UV-C Disinfection: what is it?
Cleanroom UV-C disinfection with ultraviolet C light is a method of disinfecting air, water and surfaces. The energy of the UVC light stops the division of microorganisms such as -viruses-. The UVC light disrupts DNA.
HEPA does not stop viruses
Filtering cleanroom air with HEPAs is not enough, it does not stop viruses. As visible in the image on this page, viruses are too small for that.
The advantages of disinfection with UV-C
- Environmentally friendly and organic
- Disinfects continuously (24 hours a day)
- Low operating costs
- Effective, Flexibly applicable
The principle of UVC disinfection
UV light or radiation has a shorter wavelength and is more energetic than visible light. It can be divided into UVA, UVB and UVC . UVC light has a wavelength of 100 to 300 nm, and especially the range of 240-280 nm is well absorbed by microorganisms. The energy of UVC light disrupts DNA and prevents microorganisms from dividing.
Why is UVC radiation germicidal?
The disinfecting range of UVC light runs from 240 to 280 nm, the most effect is achieved at 260 nm. This course can be compared to the development of the absorption curve of DNA. The DNA molecule consists of four building blocks in a double helix. Adenine, thymine, guanine and cytosine. If two thymines are next to each other, the UVC light binds them to each other instead of to the opposite base in the DNA molecule. UV-C disinfection kills virus with good UVC lamps. They emit most of the photons at 254 nm so the DNA is maximally disrupted. The higher the UVC intensity (expressed in mJ/cm²) and the longer the irradiation time (seconds), the higher the UVC dose (mJ/cm²) and thus the number of microorganisms that are damaged to the point where they can no longer divide.
The dose determines the degree of disinfection
In UV-C disinfection, the dose required for different types of microorganisms is known. We call this the lethal dose (LD). Resistance does not occur with UVC light. By default, we indicate the effectiveness with an LD90, which means 90% of the population is killed. Doubling the dose means 99% of the population is killed, tripling 99.9%, and so on.