Not all UVC lamps are the same. The lamp may emit a very specific UVC wavelength (such as 254 nm or 222 nm), or it may emit a wide range of UV wavelengths. Some lamps also emit visible light and infrared radiation. The wavelength emitted by the lamp may affect the efficiency of the lamp to inactivate viruses and may affect the health and safety risks associated with the lamp. Some lamps emit multiple types of wavelengths. The test of the bulb can determine whether the wavelength emitted by the bulb and other wavelengths.
There is evidence that the excimer lamp with a peak wavelength of 222 nm has less damage to the skin, eyes and DNA than the 254 nm wavelength, but long-term safety data is lacking. For more information, please refer to "Q: Where can I read more information about UV radiation and disinfection?".
What are the different types of lamps that can produce UVC radiation?
Low-pressure mercury lamp: Historically, the most common type of lamp used to generate UVC radiation is the low-pressure mercury lamp, whose main emission wavelength (>90%) is at 254 nm. This lamp also produces other wavelengths. There are other lamps available that emit ultraviolet wavelengths in a wide range, but also emit visible and infrared radiation.
Excimer lamp or extreme ultraviolet lamp: This type of lamp, called "excimer lamp", has a peak emission of about 222 nm.
Pulsed xenon lamps: These xenon lamps that emit short spectral pulses (including ultraviolet, visible and infrared light) emit mainly UVC radiation after being filtered, and are sometimes used in hospital environments to treat environmental surfaces in operating rooms or other spaces. Usually used when no one takes up the space.
LED chip Light: Light-emitting diodes (LEDs) that generate ultraviolet radiation are also becoming more common. Generally, LEDs emit very narrow radiation bands. Currently available UV LEDs have peak wavelengths at 254nm, 265nm and 275nm. Compared with low-pressure mercury lamps, one advantage of LEDs is that they do not contain mercury.