This article gives details of types of UV lights for disinfection and sterilization. There are many types of UV lights based on its spectrum. Common types are UVA & UVB.
UV Lights for disinfection: Don’t buy UVA & UVB type lights for Disinfection & Sterilization
As the world is frantically trying for various types of devices for sterilization, there are spurious suppliers taking advantage. They are supplying UVA & UVB type lights which are absolutely not suitable for disinfection.
What is the difference between UVA, UVB, UVC categories?
Ultraviolet (UV) light is a form of light emitted from the sun which occupies the portion of the electromagnetic spectrum between X-rays and visible light invisible to the human eye. UV Light is classified as UV A, UV B, UV C and UV V based on the bandwidth.
- UVA light falls between 315-400 nm which is 95 % of Sunlight. This is generally for lithography, curing and medical applications.
- UVB light has a wavelength between 280-315 nm which is 5 % of sunlight. Typical applications are for curing, tanning and medical applications.
- UVC is the part of UV Light typically between 200 to 280 nm. This has a unique characteristic in deactivating pathogens.
- Far UVC is the part of 207-222 nm part of UV Light. This UV light also is useful for disinfection.
- UV V falls between 100-200 nm wavelength spectrum. Typical applications are for nanofabrication, photography and spectroscopy.
UV Lights for disinfection: Why UVA and UVB are not effective for killing pathogens?
UVA rays fall between 315-400 nm, which is a major part of sunlight. This will penetrate deep into the skin and is harmful to the skin. Long exposure will cause skin irritation and ageing with no germicidal action.
UVB type is of wavelength 280-315 nm. This is harmful and can break the DNA of our skin. This is a root cause of skin cancer and has no known disinfection properties.
How do I know whether light is a UVA, UVB or UVC?
- If you want to test the lamp, you surely need a UV Light Meter with multiple sensors. This will show clearly the bandwidth of the UV Light and you can identify the type of UV light. The meter will indicate whether it is UVA, UVB or UVC. (UVA 315-400 nm, UVB 280-315 nm, UVC 250-280 nm.)
- Some fake LED lamps, may not be UV at all. You can test yourself with a simple method. Light up the UV Lamp and bring near a Fluorescent Tube light (off condition). if the phosphor inside the Fluorescent lamp glows, it means that the lamp is emitting UV.
- Most of the LED lamps available in the market are not UVC. UVC LED chip is expensive ranging between US$ 2 to 3 Per chip. You may find a product with several LEDs probably over 50 LEDs but at a cheap price of US $ 20 only. It is a clear indication that it is not a UVC type.
- Also, we suggest approaching a local Lighting company with a UV meter with multi-sensors for accurate results.
How long UVC technology has been used for disinfection and in which segments?
UV-C light is used as a germicidal product since the late 1800s for water treatment and indoor air quality improvements to kill pathogens. Niels Ryberg Finsen, Nobel prize winner (1860-1904) invented UV curative lamp and is used in treating diseases.
Since the early 1950s, the world has been using UV-C for sterilizing air in hospitals, Food Plants, meat storage, bakeries, breweries, dairies, pharmaceutical plants and pathology Labs. With the current advancements in LED Lighting technology, UVC lamps are having a wide range of applications.
The applications of UVC include HVAC coil sterilization, air sterilization, water treatment etc. Germicidal portable lamps are useful for Hospitals, Labs, Factories, Food processing units etc. They are also useful in large offices due to their advantages such as high pathogen killing rate and limited chemical exposure. There are large varieties of UVC fixtures available to suit the interiors.
UVC is a proven and widely used germicidal technology for over the past 100 years.
FAQ on UV lights for Disinfection
- Which UV light is useful for disinfection and sterilization? Only UVC is useful for disinfection. Most of the lights in the market are UVA and UVB types. Please see our UVC Lamp for hotels, hospitals, offices, cinema halls etc.
- UV lights are capable of killing Viruses including Coronavirus? UV lights under UVC type are capable of killing viruses.
- Where can I use UVC lights for disinfection? You can use for office, homes, elevator buttons, door handles, keys, wallet, laptop, mobile etc.
- UVC sterilizers are available in all sizes? Yes, there are sizes ranging from pocket-sized ones to large industrial ones.