The "Advanced Odor Control" (AOC®) activated carbon filter reduces strong odors from, for example, pets, cigarette smoke, volatile organic compounds as well as cooking odors. The True HEPA filter features an antimicrobial coating specially designed to prevent the growth of microbes and bacteria on the filter. The HEPA filter removes 99.97% of all dust particles and contaminants (down to 0.3 microns) in indoor air, including fine dust, pollen, allergens, mold spores and dandruff. Both filters should be changed after approximately one year. The effective life filter depends on the strength of air pollution at the place of use.