been the world’s most sought-after product. But, as confirmed cases continue to rise across the globe, sanitizers are now in limited supply, and many are turning their attention to ultraviolet (UV) light.
There is a lot of misinformation about UV light available, and if used irresponsibly, it can be very dangerous for our health as it can cause blindness and skin burns. So, before you go out and buy one, make sure you are informed first.
Let’s learn more about UV light and whether it can kill the coronavirus.
The ABCs of UV light
There are three types of UV light based on its wavelength and characteristics: UV-A, UV-B, and UV-C.
UV-A light has the longest wavelength. It accounts for about 95% of the UV radiation reaching the Earth’s surface. UV-A light is commonly used in commercial and industrial applications due to its fluorescent effect.
It can penetrate deep into human skin. In fact, scientists state that it is responsible for 80% of skin aging.
This band consists of an intermediate wavelength UV radiation. These rays can penetrate the upper layers of the dermis and damage skin DNA, leading to sunburn and even skin cancer. This is why many skincare products offer UV-A and UV-B protection.
This short-wave spectrum is the most harmful band. Remember, the shorter the wavelength, the more harmful the radiation. Luckily for humans, the Earth’s ozone layer blocks this band before it reaches our sensitive skin.
However, in the 1800s, scientists discovered that UV-C light is highly effective at destroying microorganism’s ability to reproduce, and it can kill up to 99.99% of all bacteria and viruses.
Since the discovery, UV-C light has become an important method of sterilization. In controlled amounts, it’s currently being used in the treatment of drinking water, the production of pharmaceutical products, as well as in hospitals, factories, and offices.
Now that we’ve got an overview of each band, let’s address the elephant in the room…
Can UV Light Kill Coronavirus (COVID-19)?
UV-C light can kill up to 99.99% of coronaviruses as long as the right wavelength is administered for the required amount of time.
Looking at previous coronaviruses such as the SARS and MERS, studies have shown that UV-C light is successful in deactivating them. Under controlled laboratory conditions, UV-C light of 254nm-wavelength and heat treatment of at least 65 degrees Celcius (149 degrees Fahrenheit) successfully deactivated the viruses.
Since COVID-19 can survive on surfaces as well as in the air, effective disinfecting can be challenging. Because UV light can also kill pathogens in the air, it can be a more effective disinfectant than traditional cleaning products such as bleach.
Yet, the COVID-19 is a new breed with a different structure from the previous viruses. So, thus far, testing has been very limited, and there is no scientific evidence to prove that UV light can kill the coronavirus.
However, scientists and medical professionals agree that UV-C light does not discriminate and kills pretty much anything from viruses and bacteria to fungi. It damages their DNA or RNA code as well as triggers lethal mutations that prevent them from adequately reproducing. So, there is no reason for it to not be ineffective against the novel coronavirus. All we lack is scientific evidence to verify that.
Keep in mind that not all UV-C light devices will effectively kill the coronavirus. Most low-cost UV cleansers are not powerful enough to do that.
However, strong UV-C light on humans can be disastrous; so, you should never point it at yourself, another human being, or animal. Scientists also don’t know the effects of repeated exposure of UV-C light on the materials of masks and gowns.
How About UV-A and UV-B Light?
Meanwhile, UV-A and UV-B light rays have virtually no effect on bacteria and viruses. They will, on the contrary, harm your skin and potentially lead to skin cancer and/or eye cataract.
The World Health Organization (WHO) confirms this theory and even dismisses the myth that exposure to the sun or temperatures above 25 degrees Celcius (77 degrees Fahrenheit) can prevent COVID-19. As mentioned above, UV-C light never reaches the surface of the Earth because the atmosphere absorbs it. As a result, there is no way for it t have any effect on coronavirus.
So, you should not expose yourself to the UV-A and UV-B light from the sun, hoping that it will inactivate the coronavirus. It will do more damage than good.
At the moment, the best way to protect yourself is to follow the simple guidelines of social distancing, wearing a mask, and by making sure that you’re washing your hands frequently and not touching your eyes, mouth, and nose. You can use UV light to sterilize devices such as your phone; however, you should never use it on your skin or any other areas of your body.