Approximately half of the air onboard an aircraft is recirculated and can contain dust, skin flakes, bacteria, and viruses. Coughing, sneezing, and low humidity contribute to the spread of diseases. The other half is engine bleed air, which may contain harmful volatile organic compounds.

Most commercial aircraft have High-Efficiency Particle Air (HEPA) filters that remove 99.97% of contamination. These filters help to create a healthier environment by continuously circulating and purifying the air throughout the flight. Carbon media added to air filters can help reduce odors in the cabin by adsorbing volatile organic compounds (VOCs) and other odor-causing substances. This improves the comfort of passengers during their journey by providing clean and fresh air. The Pall A-CAF (Advanced Cabin Air Filter) eliminates odors and volatile organic compounds (VOCs) that may be present from engine oil and oil degradation, de-icing fluids, and hydraulic fluids ingestion.