Ultraviolet Germicidal Irradiation (UVG) is a sterilisation method that uses UV light to break down microorganisms by destroying their DNA. It is often used in which applications?

• A. Sterilisation method that uses UV light to break down microorganisms by destroying their DNA; often used in food, air, and water purification.
• B. A chemical disinfectant used for surfaces.
• C. A method of heating air to sterilize.
• D. A method for radiation therapy.

Answer: (A)

UV germicidal irradiation uses UV-C light to inactivate microorganisms by damaging their DNA, so it disinfects without adding chemicals and acts quickly on exposed organisms. This makes it especially useful for purifying air and water, where direct exposure is achievable and consistent disinfection can be maintained, and it is also used in some food applications to reduce microbial loads on surfaces or in liquids. Because UV light requires direct exposure, it works best in environments like HVAC air streams, clear liquids, and relatively unobstructed surfaces, rather than as a broad, residual disinfectant. These factors together explain why its common uses align with food, air, and water purification, making that option the best fit.