With the maturity of ultraviolet technology, the UV disinfection products on the market are becoming more and more abundant. In 2020, due to the impact of the COVID epidemic, all kinds of new commercial and household ultraviolet disinfection equipment have appeared explosive growth.

Ultraviolet wavelength is one important indicator of UV sterilization equipment. In recent years, due to the development of ultraviolet light technology and the promotion of merchants, ordinary consumers have a rather confused understanding of the effective wavelength of ultraviolet sterilization products. For example, only 254nm wavelength UV is effective germicidal UV light, or the UV emitted by blacklight lamps (UVA\UVB light) can also achieve the sterilization effect, and so on. Misunderstandings like these are still very common among ordinary consumers. Here, we will briefly introduce the truly effective UV disinfection products on the market and their wavelengths to help you build a correct understanding of the wavelength of UV sterilizers.

UVA, UVB, and UVC

Ultraviolet usually refers to electromagnetic waves with a wavelength in the range from 10nm to 400nm. Because the physical characteristics of UV are different with different wavelengths, scientists have classified UV according to their physical characteristics and wavelengths. One of the most widely used classification methods is to divide UV into UVA (long-wave ultraviolet) with a wavelength between 320nm and 400nm, UVB (medium-wave ultraviolet) with a wavelength between 280nm and 320nm, and UVC (short-wave ultraviolet) with a wavelength between 100nm and 280nm.

This classification method can also distinguish the germicidal properties of UV rays. Although UVC has weak penetrability, it has stronger light energy, which allows it to destroy RNA and DNA in cells in a short time, and directly kill bacteria, viruses, and other microorganisms. UVA and UVB cannot achieve the same effect. Therefore, UVC of the whole 100nm~280nm band is often referred to as "germicidal ultraviolet" and is used in all kinds of real UV germicidal lights and other disinfection devices.

So why do many people think that only 254nm wavelength UV disinfection products are effective?

254nm/ 185nmUV Disinfection Products

The UVC light source used in traditional UV sterilization equipment is usually the mercury-vapor lamp. The lamp has been used in the field of sterilization since the beginning of the 20th century, with a long history and mature mass-production technology. It has the advantages of high power and low price, so it is widely used in high-strength sterilization equipment, including UV germicidal air purifier, water purification systems, public elevator disinfection lamps, etc.

Because of technical limitations, the mass-produced mercury vapor lamps in disinfection equipment produce broad-spectrum ultraviolet rays with peak wavelengths mainly concentrated at 254nm or 185nm. Among them, the 185nm wavelength UVC will react with the air to produce ozone, which poses a certain risk to people and has a relatively small application range. For a long time, when there is no safe UVC light source with other wavelengths to choose from, to distinguish from UVA / UVB products that have no sterilization effect, merchants had focused on promoting the concept that only 254nm wavelength UV products are effective sterilization product. Therefore, it leads to the public misunderstanding of the effective wavelength of UV sterilization, mistakenly thinking that only 254nm wavelength is the only effective wavelength of germicidal UV.

265nm~280nmUV Disinfection Products

With the development of science and technology, UVC light source technology is constantly innovating. UVC LED is one of the latest ultraviolet light source products in recent years. Before it can be mass-produced and widely used in civilians, it has been used in aviation, labs and other professional areas for a long time. Now, UVC LEDs that can emit UVC light with a single wavelength within 265nm~280nm have begun mass production. Because UVC LED has the characteristics of small size, energy-saving, safety, mercury-free, etc., it has become the best choice for many small household UV disinfection products, including UV sanitizer box dryer, wireless UV chopping board sterilizer, and so on.

Therefore, now there are not only UV disinfection products with 254nm and 185nm wavelengths on the market, but also products with 265nm, 270nm, 280nm, or other wavelengths. They are all effective.

Recently, some laboratories have proved that far UVC with a wavelength of 222nm can effectively kill the coronavirus. It is believed that in the near future, more UVC disinfection products with different wavelengths will enter people's lives.

Through the above introduction, I believe everyone can have a simple and correct understanding of the wavelength of germicidal ultraviolet light. I hope this article can help you choose UV disinfection products more easily.