This document describes exposures of materials and components to UV-C radiation during ultraviolet germicidal irradiation (UVGI) treatments or other processes that require UV-C exposure and test procedures to simulate those environments. Severities representing various frequencies and intensities of UV-C exposures are described. Test conditions are described and limited to devices that utilize low pressure mercury lamps which emit most of their radiation at a single spectral line at 254 nm. NOTE A more precise characterization of the wavelength of the spectral line is 253,7 nm. The ability for a laboratory to determine the wavelength to this precision is rare. Therefore, this spectral line is often quantified to the precision of 1 nm.