This 3M furnace filter is an efficient product made of fibreglass. It will capture airborne microparticles such as smoke and smog as well as airborne allergens like pollen, pet dander, and mould spores, in addition to large particles like dust and lint. It lasts 3 months and meets the American Lung Association Health House Indoor Air Quality Guidelines (1000 Microparticle Performance Rating - MERV 11). No unnecessary antimicrobial chemicals were added. Filtrete filtering material will not support the growth of bacteria, mould, mildew, or fungi in normal use.