The Oransi EJ true HEPA air purifier with activated carbon filter has a Merv 17 HEPA filter that removes 99.97 percent+ of all airborne particles. Purifies large rooms of dust, allergies, asthma, smoke, gases and odors. The medical grade filters relieve nasal stuffiness and odors to make the air more breathable. Proprietary gas filter media effective for wide range of gases, odors, smoke, formaldehyde. For home, industrial, healthcare facilities, offices, mold remediation, and abatement use. This EJ air cleaner has two filters - a 1 inch deep GAC impregnated activated carbon filter with Potassium permanganate bed pre-filter and a 3 inch deep main Hospital grade HEPA filter. Effective for smoke and smoke odor removal as well as formaldehyde, methane gas, sulfur gases, and many others.