Use of Ultraviolet C Radiation for Disinfection

Several products that use ultraviolet C rays for disinfecting objects are being developed and introduced by the DRDO for tackling the COVID-19 crisis.

Types of UV Radiations

The UV or ultraviolet radiation is a part of the electromagnetic spectrum with wavelengths in the range of 10 to 400nm. This class of radiation can be classified into 3 types:

• UV-A: it is the long wave component of UV band and has wavelength in the range of 400 to 315nm. It has very little visible portion and is called black light. It is known as soft UV.
• UV-B: medium wave UV radiations having wavelength in the range of 315 to 280nm.
• UV-C: considered as hard UV and is short-wave. It has wavelength in the range of 280 to 100nm.

Use of UV-C against COVID-19

The UV-C radiation used by several disinfection devices of DRDO has a wavelength of 254nm. These shorter and more energetic wavelength radiations are good at destroying the RNA (genetic material) of SARS CoV 2. They are also quick in killing other microbes. These radiations can be used as an environmentally friendly alternative to harmful chemical-based disinfection strategies.

Limitations

The UV-C radiations can be used only for disinfection of objects. It cannot be used for disinfection of hands or other parts of the body. Its use on humans is also not recommended by WHO. This is because the radiations are harmful to the skin and can cause burns and eye damage even upon brief exposure.