One of the most common types of gas filters is the activated carbon filter. Activated carbon, due to its high surface area and porous nature, is highly effective at adsorption—the process by which gases adhere to the surface of a solid. This type of filter is particularly effective for volatile organic compounds (VOCs), odors, and certain heavy metals. It is widely used in air purification systems, HVAC systems, and for removing contaminants in workplace environments.