This verification test evaluated the ability of the EnviroScan, Inc. Ozone Detector Card to provide reliable qualitative indications of ozone in air. Laboratory testing was conducted by delivering ozone at known concentrations in a flowing air stream to Ozone Detector Cards placed in a test apparatus. The delivered ozone concentrations ranged from zero to approximately 200 parts per billion by volume (ppbv), and were confirmed by measurements with a continuous monitor designated by EPA as a Federal Equivalent Method (FEM) for ozone. Visual readings of Ozone Detector Cards exposed in the laboratory testing were made by two non-technical Battelle staff members who had no knowledge of the ozone test concentrations. Laboratory testing also included exposure of Ozone Detector Cards to a fixed ozone concentration under lighting conditions ranging from darkness, to normal laboratory lighting, to simulated full overhead solar spectrum and intensity.