Activated carbon filter

Activated carbon filters behave as sponges and trap most airborne gases and odors. Activated carbon is charcoal that has been treated with oxygen to open millions of small pores between the carbon atoms. These pores adsorb harmful gases and odors. Due to the large surface area of the carbon granules, carbon filters are excellent at trapping gases that pass through traditional particle filters. However, as the pores become filled with trapped contaminants the filters loose effectiveness and will need to be replaced.