The Atmosphere SKY Carbon Filter is responsible for the third filtration stage. It effectively reduces unpleasant odours such as tobacco, cooking and pets. The Carbon Filter is not washable nor reusable, and has a lifespan of between 4 to 12 months (actual lifespan depends on air quality and usage).

Atmosphere SKY Carbon Filter has the following safety & quality certification: (i) Allergy UK - Seal of Approval: Recognised for its ability to reduce exposure to specific allergens and is safe for use by people with allergies. (ii) ECARF: Indicates that the Atmosphere SKY Air Treatment System has been scientifically tested by a third-party laboratory to reduce or remove allergens, and is therefore suitable for use by people with allergies. (iii) AHAM: The Atmosphere SKY Air Treatment System has been tested according to the AHAM Certification Program (ANSI/AHAM AC-a). (iv) CADR - CARD (Clean Air Delivery Rate): certified by the U.S. Association of Home Appliance Manufacturers (AHAM) for the reduction of airborne tobacco smoke, dust and pollen at air flow volumes of 300 cubic feet per minute. CADR is the main metric used to rate the performance of an air treatment system. (v) ENERGY STAR: Is a registered mark owned by the U.S. Environmental Protection Agency. ENERGY STAR is the simple choice for energy efficiency. For more than 20 years, people across America have looked to EPA's ENERGY STAR programme for guidance on saving energy, saving money and protecting the environment. Behind each blue label is a product, building or home that is independently certified to use less energy and cause fewer of the emissions that contribute to climate change.