UVGI is described as what type of method?

• A. A sterilisation method that uses UV light to break down microorganisms by destroying their DNA
• B. A chemical disinfectant method
• C. A heat-based sterilization method
• D. A mechanical filtration method

Answer: (A)

UVGI relies on ultraviolet-C light to inactivate microorganisms by damaging their DNA or RNA. The energy from the UV light creates DNA lesions that prevent replication and transcription, effectively rendering the organisms unable to reproduce. Because this method uses radiation rather than chemicals, heat, or physical filtration, it is considered a sterilisation-type approach that destroys the genetic material of microbes. Its effectiveness depends on sufficient exposure and direct line of sight; shadows or shielding can reduce performance, and some forms of microbes may be more resistant. It is not a chemical disinfectant, not heat-based, and not a mechanical filtration method.