Cabin Air Quality (CAQ)

Cabin Air Quality

Cabin air quality refers to the air supplied to the cockpit and cabin of an aircraft, often sourced from the engines using a “bleed air” system. This air can become contaminated with fumes from engine lubricants, hydraulic fluids, or de-icing chemicals, particularly if seals fail or under certain operating conditions. Contaminated air may lead to health and safety concerns for crew and passengers, including short- and long-term effects such as headaches, fatigue, nausea, and neurological symptoms​​. This is called Aerotoxic Syndrome.

Aerotoxic Syndrome

Aerotoxic syndrome is a condition linked to exposure to contaminated cabin air, typically involving organophosphate compounds from engine oils. Symptoms range from neurological effects (e.g., numbness, confusion) to chronic health issues. Key findings include:

• Cause: Exposure to pyrolysed engine oils containing toxic compounds such as tricresyl phosphate (TCP).
• Vulnerable Groups: Around 30% of individuals are poor detoxifiers and may be more susceptible​.
• Challenges: Establishing causality is difficult due to industry resistance, lack of funding for independent research, and inadequate large-scale studies​.

Actions Taken on Cabin Air Quality

BeCA’s Efforts:

• Advocacy: The Belgian Cockpit Association (BeCA) has been actively involved in addressing CAQ issues, demanding stricter regulations and better research. BeCA participated in initiatives like the European Committee for Standardization (CEN/TC 264) working group to establish new norms​​ on Cabin Air Quality.
• Awareness and Reporting: BeCA emphasizes the importance of reporting fume events, as under-reporting hinders progress. Reporting is mandatory under EU law​​ (EU376/2014). Additionally, crews can opt to report via GCARS.
• Participation in Research and Conferences: BeCA presented during several Global Conferences on Cabin Air Quality and collaborates with other pilot associations to push for safety standards and technological advancements​​.
• Developing practical guidance: In close cooperation with the Global Cabin Air Quality Executive (GCAQE), BeCA developed a Post-Smoke/Fume Event Procedure which serves as practical guidance for crews based on the peer-reviewed Medical Protocol published by Burdon et al. (2023).

Current Technological and Procedural Changes:

• Efforts to retrofit aircraft with air filtration systems have been initiated by some airlines, such as DHL and EasyJet.
• Development of detection instruments for cabin air contamination is ongoing​​.
• In 2021, NYCO, a French engine oil and lubricant manufacturer, issued a patent for a new engine oil anti wear additive said to address the issue of ‘Aerotoxic Syndrome’. In 2024, the 940 SE oil received military specification MIL-PRF-23699 approval.

What to do in case of a Fume Event?

To report a fume event:

1. Follow the checklist from the Post-Smoke/Fume Event Procedure.
2. Record symptoms for crew and passengers.
3. Seek medical assistance (use the checklist mentioned above)
4. Fill out specialized smoke and smell reports.Inform the airline and make a technical log entry.
5. Complete an occurrence report per EU376/2014, detailing the event and its effects.
6. Follow-up

If you have specific questions about any aspect of cabin air quality or Aerotoxic syndrome, feel free to ask!