The IQAir Replacement V-5 Cell Gas and Odor Filter for the HealthPro Series is a remarkable filter with the power to take out cooking odors, pet odors, paint smells, and other gas pollutants in your indoor environment. The IQAir V-5 Cell Gas and Odor Filter should be changed every two years with normal use. Consumers also need to be concerned about the fumes from household cleaners and other chemicals that can be found in their indoor environment. (And we all know how unpleasant some smells can be!) Chemical fumes and odors come from gases, and gases are filtered by a different technology that what is used to absorb fine particles. Most air cleaners truthfully do very little to absorb chemicals and gases. In contrast, the IQAir's V-5 Cell is the most powerful dual chemical and gas filter that has ever been designed for home use. IQAir based the V-5 design on filters built for industrial environments where workers are routinely exposed to dangerous chemicals.