Ozone Generation by Ultraviolet Lamps^†.

Area of Science:

• Microbiology
• Environmental Science
• Photochemistry

Background:

• The COVID-19 pandemic increased interest in UVGI for air and surface disinfection.
• Traditional UVGI uses mercury lamps (254 nm), while newer lamps emit shorter wavelengths (e.g., 222 nm).
• Shorter UV-C wavelengths (<240 nm) are known to generate ozone, raising safety concerns.

Purpose of the Study:

• To review and clarify ozone generation and dissipation by various UV-C light sources.
• To address common misunderstandings regarding UV-C and ozone production.
• To provide users with a better understanding of risks and control measures for ozone when using UV-C lamps.

Main Methods:

• Literature review of UV-C light sources and their ozone-generating properties.
• Analysis of the photochemistry involved in ozone formation by UV-C radiation.
• Compilation of data on ozone dissipation rates under different conditions.

Main Results:

• Different UV-C sources exhibit varying efficiencies in ozone generation.
• Wavelengths below 240 nm are more prone to ozone production.
• Understanding ozone dissipation is crucial for safe UVGI application.

Conclusions:

• A clear understanding of UV-C light sources and their ozone-generating potential is essential.
• Proper risk assessment and control measures are necessary for safe UVGI implementation.
• This review aims to demystify UV-C-induced ozone generation for effective disinfection practices.