The Honeywell HEPA-Type filter's efficiency is rated at 95% in capturing airborne particles such as smoke, dust, pollen, pet dander, and mold spores. A washable pre-filter captures large particles. The air purifier operates quietly while changing the air in the room up to every 12 minutes. The Electronic Filter Clean Indicator illuminates to remind you when to clean the filters. For extra air freshening there's an ionizer which can be turned on or off as desired. The slim tower design and quiet operation makes it ideal for any room in your home. Powerful fan for maximum air cleaning efficiency, 3 air cleaning levels. Claims are from the air that passes through the filter. Overall particle reduction is dependent on many factors, including the amount of air processed, the pollutant type, and the pollutants introduction rate into the environment.