Researchers from WCEC and the UC Davis Environmental Health Sciences Center will present findings from a new white paper examining ozone generation from ceiling-mounted 222 nanometer germicidal ultraviolet (GUV222) air disinfection systems. The study evaluates indoor air quality impacts in a classroom setting and compares observed ozone concentrations with the outdoor-air-only scenario defined in ASHRAE Standard 241. The work was commissioned to inform regulatory understanding of emerging air cleaning technologies and identify remaining research gaps related to GUV222 deployment.