Understanding cabin air quality

The quality of the air that passengers and aircrews are exposed to on board commercial transport aircraft has been at the core of a continuing debate for the past 60 years, both from the health and the safety points of view. This debate about cabin or cockpit air quality (CAQ) addresses most specifically single cabin/cockpit air contamination (CAC) events – e.g. due to potential oil leaks – and the intrinsic quality of the cockpit/cabin air in normal operating conditions.

A number of investigations and research projects have been conducted by various scientific teams, involving in-flight measurements, but so far has not allowed a complete characterization of the chemical compounds involved in CAC events, determination of sources and exposure levels to contamination, nor performance of comprehensive toxicological risk assessment for such events.

EASA, supported by the European Commission, has launched the new research project ”Cabin air quality assessment of long-term effects of contaminants” aimed at collecting additional scientific evidence concerning CAC events to root more extensive assessment of health risks and to support the evolution of aviation standards in this subject area.

The need and scope for additional scientific evidence were determined at the EASA workshop 2020 (go to the workshop website) together with the stakeholders who were actively involved there.

The vision of the CAQ III project is to minimize current knowledge gaps in health risk assessment of oil-related “fume events” in aircraft in a reliable, efficient and cost-effective approach, bringing together the expertise and knowledge of all relevant disciplines and stakeholders. CAQ III will unite researchers, regulators and safety scientists from industry to reduce the uncertainties in risk assessment and enhance its practical applicability in line with the requirements of the regulatory authorities. In addition, the CAQ III partners will develop new mitigation strategies to better protect passengers and crew members in commercial aircraft from potentially hazardous chemicals.

The aim of the project is to provide a comprehensive physicochemical characterization of the compounds resulting from engine or APU oil leakage or dislodgment of deposits and their impact on cabin air quality. Such characterization will be obtained through a series of measurements performed in controlled environments that are representative of flight conditions.

The measured particulates and gases, their quantities, particle types and properties, their mixture and partitioning between gas and aerosol particulate phases will support the identification of toxicological hazards and the assessment of exposure levels for crews and passengers.

CAQ III is a leading project to address the oil leakage-driven toxicological impact on cabin air quality and future risk assessments.

Therefore, we ensure scientific excellence backed up by regulatory relevance by recruiting leading experts from academia, research institutions and large industry. Partners combine state-of-the-art expertise in human toxicology, exposure assessment, molecular biology, analytical chemistry, biostatistics, aeronautical engineering and chemical risk assessment, as well as expertise in management and dissemination.

The CAQ III project pools first-class knowledge for its envisaged systematic health effects studies on oil-related “fume events”: state-of-the-art inhalation toxicity testing (RIVM), neurotoxicological analysis and biomonitoring (HMGU, RIVM, NRCWE, InstPharmToxBw, Fraunhofer ITEM) and metabolomics screening (Fraunhofer ITEM). In addition, CAQ III aspires to create the broadest possible impact for cabin air quality assessment and thus operate within the realms of the main European regulatory bodies. 

Fraunhofer ITEM already carried out the two previous projects (CAQ I and CAQ II).