The Thera Pure line of air purifiers is the only line with Triple Action Purification: (1) a uniquely engineered cleanable HEPA-Type filter helps remove particles from the air (2) a UV germicidal light helps reduce germs and bacteria and (3) a photocatalyst filter helps reduce VOCs (volatile organic compounds) which are found in paint and carpet fumes. Thera Pure air purifiers help remove allergens and pollutants including dust mites pollen cigarette smoke mold spores odors pet hair and dander for more comfortable and healthy living.