the therapure line of air purifiers is the only line with triple action purification a uniquely engineered cleanable HEPA-type filter helps remove particles from the air and in combination with a UV light helps reduce certain viruses and bacteria and a photocatalyst filter helps reduce VOCs (volatile organic compounds), which are found in paint and carpet fumes. therapure air purifiers help remove allergens and pollutants including pollen, cigarette smoke, odors, pet hair and dander for more comfortable and healthy living.