The nature and function of each band of ultraviolet

(How to choose UV products)

Solar ultraviolet radiation,
Sunlight ultraviolet rays,
Ultraviolet rays in nature

Ultraviolet rays are generated by the excitation of the outer electrons of atoms. The main source of ultraviolet light in nature is the sun. Therefore, ultraviolet rays are closely related to our lives.

Due to the impact of the new coronavirus, UV disinfection equipment has also become one of the popular products. How should we choose the correct disinfection equipment? Since improper use of UV lamps can cause more damage to the body, so understand in advance what we buy The nature of the product is necessary.

The wavelength of each band of ultraviolet,
What are the bands of ultraviolet rays,
UV 4 bands icon

According to different biological effects, ultraviolet rays are divided into four bands according to wavelength: UVA, UVB, UVC, UVD

UVA band, wavelength 320~420nm.

UVA and UVB wavelength characteristics,
The difference between UVA and UVB,
The radiation depth of UVA and UVB to the skin

also known as long-wave black spot effect ultraviolet rays. It has strong penetrating power and can penetrate the most transparent glass and plastics. More than 98% of the long-wave ultraviolet rays contained in sunlight can penetrate the ozone layer and clouds to reach the surface of the earth. UVA can directly reach the dermis of the skin, destroy elastic fibers and collagen fibers, and tan our skin. UVA ultraviolet rays with a wavelength of 360nm conform to the phototaxis response curve of insects, and can be used to make insect trap lamps. UVA ultraviolet rays with wavelengths of 300-420nm can pass through special colored glass tubes that completely cut off visible light, and only emit near-ultraviolet light centered at 365nm, which can be used for ore identification, stage decoration, currency verification and other places.

  • UVB band, wavelength 275~320nm.
Ultraviolet UVB wavelength
Will UVB sunburn the skin?
Characteristics of UVB

also known as medium wave erythema effect ultraviolet rays. Medium penetrating power, its shorter wavelength part will be absorbed by transparent glass, and most of the medium-wave ultraviolet rays contained in sunlight are absorbed by the ozone layer, and only less than 2% can reach the surface of the earth. UVB ultraviolet rays have erythema effects on the human body, can promote mineral metabolism and the formation of vitamin D in the body, but long-term or excessive exposure will cause the skin to tan and cause redness and peeling.

  • UVC band, the wavelength is 200~275nm
Ultraviolet UVD wavelength
Characteristics of UVD

Also known as short-wave sterilization ultraviolet. Its penetrating ability is the weakest, unable to penetrate most of the transparent glass and plastic. The short-wave ultraviolet rays contained in sunlight are almost completely absorbed by the ozone layer. Short-wave ultraviolet rays are very harmful to the human body. Short-term exposure can burn the skin, and long-term or high-intensity exposure can also cause skin cancer. The ultraviolet germicidal lamp emits short-wave UVC ultraviolet rays.

The UVD band, with a wavelength of 100-200nm.

Is also called vacuum ultraviolet. Penetration ability is extremely weak. It can oxidize the oxygen in the air into ozone, which is called the ozone generation line. The oxygen (O2) in the air undergoes photolysis under the irradiation of ultraviolet light to produce ozone (O3). Ozone is an effective oxidant, which can kill bacteria and viruses in water or air, and can be used for vegetable cleaning and air disinfection.

The ultraviolet light we use for disinfection is  C wave ultraviolet light, and its wavelength range is 200 ~ 275nm, especially when the wavelength is 253.7 nm, the ultraviolet ray has the strongest bactericidal effect.

Common UV disinfection lamps have the following bands:


This band is commonly used in ultraviolet mercury lamps. It uses low-pressure mercury vapor to radiate ultraviolet rays during discharge. Low-pressure mercury vapor mainly produces 254nm and 185nm ultraviolet rays. The characteristic wavelength of the mercury lamp for sterilization is 253.7nm, and its radiation power reaches watts level, has a wide range of applications in a large space environment , and has a good sterilization effect.

ultraviolet mercury lamps
UV mercury lamp, 254nm

UV mercury lamps were considered the best choice for disinfection and sterilization in the past, including most germicidal lamps on the market today are still 254nm mercury lamps. However, compared with UV LED lamps, mercury lamps have the disadvantages of large size, high energy consumption, long warm-up time, and mercury content. Under the influence of the international “Minamata Convention”, they will withdraw from the stage of history in a relatively short period of time. UV LED will have a huge application space.


Deep UV LEDs are different from mercury lamps. The mainstream products of deep ultraviolet LEDs have characteristic wavelengths of 275-280nm. 253.7nm and 275nm are on both sides of the DNA absorption peak wavelength of 265nm respectively. They have almost the same DNA absorption value, so they have almost the same sterilization efficiency.

UV 275nm  uv light

Due to its small size, low power consumption, and instant lighting, UV LEDs can be enclosed in a small space. UV leakage is easy to prevent and control, and it can coexist with humans and machines. It has obvious advantages in practical applications. With the advancement of UV LED technology, UVC LEDs that are smaller, more powerful, non-toxic, longer-lived, more energy-efficient, and allow more switching times have become a new choice for sterilization light sources.


The germicidal lamp in this band is the 222nm germicidal LED that everyone is looking for recently. Recently, researchers from several well-known foreign universities and institutions have discovered that UV light with a wavelength of 222nm cannot penetrate the stratum corneum of human skin, is harmless to the human body, and has the same sterilization effect as traditional ultraviolet lamps. This news has attracted the market. Report and follow.

222nm UV Lamp, UVC 222nm light

Shenzhen Best Bright Electronic Technology Co., Ltd. (BBT) is a professional LED lamp and UV lamp manufacturer with ten years of industry experience.

The 222nm UV Lamp developed by BBT is equipped with a filter, which effectively filters out harmful clutter, is safer in use, and has a stronger sterilization effect. It is widely used in homes, hotels, airports, theaters, gyms, hospitals, and other indoor places. (More details can be found on the website)

Based on the simple analysis of the above various bands, I believe that everyone has a basic understanding of these bands of UV light. UV sterilization has the advantages of broad-spectrum, high efficiency, and environmental protection. It is the most suitable sterilization method for daily life. BBT believes that ultraviolet LED light sources will play an important role in future life and production.

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