Cabin Air Quality.

The safety and health of passengers and crew are the top priority on board an aircraft. This also applies to cabin air, which is continuously monitored by the aviation industry, airlines, and regulatory authorities.

Technical Systems for Clean Cabin Air

Onboard an aircraft, two to three independently operated climate control systems work continuously to maintain optimal conditions: they regulate temperature, create and maintain standard pressure within the cabin, and provide a constant supply of fresh air. At the same time, used air is extracted.

How Fresh Air Supply Works in an Aircraft

The air supply onboard is a highly complex process: typically, outside air is drawn in by the engine, highly compressed, and extracted before combustion. This so-called “bleed air” is then routed through the air conditioning system into the aircraft. Special filters, known as HEPA filters, reprocess the air used onboard, cleaning it of bacteria, viruses, pollen, and dust, so it can be reused. In this way, about 50 percent of the cabin air circulates. The filtered cabin air is cleaner than the air found in homes or office buildings.

From 2017 to 2020, German airlines conducted test series with so-called HEPA-Carbon filters. In addition to traditional HEPA filters, these are equipped with activated carbon filters, which can also filter odors and other volatile organic compounds, such as combustion residues from kerosene, oil, or de-icing agents. Due to positive test results, these filters are already part of the standard equipment on some German airline aircraft or are being retrofitted for certain aircraft types.

To maintain the high quality of cabin air, engines, climate control systems, and filters are regularly inspected and maintained.

Health Impacts

Concerns are occasionally raised about whether the introduction of substances such as burned oil residues or other pollutants into cabin air could pose a health or safety risk to passengers and crew. To date, no scientific studies have supported these concerns.

The European Union Aviation Safety Agency (EASA) closely monitors all reports concerning cabin air quality. A comprehensive three-year study concluded in 2012 that cabin air in commercial aircraft is safe. A study conducted in 2017 confirmed these findings. Currently, another study is underway until 2024, investigating potential long-term health effects on cockpit and cabin crew.

Regulatory Requirements

To ensure the quality of cabin air, the aviation industry has binding regulations, responsibilities, and tasks for the companies and regulatory authorities involved. Airlines are responsible for the proper and safe operation of aircraft and must strictly follow all maintenance regulations. In addition, the BDL maintains a dialogue with aircraft manufacturers, engine producers, and suppliers of oils, sensors, and filters to jointly eliminate any potential risks to cabin air quality in the future.

Active Reporting System

To ensure safety onboard at all times, crews are trained to take unusual smells seriously. To ensure that no health risks arise when unusual or unidentified odors occur onboard, German airlines, along with cockpit and cabin crew representatives, the transport accident insurance fund, as well as doctors and scientists, have developed a standardized medical examination procedure that has been available to crews for many years. In addition to individual medical care for affected crews, this procedure allows for uniform documentation of odor incidents.