HEPA (High Efficiency Particulate Air) filter is a standard for air filters that captures at least 99.97% of airborne particles as small as 0.3 microns, including dust, pollen, mold, bacteria, and pet dander, by forcing air through a fine, pleated mesh. This makes them highly effective in air purifiers and vacuums for improving indoor air quality by removing allergens and pollutants, with even greater efficiency for particles larger or smaller than 0.3 microns.
