The Uses and Harms of UV Light
What is UV Light?
We’ve all heard of UV light before. Whether you’ve heard of UV technology in tanning beds, UV lighting for nails, or more recently, utilizing UV lighting for disinfection. All of these applications of UV light are divided into many different kinds, based on different wavelength coverages, with the most common 3 seen in our day-to-day life being: UV-A, UV-B, and UV-C.
Ultra-Violet Explained
As observed in the graphic below, UV light refers to light beyond violet; ultra-violet! These wavelengths are shorter than what human vision can register, making UV lighting invisible to the naked eye. Nonetheless, UV lighting has a multitude of applications that we see in our daily lives that fall between the 3 categories.
UV-A: 320-400nm
UV-B: 280-320nm
UV-C: 200-280nm
What is UV Light Used For?
UV-A, for example, is used to verify the authenticity of banknotes. This is the most widespread application of UV-A: it excites fluorescent substances to emit visible light. With the development of UV-violet LED technology in society, we see a growing realm of application that continues to grow today! For example, UV light glue needs to be cured under UV-A irradiation. UV-B is also widely used as a means of treating certain skin diseases. UV-C has been used for a long time in the field of disinfection due to its ability to directly destroy the DNA structure. UV light can also be found introduced in some plant factories to promote the growth of plants. Here are other common applications of UV LED light in the industry:
UV-A: Black Light for Art Illumination; UV Light for AC Unit; UV Light for Fluorescent Materials
UV-B: Phototherapy UV Lamps for Skin Conditions; UV Light for Vitamin D Deficiency
UV-C: UV Lamp for home; UV Light Bulb for Sterilization
Unlike natural UV light emmitted by the sun, that is mostly absorbed by the atmosphere before reaching the ground, artificial UV lighting sources also pose some risks when not correctly made or implemented in a protective design.
What Type of UV Radiation is Most Harmful?
UV-C light does not exist in sunlight due to absorption by the atmosphere, and UV-B is only a small fraction of sunlight because of the absorption by the air. We can think that the ultraviolet part of sunlight is mainly composed of UV-A. Therefore, when exposed to different ultraviolet light, you could experience different damages. Of course, exposure to any kind of high-power UV radiation from a light source will cause irreversible damage to the eyes.
UV-A: Usually, it doesn’t affect our health. But it increases the risk of cancer.
UV-B: It is the main cause of sunburn. It also greatly increases the risk of cancer.
UV-C: It not only causes eye damage but also damages the DNA of our cells.
The damage caused by UV-C light is far more serious than the other two. According to IEC 62471, UV-C risk must be less than 0.001W/m2, and the value of UV-A and UV-B is less than 10 W/m2. Fortunately, because of the great attenuation of UV-C in the air, we have found ways to avoid the damage of UV-C and only enjoy its benefits.
Yuji Lighting Explains How to Avoid Damage Caused UV Rays?
Usually, the atmosphere helps us block most of the UV light. However, with the more and more frequent use of UV light sources in daily life, the potential damage that could be caused by UV lighting products should definitely be considered.
Control the time of exposure to UV light
According to IEC 62471, people should avoid UV-C activities completely, and avoid staying under UV-A and UV-B light sources for more than 100s. To save the cost of lighting design, it is better to install a sensor for the light source. Once there are people in the lighting area, the UV light source will automatically turn off to ensure that people are not harmed by UV rays.
Through the lighting design, avoid direct exposure to UV
Due to the coronavirus pandemic, the use of UV-C to sterilize spaces has become a new trend. The disinfection of the space and the activities of people need to be carried out at the same time. And we can prevent people from being exposed to excessive UV-C through lighting design.
As shown in the image to the right, UV-C lights are installed in the ceiling and only have a disinfection effect on the air in the upper layer of the space. So when air circulates, the air in the entire space will be disinfected completely. Don’t worry about the harm of UV-C light to people, because the UV-C in the air will decay rapidly and will not cause any harm to people when it reaches the human body.
Which UV LED Lights Work Best?
The light emitted by the commonly used UV-C fluorescent tubes isn’t directional, and the fluorescent tubes are not easy to install. These shortcomings cause limitations on lighting design and troubles with its usage. To overcome these shortcomings, Yuji launched the UV-C LED Stirp, providing you with the best quality real UV LED lights that are optimized for directional lighting and have a flexible light strip that greatly facilitates the lighting design to ensure proper application and safety.
By fixing UV-C LED strips on a specific part of the space, corresponding optical lenses and careful lighting design, people can move freely in other parts of the space without worrying about health risks.