For many years, hospitals have been using high-intensity, high-powered ultraviolet light to kill bacteria, viruses, and “super bugs”. Because of its popularity in hospitals, smaller and less expensive UV light devices are being made for consumers.
What is UV light?
UV light stands for ultraviolet light. The most common form of UV light is sunlight. There are three types of UV light: UV-A, UV-B and UV-C.
- UV-A (315nm – 400nm): UV-A is the long wavelength UV light, which is commonly called “the black light”. It has the longest wavelength among the three types of UV light but has the lowest energy. When sunlight goes through our atmosphere, the ozone layer absorbs UV-C and some UV-B. So, most UV light we have come in contact with is UV-A light.
- UV-B (280nm – 315nm): UV-B is the mid-range UV light. It has shorter wavelength than UV-A but higher energy. UV-B is the type of UV light that causes sunburns. Luckily, there is only a small amount of UV-B that can penetrate Earth’s ozone layer.
- UV-C (100nm – 280nm): UV-C is the type of UV light that is used in hospitals to kill viruses and bacteria. It has the shortest wavelength and highest energy. Scientists have proven that the most effective wavelength for destroying pathogens lies between 200nm and 280nm, which is within the UV-C band.
How does UV light kill harmful organisms?
Most of us are familiar with the uncomfortable or even painful red blisters after a nasty sunburn. What happens when you get a sunburn is the cells in the top layer of your skin being damaged by UV radiation and trying to fix the damaged. UV-B light is absorbed by the skin cells, and the energy from the light causes errors in DNA replication. In most cases, our bodies can self-correct these errors and heal after a mild sunburn. However, if exposed under intense sunlight for a long period of time, our bodies may not be able to fix the damage caused by UV radiation, which may result in skin cancer.
UV light sanitizer works in the same principle. It uses UV-C, which does even more damage in a cellular level, to destroy the DNA or RNA structure of the viruses and bacteria. It is also effective at killing “super bugs”, the type of pathogens that have developed a resistance to modern medicine and are hard to be killed by chemical sprays. In a 2014 study in the American Journal of Infection Control, UV sanitizing wand was tested and proven that it killed 100% of several types of bacteria commonly found on surfaces in 5 seconds, and inactivated 90% of hardy spore-forming bacteria in 40 seconds. According to the researchers, a UV-C device is a reasonable alternative to using chemicals to disinfect surfaces.
Due to its destructive nature, UV-C is highly effective at eliminating germs, but at the same time, it may also cause skin cancer and cataracts if used incorrectly. In hospitals, all personnel need to leave the room before UV sanitizing process can begin. For portable in home and office use UV light devices, the UV light cannot directly shine on the skin or in the eyes. Therefore, more and more UV sanitizing wands have incorporated a gravity sensor feature in their design, in order to help prevent users from looking at the light bulb directly.
UV light sanitizer comes in many types: wands, boxes, bottles, lamps and more. They each have their own advantage. For instance, a portable wand can be used on pretty much any inanimate object, like clothes, keyboards, baby bottles, steering wheels etc. UV boxes can save you some time if your main concern is smaller objects like keys and phones. You put the items in the box, and it will automatically sanitize them for you. Whichever UV light sanitizer you choose, be sure to check the user manuals and follow necessary safety procedures. But remember, you still need to wash your hands.
